Leonore A. Herzenberg
Department of Genetics Flow Cytometry Professor
Web page: http://herzenberglab.stanford.edu
Administrative Appointments
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Endowed Chair of Flow Cytometry and Genetics, Stanford University (2015 - Present)
Honors & Awards
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Honorary Fellow, Royal Microscopical Society (2016)
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Visionary use of Information Technology in the field of Medicine, Torino Medical Science Award, (2007)
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“for contributions to the work for which the Kyoto Prize was awarded”, United States presentation of the Kyoto Prize (2006)
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Heroic Achievement in Information Technology, The ComputerWorld Smithsonian Award (1996)
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Eleanor Roosevelt Cancer Fellowship,, American Cancer Society (1986)
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Symposium Chair & Speaker, International Congress of Immunology (1986)
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Member, Genetics Society of America (0)
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Member, American Association of Immunologists (0)
Professional Education
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D.Sc-equiv., University Paris V Sorbonne, Immunolgy (1981)
Patents
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Leonore Herzenberg, David Parks, Stephen Meehan, Wayne Moore. "United StatesSystem and Methods for Selecting a Multiparameter Reagent Combination for Automated Flourescence Compensations", Leland Stanford Junior University, May 20, 2014
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Wayne Moore, David R. Parks, Leonore A. Herzenberg. "United States Patent 8,548,950 Method and system for data archiving", The Board Of Trustees Of The Leland Stanford Junior University, Oct 1, 2013
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Leonard A. Herzenberg, Leonore A. Herzenberg, Stephen C. De Rosa, James Andrus,. "United States Patent 7,723,389 N-acetylcysteine compositions and methods for the treatment and prevention of drug toxicity", The Board Of Trustees Of The Leland Stanford Junior University, May 25, 2010
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Parks, D.R., Bryan, V.M., Herzenberg, L.A.. "United States Patent 4,667,830 Cell labeling with antigen-coupled microspheres", Leland Stanford Junior University, May 26, 2002
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Roederer, M., Rabin, R., Herzenberg, L.A., Herzenberg, L.A.. "United States Patent 5,968,755 Methods for Determining T-cell Profiles of Immunocompromised Subjects", Leland Stanford Junior University, Oct 29, 1999
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Herzenberg, L.A., De Rosa, S.C, Herzenberg, L.A. and Roederer, M.. "United States Patent 5,843,785 Glutathione Deficiency as a prognosis for survival in AIDS", Leland Stanford Junior University, Dec 1, 1998
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Herzenberg, L.A., Herzenberg, L.A.. "United States Patent 5,580,577 Method of treating the symptoms of human rhinovirus infection", Leland Stanford Junior University, Dec 3, 1996
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Nolan, G.P., Feiring, S, Herzenberg, L.A.. "United States Patent 5,070,012 Monitoring of cells and trans-activating transcription elements", Leland Stanford Junior University, Dec 3, 1991
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Steinman, L., Waldor, M.K., Sriram, S., Herzenberg, L.A., Herzenberg, L.A.. "United States Patent 4,695,459 Method of treating autoimmune diseases that are mediated by LEU3/CD4 phenotype T cells.", Leland Stanford Junior University, Sep 22, 1987
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Wulf Dr oge, Leonard A. Herzenberg, Leonore A. Herzenberg. "United States Patent 5,607,974 Treatment of diseases associated with cysteine deficiency", The Board Of Trustees Of The Leland Stanford Junior University, Mar 4, 0097
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Wulf Droge, Leonard A. Herzenberg, Leonore A. Herzenberg. "United States Patent 1,339.256 Treatment of diseases associated with hiv-infections", The Board Of Trustees Of The Leland Stanford Junior University, Jan 26, 0089
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Antonio Hardan, Rabindra Tirouvanziam, Leonore A. Herzenberg. "United States Patent 2,846,789 Compositions and methods for treating autism and autism spectrum disorder", The Board Of Trustees Of The Leland Stanford Junior University, May 3, 0012
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Denong Wang, Leonore A. Herzenberg, Donna M. Peehl, Leonard A. Herzenberg. "United States Patent 7,981,625 PROSTATE CANCER GLYCAN MARKERS AND AUTOANTIBODY SIGNATURES", The Board Of Trustees Of The Leland Stanford Junior University, Jul 19, 0011
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Leonard A. Herzenberg, David Rhodes Parks, Leonore A. Herzenberg, Wayne A. Moore, Vernon T. Oi. "United States Patent 6,947,953 Internet-linked system for directory protocol based data storage, retrieval and analysis", The Board Of Trustees Of The Leland Stanford Junior University, Sep 20, 0005
Current Research and Scholarly Interests
Our laboratory focuses on understanding the basic mechanisms that determine and regulate gene expression and cell function in the immune system. Most recently, we have distinguished two functionally and physically distinct murine B cell lineages, only one of which (B-2) originates with the traditional bone marrow HSC and displays the well known characteristics of B cells that develop from the continuously renewed HSC in adult bone marrow. The other lineage, B-1a, develops from phenotypically distinct progenitors that are only detectable during fetal and early neonatal life.and give rise to mature B-1a cells that develop de novo during the first 6-8 weeks of life and persist thereafter by division of the mature B cells.
Consistent with these life-style differences, our extensive IgH sequencing studies demonstrate that the antibody repertoires expressed by the two B cell lineages are shaped by forces that operate at different times during development, i.e., the B-1a repertoire is shaped by rearrangements that occur during fetal and neonatal life and are propagated by cell division thereafter, whereas the B-2 repertoire begins to develop around weaning (>6 weeks of age) and continues de novo development from HSC throughout life.
As might be expected from these decidedly distinct life styles, B-1a and B-2 show overlapping but clearly distinct IgH repertoire differences. B-1a have long known to be the source of many "anti-self" ("natural") antibodies as well as many antibodies reactive with many microorganisms. Intriguingly, we find very little difference (<10%) between the B-1a repertoire obtained from germ-free mice versus that obtained from conventionally-reared mice, indicating that exposure to self antigen conditions the B-1a anti-bacterial repertoire rather than vice versa.
In addition to our B cell studies, our laboratory maintains a strong interest in intracellular redox influences in health and and disease. In earlier work, we showed that as HIV infection progresses, intracellular glutathione (GSH) levels decrease, resulting ultimately in severe intracellular GSH deficiency. Excessive acetaminophen (Tylenol) use also results in severe GSH deficiency due to GSH consumption during acetaminophen detoxification. N-acetylcysteine (NAC), a non-toxic source of cysteine, is the accepted antidote for GSH depletion. We have established flow cytometry assays for evaluating GSH depletion and its repletion by N-acetylcysteine and continue to explore the medical consequences of GSH depletion.
These and many other biomedical findings rely heavily on cell analysis and sorting with the Fluorescence-Activated Cell Sorting(FACS), which our laboratory developed initially and to which we continually add new software and hardware functionality. The dedicated group of engineers, physicists, staticians, mathematicians, computer scientists and programmers in our FACS development group continues to make leading edge contributions to flow technology. Most recently, we developed new, user friendly and statistically reliable software to facilitate flow data analysis. We are making this software available free of charge to laboratories at .edu, .org, and similar non-profit institutions.
Overall, our laboratory operates as a community of scholars working in diverse but inter-related areas. We tend to be highly collaborative and often have students and fellows from other laboratories working at our benches. We are always open to new collaborations and new students and fellows interested in genetics, molecular biology, immunology, cell biology and/or in technology development related to these areas.
2024-25 Courses
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Independent Studies (10)
- Directed Reading in Genetics
GENE 299 (Aut, Win, Spr, Sum) - Directed Reading in Immunology
IMMUNOL 299 (Aut, Win, Spr, Sum) - Early Clinical Experience in Immunology
IMMUNOL 280 (Aut, Win, Spr, Sum) - Graduate Research
GENE 399 (Aut, Win, Spr, Sum) - Graduate Research
IMMUNOL 399 (Aut, Win, Spr, Sum) - Medical Scholars Research
GENE 370 (Aut, Win, Spr, Sum) - Supervised Study
GENE 260 (Aut, Win, Spr, Sum) - Teaching in Immunology
IMMUNOL 290 (Aut, Win, Spr, Sum) - Undergraduate Research
GENE 199 (Aut, Win, Spr, Sum) - Undergraduate Research
IMMUNOL 199 (Aut, Win, Spr, Sum)
- Directed Reading in Genetics
All Publications
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Science not art: statistically sound methods for identifying subsets in multi-dimensional flow and mass cytometry data sets
NATURE REVIEWS IMMUNOLOGY
2018; 18 (1): 77-+
View details for PubMedID 29269766
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The early history of Stanford Immunology.
Immunologic research
2014; 58 (2-3): 164-178
Abstract
From its 1960 beginnings in a pair of windowless Genetics Department laboratories under the Stanford Medical School Dean's Office to its current broad-based program, which joins faculty members from departments across the Medical School, the Stanford Immunology Program has played a central role in shaping both basic and clinical immunology thinking. In this article, we tell the story of the beginnings of this odyssey in a reminiscence-based format that brings the flavor of the time in the words of people who lived and built the history.
View details for DOI 10.1007/s12026-014-8518-z
View details for PubMedID 24804901
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AutoGate: automating analysis of flow cytometry data.
Immunologic research
2014; 58 (2-3): 218-223
Abstract
Nowadays, one can hardly imagine biology and medicine without flow cytometry to measure CD4 T cell counts in HIV, follow bone marrow transplant patients, characterize leukemias, etc. Similarly, without flow cytometry, there would be a bleak future for stem cell deployment, HIV drug development and full characterization of the cells and cell interactions in the immune system. But while flow instruments have improved markedly, the development of automated tools for processing and analyzing flow data has lagged sorely behind. To address this deficit, we have developed automated flow analysis software technology, provisionally named AutoComp and AutoGate. AutoComp acquires sample and reagent labels from users or flow data files, and uses this information to complete the flow data compensation task. AutoGate replaces the manual subsetting capabilities provided by current analysis packages with newly defined statistical algorithms that automatically and accurately detect, display and delineate subsets in well-labeled and well-recognized formats (histograms, contour and dot plots). Users guide analyses by successively specifying axes (flow parameters) for data subset displays and selecting statistically defined subsets to be used for the next analysis round. Ultimately, this process generates analysis "trees" that can be applied to automatically guide analyses for similar samples. The first AutoComp/AutoGate version is currently in the hands of a small group of users at Stanford, Emory and NIH. When this "early adopter" phase is complete, the authors expect to distribute the software free of charge to .edu, .org and .gov users.
View details for DOI 10.1007/s12026-014-8519-y
View details for PubMedID 24825775
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A Conversation with Leonard and Leonore Herzenberg
ANNUAL REVIEW OF PHYSIOLOGY, VOL 76
2014; 76: 1-20
Abstract
Leonard and Leonore Herzenberg have left an indelible mark on the fields of immunology and cell biology, both in research and clinical aspects. They are perhaps best known for developing the technologies of fluorescence flow cytometry and hybridomas. Over six decades, they made a number of important and fundamental discoveries in lymphocyte biology by applying these technologies. During this era, they immersed themselves in the sociopolitical environment, interjecting scientific rationale into public discourse about McCarthyism, nuclear fallout, war, genetics, and other politically charged topics. Their unique philosophy has shaped their lives, their science, and ultimately the scientific community. In this Conversation, we explore some of these driving forces and the impact on the laboratory.
View details for DOI 10.1146/annurev-physiol-021113-170355
View details for Web of Science ID 000336055000002
View details for PubMedID 23957332
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Our NIH Years: A Confluence of Beginnings
JOURNAL OF BIOLOGICAL CHEMISTRY
2013; 288 (1): 687-702
View details for DOI 10.1074/jbc.X112.426742
View details for Web of Science ID 000313197200069
View details for PubMedID 23066019
View details for PubMedCentralID PMC3537067
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A MULTI-CENTER, PHASE IIB, RANDOMIZED, PLACEBO-CONTROLLED, DOUBLE-BLIND STUDY OF THE EFFECTS OF N-ACETYLCYSTEINE (NAC) ON REDOX CHANGES AND LUNG INFLAMMATION IN CYSTIC FIBROSIS PATIENTS
WILEY-BLACKWELL. 2011: 280–281
View details for Web of Science ID 000296071800275
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Automatic clustering of flow cytometry data with density-based merging.
Advances in bioinformatics
2009: 686759-?
Abstract
The ability of flow cytometry to allow fast single cell interrogation of a large number of cells has made this technology ubiquitous and indispensable in the clinical and laboratory setting. A current limit to the potential of this technology is the lack of automated tools for analyzing the resulting data. We describe methodology and software to automatically identify cell populations in flow cytometry data. Our approach advances the paradigm of manually gating sequential two-dimensional projections of the data to a procedure that automatically produces gates based on statistical theory. Our approach is nonparametric and can reproduce nonconvex subpopulations that are known to occur in flow cytometry samples, but which cannot be produced with current parametric model-based approaches. We illustrate the methodology with a sample of mouse spleen and peritoneal cavity cells.
View details for DOI 10.1155/2009/686759
View details for PubMedID 20069107
View details for PubMedCentralID PMC2801806
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Modern flow cytometry: A practical approach
CLINICS IN LABORATORY MEDICINE
2007; 27 (3): 453-?
Abstract
The demonstration that CD T-cell counts can be used to monitor HIV disease progression opened the way to the first clinical application for fluorescence activated cell sorting (FACS) technology. Modern FACS methodologies such multicolor staining and sorting has opened the way to new and constructive therapeutic and clinical applications. This article outlines approaches in which current users can use to improve the quality of their FACS work without undue effort. FACS technology development and the emergence of new software support for this technology are cooperating in this effort.
View details for DOI 10.1016/j.cII.2007.05.001
View details for Web of Science ID 000249231600002
View details for PubMedID 17658402
View details for PubMedCentralID PMC1994577
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N-Acetylcysteine - a safe antidote for cysteine/glutathione deficiency
CURRENT OPINION IN PHARMACOLOGY
2007; 7 (4): 355-359
Abstract
Glutathione (GSH) deficiency is associated with numerous pathological conditions. Administration of N-acetylcysteine (NAC), a cysteine prodrug, replenishes intracellular GSH levels. NAC, best known for its ability to counter acetaminophen toxicity, is a safe, well-tolerated antidote for cysteine/GSH deficiency. NAC has been used successfully to treat GSH deficiency in a wide range of infections, genetic defects and metabolic disorders, including HIV infection and COPD. Over two-thirds of 46 placebo-controlled clinical trials with orally administered NAC have indicated beneficial effects of NAC measured either as trial endpoints or as general measures of improvement in quality of life and well-being of the patients.
View details for DOI 10.1016/j.coph.2007.04.005
View details for Web of Science ID 000249682800002
View details for PubMedID 17602868
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Epitope-specific regulation: the elephant in the bathtub
NATURE IMMUNOLOGY
2007; 8 (8): 783-786
View details for DOI 10.1038/ni0807-783
View details for Web of Science ID 000248169400002
View details for PubMedID 17641654
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Interpreting flow cytometry data: a guide for the perplexed
NATURE IMMUNOLOGY
2006; 7 (7): 681-685
View details for Web of Science ID 000238377700002
View details for PubMedID 16785881
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B cell lineages: documented at last!
NATURE IMMUNOLOGY
2006; 7 (3): 225-226
View details for Web of Science ID 000235360400003
View details for PubMedID 16482166
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Genetics, facs, immunology, and redox: A tale of two lives intertwined
ANNUAL REVIEW OF IMMUNOLOGY
2004; 22: 1-31
View details for DOI 10.1146/annurev.immunol.22.012703.104727
View details for Web of Science ID 000221601500001
View details for PubMedID 15032572
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IL-6 Signaling Mediates the Germinal Center Response, IgM Production and Nociceptive Sensitization in Male Mice after Tibia Fracture.
Brain, behavior, and immunity
2021
Abstract
BACKGROUND: Up-regulated interleukin 6 (IL-6) signaling, immune system activation, and pronociceptive autoantibodies are characteristic of complex regional pain syndrome (CRPS). IL-6 is known to promote B cell differentiation, thus we hypothesized that IL-6 signaling plays a crucial role in the development of adaptive immune responses and nociceptive sensitization in a murine tibia fracture model of CRPS.METHODS: Mice deficient in IL-6 expression (IL-6-/-) or B cell deficient (muMT) underwent tibia fracture and 3 weeks of cast immobilization or sham injury. The deposition of IgM in fractured limbs was followed using Western blotting, and passive serum transfer to muMT fracture mice was used to detect nociception-supporting autoantibodies. Lymph nodes were assessed for hypertrophy, IL-6 expression was measured using qPCR and ELISA, and germinal center formation was evaluated using FACS and immunohistochemistry. The therapeutic effects of exogenous neutralizing anti-IL-6 antibodies were also evaluated in the CRPS fracture model.RESULTS: Functional IL-6 signaling was required for the post fracture development of nociceptive sensitization, vascular changes, and IgM immune complex deposition in the skin of injured limbs. Passive transfer of sera from wild-type, but not IL-6-/- fracture mice into muMT fracture mice caused enhanced allodynia and postural unweighting. IL-6-/- fracture mice displayed reduced popliteal lymphadenopathy after fracture. Germinal center responses were detected in the popliteal lymph nodes of wild-type, but not in IL-6-/- fracture mice. We observed that IL-6 expression was dramatically enhanced in popliteal lymph node tissue after fracture. Conversely, administration of anti-IL-6 antibodies reduced nociceptive and vascular changes after fracture and inhibited lymphadenopathy.CONCLUSIONS: Collectively, these data support the hypothesis that IL-6 signaling in the fracture limb of mice is required for germinal center formation, IgM autoantibody production and nociceptive sensitization. Anti-IL-6 therapies might, therefore, reduce pain after limb fracture or in the setting of CRPS.
View details for DOI 10.1016/j.bbi.2021.02.015
View details for PubMedID 33636311
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CTLA-4 expression by B-1a B cells is essential for immune tolerance.
Nature communications
2021; 12 (1): 525
Abstract
CTLA-4 is an important regulator of T-cell function. Here, we report that expression of this immune-regulator in mouse B-1a cells has a critical function in maintaining self-tolerance by regulating these early-developing B cells that express a repertoire enriched for auto-reactivity. Selective deletion of CTLA-4 from B cells results in mice that spontaneously develop autoantibodies, T follicular helper (Tfh) cells and germinal centers (GCs) in the spleen, and autoimmune pathology later in life. This impaired immune homeostasis results from B-1a cell dysfunction upon loss of CTLA-4. Therefore, CTLA-4-deficient B-1a cells up-regulate epigenetic and transcriptional activation programs and show increased self-replenishment. These activated cells further internalize surface IgM, differentiate into antigen-presenting cells and, when reconstituted in normal IgH-allotype congenic recipient mice, induce GCs and Tfh cells expressing a highly selected repertoire. These findings show that CTLA-4 regulation of B-1a cells is a crucial immune-regulatory mechanism.
View details for DOI 10.1038/s41467-020-20874-x
View details for PubMedID 33483505
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The class II peptide editor, H2-M, affects the development and repertoire of B-1 cells
AMER ASSOC IMMUNOLOGISTS. 2020
View details for Web of Science ID 000589972401412
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Germinal Center Formation, Immunoglobulin Production and Hindlimb Nociceptive Sensitization after Tibia Fracture.
Brain, behavior, and immunity
2020
Abstract
Emerging evidence suggests that Complex Regional Pain Syndrome (CRPS) is in part a post-traumatic autoimmune disease mediated by an adaptive immune response after limb injuries. We previously observed in a murine tibial fracture model of CRPS that pain-related behaviors were dependent upon adaptive immune mechanisms including the neuropeptide-dependent production of IgM for 5 months after injury. However, the time course of induction of this immune response and the demonstration of germinal center formation in lymphoid organs has not been evaluated. Using the murine fracture model, we employed behavioral tests of nociceptive sensitization and limb dysfunction, serum passive transfer techniques, western blot analysis of IgM accumulation, fluorescence-activated cell sorting (FACS) of lymphoid tissues and immunohistochemistry to follow the temporal activation of the adaptive immune response over the first 3 weeks after fracture. We observed that: 1) IgM protein levels in the skin of the fractured mice were elevated at 3 weeks post fracture, but not at earlier time points, 2) serum from fracture mice at 3 weeks, but not 1 and 2 weeks post fracture, had pro-nociceptive effects when passively transferred to fractured muMT mice lacking B cells, 3) fracture induced popliteal lymphadenopathy occurred ipsilateral to fracture beginning at 1 week and peaking at 3 weeks post fracture, 4) a germinal center reaction was detected by FACS analysis in the popliteal lymph nodes from injured limbs by 3 weeks post fracture but not in other lymphoid tissues, 5) germinal center formation was characterized by the induction of T follicular helper cells (Tfh) and germinal center B cells in the popliteal lymph nodes of the injured but not contralateral limbs, and 6) fracture mice treated with the Tfh signaling inhibitor FK506 had impaired germinal center reactions, reduced IgM levels, reduced nociceptive sensitization, and no pronociceptive serum effects after administration to fractured muMT mice. Collectively these data demonstrate that tibia fracture induces an adaptive autoimmune response characterized by popliteal lymph node germinal center formation and Tfh cell dependent B cell activation, resulting in nociceptive sensitization within 3 weeks.
View details for DOI 10.1016/j.bbi.2020.05.029
View details for PubMedID 32413559
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Automated subset identification and characterization pipeline for multidimensional flow and mass cytometry data clustering and visualization.
Communications biology
2019; 2 (1): 229
Abstract
When examining datasets of any dimensionality, researchers frequently aim to identify individual subsets (clusters) of objects within the dataset. The ubiquity of multidimensional data has motivated the replacement of user-guided clustering with fully automated clustering. The fully automated methods are designed to make clustering more accurate, standardized and faster. However, the adoption of these methods is still limited by the lack of intuitive visualization and cluster matching methods that would allow users to readily interpret fully automatically generated clusters. To address these issues, we developed a fully automated subset identification and characterization (SIC) pipeline providing robust cluster matching and data visualization tools for high-dimensional flow/mass cytometry (and other) data. This pipeline automatically (and intuitively) generates two-dimensional representations of high-dimensional datasets that are safe from the curse of dimensionality. This new approach allows more robust and reproducible data analysis,+ facilitating the development of new gold standard practices across laboratories and institutions.
View details for DOI 10.1038/s42003-019-0467-6
View details for PubMedID 31925064
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Hematopoietic stem cell-independent hematopoiesis and the origins of innate-like B lymphocytes.
Development (Cambridge, England)
2019; 146 (15)
Abstract
The current paradigm that a single long-term hematopoietic stem cell can regenerate all components of the mammalian immune system has been challenged by recent findings in mice. These findings show that adult tissue-resident macrophages and innate-like lymphocytes develop early in fetal hematopoiesis from progenitors that emerge prior to, and apparently independently of, conventional long-term hematopoietic stem cells. Here, we discuss these recent findings, which show that an early and distinct wave of hematopoiesis occurs for all major hematopoietic lineages. These data provide evidence that fetal hematopoietic progenitors not derived from the bona fide long-term hematopoietic stem cells give rise to tissue-resident immune cells that persist throughout adulthood. We also discuss recent insights into B lymphocyte development and attempt to synthesize seemingly contradictory recent findings on the origins of innate-like B-1a lymphocytes during fetal hematopoiesis.
View details for DOI 10.1242/dev.170571
View details for PubMedID 31371526
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Automated subset identification and characterization pipeline for multidimensional flow and mass cytometry data clustering and visualization.
Communications biology
2019; 2: 229
Abstract
When examining datasets of any dimensionality, researchers frequently aim to identify individual subsets (clusters) of objects within the dataset. The ubiquity of multidimensional data has motivated the replacement of user-guided clustering with fully automated clustering. The fully automated methods are designed to make clustering more accurate, standardized and faster. However, the adoption of these methods is still limited by the lack of intuitive visualization and cluster matching methods that would allow users to readily interpret fully automatically generated clusters. To address these issues, we developed a fully automated subset identification and characterization (SIC) pipeline providing robust cluster matching and data visualization tools for high-dimensional flow/mass cytometry (and other) data. This pipeline automatically (and intuitively) generates two-dimensional representations of high-dimensional datasets that are safe from the curse of dimensionality. This new approach allows more robust and reproducible data analysis,+ facilitating the development of new gold standard practices across laboratories and institutions.
View details for DOI 10.1038/s42003-019-0467-6
View details for PubMedID 31240267
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Omentum immune microenvironment: Metastatic niche for ovarian cancer
AMER ASSOC CANCER RESEARCH. 2018
View details for DOI 10.1158/1538-7445.AM2018-5074
View details for Web of Science ID 000468819504076
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HSC-requirement for macrophage regeneration is tissue-specific
AMER ASSOC IMMUNOLOGISTS. 2018
View details for Web of Science ID 000459977701057
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QFMatch: multidimensional flow and mass cytometry samples alignment
SCIENTIFIC REPORTS
2018; 8: 3291
Abstract
Part of the flow/mass cytometry data analysis process is aligning (matching) cell subsets between relevant samples. Current methods address this cluster-matching problem in ways that are either computationally expensive, affected by the curse of dimensionality, or fail when population patterns significantly vary between samples. Here, we introduce a quadratic form (QF)-based cluster matching algorithm (QFMatch) that is computationally efficient and accommodates cases where population locations differ significantly (or even disappear or appear) from sample to sample. We demonstrate the effectiveness of QFMatch by evaluating sample datasets from immunology studies. The algorithm is based on a novel multivariate extension of the quadratic form distance for the comparison of flow cytometry data sets. We show that this QF distance has attractive computational and statistical properties that make it well suited for analysis tasks that involve the comparison of flow/mass cytometry samples.
View details for PubMedID 29459702
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Evidence for altered levels of IgD in the nasal airway mucosa of patients with chronic rhinosinusitis
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
2017; 140 (6): 1562-+
Abstract
IgD is an enigmatic antibody isotype best known when coexpressed with IgM on naive B cells. However, increased soluble IgD (sIgD) levels and increased IgD+IgM- B-cell populations have been described in the human upper respiratory mucosa.We assessed whether levels of sIgD and IgD+ B cell counts are altered in nasal tissue from patients with chronic rhinosinusitis (CRS). We further characterized IgD+ B-cell populations and explored clinical and local inflammatory factors associated with tissue sIgD levels.sIgD levels were measured by means of ELISA in nasal tissues, nasal lavage fluid, sera, and supernatants of dissociated nasal tissues. IgD+ cells were identified by using immunofluorescence and flow cytometry. Inflammatory mediator levels in tissues were assessed by using real-time PCR and multiplex immunoassays. Bacterial cultures from the middle meatus were performed. Underlying medical history and medicine use were obtained from medical records.sIgD levels and numbers of IgD+ cells were significantly increased in uncinate tissue (UT) of patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared with that of control subjects (4-fold, P < .05). IgD+ cells were densely scattered in the periglandular regions of UT from patients with CRSsNP. We also found that IgD+CD19+CD38bright plasmablast numbers were significantly increased in tissues from patients with CRSsNP compared with control tissues (P < .05). Among numerous factors tested, IL-2 levels were increased in UT from patients with CRSsNP and were positively correlated with tissue IgD levels. Additionally, supernatants of IL-2-stimulated dissociated tissue from patients with CRSsNP had significantly increased sIgD levels compared with those in IL-2-stimulated dissociated control tissue ex vivo (P < .05). Tissue from patients with CRS with preoperative antibiotic use or those with pathogenic bacteria showed higher IgD levels compared with tissue from patients without these variables (P < .05).sIgD levels and IgD+CD19+CD38bright plasmablast counts were increased in nasal tissue of patients with CRSsNP. IgD levels were associated with increased IL-2 levels and the presence of pathogenic bacteria. These findings suggest that IgD might contribute to enhancement mucosal immunity or inflammation or respond to bacterial infections in patients with CRS, especially CRSsNP.
View details for PubMedID 28625807
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Basophil activation test determination of CD63 combined with CD203c is not superior to CD203c alone in identifying allergic bronchopulmonary aspergillosis in cystic fibrosis.
The Journal of allergy and clinical immunology
2016; 138 (4): 1195-1196
View details for DOI 10.1016/j.jaci.2016.04.002
View details for PubMedID 27215492
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Characterization of immunoglobulin E plasma cells that are elevated in the upper airway mucosa of nonatopic patients with chronic rhinosinusitis without nasal polyps
INTERNATIONAL FORUM OF ALLERGY & RHINOLOGY
2016; 6 (4): 378-384
Abstract
The immunologic mechanisms driving inflammation in the upper airways of patients with chronic rhinosinusitis (CRS) are poorly understood. Previous studies have shown that B cells and immunoglobulin E (IgE) levels are elevated in the nasal tissue of patients with atopic chronic rhinosinusitis without nasal polyps (CRSsNP). However, less is known regarding B cell subsets and IgE-producing plasmablasts in nonatopic CRSsNP patients.Human blood and ethmoid sinus mucosa samples were analyzed from control (n = 6) and nonatopic CRSsNP (n = 11) patients. Tissue samples were evaluated using high-dimensional flow cytometry.A population of IgE antibody secreting cells is significantly increased in situ within inflamed nasal tissue of nonatopic CRSsNP subjects when compared to control nasal tissue and the circulating peripheral blood (p < 0.05). This IgE plasma cell population displays ∼90% cell surface Ig lambda light chain, is mitotically active (Ki-67(+) ), and displays intracellular IgE expression. The predominant B cell population expressing IgE are plasmablasts (CD38(high) , CD138(-) ) not typically found in the blood or peripheral tissue of these patients.The nasal mucosa from nonatopic CRSsNP patients demonstrate a significant regional spike in resident in situ IgE plasmablast cells not seen in control nasal tissue or peripheral blood from the same patient. The restricted expression of Ig lambda light chain in this mitotically active IgE plasmablast population supports the hypothesis of aberrant B cell proliferation in the context of CRS. These findings suggest the presence of a unique regional immune microenvironment for B cell priming and/or selection within chronically inflamed airway tissues.
View details for DOI 10.1002/alr.21696
View details for Web of Science ID 000373618500007
View details for PubMedID 26878990
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Fetal Hematopoietic Stem Cell Transplantation Fails to Fully Regenerate the B-Lymphocyte Compartment
STEM CELL REPORTS
2016; 6 (1): 137-149
Abstract
B cells are key components of cellular and humoral immunity and, like all lymphocytes, are thought to originate and renew from hematopoietic stem cells (HSCs). However, our recent single-HSC transfer studies demonstrate that adult bone marrow HSCs do not regenerate B-1a, a subset of tissue B cells required for protection against pneumonia, influenza, and other infections. Since B-1a are regenerated by transfers of fetal liver, the question arises as to whether B-1a derive from fetal, but not adult, HSCs. Here we show that, similar to adult HSCs, fetal HSCs selectively fail to regenerate B-1a. We also show that, in humanized mice, human fetal liver regenerates tissue B cells that are phenotypically similar to murine B-1a, raising the question of whether human HSC transplantation, the mainstay of such models, is sufficient to regenerate human B-1a. Thus, our studies overtly challenge the current paradigm that HSCs give rise to all components of the immune system.
View details for DOI 10.1016/j.stemcr.2015.11.011
View details for Web of Science ID 000368099500014
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Fetal Hematopoietic Stem Cell Transplantation Fails to Fully Regenerate the B-Lymphocyte Compartment.
Stem cell reports
2016; 6 (1): 137-149
Abstract
B cells are key components of cellular and humoral immunity and, like all lymphocytes, are thought to originate and renew from hematopoietic stem cells (HSCs). However, our recent single-HSC transfer studies demonstrate that adult bone marrow HSCs do not regenerate B-1a, a subset of tissue B cells required for protection against pneumonia, influenza, and other infections. Since B-1a are regenerated by transfers of fetal liver, the question arises as to whether B-1a derive from fetal, but not adult, HSCs. Here we show that, similar to adult HSCs, fetal HSCs selectively fail to regenerate B-1a. We also show that, in humanized mice, human fetal liver regenerates tissue B cells that are phenotypically similar to murine B-1a, raising the question of whether human HSC transplantation, the mainstay of such models, is sufficient to regenerate human B-1a. Thus, our studies overtly challenge the current paradigm that HSCs give rise to all components of the immune system.
View details for DOI 10.1016/j.stemcr.2015.11.011
View details for PubMedID 26724903
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Blood basophil activation is a reliable biomarker of allergic bronchopulmonary aspergillosis in cystic fibrosis
EUROPEAN RESPIRATORY JOURNAL
2016; 47 (1): 177-185
Abstract
The diagnosis of cystic fibrosis (CF) patients with allergic bronchopulmonary aspergillosis (ABPA) is clinically challenging, due to the absence of an objective biological test. Since blood basophils play a major role in allergic responses, we hypothesised that changes in their surface activation pattern discriminate between CF patients with and without ABPA.We conducted a prospective longitudinal study (Stanford cohort) comparing basophil activation test CD203c levels by flow cytometry before and after activation with Aspergillus fumigatus allergen extract or recombinant Asp f1 in 20 CF patients with ABPA (CF-ABPA) and in two comparison groups: CF patients with A. fumigatus colonisation (AC) but without ABPA (CF-AC; n=13) and CF patients without either AC or ABPA (CF; n=12). Patients were tested every 6 months and when ill with pulmonary exacerbation. We also conducted cross-sectional validation in a separate patient set (Dublin cohort).Basophil CD203c surface expression reliably discriminated CF-ABPA from CF-AC and CF over time. Ex vivo stimulation with A. fumigatus extract or recombinant Asp f1 produced similar results within the Stanford (p<0.0001) and the Dublin cohorts. CF-ABPA patients were likelier to have elevated specific IgE to A. fumigatus and were less frequently co-infected with Staphylococcus aureus.Basophil CD203c upregulation is a suitable diagnostic and stable monitoring biomarker of ABPA in CF.
View details for DOI 10.1183/13993003.01068-2015
View details for Web of Science ID 000367443900023
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Basophil activation test determination of CD63 combined with CD203c is not superior to CD203c alone in identifying ABPA in cystic fibrosis
Journal of Allergy and Clinical Immunology
2016: 1195–96
View details for DOI 10.1016/j.jaci.2016.04.002
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Earth Mover's Distance (EMD): A True Metric for Comparing Biomarker Expression Levels in Cell Populations.
PloS one
2016; 11 (3)
Abstract
Changes in the frequencies of cell subsets that (co)express characteristic biomarkers, or levels of the biomarkers on the subsets, are widely used as indices of drug response, disease prognosis, stem cell reconstitution, etc. However, although the currently available computational "gating" tools accurately reveal subset frequencies and marker expression levels, they fail to enable statistically reliable judgements as to whether these frequencies and expression levels differ significantly between/among subject groups. Here we introduce flow cytometry data analysis pipeline which includes the Earth Mover's Distance (EMD) metric as solution to this problem. Well known as an informative quantitative measure of differences between distributions, we present three exemplary studies showing that EMD 1) reveals clinically-relevant shifts in two markers on blood basophils responding to an offending allergen; 2) shows that ablative tumor radiation induces significant changes in the murine colon cancer tumor microenvironment; and, 3) ranks immunological differences in mouse peritoneal cavity cells harvested from three genetically distinct mouse strains.
View details for DOI 10.1371/journal.pone.0151859
View details for PubMedID 27008164
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Amyloid fibrils activate B-1a lymphocytes to ameliorate inflammatory brain disease
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2015; 112 (49): 15016-15023
Abstract
Amyloid fibrils composed of peptides as short as six amino acids are therapeutic in experimental autoimmune encephalomyelitis (EAE), reducing paralysis and inflammation, while inducing several pathways of immune suppression. Intraperitoneal injection of fibrils selectively activates B-1a lymphocytes and two populations of resident macrophages (MΦs), increasing IL-10 production, and triggering their exodus from the peritoneum. The importance of IL-10-producing B-1a cells in this effective therapy was established in loss-of-function experiments where neither B-cell-deficient (μMT) nor IL10(-/-) mice with EAE responded to the fibrils. In gain-of-function experiments, B-1a cells, adoptively transferred to μMT mice with EAE, restored their therapeutic efficacy when Amylin 28-33 was administered. Stimulation of adoptively transferred bioluminescent MΦs and B-1a cells by amyloid fibrils resulted in rapid (within 60 min of injection) trafficking of both cell types to draining lymph nodes. Analysis of gene expression indicated that the fibrils activated the CD40/B-cell receptor pathway in B-1a cells and induced a set of immune-suppressive cell-surface proteins, including BTLA, IRF4, and Siglec G. Collectively, these data indicate that the fibrils activate B-1a cells and F4/80(+) MΦs, resulting in their migration to the lymph nodes, where IL-10 and cell-surface receptors associated with immune-suppression limit antigen presentation and T-cell activation. These mechanisms culminate in reduction of paralytic signs of EAE.
View details for DOI 10.1073/pnas.1521206112
View details for PubMedID 26621719
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Blood basophil activation is a reliable biomarker of allergic bronchopulmonary aspergillosis in cystic fibrosis.
The European respiratory journal
2015
Abstract
The diagnosis of cystic fibrosis (CF) patients with allergic bronchopulmonary aspergillosis (ABPA) is clinically challenging, due to the absence of an objective biological test. Since blood basophils play a major role in allergic responses, we hypothesised that changes in their surface activation pattern discriminate between CF patients with and without ABPA.We conducted a prospective longitudinal study (Stanford cohort) comparing basophil activation test CD203c levels by flow cytometry before and after activation with Aspergillus fumigatus allergen extract or recombinant Asp f1 in 20 CF patients with ABPA (CF-ABPA) and in two comparison groups: CF patients with A. fumigatus colonisation (AC) but without ABPA (CF-AC; n=13) and CF patients without either AC or ABPA (CF; n=12). Patients were tested every 6 months and when ill with pulmonary exacerbation. We also conducted cross-sectional validation in a separate patient set (Dublin cohort).Basophil CD203c surface expression reliably discriminated CF-ABPA from CF-AC and CF over time. Ex vivo stimulation with A. fumigatus extract or recombinant Asp f1 produced similar results within the Stanford (p<0.0001) and the Dublin cohorts. CF-ABPA patients were likelier to have elevated specific IgE to A. fumigatus and were less frequently co-infected with Staphylococcus aureus.Basophil CD203c upregulation is a suitable diagnostic and stable monitoring biomarker of ABPA in CF.
View details for DOI 10.1183/13993003.01068-2015
View details for PubMedID 26585435
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Co-administration of N-Acetylcysteine and Acetaminophen Efficiently Blocks Acetaminophen Toxicity.
Drug development research
2015; 76 (5): 251-258
Abstract
Preclinical Research Although acetaminophen (APAP) is an effective analgesic and anti-pyretic, APAP overdose is the most frequent cause of serious, often lethal, drug-induced hepatotoxicity. Administration of N-acetyl cysteine (NAC) within 8 hours of APAP overdose effectively mitigates APAP-induced hepatotoxicity. Thus, preventing APAP toxicity before it occurs by formulating APAP with NAC is logical and, as we show here in a mouse model, is effective in preventing APAP toxicity. Thus, toxic oral APAP doses sufficient to cause severe widespread liver damage do not cause significant damage when administered concurrently with equal amounts of NAC, that is, in the NAC-APAP treated animals, hepatic transaminases increase only marginally and liver architecture remains fully intact. Thus, we conclude that concomitant oral dosing with APAP and NAC can provide a convenient and effective way of preventing toxicity associated with large dosage of APAP. From a public health perspective, these findings support the concept that a co-formulation of APAP plus NAC is a viable over-the-counter (OTC) alternative to the current practice of providing APAP OTC and treating APAP toxicity if/when it occurs. In essence, our findings indicate that replacing the current OTC APAP with a safe and functional APAP/NAC formulation could prevent the accidental and intentional APAP toxicity that occurs today. Drug Dev Res 76 : 251-258, 2015. © 2015 Wiley Periodicals, Inc.
View details for DOI 10.1002/ddr.21262
View details for PubMedID 26250417
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Co-administration of N-Acetylcysteine and Acetaminophen Efficiently Blocks Acetaminophen Toxicity
DRUG DEVELOPMENT RESEARCH
2015; 76 (5): 251-258
Abstract
Preclinical Research Although acetaminophen (APAP) is an effective analgesic and anti-pyretic, APAP overdose is the most frequent cause of serious, often lethal, drug-induced hepatotoxicity. Administration of N-acetyl cysteine (NAC) within 8 hours of APAP overdose effectively mitigates APAP-induced hepatotoxicity. Thus, preventing APAP toxicity before it occurs by formulating APAP with NAC is logical and, as we show here in a mouse model, is effective in preventing APAP toxicity. Thus, toxic oral APAP doses sufficient to cause severe widespread liver damage do not cause significant damage when administered concurrently with equal amounts of NAC, that is, in the NAC-APAP treated animals, hepatic transaminases increase only marginally and liver architecture remains fully intact. Thus, we conclude that concomitant oral dosing with APAP and NAC can provide a convenient and effective way of preventing toxicity associated with large dosage of APAP. From a public health perspective, these findings support the concept that a co-formulation of APAP plus NAC is a viable over-the-counter (OTC) alternative to the current practice of providing APAP OTC and treating APAP toxicity if/when it occurs. In essence, our findings indicate that replacing the current OTC APAP with a safe and functional APAP/NAC formulation could prevent the accidental and intentional APAP toxicity that occurs today. Drug Dev Res 76 : 251-258, 2015. © 2015 Wiley Periodicals, Inc.
View details for DOI 10.1002/ddr.21262
View details for Web of Science ID 000360220900005
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Long-term treatment with oral N-acetylcysteine: Affects lung. function but not sputum inflammation in cystic fibrosis subjects. A phase II randomized placebo-controlled trial
JOURNAL OF CYSTIC FIBROSIS
2015; 14 (2): 219-227
Abstract
To evaluate the effects of oral N-acetylcysteine (NAC), which replenishes systemic glutathione, on decreasing inflammation and improving lung function in CF airways.A multicenter, randomized, double-blind proof of concept study in which 70 CF subjects received NAC or placebo orally thrice daily for 24weeks.primary, change in sputum human neutrophil elastase (HNE) activity; secondary, FEV1 and other clinical lung function measures; and safety, the safety and tolerability of NAC and the potential of NAC to promote pulmonary hypertension in subjects with CF.Lung function (FEV1 and FEF25-75%) remained stable or increased slightly in the NAC group but decreased in the placebo group (p=0.02 and 0.02). Log10 HNE activity remained equal between cohorts (difference 0.21, 95% CI -0.07 to 0.48, p=0.14).NAC recipients maintained their lung function while placebo recipients declined (24week FEV1 treatment effect=150mL, p<0.02). However no effect on HNE activity and other selected biomarkers of neutrophilic inflammation were detected. Further studies on mechanism and clinical outcomes are warranted.
View details for DOI 10.1016/j.jcf.2014.08.008
View details for Web of Science ID 000352662600008
View details for PubMedID 25228446
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Distinct mechanisms define murine B cell lineage immunoglobulin heavy chain (IgH) repertoires.
eLife
2015; 4
Abstract
Processes that define immunoglobulin repertoires are commonly presumed to be the same for all murine B cells. However, studies here that couple high-dimensional FACS sorting with large-scale quantitative IgH deep-sequencing demonstrate that B-1a IgH repertoire differs dramatically from the follicular and marginal zone B cells repertoires and is defined by distinct mechanisms. We track B-1a cells from their early appearance in neonatal spleen to their long-term residence in adult peritoneum and spleen. We show that de novo B-1a IgH rearrangement mainly occurs during the first few weeks of life, after which their repertoire continues to evolve profoundly, including convergent selection of certain V(D)J rearrangements encoding specific CDR3 peptides in all adults and progressive introduction of hypermutation and class-switching as animals age. This V(D)J selection and AID-mediated diversification operate comparably in germ-free and conventional mice, indicating these unique B-1a repertoire-defining mechanisms are driven by antigens that are not derived from microbiota.
View details for DOI 10.7554/eLife.09083
View details for PubMedID 26422511
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Layered evolution in the immune system: a view from history
B-1 CELL DEVELOPMENT AND FUNCTION
2015; 1362: 1-5
Abstract
Although much had still to be learned, evidence indicating that B-1a lymphocytes very likely belonged to a distinct lineage was largely in place by the time of the first large B-1a conference in 1991. The widely respected group of immunologists attending that meeting (including Tasuko Honjo and Klaus Rajewsky) developed and ultimately published the B-1a notation still in use today. Here, I briefly review some of the early B-1a findings that underlie current studies. I close with a brief summary of recent studies, mainly from my laboratory, showing that the hematopoietic stem cell (HSC) we all know and love as the origin of the cells that populate the adult lymphoid and myeloid system today is nonetheless not the origin of the B-1a lymphocytes with which most of us work today.
View details for DOI 10.1111/nyas.12795
View details for PubMedID 26096553
View details for PubMedCentralID PMC4761344
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B-1 Cell Development and Function
B-1 CELL DEVELOPMENT AND FUNCTION
2015; 1362: V-VI
View details for DOI 10.1111/nyas.12949
View details for Web of Science ID 000366286200001
View details for PubMedID 26662722
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Cysteine Oxidation Targets Peroxiredoxins 1 and 2 for Exosomal Release through a Novel Mechanism of Redox-Dependent Secretion
MOLECULAR MEDICINE
2015; 21
Abstract
Nonclassical protein secretion is of major importance as a number of cytokines and inflammatory mediators are secreted via this route. Current evidence indicates that there are several mechanistically distinct methods of nonclassical secretion. We have shown recently that peroxiredoxin (Prdx) 1 and Prdx2 are released by various cells upon exposure to inflammatory stimuli such as lipopolysaccharide (LPS) or tumor necrosis factor alpha (TNF-α). The released Prdx then acts to induce production of inflammatory cytokines. However, Prdx1 and 2 do not have signal peptides and therefore must be secreted by alternative mechanisms, as has been postulated for the inflammatory mediators interleukin-1β (IL-1β) and high mobility group box-1 (HMGB1). We show here that circulating Prdx1 and 2 are present exclusively as disulfide-linked homodimers. Inflammatory stimuli also induce in vitro release of Prdx1 and 2 as disulfide-linked homodimers. Mutation of cysteines Cys51 or Cys172 (but not Cys70) in Prdx2, and Cys52 or Cys173 (but not Cys71 or Cys83) in Prdx1 prevented dimer formation and this was associated with inhibition of their TNF-α-induced release. Thus, the presence and oxidation of key cysteine residues in these proteins are a prerequisite for their secretion in response to TNF-α, and this release can be induced with an oxidant. By contrast, the secretion of the nuclear-associated danger signal HMGB1 is independent of cysteine oxidation, as shown by experiments with a cysteine-free HMGB1 mutant. Release of Prdx1 and 2 is not prevented by inhibitors of the classical secretory pathway, instead, both Prdx1 and 2 are released in exosomes from both human embryonic kidney (HEK) cells and monocytic cells. Serum Prdx1 and 2 also are associated with the exosomes. These results describe a novel pathway of protein secretion mediated by cysteine oxidation that underlines the importance of redox-dependent signaling mechanisms in inflammation.
View details for DOI 10.2119/molmed.2015.00033
View details for Web of Science ID 000355726900010
View details for PubMedID 25715249
View details for PubMedCentralID PMC4461588
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Demonstration That Antigen-Binding Cells Are Precursors of Antibody-Producing Cells After Purification with a Fluorescence-Activated Cell Sorter
JOURNAL OF IMMUNOLOGY
2014; 193 (5): 1934-1938
View details for Web of Science ID 000341140600006
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Linkage of inflammation and oxidative stress via release of glutathionylated peroxiredoxin-2, which acts as a danger signal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2014; 111 (33): 12157-12162
Abstract
The mechanism by which oxidative stress induces inflammation and vice versa is unclear but is of great importance, being apparently linked to many chronic inflammatory diseases. We show here that inflammatory stimuli induce release of oxidized peroxiredoxin-2 (PRDX2), a ubiquitous redox-active intracellular enzyme. Once released, the extracellular PRDX2 acts as a redox-dependent inflammatory mediator, triggering macrophages to produce and release TNF-α. The oxidative coupling of glutathione (GSH) to PRDX2 cysteine residues (i.e., protein glutathionylation) occurs before or during PRDX2 release, a process central to the regulation of immunity. We identified PRDX2 among the glutathionylated proteins released in vitro by LPS-stimulated macrophages using mass spectrometry proteomic methods. Consistent with being part of an inflammatory cascade, we find that PRDX2 then induces TNF-α release. Unlike classical inflammatory cytokines, PRDX2 release does not reflect LPS-mediated induction of mRNA or protein synthesis; instead, PRDX2 is constitutively present in macrophages, mainly in the reduced form, and is released in the oxidized form on LPS stimulation. Release of PRDX2 is also observed in human embryonic kidney cells treated with TNF-α. Importantly, the PRDX2 substrate thioredoxin (TRX) is also released along with PRDX2, enabling an oxidative cascade that can alter the -SH status of surface proteins and thereby facilitate activation via cytokine and Toll-like receptors. Thus, our findings suggest a model in which the release of PRDX2 and TRX from macrophages can modify the redox status of cell surface receptors and enable induction of inflammatory responses. This pathway warrants further exploration as a potential novel therapeutic target for chronic inflammatory diseases.
View details for DOI 10.1073/pnas.1401712111
View details for Web of Science ID 000340438800063
View details for PubMedID 25097261
View details for PubMedCentralID PMC4143057
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Selective uptake of single-walled carbon nanotubes by circulating monocytes for enhanced tumour delivery.
Nature nanotechnology
2014; 9 (6): 481-487
Abstract
In cancer imaging, nanoparticle biodistribution is typically visualized in living subjects using 'bulk' imaging modalities such as magnetic resonance imaging, computerized tomography and whole-body fluorescence. Accordingly, nanoparticle influx is observed only macroscopically, and the mechanisms by which they target cancer remain elusive. Nanoparticles are assumed to accumulate via several targeting mechanisms, particularly extravasation (leakage into tumour). Here, we show that, in addition to conventional nanoparticle-uptake mechanisms, single-walled carbon nanotubes are almost exclusively taken up by a single immune cell subset, Ly-6C(hi) monocytes (almost 100% uptake in Ly-6C(hi) monocytes, below 3% in all other circulating cells), and delivered to the tumour in mice. We also demonstrate that a targeting ligand (RGD) conjugated to nanotubes significantly enhances the number of single-walled carbon nanotube-loaded monocytes reaching the tumour (P < 0.001, day 7 post-injection). The remarkable selectivity of this tumour-targeting mechanism demonstrates an advanced immune-based delivery strategy for enhancing specific tumour delivery with substantial penetration.
View details for DOI 10.1038/nnano.2014.62
View details for PubMedID 24727688
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Selective uptake of single-walled carbon nanotubes by circulating monocytes for enhanced tumour delivery.
Nature nanotechnology
2014; 9 (6): 481-487
View details for DOI 10.1038/nnano.2014.62
View details for PubMedID 24727688
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Selective uptake of single-walled carbon nanotubes by circulating monocytes for enhanced tumour delivery
Nature Nanotechnology
2014: 481–87
Abstract
In cancer imaging, nanoparticle biodistribution is typically visualized in living subjects using 'bulk' imaging modalities such as magnetic resonance imaging, computerized tomography and whole-body fluorescence. Accordingly, nanoparticle influx is observed only macroscopically, and the mechanisms by which they target cancer remain elusive. Nanoparticles are assumed to accumulate via several targeting mechanisms, particularly extravasation (leakage into tumour). Here, we show that, in addition to conventional nanoparticle-uptake mechanisms, single-walled carbon nanotubes are almost exclusively taken up by a single immune cell subset, Ly-6C(hi) monocytes (almost 100% uptake in Ly-6C(hi) monocytes, below 3% in all other circulating cells), and delivered to the tumour in mice. We also demonstrate that a targeting ligand (RGD) conjugated to nanotubes significantly enhances the number of single-walled carbon nanotube-loaded monocytes reaching the tumour (P < 0.001, day 7 post-injection). The remarkable selectivity of this tumour-targeting mechanism demonstrates an advanced immune-based delivery strategy for enhancing specific tumour delivery with substantial penetration.
View details for DOI 10.1038/nnano.2014.62
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Metabolic Adaptation of Neutrophils in Cystic Fibrosis Airways Involves Distinct Shifts in Nutrient Transporter Expression
JOURNAL OF IMMUNOLOGY
2013; 190 (12): 6043-6050
Abstract
Inflammatory conditions can profoundly alter human neutrophils, a leukocyte subset generally viewed as terminally differentiated and catabolic. In cystic fibrosis (CF) patients, neutrophils recruited to CF airways show active exocytosis and sustained phosphorylation of prosurvival, metabolic pathways. Because the CF airway lumen is also characterized by high levels of free glucose and amino acids, we compared surface expression of Glut1 (glucose) and ASCT2 (neutral amino acids) transporters, as well as that of PiT1 and PiT2 (inorganic phosphate transporters), in blood and airway neutrophils, using specific retroviral envelope-derived ligands. Neither nutrient transporter expression nor glucose uptake was altered on blood neutrophils from CF patients compared with healthy controls. Notably, however, airway neutrophils of CF patients had higher levels of PiT1 and Glut1 and increased glucose uptake compared with their blood counterparts. Based on primary granule exocytosis and scatter profiles, CF airway neutrophils could be divided into two subsets, with one of the subsets characterized by more salient increases in Glut1, ASCT2, PiT1, and PiT2 expression. Moreover, in vitro exocytosis assays of blood neutrophils suggest that surface nutrient transporter expression is not directly associated with primary (or secondary) granule exocytosis. Although expression of nutrient transporters on CF blood or airway neutrophils was not altered by genotype, age, gender, or Pseudomonas aeruginosa infection, oral steroid treatment decreased Glut1 and PiT2 levels in blood neutrophils. Thus, neutrophils recruited from blood into the CF airway lumen display augmented cell surface nutrient transporter expression and glucose uptake, consistent with metabolic adaptation.
View details for DOI 10.4049/jimmunol.1201755
View details for Web of Science ID 000320373700017
View details for PubMedID 23690474
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Blastocyst complementation generates exogenic pancreas in vivo in apancreatic cloned pigs
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2013; 110 (12): 4557-4562
Abstract
In the field of regenerative medicine, one of the ultimate goals is to generate functioning organs from pluripotent cells, such as ES cells or induced pluripotent stem cells (PSCs). We have recently generated functional pancreas and kidney from PSCs in pancreatogenesis- or nephrogenesis-disabled mice, providing proof of principle for organogenesis from PSCs in an embryo unable to form a specific organ. Key when applying the principles of in vivo generation to human organs is compensation for an empty developmental niche in large nonrodent mammals. Here, we show that the blastocyst complementation system can be applied in the pig using somatic cell cloning technology. Transgenic approaches permitted generation of porcine somatic cell cloned embryos with an apancreatic phenotype. Complementation of these embryos with allogenic blastomeres then created functioning pancreata in the vacant niches. These results clearly indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize a cloned dysorganogenetic embryo. The feasibility of blastocyst complementation using cloned porcine embryos allows experimentation toward the in vivo generation of functional organs from xenogenic PSCs in large animals.
View details for DOI 10.1073/pnas.1222902110
View details for Web of Science ID 000317521600039
View details for PubMedID 23431169
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H-Y antigen-binding B cells develop in male recipients of female hematopoietic cells and associate with chronic graft vs. host disease
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2013; 110 (8): 3005-3010
Abstract
B cells are known to play an important role in pathogenesis of human chronic graft vs. host disease (cGVHD). Our group has previously shown that IgG allo-antibodies recognize Y chromosome-encoded proteins (H-Y) and a dominant H-Y epitope, DEAD box protein (DBY-2) detectable 6-12 mo after transplant in male patients who receive grafts from female donors (F→M) hematopoietic cell transplantation (HCT). Here we present FACS studies of peripheral blood mononuclear cells collected 6 mo after transplant showing that 16 of 28 (57%) F→M HCT patients have circulating donor B cells that express B-cell receptor (mainly IgM and Igλ) specific for DBY-2. The detection of these DBY-2 B cells 6 mo after HCT are associated with cGVHD development (P = 0.004). Specifically, 15 of 16 F→M with DBY-2 B cells developed cGVHD. In contrast, cGVHD developed in only 5 of the 12 who did not have DBY-2 B cells detected. This demonstrates circulating human B cells binding an alloantigen (DBY-2) and that these DBY-2-specific B cells appear before development of cGVHD in roughly half of the F→M patients. Our study suggests that detection of anti-DBY-2 B cells may predict cGVHD and that this prediction may have clinical utility. Validation of this hypothesis will require larger prospective studies.
View details for DOI 10.1073/pnas.1222900110
View details for Web of Science ID 000315954400081
View details for PubMedID 23382226
View details for PubMedCentralID PMC3581974
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Blood basophils from cystic fibrosis patients with allergic bronchopulmonary aspergillosis are primed and hyper-responsive to stimulation by aspergillus allergens
JOURNAL OF CYSTIC FIBROSIS
2012; 11 (6): 502-510
Abstract
Fifteen to sixty percent of cystic fibrosis patients harbor Aspergillus fumigatus (Af) in their airways (CF-AC) and some will develop allergic bronchopulmonary aspergillosis (CF-ABPA). Since basophils play a key role in allergy, we hypothesized that they would display alterations in CF-ABPA patients compared to CF-AC or patients without Af colonization (CF).Using flow cytometry, we measured CD203c, CD63 and CD123 levels on basophils from CF-ABPA (N=11), CF-AC (N=14), and CF (N=12) patients before and after ex vivo stimulation with Af allergens.Baseline CD203c was increased in basophils from CF-ABPA compared to CF-AC and CF patients. Af extract and recombinant Aspf1 stimulated basophils from CF-ABPA patients to markedly upregulate CD203c, along with modest upregulation of CD63 and a CD123 downward trend. Plasma TARC/CCL17 at baseline and post-stimulation cell supernatant histamine levels were similar in the three groups.In CF-ABPA, blood basophils are primed and hyperresponsive to Af allergen stimulation.
View details for DOI 10.1016/j.jcf.2012.04.008
View details for Web of Science ID 000312115900004
View details for PubMedID 22608296
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Reversal of Paralysis and Reduced Inflammation from Peripheral Administration of beta-Amyloid in T(H)1 and T(H)17 Versions of Experimental Autoimmune Encephalomyelitis
SCIENCE TRANSLATIONAL MEDICINE
2012; 4 (145)
Abstract
β-Amyloid 42 (Aβ42) and β-amyloid 40 (Aβ40), major components of senile plaque deposits in Alzheimer's disease, are considered neurotoxic and proinflammatory. In multiple sclerosis, Aβ42 is up-regulated in brain lesions and damaged axons. We found, unexpectedly, that treatment with either Aβ42 or Aβ40 peptides reduced motor paralysis and brain inflammation in four different models of experimental autoimmune encephalomyelitis (EAE) with attenuation of motor paralysis, reduction of inflammatory lesions in the central nervous system (CNS), and suppression of lymphocyte activation. Aβ42 and Aβ40 treatments were effective in reducing ongoing paralysis induced with adoptive transfer of either autoreactive T helper 1 (T(H)1) or T(H)17 cells. High-dimensional 14-parameter flow cytometry of peripheral immune cell populations after in vivo Aβ42 and Aβ40 treatment revealed substantial modulations in the percentage of lymphoid and myeloid subsets during EAE. Major proinflammatory cytokines and chemokines were reduced in the blood after Aβ peptide treatment. Protection conferred by Aβ treatment did not require its delivery to the brain: Adoptive transfer with lymphocytes from donors treated with Aβ42 attenuated EAE in wild-type recipient mice, and Aβ deposition in the brain was not detected in treated EAE mice by immunohistochemical analysis. In contrast to the improvement in EAE with Aβ treatment, EAE was worse in mice with genetic deletion of the amyloid precursor protein. Therefore, in the absence of Aβ, there is exacerbated clinical EAE disease progression. Because Aβ42 and Aβ40 ameliorate experimental autoimmune inflammation targeting the CNS, we might now consider its potential anti-inflammatory role in other neuropathological conditions.
View details for DOI 10.1126/scitranslmed.3004145
View details for Web of Science ID 000307159500004
View details for PubMedID 22855462
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A Randomized Controlled Pilot Trial of Oral N-Acetylcysteine in Children with Autism
BIOLOGICAL PSYCHIATRY
2012; 71 (11): 956-961
Abstract
An imbalance in the excitatory/inhibitory systems with abnormalities in the glutamatergic pathways has been implicated in the pathophysiology of autism. Furthermore, chronic redox imbalance was also recently linked to this disorder. The goal of this pilot study was to assess the feasibility of using oral N-acetylcysteine (NAC), a glutamatergic modulator and an antioxidant, in the treatment of behavioral disturbance in children with autism.This was a 12-week, double-blind, randomized, placebo-controlled study of NAC in children with autistic disorder. Subjects randomized to NAC were initiated at 900 mg daily for 4 weeks, then 900 mg twice daily for 4 weeks and 900 mg three times daily for 4 weeks. The primary behavioral measure (Aberrant Behavior Checklist [ABC] irritability subscale) and safety measures were performed at baseline and 4, 8, and 12 weeks. Secondary measures included the ABC stereotypy subscale, Repetitive Behavior Scale-Revised, and Social Responsiveness Scale.Thirty-three subjects (31 male subjects, 2 female subjects; aged 3.2-10.7 years) were randomized in the study. Follow-up data was available on 14 subjects in the NAC group and 15 in the placebo group. Oral NAC was well tolerated with limited side effects. Compared with placebo, NAC resulted in significant improvements on ABC irritability subscale (F = 6.80; p < .001; d = .96).Data from this pilot investigation support the potential usefulness of NAC for treating irritability in children with autistic disorder. Large randomized controlled investigations are warranted.
View details for DOI 10.1016/j.biopsych.2012.01.014
View details for Web of Science ID 000303814800007
View details for PubMedID 22342106
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Modulation of mTOR Effector Phosphoproteins in Blood Basophils from Allergic Patients
JOURNAL OF CLINICAL IMMUNOLOGY
2012; 32 (3): 565-573
Abstract
The mammalian target of rapamycin (mTOR) pathway contributes to various immunoinflammatory processes. Yet, its potential involvement in basophil responses in allergy remains unclear. In this pilot study, we quantified two key mTOR effector phosphoproteins, the eukaryotic initiation factor 4E (peIF4E) and S6 ribosomal protein (pS6rp), in blood basophils from nut allergy patients (NA, N = 16) and healthy controls (HC, N = 13). Without stimulation in vitro, basophil peIF4E levels were higher in NA than HC subjects (P = 0.014). Stimulation with nut (offending) but not chicken / rice (non-offending) extract increased basophil peIF4E and pS6rp levels (+32%, P = 0.018, and +98%, P = 0.0026, respectively) in NA but not HC subjects, concomitant with increased surface levels of CD203c and CD63, both known to reflect basophil activation. Pre-treatment with the mTOR inhibitor rapamycin decreased pS6rp and CD203c responses in nut extract-stimulated basophils in NA subjects. Thus, basophil responses to offending allergens are associated with modulation of mTOR effector phosphoproteins.
View details for DOI 10.1007/s10875-012-9651-x
View details for Web of Science ID 000305982100019
View details for PubMedID 22350221
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Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders
JOURNAL OF AUTISM AND DEVELOPMENTAL DISORDERS
2012; 42 (5): 827-836
Abstract
The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N = 27) and neuro-typically developing controls (N = 20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating children with ASD from healthy children. Furthermore, statistical correlations suggested the lack of a typical decrease of glutamate and aspartate with age, and a non-typical increase of isoleucine and lysine with age in the ASD group. Findings from this limited prospective study warrant further examination of plasma AA levels in larger cross-sectional and longitudinal cohorts to adequately assess for relationships with developmental and clinical features of ASD.
View details for DOI 10.1007/s10803-011-1314-x
View details for Web of Science ID 000302771500017
View details for PubMedID 21713591
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Development of B Cells and Erythrocytes Is Specifically Impaired by the Drug Celastrol in Mice
PLOS ONE
2012; 7 (4)
Abstract
Celastrol, an active compound extracted from the root of the Chinese medicine "Thunder of God Vine" (Tripterygium wilfordii), exhibits anticancer, antioxidant and anti-inflammatory activities, and interest in the therapeutic potential of celastrol is increasing. However, described side effects following treatment are significant and require investigation prior to initiating clinical trials. Here, we investigated the effects of celastrol on the adult murine hematopoietic system.Animals were treated daily with celastrol over a four-day period and peripheral blood, bone marrow, spleen, and peritoneal cavity were harvested for cell phenotyping. Treated mice showed specific impairment of the development of B cells and erythrocytes in all tested organs. In bone marrow, these alterations were accompanied by decreases in populations of common lymphoid progenitors (CLP), common myeloid progenitors (CMP) and megakaryocyte-erythrocyte progenitors (MEP).These results indicate that celastrol acts through regulators of adult hematopoiesis and could be used as a modulator of the hematopoietic system. These observations provide valuable information for further assessment prior to clinical trials.
View details for DOI 10.1371/journal.pone.0035733
View details for Web of Science ID 000305343200053
View details for PubMedID 22545133
View details for PubMedCentralID PMC3335785
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Distinct B-cell lineage commitment distinguishes adult bone marrow hematopoietic stem cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (14): 5394-5398
Abstract
The question of whether a single hematopoietic stem cell (HSC) gives rise to all of the B-cell subsets [B-1a, B-1b, B-2, and marginal zone (MZ) B cells] in the mouse has been discussed for many years without resolution. Studies here finally demonstrate that individual HSCs sorted from adult bone marrow and transferred to lethally irradiated recipients clearly give rise to B-2, MZ B, and B-1b, but does not detectably reconstitute B-1a cells. These findings place B-2, MZ, and B-1b in a single adult developmental lineage and place B-1a in a separate lineage derived from HSCs that are rare or missing in adults. We discuss these findings with respect to known developmental heterogeneity in other HSC-derived lymphoid, myeloid, and erythroid lineages, and how HSC developmental heterogeneity conforms to the layered model of the evolution of the immune system that we proposed some years ago. In addition, of importance to contemporary medicine, we consider the implications that HSC developmental heterogeneity may have for selecting HSC sources for human transplantation.
View details for DOI 10.1073/pnas.1121632109
View details for Web of Science ID 000302294700059
View details for PubMedID 22431624
View details for PubMedCentralID PMC3325648
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Antigen-specific memory in B-1a and its relationship to natural immunity
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (14): 5388-5393
Abstract
In the companion article by Yang and colleagues [Yang Y, et al. (2012) Proc Natl Acad Sci USA, 109, 10.1073/pnas.1121631109], we have shown that priming with glycolipid (FtL) from Francisella tularensis live-vaccine strain (i) induces FtL-specific B-1a to produce robust primary responses (IgM >IgG); (ii) establishes persistent long-term production of serum IgM and IgG anti-FtL at natural antibody levels; and (iii) elicits FtL-specific B-1a memory cells that arise in spleen but rapidly migrate to the peritoneal cavity, where they persist indefinitely but divide only rarely. Here, we show that FtL rechallenge alone induces these PerC B-1a memory cells to divide extensively and to express a unique activation signature. However, FtL rechallenge in the context of a Toll-like receptor 4 agonist-stimulated inflammatory response readily induces these memory cells to migrate to spleen and initiate production of dominant IgM anti-FtL secondary responses. Thus, studies here reveal unique mechanisms that govern B-1a memory development and expression, and introduce B-1a memory as an active participant in immune defenses. In addition, at a practical level, these studies suggest previously unexplored vaccination strategies for pathogen-associated antigens that target the B-1a repertoire.
View details for DOI 10.1073/pnas.1121627109
View details for Web of Science ID 000302294700058
View details for PubMedID 22421135
View details for PubMedCentralID PMC3325686
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Antigen-specific antibody responses in B-1a and their relationship to natural immunity
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (14): 5382-5387
Abstract
B-1a cells are primarily thought of as natural antibody-producing cells. However, we now show that appropriate antigenic stimulation induces IgM and IgG B-1a antibody responses and long-lived T-independent antigen-specific B-1a memory that differs markedly from canonical B-2 humoral immunity. Thus, we show here that in the absence of inflammation, priming with glycolipid (FtL) from Francisella tularensis live vaccine strain induces splenic FtL-specific B-1a to mount dominant IgM and activation-induced cytidine deaminase-dependent IgG anti-FtL responses that occur within 3-5 d of FtL priming and fade within 1 wk to natural antibody levels that persist indefinitely in the absence of secondary FtL immunization. Equally surprising, FtL priming elicits long-term FtL-specific B-1a memory cells (IgM>IgG) that migrate rapidly to the peritoneal cavity and persist there indefinitely, ready to respond to appropriately administrated secondary antigenic stimulation. Unlike B-2 responses, primary FtL-specific B-1a responses and establishment of persistent FtL-specific B-1a memory occur readily in the absence of adjuvants, IL-7, T cells, or germinal center support. However, in another marked departure from the mechanisms controlling B-2 memory responses, rechallenge with FtL in an inflammatory context is required to induce B-1a secondary antibody responses. These findings introduce previously unexplored vaccination strategies for pathogens that target the B-1a repertoire.
View details for DOI 10.1073/pnas.1121631109
View details for Web of Science ID 000302294700057
View details for PubMedID 22421134
View details for PubMedCentralID PMC3325670
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Glut1-mediated glucose transport regulates HIV infection
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (7): 2549-2554
Abstract
Cell cycle entry is commonly considered to positively regulate HIV-1 infection of CD4 T cells, raising the question as to how quiescent lymphocytes, representing a large portion of the viral reservoir, are infected in vivo. Factors such as the homeostatic cytokine IL-7 have been shown to render quiescent T cells permissive to HIV-1 infection, presumably by transiently stimulating their entry into the cell cycle. However, we show here that at physiological oxygen (O(2)) levels (2-5% O(2) tension in lymphoid organs), IL-7 stimulation generates an environment permissive to HIV-1 infection, despite a significantly attenuated level of cell cycle entry. We identify the IL-7-induced increase in Glut1 expression, resulting in augmented glucose uptake, as a key factor in rendering these T lymphocytes susceptible to HIV-1 infection. HIV-1 infection of human T cells is abrogated either by impairment of Glut1 signal transduction or by siRNA-mediated Glut1 down-regulation. Consistent with this, we show that the susceptibility of human thymocyte subsets to HIV-1 infection correlates with Glut1 expression; single-round infection is markedly higher in the Glut1-expressing double-positive thymocyte population than in any of the Glut1-negative subsets. Thus, our studies reveal the Glut1-mediated metabolic pathway as a critical regulator of HIV-1 infection in human CD4 T cells and thymocytes.
View details for DOI 10.1073/pnas.1121427109
View details for Web of Science ID 000300489200077
View details for PubMedID 22308487
View details for PubMedCentralID PMC3289356
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Nerve Growth Factor A Key Local Regulator in the Pathogenesis of Inflammatory Arthritis
ARTHRITIS AND RHEUMATISM
2011; 63 (11): 3243-3252
Abstract
The effect of nerve growth factor (NGF) and its receptor (NGFR) in inflammatory diseases is a novel research field. The purpose of this study was to investigate the role of NGF/NGFR in human T cell subpopulations and fibroblast-like synovial cells (FLS) and examine its pathophysiologic significance in psoriatic arthritis (PsA) and rheumatoid arthritis (RA).Expression of NGF/NGFR was examined in synovial fluid (SF), FLS, peripheral blood (PB)-derived T cells, and SF-derived T cells from patients with PsA, RA, and osteoarthritis (OA). NGF levels were determined by enzyme-linked immunosorbent assay. NGF-induced T cell/FLS proliferation was examined by MTT assay. Low-affinity (p75)/high-affinity (TrkA) NGFR expression was determined by high-dimensional fluorescence-activated cell sorting. A monochlorobimane assay was used to determine the effect of NGF on T cell survival.Levels of NGF were higher in SF samples from PsA and RA patients as compared to SF samples from OA patients. NGF-induced FLS proliferation was more marked in PsA and RA patients. TrkA was up-regulated on activated SF T cells from PsA (mean ± SD 22 ± 6.2%) and RA (8 ± 1.3%) patients, whereas in SF samples from OA patients, TrkA+CD3+ T cells were not detectable. NGF induced the proliferation of PB T cells, induced the phosphorylation of Akt in activated T cells, and consistent with known pAkt activity, inhibited tumor necrosis factor α-induced cell death in these T cells.Based on our findings, we propose a model in which NGF secreted by FLS into PsA and RA synovium promotes the survival of activated autoreactive T cells as well as FLS proliferation. Thus, NGF has the potential to sustain the chronic inflammatory cascades of arthritis of autoimmune origin.
View details for DOI 10.1002/art.30564
View details for Web of Science ID 000297221100008
View details for PubMedID 21792838
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Distinct progenitors for B-1 and B-2 cells are present in adult mouse spleen
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2011; 108 (7): 2879-2884
Abstract
Recent studies by Dorshkind, Yoder, and colleagues show that embryonic (E9) B-cell progenitors located in the yolk sac and intraembryonic hemogenic endothelium before the initiation of circulation give rise to B-1 and marginal zone B cells but do not give rise to B-2 cells. In studies here, we confirm and extend these findings by showing that distinct progenitors for B-1 and B-2 cells are present in the adult spleen. Furthermore, we show that the splenic B-cell progenitor population (lin(-)CD19(+)/B220(lo/-)/CD43(-)) that gives rise to B-1 cells is likely to be heterogeneous because, in some recipients, it also gives rise to B cells expressing the marginal zone phenotype (B220(hi)IgM(hi)IgD(lo)CD21(hi)) and to some (CD19(-)CD5(hi)) T cells. In addition to the well-known function differences between B-1 and B-2, our studies demonstrate that substantial developmental differences separate these B-cell lineages. Thus, consistent with the known dependence of B-2 development on IL-7, all B-2 progenitors express IL-7R. However, >30% of the B-1 progenitors do not express this marker, enabling the known IL-7 independent development of B-1 cells in IL-7(-/-) mice. In addition, marker expression on cells in the early stages of the B-2 development pathway (CD19(-)/c-Kit(lo/-)/Sca-1(lo/-)) in adult bone marrow distinguish it from the early stages of B-1 development (CD19(hi)/c-Kit(+)/Sca-1(+)), which occur constitutively in neonates. In adults, in vivo inflammatory stimulation (LPS) triggers B-1 progenitors in spleen to expand and initiate development along this B-1 developmental pathway.
View details for DOI 10.1073/pnas.1019764108
View details for Web of Science ID 000287377000049
View details for PubMedID 21282663
View details for PubMedCentralID PMC3041118
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Basophil CD203c Levels Are Increased at Baseline and Can Be Used to Monitor Omalizumab Treatment in Subjects with Nut Allergy
INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY
2011; 154 (4): 318-327
Abstract
Basophils contribute to anaphylaxis and allergies. We examined the utility of assessing basophil-associated surface antigens (CD11b/CD63/CD123/CD203c/CD294) in characterizing and monitoring subjects with nut allergy.We used flow cytometry to analyze basophils at baseline (without any activation) and after ex vivo stimulation of whole blood by addition of nut or other allergens for 2, 10, and 30 min. We also evaluated whether basophil expression of CD11b/CD63/CD123/CD203c/CD294 was altered in subjects treated with anti-IgE monoclonal antibody (omalizumab) to reduce plasma levels of IgE.We demonstrate that basophil CD203c levels are increased at baseline in subjects with nut allergy compared to healthy controls (13 subjects in each group, p < 0.0001). Furthermore, we confirm that significantly increased expression of CD203c occurs on subject basophils when stimulated with the allergen to which the subject is sensitive and can be detected rapidly (10 min of stimulation, n = 11, p < 0.0008). In 5 subjects with severe peanut allergy, basophil CD203c expression following stimulation with peanut allergen was significantly decreased (p < 0.05) after 4 and 8 weeks of omalizumab treatment but returned toward pretreatment levels after treatment cessation.Subjects with nut allergy show an increase of basophil CD203c levels at baseline and following rapid ex vivo stimulation with nut allergen. Both can be reduced by omalizumab therapy. These results highlight the potential of using basophil CD203c levels for baseline diagnosis and therapeutic monitoring in subjects with nut allergy.
View details for DOI 10.1159/000321824
View details for Web of Science ID 000288529200007
View details for PubMedID 20975283
View details for PubMedCentralID PMC3214954
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METABOLITE PROFILING OF CF AIRWAY FLUID SUGGESTS A ROLE FOR CATECHOLAMINES IN EARLY AND CHRONIC DISEASE
WILEY-BLACKWELL. 2011: 240–240
View details for Web of Science ID 000296071800163
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Genetic immunization in the lung induces potent local and systemic immune responses
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2010; 107 (51): 22213-22218
Abstract
Successful vaccination against respiratory infections requires elicitation of high levels of potent and durable humoral and cellular responses in the lower airways. To accomplish this goal, we used a fine aerosol that targets the entire lung surface through normal respiration to deliver replication-incompetent recombinant adenoviral vectors expressing gene products from several infectious pathogens. We show that this regimen induced remarkably high and stable lung T-cell responses in nonhuman primates and that it also generated systemic and respiratory tract humoral responses of both IgA and IgG isotypes. Moreover, strong immunogenicity was achieved even in animals with preexisting antiadenoviral immunity, overcoming a critical hurdle to the use of these vectors in humans, who commonly are immune to adenoviruses. The immunogenicity profile elicited with this regimen, which is distinct from either intramuscular or intranasal delivery, has highly desirable properties for protection against respiratory pathogens. We show that it can be used repeatedly to generate mucosal humoral, CD4, and CD8 T-cell responses and as such may be applicable to other mucosally transmitted pathogens such as HIV. Indeed, in a lethal challenge model, we show that aerosolized recombinant adenoviral immunization completely protects ferrets against H5N1 highly pathogenic avian influenza virus. Thus, genetic immunization in the lung offers a powerful platform approach to generating protective immune responses against respiratory pathogens.
View details for DOI 10.1073/pnas.1015536108
View details for Web of Science ID 000285521800052
View details for PubMedID 21135247
View details for PubMedCentralID PMC3009829
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Two physically, functionally, and developmentally distinct peritoneal macrophage subsets
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2010; 107 (6): 2568-2573
Abstract
The peritoneal cavity (PerC) is a unique compartment within which a variety of immune cells reside, and from which macrophages (MØ) are commonly drawn for functional studies. Here we define two MØ subsets that coexist in PerC in adult mice. One, provisionally called the large peritoneal MØ (LPM), contains approximately 90% of the PerC MØ in unstimulated animals but disappears rapidly from PerC following lipopolysaccharide (LPS) or thioglycolate stimulation. These cells express high levels of the canonical MØ surface markers, CD11b and F4/80. The second subset, referred to as small peritoneal MØ (SPM), expresses substantially lower levels of CD11b and F4/80 but expresses high levels of MHC-II, which is not expressed on LPM. SPM, which predominates in PerC after LPS or thioglycolate stimulation, does not derive from LPM. Instead, it derives from blood monocytes that rapidly enter the PerC after stimulation and differentiate to mature SPM within 2 to 4 d. Both subsets show clear phagocytic activity and both produce nitric oxide (NO) in response to LPS stimulation in vivo. However, their responses to LPS show key differences: in vitro, LPS stimulates LPM, but not SPM, to produce NO; in vivo, LPS stimulates both subsets to produce NO, albeit with different response patterns. These findings extend current models of MØ heterogeneity and shed new light on PerC MØ diversity, development, and function. Thus, they introduce a new context for interpreting (and reinterpreting) data from ex vivo studies with PerC MØ.
View details for DOI 10.1073/pnas.0915000107
View details for Web of Science ID 000274408100039
View details for PubMedID 20133793
View details for PubMedCentralID PMC2823920
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Human Basophils: New Mechanisms Of Action And Role In Food Allergy
66th Annual Meeting of the American-Academy-of-Allergy-Asthma-and-Immunology (AAAAI)
MOSBY-ELSEVIER. 2010: AB86–AB86
View details for Web of Science ID 000280204100339
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SMALL METABOLITE PROFILING OF AIRWAY FLUID UNCOVERS SPECIFIC ALTERATIONS IN CF
WILEY-BLACKWELL. 2010: 243–243
View details for Web of Science ID 000282988800151
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Activation of critical, host-induced, metabolic and stress pathways marks neutrophil entry into cystic fibrosis lungs
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2009; 106 (14): 5779-5783
Abstract
Cystic fibrosis (CF) patients undergo progressive airway destruction caused in part by chronic neutrophilic inflammation. While opportunistic pathogens infecting CF airways can cause inflammation, we hypothesized that host-derived metabolic and stress signals would also play a role in this process. We show that neutrophils that have entered CF airways have increased phosphorylation of the eukaryotic initiation factor 4E and its partner the 4E-binding protein 1; 2 key effectors in the growth factor- and amino acid-regulated mammalian target of rapamycin (mTOR) pathway. Furthermore CF airway neutrophils display increased phosphorylation of the cAMP response element binding protein (CREB), a major transcriptional coactivator in stress signaling cascades. These active intracellular pathways are associated with increased surface expression of critical adaptor molecules, including the growth factor receptor CD114 and the receptor for advanced glycation end-products (RAGE), a CREB inducer and sensor for host-derived damage-associated molecular patterns (DAMPs). Most CF airway fluids lack any detectable soluble RAGE, an inhibitory decoy receptor for DAMPs. Concomitantly, CF airway fluids displayed high and consequently unopposed levels of S100A12; a potent mucosa- and neutrophil-derived DAMP. CF airway neutrophils also show increased surface levels of 2 critical CREB targets, the purine-recycling enzyme CD39 and the multifunctional, mTOR-inducing CXCR4 receptor. This coordinated set of events occurs in all patients, even in the context of minimal airway inflammation and well-preserved lung function. Taken together, our data demonstrate an early and sustained activation of host-responsive metabolic and stress pathways upon neutrophil entry into CF airways, suggesting potential targets for therapeutic modulation.
View details for DOI 10.1073/pnas.0813410106
View details for Web of Science ID 000264967500059
View details for PubMedID 19293384
View details for PubMedCentralID PMC2667067
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Antigen- specific B-1a antibodies induced by Francisella tularensis LPS provide long-term protection against F. tularensis LVS challenge
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2009; 106 (11): 4343-4348
Abstract
Francisella tularensis (Ft), a gram-negative intracellular bacterium, is the etiologic agent of tularemia. Infection of mice with <10 Ft Live Vaccine Strain (Ft LVS) organisms i.p. causes a lethal infection that resembles human tularemia. Here, we show that immunization with as little as 0.1 ng Ft LVS lipopolysaccharide (Ft-LPS), but not Ft lipid A, generates a rapid antibody response that protects wild-type (WT) mice against lethal Ft LVS challenge. Protection is not induced in Ft-LPS-immunized B cell-deficient mice (muMT or JhD), male xid mice, or Ig transgenic mice that produce a single IgH (not reactive with Ft-LPS). Focusing on the cellular mechanisms that underlie this protective response, we show that Ft-LPS specifically stimulates proliferation of B-1a lymphocytes that bind fluorochrome-labeled Ft-LPS and the differentiation of these cells to plasma cells that secrete antibodies specific for Ft-LPS. This exclusively B-1a antibody response is equivalent in WT, T-deficient (TCRalphabeta(-/-), TCRgammadelta(-/-)), and Toll-like receptor 4 (TLR4)-deficient (TLR4(-/-)) mice and thus is not dependent on T cells or typical inflammatory processes. Serum antibody levels peak approximately 5 days after Ft-LPS immunization and persist at low levels for months. Thus, immunization with Ft-LPS activates a rare population of antigen-specific B-1a cells to produce a persistent T-independent antibody response that provides long-term protection against lethal Ft LVS infection. These data support the possibility of creating effective, minimally invasive vaccines that can provide effective protection against pathogen invasion.
View details for DOI 10.1073/pnas.0813411106
View details for Web of Science ID 000264278800053
View details for PubMedID 19251656
View details for PubMedCentralID PMC2657382
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Inherited disorders affecting mitochondrial function are associated with glutathione deficiency and hypocitrullinemia
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2009; 106 (10): 3941-3945
Abstract
Disorders affecting mitochondria, including those that directly affect the respiratory chain function or result from abnormalities in branched amino acid metabolism (organic acidemias), have been shown to be associated with impaired redox balance. Almost all of the evidence underlying this conclusion has been obtained from studies on patient biopsies or animal models. Since the glutathione (iGSH) system provides the main protection against oxidative damage, we hypothesized that untreated oxidative stress in individuals with mitochondrial dysfunction would result in chronic iGSH deficiency. We confirm this hypothesis here in studies using high-dimensional flow cytometry (Hi-D FACS) and biochemical analysis of freshly obtained blood samples from patients with mitochondrial disorders or organic acidemias. T lymphocyte subsets, monocytes and neutrophils from organic acidemia and mitochondrial patients who were not on antioxidant supplements showed low iGSH levels, whereas similar subjects on antioxidant supplements showed normal iGSH. Measures of iROS levels in blood were insufficient to reveal the chronic oxidative stress in untreated patients. Patients with organic acidemias showed elevated plasma protein carbonyls, while plasma samples from all patients tested showed hypocitrullinemia. These findings indicate that measurements of iGSH in leukocytes may be a particularly useful biomarker to detect redox imbalance in mitochondrial disorders and organic acidemias, thus providing a relatively non-invasive means to monitor disease status and response to therapies. Furthermore, studies here suggest that antioxidant therapy may be useful for relieving the chronic oxidative stress that otherwise occurs in patients with mitochondrial dysfunction.
View details for DOI 10.1073/pnas.0813409106
View details for PubMedID 19223582
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FR255734, a humanized, Fc-silent, anti-CD28 antibody, improves psoriasis in the SCID mouse-psoriasis xenograft model
JOURNAL OF INVESTIGATIVE DERMATOLOGY
2008; 128 (8): 1969-1976
Abstract
In psoriasis, CD28/B7 costimulatory molecules are well characterized. Here, using the severe combined immunodeficient (SCID) mouse-psoriasis xenograft model, we report therapeutic efficacy of a humanized anti-CD28 monoclonal antibody (FR255734; Astellas Pharmaceuticals Inc., Tokyo, Japan). Transplanted psoriasis plaques on the SCID mouse were treated weekly for 4 weeks with intraperitoneal injections of FR255734 at 10, 3, and 1-mg kg(-1) doses. Groups treated with doses of 10 and 3 mg kg(-1) had significant thinning of the epidermis and reduced HLA-DR-positive lymphocytic infiltrates. The length of the rete pegs changed from 415.2+/-59.6 to 231.4+/-40.4 microm (P<0.005) in the 10-mg kg(-1) group, and from 323.4+/-69.6 to 237.5+/-73.6 microm in the 3-mg kg(-1) group (P=0.002). Positive controls treated with CTLA4-Ig and cyclosporine had significant histological improvement, whereas plaques treated with saline and isotype controls (human and mouse IgG2) remained unchanged. In vitro studies have shown that FR255734 effectively blocked T-cell proliferation and proinflammatory cytokine production. These observations warrant studies to evaluate the efficacy of FR255734 in human autoimmune diseases.
View details for DOI 10.1038/jid.2008.38
View details for Web of Science ID 000258031700016
View details for PubMedID 18337836
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CD11b expression distinguishes sequential stages of peritoneal B-1 development
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2008; 105 (13): 5195-5200
Abstract
Peritoneal cavity (PerC) B-1 cells have long been known to express CD11b, which is coexpressed with CD18 to form the Mac-1/CR3 complement receptor and adhesion molecule. However, although all PerC B-1 cells are commonly believed to express CD11b, we show here that nearly half of the cells in each of the PerC B-1 subsets (B-1a and B-1b) do not express this surface receptor. The CD11b(+) cells in each B-1 subset are larger and more granular and express higher levels of surface IgM than the CD11b(-) B-1 cells. In addition, the CD11b(+) B-1 cells initiate the formation of tightly associated doublets that are present at high frequency in adult PerC. Finally, and most importantly from a developmental standpoint, the CD11b(+) B-1 cells have a limited reconstitution capability: when sorted and transferred into congenic recipients, they reconstitute their own (CD11b(+)) B-1 subset but do not reconstitute the CD11b(-) B-1 subset. In contrast, CD11b(-) B-1 cells transferred under the same conditions efficiently replenish all components of the PerC B-1 population in appropriate proportions. During ontogeny, CD11b(-) B-1 cells appear before CD11b(+) B-1 cells. However, the clear phenotypic differences between the neonatal and adult CD11b B-1 subsets argue that although CD11b(-) B-1 give rise to CD11b(+) B-1 in both cases different forces may regulate this transition.
View details for DOI 10.1073/pnas.0712350105
View details for Web of Science ID 000254723700044
View details for PubMedID 18375763
View details for PubMedCentralID PMC2278228
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Antigen-induced B-1 class switch and persistent B-1 memory
FEDERATION AMER SOC EXP BIOL. 2008
View details for Web of Science ID 000208467700543
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Culturing of human peripheral blood cells reveals unsuspected lymphocyte responses relevant to HIV disease
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2008; 105 (13): 5111-5116
Abstract
Recombinant HIV-Tat (Tat) induces extensive apoptosis in peripheral blood mononuclear cells (PBMCs) cultured in typical CO2 incubators, which are equilibrated with air (21% O2). However, as we show here, Tat apoptosis induction fails in PBMCs cultured at physiological oxygen levels (5% O2). Under these conditions, Tat induces PBMCs to divide, efficiently primes them for HIV infection, and supports virus production by the infected cells. Furthermore, Tat takes only 2 h to prime PBMCs under these conditions. In contrast, PHA/IL-2, which is widely used to prime cells for HIV infection, takes 2-3 days. These findings strongly recommend culturing primary cells at physiological oxygen levels. In addition, they suggest HIV-Tat as a key regulator of HIV disease progression.
View details for DOI 10.1073/pnas.0712363105
View details for Web of Science ID 000254723700029
View details for PubMedID 18364393
View details for PubMedCentralID PMC2278183
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Profound functional and signaling changes in viable inflammatory neutrophils homing to cystic fibrosis airways
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2008; 105 (11): 4335-4339
Abstract
Blood neutrophils recruited to cystic fibrosis (CF) airways are believed to be rapidly killed by resident bacteria and to passively release elastase and other toxic by-products that promote disease progression. By single-cell analysis, we demonstrate that profound functional and signaling changes readily occur within viable neutrophils recruited to CF airways, compared with their blood counterparts. Airway neutrophils have undergone conventional activation, as shown by decreased intracellular glutathione, increased lipid raft assembly, surface mobilization of CD11b+ and CD66b+ granules, and increased levels of the cytoskeleton-associated phospho-Syk kinase. Unexpectedly, they also mobilize to the surface CD63+ elastase-rich granules, usually confined intracellularly, and lose surface expression of CD16 and CD14, both key receptors in phagocytosis. Furthermore, they express CD80, major histocompatibility complex type II, and the prostaglandin D2 receptor CD294, all normally associated with other lineages, which reflects functional reprogramming. This notion is reinforced by their decreased total phosphotyrosine levels, mirroring a postactivated stage, and increased levels of the phospho-S6 ribosomal protein, a key anabolic switch. Thus, we identified a subset of neutrophils within CF airways with a viable but dysfunctional phenotype. This subset provides a possible therapeutic target and indicates a need to revisit current paradigms of CF airway disease.
View details for DOI 10.1073/pnas.0712386105
View details for Web of Science ID 000254263300048
View details for PubMedID 18334635
View details for PubMedCentralID PMC2393742
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B cell lineage contributions to antiviral host responses
SPECIALIZATION AND COMPLEMENTATION OF HUMORAL IMMUNE RESPONSES TO INFECTION
2008; 319: 41-61
Abstract
B cell responses are a major immune protective mechanism induced against a large variety of pathogens. Technical advances over the last decade, particularly in the isolation and characterization of B cell subsets by multicolor flow cytometry, have demonstrated the multifaceted nature of pathogen-induced B cell responses. In addition to participation by the major follicular B cell population, three B cell subsets are now recognized as key contributors to pathogen-induced host defenses: marginal zone (MZ) B cells, B-1a and B-1b cells. Each of these subsets seems to require unique activation signals and to react with distinct response patterns. Here we provide a brief review of the main developmental and functional features of these B cell subsets. Furthermore, we outline our current understanding of how each subset contributes to the humoral response to influenza virus infection and what regulates their differential responses. Understanding of the multilayered nature of the humoral responses to infectious agents and the complex innate immune signals that shape pathogen-specific humoral responses are likely at the heart of enhancing our ability to induce appropriate and long-lasting humoral responses for prophylaxis and therapy.
View details for Web of Science ID 000252396900003
View details for PubMedID 18080414
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Joshua Lederberg: The Stanford Years (1958-1978)
ANNUAL REVIEW OF GENETICS
2008; 42: 19-25
View details for DOI 10.1146/annurev-genet-072408-095841
View details for Web of Science ID 000261767000002
View details for PubMedID 18983254
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Phospho-FACS: a powerful tool for exploring intracellular transduction cascades
REVUE DES MALADIES RESPIRATOIRES
2007; 24 (8): 955-964
Abstract
FACS (fluorescence-activated cell sorting), or flow cytometry, was developed in 1971 by Leonard Herzenberg's team at Stanford University. Under continuous development, this technology enables single-cell multiparametric analysis and sorting, based on physical properties of cells and/or their relative expression levels of specific glycoproteic epitopes and metabolites.Recently, the use of fluorescent antibodies specific for phosphorylated epitopes - or "phospho-epitopes" - within proteins of interest has further extended the range of FACS analyses. This new application, dubbed "phospho-FACS", has quickly become a tool of choice for delineating intracellular phosphorylation cascades.In both basic research and clinical research, the application of phospho-FACS to cellular subsets from blood or the periphery, whether frequent or rare, enables the discovery of pathological biomarkers and therapeutic innovation.Thanks to its rapid implementation and its ability to generate single-cell data, the phospho-FACS technique features numerous advantages compared to preexisting analytical methods for intracellular phosphorylation cascades.
View details for DOI 10.1019/20072001118
View details for Web of Science ID 000251260100004
View details for PubMedID 18033184
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B-cell development fails in the absence of the Pbx1 proto-oncogene
BLOOD
2007; 109 (10): 4191-4199
Abstract
Pbx1, a homeodomain transcription factor that was originally identified as the product of a proto-oncogene in acute pre-B-cell leukemia, is a global regulator of embryonic development. However, embryonic lethality in its absence has prevented an assessment of its role in B-cell development. Here, using Rag1-deficient blastocyst complementation assays, we demonstrate that Pbx1 null embryonic stem (ES) cells fail to generate common lymphoid progenitors (CLPs) resulting in a complete lack of B and NK cells, and a partial impairment of T-cell development in chimeric mice. A critical role for Pbx1 was confirmed by rescue of B-cell development from CLPs following restoration of its expression in Pbx1-deficient ES cells. In adoptive transfer experiments, B-cell development from Pbx1-deficient fetal liver cells was also severely compromised, but not erased, since transient B lymphopoiesis was detected in Rag-deficient recipients. Conditional inactivation of Pbx1 in pro-B (CD19(+)) cells and thereafter revealed that Pbx1 is not necessary for B-cell development to proceed from the pro-B-cell stage. Thus, Pbx1 critically functions at a stage between hematopoietic stem cell development and B-cell commitment and, therefore, is one of the earliest-acting transcription factors that regulate de novo B-lineage lymphopoiesis.
View details for DOI 10.1182/blood-2006-10-054213
View details for Web of Science ID 000246609100023
View details for PubMedID 17244677
View details for PubMedCentralID PMC1885499
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Unraveling B-1 progenitors
CURRENT OPINION IN IMMUNOLOGY
2007; 19 (2): 150-155
Abstract
B-1 cells comprise a small percentage of the B lymphocytes that reside in multiple tissues in the mouse, including the peritoneal and pleural cavities. Functionally, B-1 cells participate in innate immunity by producing the majority of the natural IgM in serum, which protects against invading pathogens before the onset of the adaptive immune response. B-1 cells arise from fetal and neonatal progenitors and are distinct from the adult bone marrow progenitors that give rise to follicular and marginal zone B-2 cells. Recent studies have attempted to delineate the progenitors of B-1 cells from those of B-2 cells. Notably, the identification of CD45R(-/lo)CD19(+) B-1 progenitors and expression of two surface determinants, CD138 and major histocompatibility class II antigens, distinguish developing B-1 cells from B-2 cells.
View details for DOI 10.1016/j.coi.2007.02.012
View details for Web of Science ID 000245355400007
View details for PubMedID 17303402
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Division and differentiation of natural antibody-producing cells in mouse spleen
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2007; 104 (11): 4542-4546
Abstract
B-1a cells reside in both the peritoneal cavity and the spleen. LPS stimulates splenic B-1a to differentiate to plasma cells producing natural IgM specific for microbial and self antigens. However, there are conflicting views as to whether the B-1a cells divide before this differentiation occurs, and hence how the resident B-1a population is maintained in the spleen. Studies here resolve this dispute in favor of both sides: we show that (some or all) B-1a cells resident in the spleen respond to LPS by differentiating to plasma cells immediately, without dividing; however, we also show that additional B-1a cells immigrate into the spleen after LPS stimulation and divide at least once before differentiating. Importantly, the studies we presently describe reveal the complex cell migration and differentiation events that collectively underlie the rapid production of natural antibodies in response to in vivo LPS stimulation. Thus, the studies present a different view of the roles that B-1a cells play in the early phases of the innate immune response.
View details for DOI 10.1073/pnas.0700001104
View details for Web of Science ID 000244972700054
View details for PubMedID 17360560
View details for PubMedCentralID PMC1838637
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Importance of culturing primary lymphocytes at physiological oxygen levels
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2007; 104 (11): 4547-4552
Abstract
Although studies with primary lymphocytes are almost always conducted in CO(2) incubators maintained at atmospheric oxygen levels (atmosO(2); 20%), the physiological oxygen levels (physO(2); 5%) that cells encounter in vivo are 2-4 times lower. We show here that culturing primary T cells at atmosO(2) significantly alters the intracellular redox state (decreases intracellular glutathione, increases oxidized intracellular glutathione), whereas culturing at physO(2) maintains the intracellular redox environment (intracellular glutathione/oxidized intracellular glutathione) close to its in vivo status. Furthermore, we show that CD3/CD28-induced T cell proliferation (based on proliferation index and cell yield) is higher at atmosO(2) than at physO(2). This apparently paradoxical finding, we suggest, may be explained by two additional findings with CD3/CD28-stimulated T cells: (i) the intracellular NO (iNO) levels are higher at physO(2) than at atmosO(2); and (ii) the peak expression of CD69 is significantly delayed and more sustained at physO(2) that at atmosO(2). Because high levels of intracellular NO and sustained CD69 tend to down-regulate T cell responses in vivo, the lower proliferative T cell responses at physO(2) likely reflect the in vitro operation of the natural in vivo regulatory mechanisms. Thus, we suggest caution in culturing primary lymphocytes at atmosO(2) because the requisite adaptation to nonphysiological oxygen levels may seriously skew T cell responses, particularly after several days in culture.
View details for DOI 10.1073/pnas.0611732104
View details for Web of Science ID 000244972700055
View details for PubMedID 17360561
View details for PubMedCentralID PMC1838638
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Photogenerated glycan arrays identify immunogenic sugar moieties of Bacillus anthracis exosporium
PROTEOMICS
2007; 7 (2): 180-184
Abstract
Using photogenerated glycan arrays, we characterized a large panel of synthetic carbohydrates for their antigenic reactivities with pathogen-specific antibodies. We discovered that rabbit IgG antibodies elicited by Bacillus anthracis spores specifically recognize a tetrasaccharide chain that decorates the outermost surfaces of the B. anthracis exosporium. Since this sugar moiety is highly specific for the spores of B. anthracis, it appears to be a key biomarker for detection of B. anthracis spores and development of novel vaccines that target anthrax spores.
View details for DOI 10.1002/pmic.200600478
View details for Web of Science ID 000243957700003
View details for PubMedID 17205603
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Knowledge acquisition and visualization for biomedical research.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium
2007: 1177-?
Abstract
The TreeTableWidget is a user interface component that allows instances in a knowledge-base to be sorted on the value of one or more of its attributes. Any combination of attributes can be sorted simultaneously by assigning a precedence to each sort. This results in a hierarchy of attributes such that instances can be grouped and visualized according to shared attribute values in a tree view. The resulting tree provides a mechanism to navigate and edit a large number of instances based on attribute values. The component is available as a Protégé slot-widget plug-in.
View details for PubMedID 18694273
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FR255734, a humanized CD28 antibody is therapeutically effective in psoriasis: An in vivo study using the SCID mouse-psoriasis xenograft model.
70th Annual Scientific Meeting of the American-College-of-Rheumatology/41st Annual Scientific Meeting of the Association-of-Rheumatology-Health-Professionals
WILEY-BLACKWELL. 2006: 4090–90
View details for Web of Science ID 000242780700173
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Utilization of host SR protein kinases and RNA-splicing machinery during viral replication
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (30): 11329-11333
Abstract
Although the viral genome is often quite small, it encodes a broad series of proteins. The virus takes advantage of the host-RNA-processing machinery to provide the alternative splicing capability necessary for the expression of this proteomic diversity. Serine-arginine-rich (SR) proteins and the kinases that activate them are central to this alternative splicing machinery. In studies reported here, we use the HIV genome as a model. We show that HIV expression decreases overall SR protein/activity. However, we also show that HIV expression is significantly increased (20-fold) when one of the SR proteins, SRp75 is phosphorylated by SR protein kinase (SRPK)2. Thus, inhibitors of SRPK2 and perhaps of functionally related kinases, such as SRPK1, could be useful antiviral agents. Here, we develop this hypothesis and show that HIV expression down-regulates SR proteins in Flp-In293 cells, resulting in only low-level HIV expression in these cells. However, increasing SRPK2 function up-regulates HIV expression. In addition, we introduce SR protein phosphorylation inhibitor 340 (SRPIN340), which preferentially inhibits SRPK1 and SRPK2 and down-regulates SRp75. Although an isonicotinamide compound, SPRIN340 (or its derivatives) remain to be optimized for better specificity and lower cytotoxicity, we show here that SRPIN340 suppresses propagation of Sindbis virus in plaque assay and variably suppresses HIV production. Thus, we show that SRPK, a well known kinase in the cellular RNA-processing machinery, is used by at least some viruses for propagation and hence suggest that SRPIN340 or its derivatives may be useful for curbing viral diseases.
View details for DOI 10.1073/pnas.0604616103
View details for Web of Science ID 000239353900041
View details for PubMedID 16840555
View details for PubMedCentralID PMC1544086
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MYC can induce DNA breaks in vivo and in vitro independent of reactive oxygen species
CANCER RESEARCH
2006; 66 (13): 6598-6605
Abstract
MYC overexpression is thought to initiate tumorigenesis by inducing cellular proliferation and growth and to be restrained from causing tumorigenesis by inducing cell cycle arrest, cellular senescence, and/or apoptosis. Here we show that MYC can induce DNA breaks both in vitro and in vivo independent of increased production of reactive oxygen species (ROS). We provide an insight into the specific circumstances under which MYC generates ROS in vitro and propose a possible mechanism. We found that MYC induces DNA double-strand breaks (DSBs) independent of ROS production in murine lymphocytes in vivo as well as in normal human foreskin fibroblasts (NHFs) in vitro in normal (10%) serum, as measured by gammaH2AX staining. However, NHFs cultured in vitro in low serum (0.05%) and/or ambient oxygen saturation resulted in ROS-associated oxidative damage and DNA single-strand breaks (SSBs), as measured by Ape-1 staining. In NHFs cultured in low versus normal serum, MYC induced increased expression of CYP2C9, a gene product well known to be associated with ROS production. Specific inhibition of CYP2C9 by small interfering RNA was shown to partially inhibit MYC-induced ROS production. Hence, MYC overexpression can induce ROS and SSBs under some conditions, but generally induces widespread DSBs in vivo and in vitro independent of ROS production.
View details for DOI 10.1158/0008-5472.CAN-05-3115
View details for PubMedID 16818632
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Phenotypically distinct B cell development pathways map to the three B cell lineages in the mouse
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (16): 6293-6298
Abstract
A recent article by Montecino-Rodriguez et al. [Montecino-Rodriguez, E., Leathers, H. & Dorshkind, K. (2006) Nat. Immunol.7, 293-301] has distinguished the early progenitors for B-1 cells, which principally develop in neonates, from early progenitors for B-2 cells, which principally develop in adult bone marrow. Here we introduce syndecan-1 (CD138) and MHC class II (I-A) as markers of early B cell development [Hardy, R. R., Carmack, C. E., Shinton, S. A., Kemp, J. D. & Hayakawa, K. (1991) J. Exp. Med. 173, 1213-1225; Hardy fractions B-D] and show that the expression of these markers distinguishes the predominant B cell development pathway in neonates from the corresponding predominant pathway in adults (both progenitors are present but differently represented in each case). We show that pre-B cells (Hardy fraction D) in the predominant adult pathway express high levels of CD138 and intermediate levels of I-A, whereas the corresponding pre-B cells in the pathway that predominates in neonates do not express either of these markers. As expected, because most of the pre-B cells in adults express CD138, we find that sorted CD138+ adult pre-B cells differentiate to IgM+ B cells in vitro. Sorted CD138- pre-B cells from neonates, the majority subset at this age, also mature to IgM+ cells (without passing through a CD138+ stage). Importantly, our studies here confirm the differential representation of adult and neonatal progenitor populations and further demonstrate that CD138 expression subdivides the adult CD19+, B220-6B2-/low population shown to contain B-1 progenitors in a way consistent with the predominance of B-1b progenitors in adults. Thus, CD138 expression provides a key route to distinguishing early B cell development pathway for what now are clearly three B cell lineages.
View details for DOI 10.1073/pnas.0511305103
View details for Web of Science ID 000236999000043
View details for PubMedID 16606838
View details for PubMedCentralID PMC1458871
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High-dose oral N-acetylcysteine, a glutathione prodrug, modulates inflammation in cystic fibrosis
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (12): 4628-4633
Abstract
Neutrophilic airway inflammation is a hallmark of cystic fibrosis (CF). As high oxidant producers, airway neutrophils contribute largely to the systemic redox imbalance seen in CF. In turn, this chronic and profound imbalance can impact circulating neutrophils before their migration into airways. Indeed, in 18 CF patients with stable disease, blood neutrophils were readily deficient in the pivotal antioxidant glutathione (P = 0.003, compared with 9 healthy controls). In a phase 1 study, this deficiency was improved (P = 0.025) by the glutathione prodrug N-acetylcysteine, given orally in high doses (0.6 to 1.0 g three times daily, for 4 weeks). This treatment was safe and markedly decreased sputum elastase activity (P = 0.006), the strongest predictor of CF pulmonary function. Consistently, neutrophil burden in CF airways was decreased upon treatment (P = 0.003), as was the number of airway neutrophils actively releasing elastase-rich granules (P = 0.005), as measured by flow cytometry. Pulmonary function measures were not improved, as expected with short-term treatment. After excluding data from subjects without baseline airway inflammation, positive treatment effects were more pronounced and included decreased sputum IL-8 levels (P = 0.032). Thus, high-dose oral N-acetylcysteine has the potential to counter the intertwined redox and inflammatory imbalances in CF.
View details for DOI 10.1073/pnas.0511304103
View details for Web of Science ID 000236362600055
View details for PubMedID 16537378
View details for PubMedCentralID PMC1450222
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Wnt signaling in the thymus is regulated by differential expression of intracellular signaling molecules
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (9): 3322-3326
Abstract
Wnt signaling is essential for T cell development in the thymus, but the stages in which it occurs and the molecular mechanisms underlying Wnt responsiveness have remained elusive. Here we examined Wnt signaling activity in both human and murine thymocyte populations by determining beta-catenin levels, Tcf-reporter activation and expression of Wnt-target genes. We demonstrate that Wnt signaling occurs in all thymocyte subsets, including the more mature populations, but most prominently in the double negative (DN) subsets. This differential sensitivity to Wnt signaling was not caused by differences in the presence of Wnts or Wnt receptors, as these appeared to be expressed at comparable levels in all thymocyte subsets. Rather, it can be explained by high expression of activating signaling molecules in DN cells, e.g., beta-catenin, plakoglobin, and long forms of Tcf-1, and by low levels of inhibitory molecules. By blocking Wnt signaling from the earliest stage onwards using overexpression of Dickkopf, we show that inhibition of the canonical Wnt pathway blocks development at the most immature DN1 stage. Thus, responsiveness to developmental signals can be regulated by differential expression of intracellular mediators rather than by abundance of receptors or ligands.
View details for DOI 10.1073/pnas.0511299103
View details for Web of Science ID 000235780700058
View details for PubMedID 16492759
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Haploidentical non-myeloablative allogeneic hematopoietic cell transplantation (HCT) using total lymphoid irradiation (TLI) and anti-thymocyte globulin (ATG) conditioning protects against acute graft versus host disease (GVHD)
47th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2005: 814A–815A
View details for Web of Science ID 000233426005224
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Molecular imaging using labeled donor tissues reveals patterns of engraftment, rejection, and survival in transplantation
TRANSPLANTATION
2005; 80 (1): 134-139
Abstract
Tissue regeneration and transplantation of solid organs involve complex processes that can only be studied in the context of the living organism, and methods of analyzing these processes in vivo are essential for development of effective transplantation and regeneration procedures. We utilized in vivo bioluminescence imaging (BLI) to noninvasively visualize engraftment, survival, and rejection of transplanted tissues from a transgenic donor mouse that constitutively expresses luciferase. Dynamic early events of hematopoietic reconstitution were accessible and engraftment from as few as 200 transplanted whole bone marrow (BM) cells resulted in bioluminescent foci in lethally irradiated, syngeneic recipients. The transplantation of autologous pancreatic Langerhans islets and of allogeneic heart revealed the tempo of transplant degeneration or immune rejection over time. This imaging approach is sensitive and reproducible, permits study of the dynamic range of the entire process of transplantation, and will greatly enhance studies across various disciplines involving transplantation.
View details for DOI 10.1097/01.TP.0000164347.50559.A3
View details for Web of Science ID 000230473800023
View details for PubMedID 16003245
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Culturing at atmospheric oxygen levels impacts lymphocyte function
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2005; 102 (10): 3756-3759
Abstract
To determine whether culturing peripheral blood mononuclear cells at atmospheric oxygen levels skews responses in comparison with culturing lymphocytes at physiologic oxygen levels, we cultured peripheral blood mononuclear cells at 5%, 10%, and atmospheric (20%) gas-phase oxygen for 5 days. We found that incubator oxygen levels influenced lymphocyte proliferation stimulated by two commonly used stimuli: Con A and antibodies that crosslink surface CD3 and CD28 to mimic antigen presentation. In both cases, proliferation increased as gas-phase oxygen levels increased. In contrast, oxygen levels did not influence proliferation stimulated by phytohemagglutinin, another commonly used mitogen. Similarly, oxygen levels did not impact cell viability in unstimulated cultures. Thus, we conclude that the influence of oxygen levels on proliferation depends on the stimulus, and, most importantly from the standpoint of immune responses, culturing cells at atmospheric rather than physiologic oxygen levels results in significantly increased proliferation responses to the CD3/CD28 crosslinking, a proliferation stimulus commonly used to mimic T cell antigen receptor signaling.
View details for DOI 10.1073/pnas.0409910102
View details for Web of Science ID 000227533100043
View details for PubMedID 15738407
View details for PubMedCentralID PMC553335
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Inherent specificities in natural antibodies: a key to immune defense against pathogen invasion
SPRINGER SEMINARS IN IMMUNOPATHOLOGY
2005; 26 (4): 347-362
Abstract
Natural antibodies are produced at tightly regulated levels in the complete absence of external antigenic stimulation. They provide immediate, early and broad protection against pathogens, making them a crucial non-redundant component of the humoral immune system. These antibodies are produced mainly, if not exclusively, by a subset of long-lived, self-replenishing B cells termed B-1 cells. We argue here that the unique developmental pattern of these B-1 cells, which rests on positive selection by self antigens, ensures production of natural antibodies expressing evolutionarily important specificities that are required for the initial defense against invading pathogens. Positive selection for reactivity with self antigens could also result in the production of detrimental anti-self antibodies. However, B-1 cells have evolved a unique response pattern that minimizes the risk of autoimmunity. Although these cells respond rapidly and strongly to host-derived innate signals, such as cytokines, and to pathogen-encoded signals, such as lipopolysaccharide and phosphorylcholine, they respond very poorly to receptor-mediated activation. In addition, they rarely enter germinal centers and undergo affinity maturation. Thus, their potential for producing high-affinity antibodies with harmful anti-self specificity is highly restricted. The positive selection of B-1 cells occurs during the neonatal period, during which the long-lived self-renewing B-1 population is constituted. Many of these cells (B-1a) express CD5, although a smaller subset (B-1b) does not express this surface marker. Importantly, B-1a cells should not be confused with short-lived anergic B-2 cells, which originate in the bone marrow in adults and initiate CD5 expression and programmed cell death following self-antigen recognition. In summary, we argue here that the mechanisms that enable natural antibody production by B-1 cells reflect the humoral immune system, which has evolved in layers whose distinct developmental mechanisms generate complementary repertoires that collectively operate to maximize flexibility in responses to invading pathogens. B-2 cells, present in what may be the most highly evolved layer(s), express a repertoire that is explicitly selected against self recognition and directed towards the generation of high-affinity antibody response to external antigenic stimuli. B-1 cells, whose repertoire is selected by recognition of self antigen, belong to what may be earlier layer(s) and inherently maintain production of evolutionarily important antibody specificities that respond to pathogen-related, rather then antigen-specific signals.
View details for DOI 10.1007/s00281-004-0182-2
View details for Web of Science ID 000228526100002
View details for PubMedID 15633017
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The extracellular microenvironment plays a key role in regulating the redox status of cell surface proteins in HIV-infected subjects
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
2005; 434 (1): 26-32
Abstract
There is an overwhelming interest in the study of the redox status of the cell surface affecting redox signaling in the cells and also predicting the total redox status of the cells. Measuring the total surface thiols (cell surface molecule thiols, csm-SH) we have shown that the overall level of surface thiols is tightly controlled. In vitro, the total concentration of intracellular glutathione (iGSH) seems to play a regulatory role in determination of the amounts of reduced proteins on cells. In addition, short term exposure of the cell surface to glutathione disulfide (GSSG, oxidized GSH) seems to reduce the overall levels of csm-SH suggesting that the function of some cysteine containing proteins on the cell surface may be regulated by the amount of GSSG secreted from the cells or the GSSG available in the extracellular environment. Examination of peripheral blood mononuclear cells (PBMCs) from healthy or HIV-infected subjects failed to reveal a similar correlation between the intra- and extracellular thiol status of cells. Although there is a relatively wide variation between individuals in both csm-SH and iGSH there is no correlation between the iGSH and csm-SH levels measured for healthy and HIV-infected individuals. There are many reports suggesting different redox active proteins on the cell surface to be the key players in the total cell surface redox regulation. However, we suggest that the redox status of the cells is regulated through a complex and tightly regulated mechanism that needs further investigation. In the mean time, overall surface thiol measurements together with case specific protein determinations may offer the most informative approach. In this review, we discuss our own results as well as results from other laboratories to argue that the overall levels of surface thiols on the exofacial membrane are regulated primarily by redox status of the cell surface microenvironment.
View details for DOI 10.1016/j.jabb.2004.11.015
View details for Web of Science ID 000226457700005
View details for PubMedID 15629105
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Functional evolution of the vertebrate Myb gene family: B-Myb, but neither A-Myb nor C-Myb, complements drosophila Myb in hemocytes
GENETICS
2005; 169 (1): 215-229
Abstract
The duplication of genes and genomes is believed to be a major force in the evolution of eukaryotic organisms. However, different models have been presented about how duplicated genes are preserved from elimination by purifying selection. Preservation of one of the gene copies due to rare mutational events that result in a new gene function (neofunctionalization) necessitates that the other gene copy retain its ancestral function. Alternatively, preservation of both gene copies due to rapid divergence of coding and noncoding regions such that neither retains the complete function of the ancestral gene (subfunctionalization) may result in a requirement for both gene copies for organismal survival. The duplication and divergence of the tandemly arrayed homeotic clusters have been studied in considerable detail and have provided evidence in support of the subfunctionalization model. However, the vast majority of duplicated genes are not clustered tandemly, but instead are dispersed in syntenic regions on different chromosomes, most likely as a result of genome-wide duplications and rearrangements. The Myb oncogene family provides an interesting opportunity to study a dispersed multigene family because invertebrates possess a single Myb gene, whereas all vertebrate genomes examined thus far contain three different Myb genes (A-Myb, B-Myb, and c-Myb). A-Myb and c-Myb appear to have arisen by a second round of gene duplication, which was preceded by the acquisition of a transcriptional activation domain in the ancestral A-Myb/c-Myb gene generated from the initial duplication of an ancestral B-Myb-like gene. B-Myb appears to be essential in all dividing cells, whereas A-Myb and c-Myb display tissue-specific requirements during spermatogenesis and hematopoiesis, respectively. We now report that the absence of Drosophila Myb (Dm-Myb) causes a failure of larval hemocyte proliferation and lymph gland development, while Dm-Myb(-/-) hemocytes from mosaic larvae reveal a phagocytosis defect. In addition, we show that vertebrate B-Myb, but neither vertebrate A-Myb nor c-Myb, can complement these hemocyte proliferation defects in Drosophila. Indeed, vertebrate A-Myb and c-Myb cause lethality in the presence or absence of endogenous Dm-Myb. These results are consistent with a neomorphic origin of an ancestral A-Myb/c-Myb gene from a duplicated B-Myb-like gene. In addition, our results suggest that B-Myb and Dm-Myb share essential conserved functions that are required for cell proliferation. Finally, these experiments demonstrate the utility of genetic complementation in Drosophila to explore the functional evolution of duplicated genes in vertebrates.
View details for DOI 10.1534/genetics.104.034132
View details for Web of Science ID 000227039900018
View details for PubMedID 15489525
View details for PubMedCentralID PMC1448883
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The E47 transcription factor negatively regulates CD5 expression during thymocyte development
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2004; 101 (11): 3898-3902
Abstract
The expression of CD5 increases progressively as thymocytes mature. We have shown that CD5 expression is controlled by a tissue-specific regulatory promoter located upstream of the CD5 translation start sites. Deletion of this regulatory promoter, which contains three potential transcription factor binding sites (CCAAT, kappa E2, and ets) reduces the promoter activity to basal level. Of these sites, only ets proved essential for CD5 expression in T cell lines. Here, we introduce a role for the E47 transcription factor and the CD5 promoter kappa E2 site in regulating CD5 expression during thymocyte development. Using T cell lines, we show that (i) mutation of the kappa E2 site in the CD5 regulatory promoter results in a significant elevation of CD5 promoter activity; (ii) the E47 transcription factor binds to the kappa E2 site; and (iii) overexpression of E47 inhibits CD5 expression. We then show, in high-dimensional fluorescence-activated cell sorting studies with primary thymocytes at successive developmental stages, that (i) intracellular E47 levels decrease as surface CD5 expression increases; (ii) E47 expression is down-regulated and CD5 expression is correspondingly up-regulated in DN3 thymocytes in RAG-2-deficient mice injected with anti-CD3 to mimic pre-T cell receptor stimulation; and (iii) E47 expression is down-regulated and CD5 expression is up-regulated when double positive thymocytes are stimulated in vitro with anti-CD3. Based on these data, we propose that E47 negatively regulates CD5 expression by interacting with the kappa E2 site in the CD5 regulatory promoter and that decreases in E47 in response to developmental signals are critical to the progressive increase in CD5 expression as thymocytes mature.
View details for DOI 10.1073/pnas.0308764101
View details for Web of Science ID 000220314500034
View details for PubMedID 15001710
View details for PubMedCentralID PMC374341
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Fluorescence-activated cell sorting (FACS) of Drosophila hemocytes reveals important functional similarities to mammalian leukocytes
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2004; 101 (9): 2912-2917
Abstract
Drosophila is a powerful model for molecular studies of hematopoiesis and innate immunity. However, its use for functional cellular studies remains hampered by the lack of single-cell assays for hemocytes (blood cells). Here we introduce a generic method combining fluorescence-activated cell sorting and nonantibody probes that enables the selective gating of live Drosophila hemocytes from the lymph glands (larval hematopoietic organ) or hemolymph (blood equivalent). Gated live hemocytes are analyzed and sorted at will based on precise quantitation of fluorescence levels originating from metabolic indicators, lectins, reporters (GFP and beta-galactosidase) and antibodies. With this approach, we discriminate and sort plasmatocytes, the major hemocyte subset, from lamellocytes, an activated subset present in gain-of-function mutants of the Janus kinase and Toll pathways. We also illustrate how important, evolutionarily conserved, blood-cell-regulatory molecules, such as calcium and glutathione, can be studied functionally within hemocytes. Finally, we report an in vivo transfer of sorted live hemocytes and their successful reanalysis on retrieval from single hosts. This generic and versatile fluorescence-activated cell sorting approach for hemocyte detection, analysis, and sorting, which is efficient down to one animal, should critically enhance in vivo and ex vivo hemocyte studies in Drosophila and other species, notably mosquitoes.
View details for DOI 10.1073/pnas.0308734101
View details for Web of Science ID 000220065300049
View details for PubMedID 14976247
View details for PubMedCentralID PMC365719
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New approaches to fluorescence compensation and visualization of FACS data
CLINICAL IMMUNOLOGY
2004; 110 (3): 277-283
Abstract
The Fluorescence Activated Cell Sorter (FACS) is an invaluable tool for clinicians and researchers alike in phenotyping and sorting individual cells. With the advances in FACS methodology, notably intracellular staining for cytokines, transcription factors and phosphoproteins, and with increases in the number of fluorescence detection channels, researchers now have the opportunity to study individual cells in far greater detail than previously possible. In this chapter, we discuss High-Definition (Hi-D) FACS methods that can improve analysis of lymphocyte subsets in mouse and man. We focus on the reasons why fluorescence compensation, which is necessary to correct for spectral overlap between two or more fluorochromes used in the same staining combination, is best done as a computed transformation rather than using the analog circuitry available on many flow cytometers. In addition, we introduce a new data visualization method that scales the axes on histograms and two-dimensional contour (or dot) plots to enable visualization of signals from all cells, including those that have minimal fluorescence values and are not properly represented with traditional logarithmic axes. This "Logicle" visualization method, we show, provides superior representations of compensated data and makes correctly compensated data look correct. Finally, we discuss controls that facilitate recognition of boundaries between positive and negative subsets.
View details for DOI 10.1016/j.clim.2003.11.016
View details for Web of Science ID 000220831800009
View details for PubMedID 15047205
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B lineage-specific regulation of V(D)J recombinase activity is established in common lymphoid progenitors
JOURNAL OF EXPERIMENTAL MEDICINE
2004; 199 (4): 491-502
Abstract
Expression of V(D)J recombinase activity in developing lymphocytes is absolutely required for initiation of V(D)J recombination at antigen receptor loci. However, little is known about when during hematopoietic development the V(D)J recombinase is first active, nor is it known what elements activate the recombinase in multipotent hematopoietic progenitors. Using mice that express a fluorescent transgenic V(D)J recombination reporter, we show that the V(D)J recombinase is active as early as common lymphoid progenitors (CLPs) but not in the upstream progenitors that retain myeloid lineage potential. Evidence of this recombinase activity is detectable in all four progeny lineages (B, T, and NK, and DC), and rag2 levels are the highest in progenitor subsets immediately downstream of the CLP. By single cell PCR, we demonstrate that V(D)J rearrangements are detectable at IgH loci in approximately 5% of splenic natural killer cells. Finally, we show that recombinase activity in CLPs is largely controlled by the Erag enhancer. As activity of the Erag enhancer is restricted to the B cell lineage, this provides the first molecular evidence for establishment of a lineage-specific transcription program in multipotent progenitors.
View details for DOI 10.1084/jem.20031800
View details for Web of Science ID 000189185600006
View details for PubMedID 14769852
View details for PubMedCentralID PMC2211824
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Ontogeny of gamma delta T cells in humans
JOURNAL OF IMMUNOLOGY
2004; 172 (3): 1637-1645
Abstract
T cell receptors consist either of an alpha-chain combined with a beta-chain or a gamma-chain combined with a delta-chain. alphabeta T cells constitute the majority of T cells in human blood throughout life. Flow cytometric analyses presented in this study, which focus on the representation of the developmental (naive and memory) subsets of gammadelta T cells, show by function and phenotype that this lineage contains both naive and memory cells. In addition, we show that the representation of naive T cells is higher among alphabeta than gammadelta T cells in adults and that the low frequency of naive gammadelta T cells in adults reflects ontological differences between the two major gammadelta subsets, which are distinguished by expression of Vdelta1 vs Vdelta2 delta-chains. Vdelta1 cells, which mirror alphabeta cells with respect to naive representation, predominate during fetal and early life, but represent the minority of gammadelta cells in healthy adults. In contrast, Vdelta2 cells, which constitute the majority of adult gammadelta cells, show lower frequencies of naive cells than Vdelta1 early in life and show vanishingly small naive frequencies in adults. In essence, nearly all naive Vdelta2 cells disappear from blood by 1 year of life. Importantly, even in children less than 1 year old, most of the nonnaive Vdelta2 cells stain for perforin and produce IFN-gamma after short-term in vitro stimulation. This represents the earliest immunological maturation of any lymphocyte compartment in humans and most likely indicates the importance of these cells in controlling pathology due to common environmental challenges.
View details for Web of Science ID 000188378700039
View details for PubMedID 14734745
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Identification of B-cell subsets: an exposition of 11-color (Hi-D) FACS methods.
Methods in molecular biology (Clifton, N.J.)
2004; 271: 37-58
Abstract
In the last few years, the effectiveness of developmental and functional studies of individual subsets of cells has increased dramatically owing to the identification of additional subset markers and the extension of fluorescence-activated cell sorter (FACS) capabilities to simultaneously measure the expression of more markers on individual cells. For example, introduction of a 6-8 multiparameter FACS instrument resulted in significant advances in understanding B-cell development. In this chapter, we describe 11-color high-dimensional (Hi-D) FACS staining and data analysis methods that provide greater clarity in identifying the B-cell subsets in bone marrow, spleen, and peritoneal cavity. Further, we show how a single Hi-D FACS antibody reagent combination is sufficient to unambiguously identify most of the currently defined B-cell developmental subsets in the bone marrow (Hardy fractions A-F) and the functional B-cell subsets (B-1a, B-1b, B-2, and marginal zone [MZ] B cells) in the periphery. Although we focus on murine B-cell subsets, the methods we discuss are relevant to FACS studies conducted with all types of cells and other FACS instruments. We introduce a new method for scaling axes for histograms or contour plots of FACS data. This method, which we refer to as Logicle visualization, is particularly useful in promoting correct interpretations of fluorescence-compensated FACS data and visual confirmation of correct compensation values. In addition, it facilitates discrimination of valid subsets. Application of Logicle visualization tools in the Hi-D FACS studies discussed here creates a strong new base for in-depth analysis of B-cell development and function.
View details for PubMedID 15146111
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Non-myeloablative conditioning with total lymphoid irradiation (TLI) and anti-thymocyte globulin (ATG) for allogeneic hematopoietic cell transplantation (HCT) results in high levels of regulatory natural killer T cells and low incidences of acute GVHD and tumor relapse.
45th Annual Meeting and Exhibition of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2003: 152A–153A
View details for Web of Science ID 000186536700525
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Leukocyte functional antigen 1 lowers T cell activation thresholds and signaling through cytohesin-1 and Jun-activating binding protein 1
NATURE IMMUNOLOGY
2003; 4 (11): 1083-1092
Abstract
Leukocyte functional antigen 1 (LFA-1), with intercellular adhesion molecule ligands, mediates T cell adhesion, but the signaling pathways and functional effects imparted by LFA-1 are unclear. Here, intracellular phosphoprotein staining with 13-dimensional flow cytometry showed that LFA-1 activation induced phosphorylation of the beta(2) integrin chain and release of Jun-activating binding protein 1 (JAB-1), and mediated signaling of kinase Erk1/2 through cytohesin-1. Dominant negatives of both JAB-1 and cytohesin-1 inhibited interleukin 2 production and impaired T helper type 1 differentiation. LFA-1 stimulation lowered the threshold of T cell activation. Thus, LFA-1 signaling contributes to T cell activation and effects T cell differentiation.
View details for DOI 10.1038/ni984
View details for Web of Science ID 000186241100012
View details for PubMedID 14528303
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Lymphocyte surface thiol levels
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2003; 100 (7): 4001-4005
Abstract
Recent studies have implicated reduced thiols (cysteine -SH) in the function of individual cell surface proteins. Studies presented here demonstrate that the overall level of reduced thiols on cell surface molecules differs on individual subsets of peripheral blood mononuclear cells and that these levels can be manipulated in vitro by altering the level of intracellular glutathione (iGSH). To quantitate cell surface thiols, we have developed a Hi-D (11-color) fluorescence-activated cell sorter method in which we covalently couple a fluorescent molecule, Alexa-maleimide, to free (reduced) -SH groups on proteins or other molecules exposed on the cell surface (exofacial membrane). In addition, to reveal changes in cell surface thiol levels in response to various in vitro treatments, we used a pair of fluorescent Alexa dyes with distinct excitation and emission spectra to stain the cells before and after treatments. These in vitro studies demonstrate that decreasing iGSH, by specifically inhibiting its synthesis, decreases cell surface molecule thiols (csm-SH) and that preventing loss of iGSH also prevents loss of csm-SH. However, examination of peripheral blood mononuclear cell subsets tested immediately after isolation from healthy or HIV-infected subjects failed to reveal a similar relationship between internal iGSH and csm-SH. Although there is a relatively wide variation between individuals in both csm-SH and iGSH, there is no correlation between median iGSH and csm-SH compared for 22 healthy and 36 HIV-infected subjects. Collectively, our findings indicate that local environment plays a greater role in determining the redox status of cell surface molecules than the internal redox status of the cells.
View details for DOI 10.1073/pnas.2628032100
View details for Web of Science ID 000182058400085
View details for PubMedID 12642656
View details for PubMedCentralID PMC153037
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B cell-dependent T cell responses: IgM antibodies are required to elicit contact sensitivity
JOURNAL OF EXPERIMENTAL MEDICINE
2002; 196 (10): 1277-1290
Abstract
Contact sensitivity (CS) is a classic example of in vivo T cell immunity in which skin sensitization with reactive hapten leads to immunized T cells, which are then recruited locally to mediate antigen-specific inflammation after subsequent skin challenge. We have previously shown that T cell recruitment in CS is triggered by local activation of complement, which generates C5a that triggers C5a receptors most likely on mast cells. Here, we show that B-1 cell-derived antihapten IgM antibodies generated within 1 day (d) of immunization combine with local challenge antigen to activate complement to recruit the T cells. These findings overturn three widely accepted immune response paradigms by showing that (a) specific IgM antibodies are required to initiate CS, which is a classical model of T cell immunity thought exclusively due to T cells, (b) CS priming induces production of specific IgM antibodies within 1 d, although primary antibody responses typically begin by day 4, and (c) B-1 cells produce the 1-d IgM response to CS priming, although these cells generally are thought to be nonresponsive to antigenic stimulation. Coupled with previous evidence, our findings indicate that the elicitation of CS is initiated by rapidly formed IgM antibodies. The IgM and challenge antigen likely form local complexes that activate complement, generating C5a, leading to local vascular activation to recruit the antigen-primed effector T cells that mediate the CS response.
View details for DOI 10.1084/jem.20020649
View details for Web of Science ID 000179412600002
View details for PubMedID 12438420
View details for PubMedCentralID PMC2193992
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The history and future of the fluorescence activated cell sorter and flow cytometry: A view from Stanford
34th Annual Oak Ridge Conference
AMER ASSOC CLINICAL CHEMISTRY. 2002: 1819–27
Abstract
The Fluorescence Activated Cell Sorter (FACS) was invented in the late 1960s by Bonner, Sweet, Hulett, Herzenberg, and others to do flow cytometry and cell sorting of viable cells. Becton Dickinson Immunocytometry Systems introduced the commercial machines in the early 1970s, using the Stanford patent and expertise supplied by the Herzenberg Laboratory and a Becton Dickinson engineering group under Bernie Shoor. Over the years, we have increased the number of measured FACS dimensions (parameters) and the speed of sorting to where we now simultaneously measure 12 fluorescent colors plus 2 scatter parameters. In this history, I illustrate the great utility of this state-of-the-art instrument, which allows us to simultaneously stain, analyze, and then sort cells from small samples of human blood cells from AIDS patients, infants, stem cell transplant patients, and others. I also illustrate analysis and sorting of multiple subpopulations of lymphocytes by use of 8-12 colors. In addition, I review single cell sorting used to clone and analyze hybridomas and discuss other applications of FACS developed over the past 30 years, as well as give our ideas on the future of FACS. These ideas are currently being implemented in new programs using the internet for data storage and analysis as well as developing new fluorochromes, e.g., green fluorescent protein and tandem dyes, with applications in such areas as apoptosis, gene expression, cytokine expression, cell biochemistry, redox regulation, and AIDS. Finally, I describe new FACS methods for measuring activated kinases and phosphatases and redox active enzymes in individual cells simultaneously with cell surface phenotyping. Thus, key functions can be studied in various subsets of cells without the need for prior sorting.
View details for Web of Science ID 000178238100033
View details for PubMedID 12324512
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Identification of a germ-line pro-B cell subset that distinguishes the fetal/neonatal from the adult B cell development pathway
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2002; 99 (5): 3007-3012
Abstract
Studies presented here show that the expression of CD4, MHC class II (Ia,) and B220 cleanly resolves a major and a minor subset within the earliest pro-B cell population (germ-line pro-B) in adult bone marrow (BM). The major subset expresses intermediate B220 and low CD4 levels. The minor subset, which constitutes roughly 20% of the adult germ-line pro-B, expresses very low B220 levels and does not express CD4. Ia is clearly detectable at low levels on the major germ-line pro-B subset, both in wild-type adult mice and in gene-targeted mice (RAG2-/- and microMT), in which B cell development terminates before the pre-B cell stage. A small proportion of cells in the more mature pro-B cell subsets (Hardy Fractions B and C) also express Ia at this level. In contrast, Ia levels on the minor subset are barely above (or equal to) background. Surprisingly, the major germ-line pro-B cell subset found in adults is missing in fetal and neonatal animals. All of the germ-line pro-B in these immature animals express a phenotype (very low B220, no CD4, or Ia) similar to that of the minor pro-B cell subset in adult BM. Because B cell development in fetal/neonatal animals principally results in B-1 cells, these findings demonstrate that the B-1 development pathway does not include the major germ-line pro-B subset found in adult BM and hence identify a very early difference between the B-1 and -2 development pathways.
View details for DOI 10.1073/pnas.052715399
View details for Web of Science ID 000174284600075
View details for PubMedID 11867763
View details for PubMedCentralID PMC122463
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Motexafin gadolinium (Gd-Tex) selectively induces apoptosis in HIV-1 infected CD4+T helper cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2002; 99 (4): 2270-2274
Abstract
Here, we show that motexafin gadolinium (Gd-Tex), a compound that promotes intracellular oxidative stress, selectively induces apoptosis in HIV-1-infected CD4(+) T cells in IL-2-stimulated cultures of peripheral blood mononuclear cells infected in vitro with HIV-1. This selective induction of apoptosis, which we detect by FACS analysis of intracellular HIV/p24 and concomitant surface and apoptosis marker expression, is abrogated by the glutathione precursor, N-acetyl-l-cysteine. Importantly, it occurs at Gd-Tex concentrations that are not cytotoxic to uninfected cells in the culture. These findings suggest that Gd-Tex may have therapeutic utility as an anti-HIV agent capable of selectively targeting and removing HIV-infected cells in an infected host.
View details for DOI 10.1073/pnas.261711499
View details for Web of Science ID 000174031100093
View details for PubMedID 11854523
View details for PubMedCentralID PMC122354
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Protein glutathionylation: coupling and uncoupling of glutathione to protein thiol groups in lymphocytes under oxidative stress and HIV infection
MOLECULAR IMMUNOLOGY
2002; 38 (10): 773-780
Abstract
We show here that exposure to oxidative stress induces glutathione (GSH) modification of protein cysteinyl residues (glutathionylation) in T cell blasts. Treating the cells with the oxidant diamide induces thiolation of a series of proteins that can be detected by 2D electrophoresis when 35S-cysteine is used to label the intracellular GSH pool. This thiolation is reversible, proteins are rapidly dethiolated and GSH is released from proteins once the oxidants are washed and the cells are allowed to recover. Dethiolation is dependent on the availability of GSH and thiols, since it is inhibited by GSH-depleting agents and improved by N-acetyl-L-cysteine (NAC). The capacity of these agents to reverse glutathionylation is diminished in T cell blasts infected in vitro with HIV, which is known to cause oxidative stress. Consistent with these findings, the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an enzyme known to be inhibited by glutathionylation, is inhibited in diamide-treated cells and recovers rapidly when cells are allowed to dethiolate. Further, GAPDH activity is diminished by GSH-depleting agents and augmented by NAC. Thus, reversible glutathionylation of proteins can rapidly shift the activity of a key metabolic enzyme and thereby result in dramatic, reversible changes in cellular metabolism.
View details for Web of Science ID 000174234700008
View details for PubMedID 11841837
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Circulating thioredoxin suppresses lipopolysaccharide-induced neutrophil chemotaxis
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2001; 98 (26): 15143-15148
Abstract
Thioredoxin (Trx), a redox enzyme with a conserved active site (Cys-32-Gly-Pro-Cys-35), is induced and secreted into circulation in response to inflammation. Studies here demonstrate that elevating Trx levels in circulation either by i.v. injection of recombinant Trx or stimulating Trx release in Trx-transgenic mice dramatically blocks lipopolysaccharide (LPS)-stimulated neutrophil migration in the murine air pouch chemotaxis model. Furthermore, we show that leukocyte recruitment induced by the murine chemokines KC/GROalpha, RANTES (regulated upon activation, normal T cell expressed and secreted), and monocyte chemoattractant protein-1 (MCP-1) is suppressed also in Trx-transgenic mice. Addressing the mechanism responsible for this suppression, we show that circulating Trx blocks (i) the LPS-stimulated in vitro activation of neutrophil p38 mitogen-activated protein kinase, (ii) the normal down-regulation of CD62L on neutrophils migrating into the LPS-stimulated air pouch, and (iii) the in vitro adhesion of LPS-activated neutrophils on endothelial cells. However, as we also show, Trx does not alter the expression of endothelial cell adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, CD62P, and CD62E) within 3 h. Collectively, these findings indicate that elevated levels of circulating Trx interfere with chemotaxis by acting directly on neutrophils. We discuss these findings in the context of recent studies reporting beneficial effects of acutely elevated Trx in ischemic injury and negative effects associated with chronically elevated Trx in HIV disease.
View details for Web of Science ID 000172848800073
View details for PubMedID 11742067
View details for PubMedCentralID PMC64997
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Dynamics of cytokine and perforin expression in T cells after allogeneic bone marrow transplantation: Possible predictors of GVHD.
AMER SOC HEMATOLOGY. 2001: 661A–661A
View details for Web of Science ID 000172134102784
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V delta and V delta 2 gamma delta T cells express distinct surface markers and might be developmentally distinct lineages
JOURNAL OF LEUKOCYTE BIOLOGY
2001; 70 (4): 518-526
Abstract
We report here that the two major types of gammadelta T cells found in human blood, Vdelta1 and Vdelta2, were found to have markedly different phenotypes. Vdelta2 cells had a phenotype typical of most alphabeta T cells in blood; i.e., they were CD5(+), CD28(+), and CD57(-). In contrast, Vdelta1 cells tended to be CD5(-/dull), CD28(-), and CD57(+). Furthermore, although Vdelta1 T cells appeared to be "naive" in that they were CD45RA(+), they were CD62L(-) and on stimulation uniformly produced interferon-gamma, indicating that they are in fact memory/effector cells. This phenotype for Vdelta1 cells was similar to that of intestinal intraepithelial lymphocytes, a subset that can develop in the absence of the thymus. We suggest that the Vdelta1 and Vdelta2 T cell subsets represent distinct lineages with different developmental pathways. The disruption of the supply of normal, thymus-derived T cells in HIV-infected individuals might be responsible for the shift in the Vdelta2/Vdelta1 ratio that occurs in the blood of individuals with HIV disease.
View details for Web of Science ID 000171467500005
View details for PubMedID 11590187
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Naive CD4 T cells inhibit CD28-costimulated R5 HIV replication in memory CD4 T cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2001; 98 (20): 11644-11649
Abstract
Stimulation with antibodies to CD3 and CD28 coimmobilized on beads can be used to significantly expand T cells ex vivo. With CD4 T cells from HIV-infected patients, this expansion usually is accompanied by complete suppression of viral replication, presumed to be caused by down-regulation of the viral coreceptor CCR5 and up-regulation of CCR5 ligands. Here we show that this suppression occurs in total CD4 T cells acutely infected with R5 HIV, but not in purified CD62L(-) memory CD4 T cells. The lack of complete suppression in these memory cells, typically comprising 10-40% of total CD4 T cells, occurs despite high levels of CCR5 ligand secretion and down-regulation of CCR5. Significantly, adding back naive or CD62L(+) memory CD4 T cells inhibits the viral replication in the CD62L(-) cells, with the naive cells capable of completely repressing the virus. Although this inhibition was previously thought to be specific to bead-bound anti-CD3/CD28 stimulation, we show that the same suppression is obtained with sufficiently strong anti-CD3/B7.1 stimulation. Our results show that inhibitory mechanisms, expressed predominantly by strongly stimulated naive CD4 T cells and mediated independently of CCR5-binding chemokines, play a role in the inhibition of R5 HIV replication in CD4 T cells upon CD28 costimulation.
View details for Web of Science ID 000171237100118
View details for PubMedID 11562498
View details for PubMedCentralID PMC58783
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Probability binning comparison: A metric for quantitating univariate distribution differences
CYTOMETRY
2001; 45 (1): 37-46
Abstract
Comparing distributions of data is an important goal in many applications. For example, determining whether two samples (e.g., a control and test sample) are statistically significantly different is useful to detect a response, or to provide feedback regarding instrument stability by detecting when collected data varies significantly over time.We apply a variant of the chi-squared statistic to comparing univariate distributions. In this variant, a control distribution is divided such that an equal number of events fall into each of the divisions, or bins. This approach is thereby a mini-max algorithm, in that it minimizes the maximum expected variance for the control distribution. The control-derived bins are then applied to test sample distributions, and a normalized chi-squared value is computed. We term this algorithm Probability Binning.Using a Monte-Carlo simulation, we determined the distribution of chi-squared values obtained by comparing sets of events derived from the same distribution. Based on this distribution, we derive a conversion of any given chi-squared value into a metric that is analogous to a t-score, i.e., it can be used to estimate the probability that a test distribution is different from a control distribution. We demonstrate that this metric scales with the difference between two distributions, and can be used to rank samples according to similarity to a control. Finally, we demonstrate the applicability of this metric to ranking immunophenotyping distributions to suggest that it indeed can be used to objectively determine the relative distance of distributions compared to a single control.Probability Binning, as shown here, provides a useful metric for determining the probability that two or more flow cytometric data distributions are different. This metric can also be used to rank distributions to identify which are most similar or dissimilar. In addition, the algorithm can be used to quantitate contamination of even highly-overlapping populations. Finally, as demonstrated in an accompanying paper, Probability Binning can be used to gate on events that represent significantly different subsets from a control sample. Published 2001 Wiley-Liss, Inc.
View details for Web of Science ID 000171015000005
View details for PubMedID 11598945
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Probability binning comparison: A metric for quantitating multivariate distribution differences
CYTOMETRY
2001; 45 (1): 47-55
Abstract
While several algorithms for the comparison of univariate distributions arising from flow cytometric analyses have been developed and studied for many years, algorithms for comparing multivariate distributions remain elusive. Such algorithms could be useful for comparing differences between samples based on several independent measurements, rather than differences based on any single measurement. It is conceivable that distributions could be completely distinct in multivariate space, but unresolvable in any combination of univariate histograms. Multivariate comparisons could also be useful for providing feedback about instrument stability, when only subtle changes in measurements are occurring.We apply a variant of Probability Binning, described in the accompanying article, to multidimensional data. In this approach, hyper-rectangles of n dimensions (where n is the number of measurements being compared) comprise the bins used for the chi-squared statistic. These hyper-dimensional bins are constructed such that the control sample has the same number of events in each bin; the bins are then applied to the test samples for chi-squared calculations.Using a Monte-Carlo simulation, we determined the distribution of chi-squared values obtained by comparing sets of events from the same distribution; this distribution of chi-squared values was identical as for the univariate algorithm. Hence, the same formulae can be used to construct a metric, analogous to a t-score, that estimates the probability with which distributions are distinct. As for univariate comparisons, this metric scales with the difference between two distributions, and can be used to rank samples according to similarity to a control. We apply the algorithm to multivariate immunophenotyping data, and demonstrate that it can be used to discriminate distinct samples and to rank samples according to a biologically-meaningful difference.Probability binning, as shown here, provides a useful metric for determining the probability with which two or more multivariate distributions represent distinct sets of data. The metric can be used to identify the similarity or dissimilarity of samples. Finally, as demonstrated in the accompanying paper, the algorithm can be used to gate on events in one sample that are different from a control sample, even if those events cannot be distinguished on the basis of any combination of univariate or bivariate displays. Published 2001 Wiley-Liss, Inc.
View details for Web of Science ID 000171015000006
View details for PubMedID 11598946
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Isoelectric focusing and enzyme overlay membrane analysis of caspase 3 activation
ANALYTICAL BIOCHEMISTRY
2001; 292 (2): 313-316
View details for Web of Science ID 000168902300023
View details for PubMedID 11355870
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Phycoerythrin-allophycocyanin: A resonance energy transfer fluorochrome for immunofluorescence
CYTOMETRY
2001; 44 (1): 24-29
Abstract
As immunofluorescence experiments become more complex, the demand for new dyes with different properties increases. Fluorescent dyes with large Stoke's shifts that are very bright and have low background binding to cells are especially desirable. We report on the properties of the resonance energy tandems of phycoerythrin and allophycocyanin (PE-APC). PE-APC is the original fluorescence resonance energy tandem dye described in the literature, but it has not been utilized because of the difficulty of synthesizing and preparing a consistent product.PE-APC complexes comprising different ratios of the two phycobiliproteins conjugated to streptavidin were synthesized using standard protein-protein conjugation chemistry. The PE-APC streptavidins were evaluated for flow cytometric analysis. They were compared directly to Cy5PE conjugates because Cy5PE is the fluorophore that is spectrally most like the PE-APC.PE-APC complexes showed the expected fluorescence spectral properties of a tandem: excitation was excellent at 488 nm (and best at the PE excitation maximum) and emission was greatest at the APC emission maximum at about 660 nm. The efficiency of transfer of energy from PE to APC was about 90%.PE-APC can be considered an excellent substitute for Cy5PE. Compared with Cy5PE, PE-APC has similar brightness (in staining experiments), slightly greater compensation requirements with PE but much lower compensation with Cy5.5PE or Cy5.5PerCP, and lower nonspecific background binding. PE-APC is a useful alternative to Cy5PE, especially in applications in which the use of Cy5 is impractical. Cytometry 44:24-29, 2001. Published 2001 Wiley-Liss, Inc.
View details for Web of Science ID 000168346600004
View details for PubMedID 11309805
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MHC class II expression is initiated at the earliest stage of B cell development in murine bone marrow
FEDERATION AMER SOC EXP BIOL. 2001: A320–A320
View details for Web of Science ID 000167438101827
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Chronic elevation of plasma thioredoxin: Inhibition of chemotaxis and curtailment of life expectancy in AIDS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2001; 98 (5): 2688-2693
Abstract
Thioredoxin (Trx) is an intracellular redox protein with extracellular cytokine-like and chemokine-like activities. We show here that, although plasma Trx levels are unrelated to survival of HIV-infected individuals with CD4 cell counts above 200/microl blood, survival is significantly impaired (P = 0.003) when plasma Trx is chronically elevated in HIV-infected subjects with CD4 T cell counts below this level (i.e., with Centers for Disease Control (CDC)-defined AIDS). Relevant to the mechanism potentially underlying this finding, we also present data from experimental studies in mice showing that elevated plasma Trx efficiently blocks lipopolysaccharide (LPS)-induced chemotaxis, an innate immune mechanism that is particularly crucial when adaptive immunity is compromised. Thus, we propose that elevated plasma Trx in HIV-infected individuals with low CD4 T cell counts directly impairs survival by blocking pathogen-induced chemotaxis, effectively eliminating the last (innate) barrier against establishment of opportunistic and other infections in these immunodeficient individuals.
View details for Web of Science ID 000167258900104
View details for PubMedID 11226300
View details for PubMedCentralID PMC30199
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11-color, 13-parameter flow cytometry: Identification of human naive T cells by phenotype, function, and T-cell receptor diversity
NATURE MEDICINE
2001; 7 (2): 245-248
View details for Web of Science ID 000166756300044
View details for PubMedID 11175858
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The regulation of CD5 expression in murine T cells.
BMC molecular biology
2001; 2: 5-?
Abstract
CD5 is a pan-T cell surface marker that is also present on a subset of B cells, B-1a cells. Functional and developmental subsets of T cells express characteristic CD5 levels that vary over roughly a 30-fold range. Previous investigators have cloned a 1.7 Kb fragment containing the CD5 promoter and showed that it can confer similar lymphocyte-specific expression pattern as observed for endogenous CD5 expression.We further characterize the CD5 promoter and identify minimal and regulatory regions on the CD5 promoter. Using a luciferase reporter system, we show that a 43 bp region on the CD5 promoter regulates CD5 expression in resting mouse thymoma EL4 T cells and that an Ets binding site within the 43 bp region mediates the CD5 expression. In addition, we show that Ets-1, a member of the Ets family of transcription factors, recognizes the Ets binding site in the electrophoretic mobility shift assay (EMSA). This Ets binding site is directly responsible for the increase in reporter activity when co-transfected with increasing amounts of Ets-1 expression plasmid.We also identify two additional evolutionarily-conserved regions in the CD5 promoter (CD5X and CD5Y) and demonstrate the respective roles of the each region in the regulation of CD5 transcription.Our studies define a minimal and regulatory promoter for CD5 and show that the CD5 expression level in T cells is at least partially dependent on the level of Ets-1 protein. Based on the findings in this report, we propose a model of CD5 transcriptional regulation in T cells.
View details for PubMedID 11389772
View details for PubMedCentralID PMC32207
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Increased production of IL-7 accompanies HIV-l-mediated T-cell depletion: implications for T-cell homeostasis
NATURE MEDICINE
2001; 7 (1): 73-79
Abstract
We hypothesized that HIV-1-mediated T-cell loss might induce the production of factors that are capable of stimulating lymphocyte development and expansion. Here we perform cross-sectional (n = 168) and longitudinal (n = 11) analyses showing that increased circulating levels of interleukin (IL)-7 are strongly associated with CD4+ T lymphopenia in HIV-1 disease. Using immunohistochemistry with quantitative image analysis, we demonstrate that IL-7 is produced by dendritic-like cells within peripheral lymphoid tissues and that IL-7 production by these cells is greatly increased in lymphocyte-depleted tissues. We propose that IL-7 production increases as part of a homeostatic response to T-cell depletion.
View details for Web of Science ID 000166243100038
View details for PubMedID 11135619
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Apoptolidin, a selective cytotoxic agent, is an inhibitor of F0F1-ATPase
CHEMISTRY & BIOLOGY
2001; 8 (1): 71-80
Abstract
Apoptolidin is a macrolide originally identified on the basis of its ability to selectively kill E1A and E1A/E1B19K transformed rat glial cells while not killing untransformed glial cells. The goal of this study was to identify the molecular target of this newly discovered natural product.Our approach to uncovering the mechanism of action of apoptolidin utilized a combination of molecular and cell-based pharmacological assays as well as structural comparisons between apoptolidin and other macrocyclic polyketides with known mechanism of action. Cell killing induced by apoptolidin was independent of p53 status, inhibited by BCL-2, and dependent on the action of caspase-9. PARP was completely cleaved in the presence of 1 microM apoptolidin within 6 h in a mouse lymphoma cell line. Together these results suggested that apoptolidin might target a mitochondrial protein. Structural comparisons between apoptolidin and other macrolides revealed significant similarity between the apoptolidin aglycone and oligomycin, a known inhibitor of mitochondrial F0F1-ATP synthase. The relevance of this similarity was established by demonstrating that apoptolidin is a potent inhibitor of the F0F1-ATPase activity in intact yeast mitochondria as well as Triton X-100-solubilized ATPase preparations. The K(i) for apoptolidin was 4-5 microM. The selectivity of apoptolidin in the NCI-60 cell line panel was found to correlate well with that of several known anti-fungal natural products that inhibit the eukaryotic mitochondrial F0F1-ATP synthase.Although the anti-fungal activities of macrolide inhibitors of the mitochondrial F0F1-ATP synthase such as oligomycin, ossamycin and cytovaricin are well-documented, their unusual selectivity toward certain cell types is not widely appreciated. The recent discovery of apoptolidin, followed by the demonstration that it is an inhibitor of the mitochondrial F0F1-ATP synthase, highlights the potential relevance of these natural products as small molecules to modulate apoptotic pathways. The mechanistic basis for selective cytotoxicity of mitochondrial ATP synthase inhibitors is discussed.
View details for Web of Science ID 000167275800008
View details for PubMedID 11182320
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Understanding and exploiting the mechanistic basis for selectivity of polyketide inhibitors of F0F1-ATPase
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2000; 97 (26): 14766-14771
Abstract
Recently, a family of polyketide inhibitors of F(0)F(1)-ATPase, including apoptolidin, ossamycin, and oligomycin, were shown to be among the top 0.1% most cell line selective cytotoxic agents of 37, 000 molecules tested against the 60 human cancer cell lines of the National Cancer Institute. Many cancer cells maintain a high level of anaerobic carbon metabolism even in the presence of oxygen, a phenomenon that is historically known as the Warburg effect. A mechanism-based strategy to sensitize such cells to this class of potent small molecule cytotoxic agents is presented. These natural products inhibit oxidative phosphorylation by targeting the mitochondrial F(0)F(1) ATP synthase. Evaluation of gene expression profiles in a panel of leukemias revealed a strong correlation between the expression level of the gene encoding subunit 6 of the mitochondrial F(0)F(1) ATP synthase (known to be the binding site of members of this class of macrolides) and their sensitivity to these natural products. Within the same set of leukemia cell lines, comparably strong drug-gene correlations were also observed for the genes encoding two key enzymes involved in central carbon metabolism, pyruvate kinase, and aspartate aminotransferase. We propose a simple model in which the mitochondrial apoptotic pathway is activated in response to a shift in balance between aerobic and anaerobic ATP biosynthesis. Inhibitors of both lactate formation and carbon flux through the Embden-Meyerhof pathway significantly sensitized apoptolidin-resistant tumors to this drug. Nine different cell lines derived from human leukemias and melanomas, and colon, renal, central nervous system, and ovarian tumors are also sensitized to killing by apoptolidin.
View details for Web of Science ID 000165993700138
View details for PubMedID 11121076
View details for PubMedCentralID PMC18993
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An early oxygen-dependent step is required for dexamethasone-induced apoptosis of immature mouse thymocytes
JOURNAL OF IMMUNOLOGY
2000; 165 (9): 4822-4830
Abstract
The roles of oxygen and reactive oxygen intermediates in apoptosis are unclear at present. Although oxygen and reactive oxygen intermediates are not required for the execution of apoptosis, oxygen may be involved in at least some forms of apoptosis. In this study we show that dexamethasone (Dex)-induced apoptosis of immature mouse thymocytes is completely inhibited by hypoxic culture. In contrast, anti-CD95 thymocyte apoptosis is unaffected by hypoxia, indicating the existence of two forms of thymocyte apoptosis: an oxygen-dependent pathway (Dex induced) and an oxygen-independent pathway (anti-CD95 induced). Furthermore, hypoxia inhibited mitochondrial permeability transition (PT) in Dex-treated, but not in anti-CD95-treated, thymocytes, suggesting that the oxygen-sensitive step is upstream of mitochondria. Both Dex- and anti-CD95-induced PT and apoptosis were dependent on activation of IL-converting enzyme-like protease, as PT and apoptosis were inhibited by preincubation with Cbz-Val-Ala-Asp-fluoromethyl ketone, an irreversible inhibitor of IL-converting enzyme-like proteases. In addition, hypoxia inhibited the activation by Dex of caspase-3 (CPP32)-like proteases. Our data show that the private signaling pathways of Dex (oxygen dependent) and anti-CD95 (oxygen independent) both converge upstream of mitochondrial changes. The oxygen-dependent step in Dex-induced apoptosis lies upstream of caspase-3-like protease activation. Our observations support a model of apoptosis signaling in which independent pathways (oxygen dependent and oxygen independent) particular to each stimuli converge at a central point in the apoptotic cascade.
View details for Web of Science ID 000090076000009
View details for PubMedID 11046005
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N-acetylcysteine replenishes glutathione in HIV infection
EUROPEAN JOURNAL OF CLINICAL INVESTIGATION
2000; 30 (10): 915-929
Abstract
Glutathione (GSH) deficiency is common in HIV-infected individuals and is associated with impaired T cell function and impaired survival. N-acetylcysteine (NAC) is used to replenish GSH that has been depleted by acetaminophen overdose. Studies here test oral administration of NAC for safe and effective GSH replenishment in HIV infection.Oral NAC administration in a randomized, 8-week double-blind, placebo-controlled trial followed by optional open-label drug for up to 24 weeks.HIV-infected, low GSH, CD4 T cells < 500 micro L(-1), no active opportunistic infections or other debilitation; n = 81. Study conducted prior to introduction of protease inhibitors.Whole blood GSH levels in NAC arm subjects significantly increased from 0.88 mM to 0.98 mM, bringing GSH levels in NAC-treated subjects to 89% of uninfected controls (P = 0.03). Baseline GSH levels in the placebo group (0.91) remained essentially the same during the 8 week placebo-controlled trial. T cell GSH, adjusted for CD4 T cell count and beta2-microglobulin levels, also increased in the NAC-treated subjects (P = 0.04). Adverse effects were minimal and not significantly associated with NAC ingestion.NAC treatment for 8 weeks safely replenishes whole blood GSH and T cell GSH in HIV-infected individuals. Thus, NAC offers useful adjunct therapy to increase protection against oxidative stress, improve immune system function and increase detoxification of acetaminophen and other drugs. These findings suggest that NAC therapy could be valuable in other clinical situations in which GSH deficiency or oxidative stress plays a role in disease pathology, e.g. rheumatoid arthritis, Parkinson's disease, hepatitis, liver cirrhosis, septic shock and diabetes.
View details for Web of Science ID 000090133200012
View details for PubMedID 11029607
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Monoclonal antibodies and the FACS: complementary tools for immunobiology and medicine
IMMUNOLOGY TODAY
2000; 21 (8): 383-390
Abstract
The histories of monoclonal antibodies and the fluorescence activated cell sorter (FACS) are as closely intertwined as their current uses in biology and medicine. Here, Leonore Herzenberg, Stephen De Rosa and Leonard Herzenberg recount the meeting and the mating of these two technologies, whose offspring now populate clinical and research laboratories throughout the world.
View details for Web of Science ID 000088680900007
View details for PubMedID 10916141
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B-1 and B-2 cell-derived immunoglobulin M antibodies are nonredundant components of the protective response to influenza virus infection
JOURNAL OF EXPERIMENTAL MEDICINE
2000; 192 (2): 271-280
Abstract
We have studied the role of secreted immunoglobulin (Ig)M in protection from infection with influenza virus and delineated the relative contributions of B-1 versus B-2 cell-derived IgM in this process. Mice deficient in secreted IgM but capable of expressing surface IgM and secreting other Ig classes show significantly reduced virus clearance and survival rates compared with wild-type controls. Irradiation chimeras in which only either B-1 or B-2 cells lack the ability to secrete IgM show mortality rates similar to those of mice in which neither B-1 nor B-2 cells secrete IgM. Dependence on both sources of IgM for survival is partially explained by findings in allotype chimeras that broadly cross-reactive B-1 cell-derived natural IgM is present before infection, whereas virus strain-specific, B-2 cell-derived IgM appears only after infection. Furthermore, lack of IgM secreted from one or both sources significantly impairs the antiviral IgG response. Reconstitution of chimeras lacking B-1 cell-derived IgM only with IgM-containing serum from noninfected mice improved both survival rates and serum levels of virus-specific IgG. Thus, virus-induced IgM must be secreted in the presence of natural IgM for efficient induction of specific IgG and for immune protection, identifying B-1 and B-2 cell-derived IgM antibodies as nonredundant components of the antiviral response.
View details for Web of Science ID 000088261100013
View details for PubMedID 10899913
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B-1 cells: the lineage question revisited
IMMUNOLOGICAL REVIEWS
2000; 175: 9-22
Abstract
The origins and functions of B-1 cells have sparked a good deal of controversy, largely centered on whether these B cells are developmentally distinct from the principal B cell populations (B-2) found in peripheral lymphoid organs. However, the prime criteria for assigning B-1 and B-2 cells to separate developmental lineages are satisfied by studies published some time ago that 1) identify distinct sources of progenitors for B-1 and B-2 cells; 2) show that these progenitors express their inherent commitment developing under the same conditions in co-transfer recipients; and, 3) have distinctive developmental patterns revealed by analysis of cells at various stages along the B-cell development pathway. I review these developmental studies here both to clarify the issue and to set the stage for presentation of evidence from more recent studies, which further define the functional differences between B-1 and B-2 cells and reveal intriguing complexities in the selective and other mechanisms that control the V(H) composition of the B-1 antibody repertoire.
View details for Web of Science ID 000088202800002
View details for PubMedID 10933587
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CD4(+) T cells derived from B cell-deficient mice inhibit the establishment of peripheral B cell pools
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2000; 97 (9): 4766-4771
Abstract
We demonstrate that adoptive transfer of peritoneal cavity B cells fails to replenish the peripheral B-1 cells in adult B cell-deficient (mu(-/-)) mice but does replenish adult RAG-1(-/-) mice. We show that this lack of self-replenishment in mu(-/-) mice is mediated by strongly inhibitory, radiation-sensitive CD4(+) T cells that also function in cotransfer studies to block the reconstitution of B-1 cells and inhibit accumulation of bone marrow-derived B-2 cells in the periphery in irradiated recipients. CD8(+) T cells from mu(-/-) do not mediate this inhibition. The inhibitory CD4(+) T cells develop early in life, because B-1 cell replenishment occurs normally when B-1 cells are transferred into mu(-/-) neonates. Thus, we conclude that the presence of B cells in the neonate conditions the CD4(+) T-cell population to permit the establishment and maintenance of normal B cell pools throughout life.
View details for Web of Science ID 000086703000068
View details for PubMedID 10781082
View details for PubMedCentralID PMC18307
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Gene microarray identification of redox and mitochondrial elements that control resistance or sensitivity to apoptosis
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2000; 97 (6): 2680-2685
Abstract
Multigenic programs controlling susceptibility to apoptosis in response to ionizing radiation have not yet been defined. Here, using DNA microarrays, we show gene expression patterns in an apoptosis-sensitive and apoptosis-resistant murine B cell lymphoma model system both before and after irradiation. From the 11,000 genes interrogated by the arrays, two major patterns emerged. First, before radiation exposure the radioresistant LYar cells expressed significantly greater levels of message for several genes involved in regulating intracellular redox potential. Compared with LYas cells, LYar cells express 20- to 50-fold more mRNA for the tetraspanin CD53 and for fructose-1,6-bisphosphatase. Expression of both of these genes can lead to the increase of total cellular glutathione, which is the principle intracellular antioxidant and has been shown to inhibit many forms of apoptosis. A second pattern emerged after radiation, when the apoptosis-sensitive LYas cells induced rapid expression of a unique cluster of genes characterized by their involvement in mitochondrial electron transport. Some of these genes have been previously recognized as proapoptotic; however others, such as uncoupling protein 2, were not previously known to be apoptotic regulatory proteins. From these observations we propose that a multigenic program for sensitivity to apoptosis involves induction of transcripts for genes participating in mitochondrial uncoupling and loss of membrane potential. This program triggers mitochondrial release of apoptogenic factors and induces the "caspase cascade." Conversely, cells resistant to apoptosis down-regulate these biochemical pathways, while activating pathways for establishment and maintenance of high intracellular redox potential by means of elevated glutathione.
View details for Web of Science ID 000085941400051
View details for PubMedID 10716996
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The role of B-1 and B-2 cells in immune protection from influenza virus infection
16th Workshop on the Mechanisms of B Cell Neoplasia
SPRINGER-VERLAG BERLIN. 2000: 163–169
View details for Web of Science ID 000167097400017
View details for PubMedID 11125473
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B-1 cell origins and V-H repertoire determination
16th Workshop on the Mechanisms of B Cell Neoplasia
SPRINGER-VERLAG BERLIN. 2000: 3–13
View details for Web of Science ID 000167097400001
View details for PubMedID 11125487
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Differential representations of memory T cell subsets are characteristic of polarized immunity in leprosy and atopic diseases
INTERNATIONAL IMMUNOLOGY
1999; 11 (11): 1801-1810
Abstract
We identified functionally polarized subsets of CD4 memory T cells on the basis of the expression of CD11a, CD45RA and CD62L. Within the several phenotypically distinct subsets of CD4 memory cells are two that, upon stimulation, produce primarily IL-4 (MT(2), CD45RA(-)CD62L(+)CD11a(dim)) or primarily IFN-gamma (MT(1), CD45RA(-)CD62L(-)CD11a(bright)). In addition, four other phenotypically distinct subsets of CD4 cells have unique cytokine profiles. To determine the clinical relevance of the representation of these cell types, we analyzed blood from patients with the chronic diseases leprosy and atopy. These diseases are characterized as immunologically polarized, since T cell responses in affected individuals are often strongly biased towards T(h)1 (dominated by IFN-gamma production) or T(h)2 (IL-4 production). We show here that this polarization reflects homeostatic or differentiation mechanisms affecting the representation of the functionally distinct subsets of memory CD4 T cells, MT(1) and MT(2). Significantly, the representation of the MT(1) and MT(2) subsets differs dramatically between subjects with tuberculoid leprosy (a T(h)1 disease), or lepromatous leprosy or atopic disease (T(h)2 diseases). However, there was no difference in the cytokine profiles of these or any of the other finely resolved CD4 subsets, when compared between individuals across all disease states. Thus, it is the representation of these subsets in peripheral blood that is diagnostic of the polarized state of the immune system.
View details for Web of Science ID 000083797800009
View details for PubMedID 10545484
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An improved monobromobimane assay for glutathione utilizing tris(2-carboxyethyl)phosphine as the reductant
ANALYTICAL BIOCHEMISTRY
1999; 272 (1): 107-109
View details for Web of Science ID 000081616600015
View details for PubMedID 10405300
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Thioredoxin, a redox enzyme released in infection and inflammation, is a unique chemoattractant for neutrophils, monocytes, and T cells
JOURNAL OF EXPERIMENTAL MEDICINE
1999; 189 (11): 1783-1789
Abstract
Thioredoxin (Trx) is a ubiquitous intracellular protein disulfide oxidoreductase with a CXXC active site that can be released by various cell types upon activation. We show here that Trx is chemotactic for monocytes, polymorphonuclear leukocytes, and T lymphocytes, both in vitro in the standard micro Boyden chamber migration assay and in vivo in the mouse air pouch model. The potency of the chemotactic action of Trx for all leukocyte populations is in the nanomolar range, comparable with that of known chemokines. However, Trx does not increase intracellular Ca2+ and its activity is not inhibited by pertussis toxin. Thus, the chemotactic action of Trx differs from that of known chemokines in that it is G protein independent. Mutation of the active site cysteines resulted in loss of chemotactic activity, suggesting that the latter is mediated by the enzyme activity of Trx. Trx also accounted for part of the chemotactic activity released by human T lymphotropic virus (HTLV)-1-infected cells, which was inhibited by incubation with anti-Trx antibody. Since Trx production is induced by oxidants, it represents a link between oxidative stress and inflammation that is of particular interest because circulating Trx levels are elevated in inflammatory diseases and HIV infection.
View details for Web of Science ID 000080855200012
View details for PubMedID 10359582
View details for PubMedCentralID PMC2193090
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Nine color eleven parameter immunophenotyping using three laser flow cytometry
CYTOMETRY
1999; 36 (1): 36-45
Abstract
This study describes a three laser flow cytometer, reagents, and software used to simultaneously evaluate nine distinct fluorescent parameters on one cell sample. We compare the quality of data obtained with (1) full software compensation and (2) the use of partial spectral compensation of selected pairs of parameters in analog hardware, in combination with final software compensation. An application characterizing low frequency murine B cell subpopulations is given.The fluorochromes used are: fluorescein (FITC), phycoerythrin (PE), Cy5PE and Cy7PE, excited at 488 nm by an argon laser; Texas Red (TR), allophycocyanin (APC), and Cy7APC excited at 595 nm by a pumped dye laser; and cascade blue (CB) and cascade yellow (CY) excited at 407 nm by a violet-enhanced krypton laser. Custom additions to commercial electronics and an extended optical bench allow the measurement of these nine parameters plus forward and side scatter light signals.We find the use of partial analog compensation reduces the variation in the background staining levels introduced by the compensation process. Novel B cell populations with frequencies below 1% are characterized.Nine color flow cytometry is capable of providing measurements with high information content. The choice of reagent-dye combinations and the ability to compensate in multi-parameter measurement space are crucial to obtaining satisfactory results.
View details for Web of Science ID 000079988800005
View details for PubMedID 10331625
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Predominant V-H genes expressed in innate antibodies are associated with distinctive antigen-binding sites
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1999; 96 (5): 2262-2267
Abstract
Antibodies to phosphatidylcholine (PtC), a common constituent of mammalian and bacterial cell membranes, represent a large proportion of the natural antibody repertoire in mice. Previous studies of several mouse strains (e.g., C57BL/6) have shown that anti-PtC antibodies are mainly encoded by the VH11 and VH12 immunoglobulin heavy chain variable region gene families. We show here, however, that VH11 and VH12 encode only a small proportion of the anti-PtC antibodies in BALB/c mice. Instead, VHQ52-encoded antibodies predominate in this strain. In addition, two-thirds of the cells expressing VHQ52 family genes use a single gene (which, interestingly, has been previously shown to predominate in the anti-oxazolone response). We also show here that in anti-PtC antibodies from all strains, the distinctive antigen-binding sites associated with VHQ52 differ substantially from those associated with VH11 and VH12. That is, VHQ52-containing transcripts preferentially use the joining region JH4 rather than JH1 and exhibit more diverse complementarity-determining region 3 (CDR3) junctions with more N-region nucleotide additions at the gene segment junctions. Thus, the VH gene family that predominates in the anti-PtC repertoire differs among mouse strains, whereas the distinctive VHDJH rearrangements (CDR3, JH) associated with each VH gene family are similar in all strains. We discuss these findings in the context of a recent hypothesis suggesting that CDR3 structure, independent of VH framework, is sufficient to define the specificity of an antibody.
View details for Web of Science ID 000078956600082
View details for PubMedID 10051629
View details for PubMedCentralID PMC26771
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Innate and acquired humoral immunities to influenza virus are mediated by distinct arms of the immune system
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1999; 96 (5): 2250-2255
Abstract
"Natural" Igs, mainly IgM, comprise part of the innate immune system present in healthy individuals, including antigen-free mice. These Igs are thought to delay pathogenicity of infecting agents until antigen-induced high affinity Igs of all isotypes are produced. Previous studies suggested that the acquired humoral response arises directly from the innate response, i.e., that B cells expressing natural IgM, upon antigen encounter, differentiate to give rise both to cells that secrete high amounts of IgM and to cells that undergo affinity maturation and isotype switching. However, by using a murine model of influenza virus infection, we demonstrate here that the B cells that produce natural antiviral IgM neither increase their IgM production nor undergo isotype switching to IgG2a in response to the infection. These cells are distinct from the B cells that produce the antiviral response after encounter with the pathogen. Our data therefore demonstrate that the innate and the acquired humoral immunities to influenza virus are separate effector arms of the immune system and that antigen exposure per se is not sufficient to increase natural antibody production.
View details for Web of Science ID 000078956600080
View details for PubMedID 10051627
View details for PubMedCentralID PMC26769
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Single cell analysis and selection of living retrovirus vector-corrected mucopolysaccharidosis VII cells using a fluorescence-activated cell sorting-based assay for mammalian beta-glucuronidase enzymatic activity
JOURNAL OF BIOLOGICAL CHEMISTRY
1999; 274 (2): 657-665
Abstract
Mutations in the acid beta-glucuronidase gene lead to systemic accumulation of undegraded glycosaminoglycans in lysosomes and ultimately to clinical manifestations of mucopolysaccharidosis VII (Sly disease). Gene transfer by retrovirus vectors into murine mucopolysaccharidosis VII hematopoietic stem cells or fibroblasts ameliorates glycosaminoglycan accumulation in some affected tissues. The efficacy of gene therapy for mucopolysaccharidosis VII depends on the levels of beta-glucuronidase secreted by gene-corrected cells; therefore, enrichment of transduced cells expressing high levels of enzyme prior to transplantation is desirable. We describe the development of a fluorescence-activated cell sorter-based assay for the quantitative analysis of beta-glucuronidase activity in viable cells. Murine mucopolysaccharidosis VII cells transduced with a beta-glucuronidase retroviral vector can be isolated by cell sorting on the basis of beta-glucuronidase activity and cultured for further use. In vitro analysis revealed that sorted cells have elevated levels of beta-glucuronidase activity and secrete higher levels of cross-correcting enzyme than the population from which they were sorted. Transduced fibroblasts stably expressing beta-glucuronidase after subcutaneous passage in the mucopolysaccharidosis VII mouse can be isolated by cell sorting and expanded ex vivo. A relatively high percentage of these cells maintain stable expression after secondary transplantation, yielding significantly higher levels of enzymatic activity than that generated in the primary transplant.
View details for Web of Science ID 000077968500014
View details for PubMedID 9872999
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Flow cytometric analysis and FACS sorting of cells based on GFP accumulation
METHODS IN CELL BIOLOGY, VOL 58
1999; 58: 315-341
View details for Web of Science ID 000165166500019
View details for PubMedID 9891389
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Flow cytometric analysis of transgene expression in higher plants: Green fluorescent protein
GREEN FLUORESCENT PROTEIN
1999; 302: 296-315
View details for Web of Science ID 000087254200026
View details for PubMedID 12876781
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Pairs of violet-light-excited fluorochromes for flow cytometric analysis
CYTOMETRY
1998; 33 (4): 435-444
Abstract
We describe pairs of fluorochromes for use with the 407-nm line of a violet-light-enhanced krypton ion laser. These fluorochromes and a previously described violet-light-excited reporter variant, GFP-Vex, fall into two emission classes: blue for Cascade Blue, and green/yellow for Cascade Yellow, Lucifer Yellow, and GFP-Vex. Cascade Yellow is a new fluorochrome that we have synthesized and is used for the first time in the present study. The two emission classes are sufficiently different that Cascade Blue can be paired with Cascade Yellow, Lucifer Yellow, or GFP-Vex in flow cytometric analysis. Furthermore, with proper detection filters, these fluorochromes can be combined with all of the currently used fluorochromes in a three-laser FACS system. With these data, the total number of fluorochromes that can be used as antibody labels for simultaneous detection in combined FACS analysis increases to nine. This study demonstrates the sensitivity and power of the combined use of these reagents in a single eight-color analysis by identifying murine T-lymphocyte subsets that could not otherwise be readily distinguished.
View details for Web of Science ID 000077135400007
View details for PubMedID 9845438
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CD1 expression defines subsets of follicular and marginal zone B cells in the spleen: beta(2)-microglobulin-dependent and independent forms
JOURNAL OF IMMUNOLOGY
1998; 161 (4): 1710-1717
Abstract
We have used multicolor FACS analysis, immunohistology, and functional assays to study the expression of CD1 on B cell subsets from normal and beta 2m-/- mice. Two B cell subpopulations were identified that express high levels of CD1 in normal mice: splenic marginal zone B cells (IgMhigh IgDlow CD21high CD24intermediate CD23- CD43-) and a newly identified subpopulation of follicular B cells. The latter cells are unusual, because they are IgDhigh CD23+, like follicular B cells, but express high levels of CD21 and IgM, an expression pattern that is associated with marginal zone B cells. Therefore, the high-level expression of CD1 and CD21 was found to be closely associated on splenic B cells. Immunohistology confirmed the expression of CD1 on marginal zone B cells and on clusters of B cells in splenic follicles. Both the high-level CD1 expression by these cells and the low-level CD1 expression by subpopulations of B cells in the spleen, lymph node, peritoneal cavity, and bone marrow were markedly reduced in beta 2m-/- mice. Despite this, a CD1-restricted T cell clone proliferated vigorously in response to LPS-activated spleen cells that had been obtained from both beta 2m-/- and wild-type mice. This response was inhibited by the 3C11 anti-CD1 mAb. These results show the heterogeneity of B cell subsets in their expression of the beta 2m-dependent form of CD1. They further suggest that a beta 2m-independent form of CD1 is expressed on B cells that can stimulate T cells; however, this form is not easily visualized with the anti-CD1 mAb used here.
View details for Web of Science ID 000075345400018
View details for PubMedID 9712035
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Neutrophil CD11b expression as a diagnostic marker for early-onset neonatal infection
JOURNAL OF PEDIATRICS
1998; 132 (3): 445-451
Abstract
To determine whether neutrophil surface expression of CD11b predicts early-onset infection or suspected infection in at-risk infants.CD11b expression on peripheral blood neutrophils was determined by flow cytometry of whole blood samples. Blood (0.1 ml) was obtained from a convenience sample of at-risk infants admitted to the neonatal intensive care unit, stained with antibodies detecting CD11b and CD15, chilled, and analyzed within 8 hours. Blood for culture, blood counts, and C-reactive protein (CRP) determination was obtained simultaneously. Subjects were grouped on the basis of culture results and clinical signs, and investigators were blinded to CD11b level.Of 106 subjects, seven had positive bacterial or viral cultures ("confirmed infection"), 17 had clinical signs of infection but negative cultures ("suspected infection"), and 82 had negative cultures and no clinical signs ("no infection"). Neutrophil CD11b was elevated in all infants with confirmed infection, 94% with suspected infection, and none with no infection. The negative and positive predictive values, sensitivity, and specificity were 100%, 99%, 96%, and 100%, respectively, for diagnosis of neonatal infection at initial evaluation. CD11b levels correlated with peak CRP (r2 = 0.76, p < 0.0001); however, CD11b was elevated at the time of admission in all five infants with proven bacterial infection, whereas CRP was normal until the second day in the neonatal intensive care unit in three of these five. Both infants with positive viral cultures had elevated CD11b, but the CRP levels remained within normal limits. The negative predictive value of neutrophil CD11b for identifying suspected or confirmed infection was 99%.This assay for neutrophil CD11b is a promising test for exclusion of early-onset neonatal infection. If validated prospectively, this assay may reduce hospital and antibiotic use in the population of neonates at risk for early-onset infection.
View details for Web of Science ID 000072877800018
View details for PubMedID 9544899
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Presence of germline and full-length IgA RNA transcripts among peritoneal B-1 cells.
Developmental immunology
1998; 6 (1-2): 81-87
Abstract
Next to conventional B cells (or B-2 cells), peritoneal B-1 cells have been shown to contribute significantly to the production of IgA-secreting plasma cells in the gut. Evidence for this was mainly based on studies comprising manipulated animals, including lethally X-irradiated and transgenic mice. To examine the ability of peritoneal B-1 cells from untreated mice to switch actively to IgA in vivo, we performed RT-PCR analysis on FACS-sorted peritoneal B-cell subsets from untreated BALB/c mice in order to examine the presence of germline C alpha mRNA and mature C alpha mRNA transcripts. Germline C alpha and mature C alpha transcripts were readily detectable in peritoneal B-1 cells (defined as IgMbright/IgDdull), but not, or very little, in peritoneal B-2 cells (defined as IgMdull/IgDbright). Moreover, by subdividing the B-1-cell population in CD5+ B-1a cells and CD5- B-1b cells, it was shown that in vivo expression of germline C alpha and mature C alpha transcripts was largely restricted to the B-1b-cell lineage. These results indicate that peritoneal B-1 cells indeed are capable to switch to IgA under normal physiological conditions and hereby further support the view that B-1 cells contribute significantly to the mucosal IgA response, albeit this function appears to be restricted to the B-1b-cell subset.
View details for PubMedID 9716908
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Dynamics of fine T-cell subsets during HIV disease and after thymic ablation by mediastinal irradiation.
Seminars in immunology
1997; 9 (6): 389-396
Abstract
The T-cell compartment is considerably more complex than just CD4 and CD8 T cells. Indeed, we can identify dozens of functionally and phenotypically distinct subsets within the peripheral blood of humans. These subsets are differentially affected in diseases which may underly some of the functional defects attributable to the disease. In HIV disease, all thymic-derived T-cell populations are gradually lost at identical rates during late-stage disease progression, while unusual, perhaps extrathymically-derived T cells expand. This expansion may reflect an attempt on the part of the immune system to compensate for the significant insult of HIV infection to the host: the abrogation of normal thymopoiesis and T-cell homeostasis.
View details for PubMedID 9405268
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8 color, 10-parameter flow cytometry to elucidate complex leukocyte heterogeneity
CYTOMETRY
1997; 29 (4): 328-339
Abstract
We developed the chemistry, instrumentation, and software technologies needed to measure, simultaneously and independently, eight different fluorescent molecules on individual cells. Conjugation of these fluorochromes to monoclonal antibodies is straightforward; all immunofluorescence staining is accomplished with direct stains only. We built a hybrid flow cytometer with eight fluorescence detectors and two light scatter channels, with excitation provided by three spatially separated laser beams emitting at 407 nm, 488 nm, and 595 nm. The fluorescence compensation required to make the data orthogonal is of sufficient complexity that it cannot be performed manually; thus, we use software to compensate the data post hoc, based on data collected from singly stained compensation control samples. In this report, we evaluate the 8 color staining technology. Of the seven fluorochromes other than fluorescein, six have a useful brightness at least as great as fluorescein. Three of the fluorochromes (phycoerythrin, allophycocyanin, and the Cy5 resonance energy tandem of phycoerythrin) are considerably brighter than fluorescein and are useful for detecting antigens expressed at low levels. Finally, we show the power and utility of the 8 color, 10-parameter technology using staining experiments on both human and murine immune systems.
View details for Web of Science ID A1997YK15100009
View details for PubMedID 9415416
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Long-term depletion of naive T cells in patients treated for Hodgkin's disease
BLOOD
1997; 90 (9): 3662-3672
Abstract
We investigated the representation of T cells in patients who had been treated for Hodgkin's disease (HD). We found a marked depletion in both CD4 and CD8 naive T-cell counts that persists up to 30 years after completion of treatment. In contrast, CD4 and CD8 memory T-cell subsets recovered to normal or above normal levels by 5 years posttreatment. Thus, the previously-reported long-term deficit in total CD4 T-cell counts after treatment for HD is due to specific depletion of naive T cells. Similarly, total CD8 T-cell counts return to normal by 5 years only because CD8 memory T cells expand to higher than normal levels. These findings suggest that the treatment (mediastinal irradiation) results in a longterm dysregulation of T-cell subset homeostasis. The profound depletion of naive T cells may explain the altered T-cell function in treated patients, including the poor response to immunization after treatment for HD. Further, in some individuals, we identified expansions of unusual subsets expressing low levels of CD8. Eight-color fluorescence-activated cell sorting analyses showed that these cells largely express CD8alphaalpha homodimers and CD57, consistent with the phenotype of potentially extrathymically derived T cells. In addition, these cells, both CD4+ and CD4-, are probably cytotoxic lymphocytes, as they express high levels of intracellular perforin. In adults treated for HD, an increased activity of extrathymic T-cell differentiation may partially compensate for the loss of thymic-derived T cells.
View details for Web of Science ID A1997YD10800043
View details for PubMedID 9345051
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Interleukin-1 beta converting enzyme-like protease involvement in Fas-induced and activation-induced peripheral blood T cell apoptosis in HIV infection. TNF-related apoptosis-inducing ligand can mediate activation-induced T cell death in HIV infection
JOURNAL OF EXPERIMENTAL MEDICINE
1997; 186 (8): 1365-1372
Abstract
Apoptosis of peripheral blood T cells has been suggested to play an important role in the pathogenesis of human immunodeficiency virus (HIV) infection. Spontaneous, Fas (CD95)-induced and activation-induced T cell apoptosis have all been described in peripheral blood mononuclear cell cultures of HIV-infected individuals. We have previously shown that activation-induced T cell apoptosis is Fas independent in peripheral blood T cells from HIV+ individuals. In this study, we extend and confirm these observations by using an inhibitor of interleukin-1 beta converting enzyme (ICE) homologues. We show that z-VAD-fmk, a tripeptide inhibitor of ICE homologues, can inhibit Fas-induced apoptosis of peripheral blood CD4(+) and CD8+ T cells from asymptomatic HIV+ individuals. z-VAD-fmk also inhibited activation (anti-CD3)- induced CD4+ and CD8+ T cell apoptosis (AICD) in some but not all asymptomatic HIV+ individuals. Apoptosis was measured by multiparameter flow cytometry. The z-VAD-fmk inhibitor also enhanced survival of T cells in anti-Fas or anti-CD3 antibody-treated cultures and inhibited DNA fragmentation. AICD that could be inhibited by z-VAD-fmk was Fas independent and could be inhibited with a blocking monoclonal antibody to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a recently described member of the TNF/nerve growth factor ligand family. The above findings show that Fas-induced T cell apoptosis is ICE dependent in HIV infection. AICD can be blocked by ICE inhibitors in some patients, and this AICD is mediated by TRAIL. These results show that TRAIL can be a mediator of AICD in T cells. These different mechanisms of peripheral blood T cell apoptosis may play different roles in the pathogenesis of HIV infection.
View details for Web of Science ID A1997YC95000021
View details for PubMedID 9334376
View details for PubMedCentralID PMC2199088
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HIV type 1 Tat protein enhances activation- not Fas (CD95)-induced peripheral blood T cell apoptosis in healthy individuals
INTERNATIONAL IMMUNOLOGY
1997; 9 (6): 835-841
Abstract
T cell apoptosis may play an important role in the depletion and functional defects of T cells in HIV disease. A number of investigators have shown that peripheral blood T cells in HIV disease undergo spontaneous and activation-induced apoptosis. We found recently that peripheral blood T cells from HIV+ individuals undergo apoptosis when stimulated through Fas. Also, a number of investigators have shown that Tat protein from HIV-1 can increase spontaneous and activation-induced apoptosis. In the present study we examined the effect of HIV type 1 Tat protein on spontaneous, activation-induced and Fas-induced apoptosis of peripheral blood T cells from HIV- individuals. We find that Tat protein has no effect on spontaneous apoptosis but does enhance activation-induced apoptosis of both CD4+ and CD8+ T cells. Tat, however, failed to enhance Fas-induced apoptosis of CD4+ and CD8+ T cells. Examining the mechanisms by which Tat induces apoptosis, we found that inhibitors of reactive oxygen intermediate (ROI) generation or neutralizers of ROI, such as rotenone, a potent inhibitor of mitochondrial complex I of the respiratory chain, and 3,3,5,5-tetramethylpyrroline N-oxide (TMPO), an electron spin trap, could both enhance the spontaneous apoptosis induced by Tat. This enhancement of Tat-induced apoptosis by rotenone and TMPO was independent of ICE activation as it could not be inhibited by the tripeptide z-VAD-fmk, an irreversible inhibitor of ICE/ced-3 protease homologs. These findings suggest that Tat induced enhancement of activation-induced cell death may involve complex mechanisms, some of which are ROI independent. These results indicate that a HIV-specific mechanism other than Tat is responsible for the previously observed increased susceptibility of peripheral blood T cells from HIV-infected individuals to undergo apoptosis in response to Fas stimulation.
View details for Web of Science ID A1997XE89100004
View details for PubMedID 9199966
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Detection and isolation of gene-corrected cells in Gaucher disease via a fluorescence-activated cell sorter assay for lysosomal glucocerebrosidase activity
BLOOD
1997; 89 (9): 3412-3420
Abstract
Gaucher disease type 1 results from the accumulation of glucocerebroside in macrophages of the reticuloendothelial system, as a consequence of a deficiency in glucocerebrosidase (GC) activity. Recent improvements in the methodologies for introducing foreign genes into bone marrow stem cells have prompted several groups to test the efficacy of gene transfer therapy as a curative treatment for Gaucher disease. Limitations of this approach include the potential for insufficient engraftment of gene-corrected cells and incomplete transduction of hematopoietic stem cells using retroviral gene transfer. Overcoming these obstacles may be critical in the case of treatment for Gaucher disease type 1, because GC transduced cells have not been shown to have a growth advantage over noncorrected cells. Here, we describe the development and application of a novel, fluorescence-activated cell sorter based assay that directly quantitates GC activity at the single cell level. In a test of this application, fibroblasts from a Gaucher patient were transduced, and high expressing cells sorted based on GC activity. Reanalysis of cultured sorted fibroblasts reveals that these cells maintain high levels of enzymatic activity, compared with the heterogeneous population from which they were sorted. The assay is sufficiently sensitive to distinguish GC activity found in Gaucher patient monocytes from that in normal controls. Furthermore, preliminary results indicate that increased GC activity can be detected in transduced, CD34+ enriched peripheral blood mononuclear cells isolated from a Gaucher patient. This method should be a useful addition to current gene therapy protocols as a means to quantitatively assess gene correction of relevant cell populations and potentially purify transduced cells for transplantation.
View details for Web of Science ID A1997WX54200041
View details for PubMedID 9129049
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Frequent occurrence of identical heavy and light chain Ig rearrangements
INTERNATIONAL IMMUNOLOGY
1997; 9 (5): 689-702
Abstract
Single-cell PCR analyses of expressed Ig H and L chain sequences presented here show that certain rearrangements occur repeatedly and account for a major segment of the well-studied repertoire of B-1 cell autoantibodies that mediate the lysis of bromelain-treated mouse erythrocytes, i.e. antibodies reactive with phosphatldyicholine (PtC). We repeatedly isolated at least 10 different types of VH region rearrangements, involving three distinct germline genes, among FACS-sorted PtC-binding B-1 cells from three strains of mice (C57BL/6J, BALB/c and C.B-17). The predominant rearrangement, VH11-DSP-JH1 (VH11 type 1), has been previously found in anti-PtC hybridomas in several studies. We show that within each of six mice from two strains (C57BL/6J and BALB/c), unique instances of IgH/IgL pairing arose either from different B cell progenitors prior to IgH rearrangement or from pre-B cells which expanded after IgH rearrangement but prior to IgL rearrangement. Together with other recurrent rearrangements described here, our findings demonstrate that clonal expansion of mature B cells cannot account for all repeated rearrangements. As suggested by initial studies of dominant idiotype expression, these findings confirm that clonal expansion is only one of the mechanisms contributing to the establishment of recurrent rearrangements.
View details for Web of Science ID A1997XD24000006
View details for PubMedID 9184914
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Disruption of overlapping transcripts in the ROSA beta geo 26 gene trap strain leads to widespread expression of beta-galactosidase in mouse embryos and hematopoietic cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1997; 94 (8): 3789-3794
Abstract
The ROSA beta geo26 (ROSA26) mouse strain was produced by random retroviral gene trapping in embryonic stem cells. Staining of ROSA26 tissues and fluorescence-activated cell sorter-Gal analysis of hematopoietic cells demonstrates ubiquitous expression of the proviral beta geo reporter gene, and bone marrow transfer experiments illustrate the general utility of this strain for chimera and transplantation studies. The gene trap vector has integrated into a region that produces three transcripts. Two transcripts, lost in ROSA26 homozygous animals, originate from a common promoter and share identical 5' ends, but neither contains a significant ORF. The third transcript, originating from the reverse strand, shares antisense sequences with one of the noncoding transcripts. This third transcript potentially encodes a novel protein of at least 505 amino acids that is conserved in humans and in Caenorhabditis elegans.
View details for Web of Science ID A1997WW81000057
View details for PubMedID 9108056
View details for PubMedCentralID PMC20519
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HIV does not replicate in naive CD4 T cells stimulated with CD3/CD28
JOURNAL OF CLINICAL INVESTIGATION
1997; 99 (7): 1555-1564
Abstract
In this report, we demonstrate that the T cell tropic strain of HIV, LAI, does not replicate in naive CD4 T cells stimulated by cross-linking CD3 and CD28. In contrast, LAI replicates well in memory CD4 T cells stimulated in the same way. Unlike this physiologically relevant stimulation, PHA stimulates productive LAI replication in both naive and memory T cells. These studies were conducted with highly purified (FACS-isolated) subsets of CD4 T cells identified by expression of both CD45RA and CD62L. Remixing of purified T cells showed that naive T cells do not suppress LAI replication in memory T cells and that memory T cells do not restore LAI expression in naive T cells. The suppression of productive LAI replication in naive T cells is not due to differential expression of viral coreceptors, nor is it due to inhibition of activation of the important HIV transcription factors, nuclear factor-kappaB and activator protein-1. The inherent resistance of naive T cells to productive HIV infection, coupled with their proliferative advantage as demonstrated here, provides a sound basis for proposed clinical therapies using ex vivo expansion and reinfusion of CD4 T cells from HIV-infected adults.
View details for Web of Science ID A1997WT44400014
View details for PubMedID 9119999
View details for PubMedCentralID PMC507975
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Glutathione deficiency is associated with impaired survival in HIV disease
Oxidative Stress and Redox Regulation Meeting
NATL ACAD SCIENCES. 1997: 1967–72
Abstract
Glutathione (GSH), a cysteine-containing tripeptide, is essential for the viability and function of virtually all cells. In vitro studies showing that low GSH levels both promote HIV expression and impair T cell function suggested a link between GSH depletion and HIV disease progression. Clinical studies presented here directly demonstrate that low GSH levels predict poor survival in otherwise indistinguishable HIV-infected subjects. Specifically, we show that GSH deficiency in CD4 T cells from such subjects is associated with markedly decreased survival 2-3 years after baseline data collection (Kaplan-Meier and logistic regression analyses, P < 0.0001 for both analyses). This finding, supported by evidence demonstrating that oral administration of the GSH prodrug N-acetylcysteine replenishes GSH in these subjects and suggesting that N-acetylcysteine administration can improve their survival, establishes GSH deficiency as a key determinant of survival in HIV disease. Further, it argues strongly that the unnecessary or excessive use of acetaminophen, alcohol, or other drugs known to deplete GSH should be avoided by HIV-infected individuals.
View details for Web of Science ID A1997WM05900068
View details for PubMedID 9050888
View details for PubMedCentralID PMC20026
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An unbiased analysis of V-H-D-J(H) sequences from B-1a, B-1b, and conventional B cells
JOURNAL OF IMMUNOLOGY
1997; 158 (3): 1175-1186
Abstract
Previous studies conclude that the repertoire of B-1a (CD5+ B) cells is highly restricted. Studies here, which use FACS sorting and single-cell PCR methodology to develop an unbiased representation of the IgH repertoires of B-1a, B-1b, and conventional B cells from the peritoneal cavity, demonstrate that the B-1a cell repertoire is more diverse than previously thought. Furthermore, adult B-1a cells have significantly fewer noncoded nucleotide (N) insertions than conventional B cells. However, B-1a cells are not defined by the absence of these regions, since such insertions are present in two-thirds of B-1a cell transcripts. All three B cell populations use a wide spectrum of V(H), D, and J(H) elements and display considerable diversity in complementarity-determining region 3 (CDR3). However, characteristic differences in the repertoires of all three B cell populations also exist, suggesting different selective and/or developmental forces act to shape each repertoire.
View details for Web of Science ID A1997WE02000019
View details for PubMedID 9013957
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Recurrent identical rearrangement and repeated expression of identical heavy and light chains in single anti-phosphatidylcholine B cells
Conference on B Lymphocytes and Autoimmunity
NEW YORK ACAD SCIENCES. 1997: 484–488
View details for Web of Science ID A1997BH93X00071
View details for PubMedID 9186705
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NF-kappa B homodimer binding within the HIV-1 initiator region and interactions with TFII-I
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1996; 93 (22): 12376-12381
Abstract
We show that the binding of Rel p50 and p52 homodimers at sites within the transcriptional initiation region of HIV-1 provides for their ability to interact with other proteins that bind the initiator. The binding of one such protein, the initiator protein TFII-I, to the initiation region of HIV-1 is augmented in the presence of Rel p50 and Rel p52 homodimers. Consistent with this, in vitro Rel homodimers potentiate HIV-1 transcription in a manner dependent upon TFII-I. The findings suggest that Rel dimers may regulate HIV-1 transcription in two ways. First, through binding at the kappa B enhancer sites at (-104 to -80), NF-kappa B p50:p65 participates in classical transcriptional activation. Second, Rel dimers such as p50 or p52 might bind at initiator sequences to regulate the de novo binding of components of certain preinitiation complexes. These findings, and the existence of Rel binding sites at the initiators of other genes, suggest roles for Rel proteins in early events determining transcriptional control.
View details for Web of Science ID A1996VP93700060
View details for PubMedID 8901589
View details for PubMedCentralID PMC37999
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Simultaneous fluorescence-activated cell sorter analysis of two distinct transcriptional elements within a single cell using engineered green fluorescent proteins
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1996; 93 (16): 8508-8511
Abstract
Green fluorescent protein (GFP) is widely used as a reporter gene in both prokaryotes and eukaryotes. However, the fluorescence levels of wild-type GFP (wtGFP) are not bright enough for fluorescence-activated cell sorting or flow cytometry. Several GFP variants were generated that are brighter or have altered excitation spectra when expressed in prokaryotic cells. We engineered two GFP genes with different combinations of these mutations, GFP(S65T,V163A) termed GFP-Bex1, and GFP(S202F,T203I,V163A) termed GFP-Vex1. Both show enhanced brightness and improved signal-to-noise ratios when expressed in mammalian cells and appropriately excited, compared with wtGFP. Each mutant retains only one of the two excitation peaks of the wild-type protein. GFP-Bex1 excites at 488 nm (blue) and GFP-Vex1 excites at 406 nm (violet), both of which are available laser lines. Excitation at these wavelengths allows for the independent analyses of these mutants by fluorescence-activated cell sorting, permitting simultaneous, quantitative detection of expression from two different genes within single mammalian cells.
View details for Web of Science ID A1996VB32500065
View details for PubMedID 8710900
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Activation-induced peripheral blood T cell apoptosis is fas independent in HIV-infected individuals
INTERNATIONAL IMMUNOLOGY
1996; 8 (8): 1311-1317
Abstract
T cell apoptosis has been proposed as an important contributor to the functional defects and depletion of T cells in HIV-infected individuals. However, the mechanisms involved in this apoptosis have not been elucidated. We recently showed that peripheral blood T cells from HIV-infected individuals are especially susceptible to Fas antigen-induced apoptosis. In this study we examine the role of Fas, CTLA-4, tumor necrosis factor (TNF) receptors (TNFR) and CD30, receptors known to be involved in T cell activation-induced cell death (AICD), in the spontaneous and activation (anti-CD3)-induced apoptosis of peripheral blood T cells from asymptomatic HIV-infected individuals. We report here that spontaneous and activation-induced T cell apoptosis cannot be inhibited by reagents that block interactions of Fas, CTLA-4, p55 and p75 TNFR and CD30 with their respective ligands. We also show that IL-12, IFN-gamma, IL-4 and IL-10 cannot modify spontaneous, activation- and anti-Fas-induced apoptosis. Anti-Fas preferentially induced CD4+ T cell apoptosis whereas AICD induced apoptosis equally in CD4+ and CD8+ T cells. We conclude that T cell AICD in HIV infection is not mediated by Fas, thus indicating that Fas-induced and activation-induced T cell apoptosis are independent mechanisms of apoptosis which may play different roles in the pathogenesis of HIV infection.
View details for Web of Science ID A1996VE10900014
View details for PubMedID 8918700
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Enzyme-generated intracellular fluorescence for single-cell reporter gene analysis utilizing Escherichia coli beta-glucuronidase
CYTOMETRY
1996; 24 (4): 321-329
Abstract
We report the development of a new fluorescence-activated cell sorter (FACS)-based reporter gene system utilizing the enzymatic activity of the E. coli beta-glucuronidase (gus) gene. When loaded with the Gus substrate fluorescein-di-beta-D-glucuronide (FDGlcu), individual mammalian cells expressing and translating gus mRNA liberate sufficient levels of intracellular fluorescein for quantitative analysis by flow cytometry. This assay can be used to FACS sort viable cells based on Gus enzymatic activity, and the efficacy of the assay can be measured independently by using a fluorometric lysate assay. Furthermore, both the beta-glucuronidase and the previously described E. coli beta-galactosidase enzymes have high specificities for their cognate substrates, allowing each reporter gene to be measured by FACS independently.
View details for Web of Science ID A1996VD78900004
View details for PubMedID 8866216
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Cy7PE and Cy7APC: Bright new probes for immunofluorescence
CYTOMETRY
1996; 24 (3): 191-197
Abstract
We demonstrate the utility of indotricarbocyanine (Cy7) conjugates of the phycobiliproteins phycoerythrin (PE) and allophycocyanin (APC) in flow cytometry. This is the first demonstration of the use of an APC tandem dye for fluorescence measurements. These resonance energy transfer tandem dyes can be excited by the phycobiliprotein-specific excitation wavelengths and fluoresce at wavelengths above 780 nm. The tandem dyes, when conjugated to antibodies, are suitable for flow cytometry and other immunofluorescence applications. These conjugates are easily detectable above the very low autofluorescence in this part of the spectrum. Indeed, the Cy7-conjugated PE tandem (Cy7PE) has a "brightness" (fluorescence signal over cellular autofluorescence) comparable to that of fluorescein, and the Cy7APC tandem has a "brightness" comparable to that of APC. These tandems are also easily distinguished from other commonly used fluorophores, making them suitable for high-order multiparametric analysis. We show an example of six-color immunofluorescence analysis by flow cytometry, simultaneously measuring fluorescences from fluorescein, PE, Cy5PE, Texas red, APC, and Cy7APC.
View details for Web of Science ID A1996UU65300001
View details for PubMedID 8800551
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Analysis of lipopolysaccharide-response genes in B-lineage cells demonstrates that they can have differentiation stage-restricted expression and contain SH2 domains
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1996; 93 (9): 3947-3952
Abstract
Bacterial lipopolysaccharide (LPS) is a potent stimulator of B-cell activation, proliferation, and differentiation. We examined the genetic response of B-lineage cells to LPS via trapping of expressed genes with a gene-trap retrovirus. This analysis showed that expression of only a small fraction of genes is altered during LPS stimulation of B-lineage cells. Isolation of the cellular portion of the trapped LPS-response genes via 5' RACE (rapid amplification of cDNA ends) cloning identified novel genes for all the cloned loci. These novel LPS-response genes were also found to have differentiation stage-restricted expression within the B-lymphoid lineage. That LPS-response genes in B cells also have differentiation stage-restricted expression suggests that these genes may be involved in the control of B-cell function and differentiation, since the known members of this class of genes have frequently been found to play a role in the function and differentiation of B-lineage cells. The isolation of novel members of this class of genes, including a gene that contains a putative SH2 domain, will further increase our understanding of the molecular events involved in the control of B-cell differentiation and function.
View details for Web of Science ID A1996UK55700039
View details for PubMedID 8632995
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Elevation of plasma thioredoxin levels in HIV-infected individuals
INTERNATIONAL IMMUNOLOGY
1996; 8 (4): 603-611
Abstract
Thioredoxin (Trx), a ubiquitous protein intimately involved in redox and protein disulfide reductions, has been shown to be released from cells and to have cytokine-like activities. In addition, Trx has been implicated in the redox regulation of immunological responses and shown to be deficient in tissues from AIDS patients. In studies presented here, plasma Trx levels were measured by ELISA in plasma samples from HIV-infected individuals (n = 136) and HIV-negative controls (n = 47). To account for the release of Trx into plasma due to hemolysis, the Trx measurements were corrected according to the level of hemoglobin in the plasma sample. Data presented show that, in contrast to tissue Trx levels, corrected plasma Trx levels are significantly higher in HIV-infected individuals than in controls (P < 0.0001). Furthermore, approximately 25% of the HIV-infected individuals studied have plasma Trx levels greater than the highest levels found in controls (37 ng/ml). Detailed multiparameter FACS analysis of peripheral blood mononuclear cells (PBMC) from the infected individuals demonstrates that those with higher plasma Trx levels (37 ng/ml or greater) tend to have lower overall CD4 counts. In addition, increases in plasma Trx levels correlate with decreases in monochlorobimane staining (indicative of lower intracellular glutathione levels in PBMC) and with changes in surface antigen expression (CD62L, CD38 and CD20) that occur in the later stages of HIV infection. These correlations suggest that elevation of plasma Trx levels may be an important component of advanced HIV disease, perhaps related to the oxidative stress that often occurs at this stage.
View details for Web of Science ID A1996UG69100019
View details for PubMedID 8671648
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Changes in antigen densities on leukocyte subsets correlate with progression of HIV disease
INTERNATIONAL IMMUNOLOGY
1996; 8 (1): 1-11
Abstract
In a cross-sectional study of 154 HIV-infected and 33 uninfected healthy adults, we show that characteristic changes in the levels of expression of leukocyte surface antigens occur in the HIV-infected individuals. These changes, which collectively occur on virtually every leukocyte subset, are specific: a particular antigen may increase or decrease on one subset of PBMC but remain constant on another. Furthermore, within any particular subset, the levels of one or more antigens may change, while the levels of other surface antigens on the same cells remain constant. Some of these antigens density changes have been noted before, e.g. increased CD20 on B cells, and increased CD38 and HLA-DR on CD8 T cells. However, the multiparameter flow cytometry methodology used here reveals changes in a substantially larger number of surface markers, some of which are restricted to fine subsets of PBMC, such as naive or memory T cell subsets. For many of these antigens, the change in expression correlates with absolute CD4 counts >500/microl; others differ only in those with counts >100microl. The changes in antigen densities we observed on B and T cells are consistent with the observation of a persistent quasi-activated state of these cells in HIV-infected individuals. Similarly, the altered expression of the signal-transducing molecules CD7 and CD16 that we demonstrated for NK cells may correlate with the functional defects previously demonstrated in NK cells. Thus, measurements of antigen densities such as those demonstrated here may provide surrogate markers for the altered functional capacities of PBMC subsets in HIV-infected individuals, and may thereby provide a much simpler assay for immunocompetence than in vitro functional assays.
View details for Web of Science ID A1996TT32900001
View details for PubMedID 8671584
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HETEROGENEOUS CALCIUM FLUX IN PERIPHERAL T-CELL SUBSETS REVEALED BY 5-COLOR FLOW-CYTOMETRY USING LOG-RATIO CIRCUITRY
CYTOMETRY
1995; 21 (2): 187-196
Abstract
Calcium flux measurements of different subpopulations of cells by flow cytometry are important in understanding complex interactions in the immune system. This paper discusses the use of the difference of Log signals as a preferred method for obtaining this information simultaneously with other immunofluorescence parameters. We describe simple modifications to a commercial instrument that enables the measurement of calcium flux in addition to three immunofluorescence parameters. Finally, we show an application of this technique to measuring calcium flux of T cell subsets in human blood. We show that different subsets of peripheral CD4 T cells have significantly different capabilities to flux calcium after CD3 stimulation. These differences are related to the functional capacities of the cells within these subsets.
View details for Web of Science ID A1995TA35300010
View details for PubMedID 8582239
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DEFECTIVE B-CELL DEVELOPMENT AND FUNCTION IN BTK-DEFICIENT MICE
IMMUNITY
1995; 3 (3): 283-299
Abstract
Mutations in the Bruton's tyrosine kinase (Btk) gene have been linked to severe early B cell developmental blocks in human X-linked agammaglobulinemia (XLA), and to milder B cell activation deficiencies in murine X-linked immune deficiency (Xid). To elucidate unequivocally potential Btk functions in mice, we generated mutations in embryonic stem cells, which eliminated the ability to encode Btk pleckstrin homology or kinase domains, and assayed their effects by RAG2-deficient blastocyst complementation or introduction into the germline. Both mutations block expression of Btk protein and lead to reduced numbers of mature conventional B cells, severe B1 cell deficiency, serum IgM and IgG3 deficiency, and defective responses in vitro to various B cell activators and in vivo to immunization with thymus-independent type II antigens. These results prove that lack of Btk function results in an Xid phenotype and further suggest a differential requirement for Btk during the early stages of murine versus human B lymphocyte development.
View details for Web of Science ID A1995RX64500004
View details for PubMedID 7552994
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ISOLATION OF MUTANT T-LYMPHOCYTES WITH DEFECTS IN CAPACITATIVE CALCIUM-ENTRY
IMMUNITY
1995; 3 (2): 239-250
Abstract
Calcium and calcium-binding proteins play important roles in the signaling cascade leading from the initial engagement of TCRs on T cells to the fully activated state. To undertake a molecular dissection of this cascade, we first isolated a Jurkat T cell line derivative containing the NF-AT promoter element driving transcription of the diphtheria toxin A chain gene (dipA), resulting in rapid cell death. Selecting viable cells that fail to activate NF-AT-dependent transcription, we isolated two independent cell lines possessing defects in capacitative Ca2+ entry. NF-AT-dependent transcription can be restored in these cells by expression of a constitutively active calcineurin, but not overexpression of the Ca2+ regulatory protein CAML, which can normally replace the Ca2+ signal. The defect in these cell lines probably lies between CAML and calcineurin in the T cell activation cascade.
View details for Web of Science ID A1995RR33900009
View details for PubMedID 7648396
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FAS ANTIGEN STIMULATION INDUCES MARKED APOPTOSIS OF T-LYMPHOCYTES IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED INDIVIDUALS
JOURNAL OF EXPERIMENTAL MEDICINE
1995; 181 (6): 2029-2036
Abstract
Apoptosis (programmed cell death) of T lymphocytes has been proposed as a mechanism which plays an important role in the pathogenesis of human immunodeficiency virus (HIV) disease. Activation of Fas (CD95) can either result in costimulation of proliferation and cytokine production or in the induction of apoptosis of T lymphocytes. This raises the possibility that Fas is involved in the observed T cell apoptosis during HIV disease. In this report we show that peripheral blood CD4+ and CD8+ T lymphocytes from HIV-infected individuals undergo apoptosis in vitro in response to antibody stimulation (cross-linking) of Fas at a much higher frequency than from uninfected controls. This anti-Fas-induced T cell apoptosis is markedly higher than spontaneous T cell apoptosis in HIV-infected individuals. Antibodies against other members of the tumor necrosis factor (TNF)/nerve growth factor receptor family such as CD27, CD30, CD40, 4-1BB, p55 TNF receptor, p75 TNF receptor, and TNF receptor-related protein did not result in any increase of T cell apoptosis above that spontaneously observed in HIV+ individuals. Anti-Fas-induced apoptosis was much higher in symptomatic HIV-infected individuals; and the magnitude of anti-Fas-induced CD4+ T cell apoptosis correlated inversely with peripheral blood CD4+ T cell absolute counts. Surface expression of Fas on T cells was also found to be higher in HIV-infected individuals. Resting and activated CD4+ and CD8+ T cells both underwent apoptosis in response to anti-Fas antibody. L-Selectin positive memory CD4+ T cells were especially susceptible to anti-Fas-induced apoptosis. These findings show that CD4+ and CD8+ T lymphocytes in HIV-infected individuals are primed in vivo to undergo apoptosis in response to Fas stimulation, suggesting that Fas signaling may be responsible for the T lymphocyte functional defects and depletion observed in HIV disease.
View details for Web of Science ID A1995RA60500011
View details for PubMedID 7539037
View details for PubMedCentralID PMC2192074
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ALTERED REPRESENTATION OF NAIVE AND MEMORY CD8 T-CELL SUBSETS IN HIV-INFECTED CHILDREN
JOURNAL OF CLINICAL INVESTIGATION
1995; 95 (5): 2054-2060
Abstract
CD8 T cells are divided into naive and memory subsets according to both function and phenotype. In HIV-negative children, the naive subset is present at high frequencies, whereas memory cells are virtually absent. Previous studies have shown that the overall number of CD8 T cells does not decrease in HIV-infected children. In studies here, we use multiparameter flow cytometry to distinguish naive from memory CD8 T cells based on expression of CD11a, CD45RA, and CD62L. With this methodology, we show that within the CD8 T cell population, the naive subset decreases markedly (HIV+ vs. HIV-, 190 vs. 370 cells/microliter; P < or = 0.003), and that there is a reciprocal increase in memory cells, such that the total CD8 T cell counts remained unchanged (800 vs. 860 cells/microliter; P < or = 0.76). In addition, we show that for HIV-infected children, the naive CD8 T cell and total CD4 T cell counts correlate (chi 2 P < or = 0.001). This correlated loss suggests that the loss of naive CD8 T cells in HIV infection may contribute to the defects in cell-mediated immunity which become progressively worse as the HIV disease progresses and CD4 counts decrease.
View details for Web of Science ID A1995QW20500014
View details for PubMedID 7738172
View details for PubMedCentralID PMC295792
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CD8 NAIVE T-CELL COUNTS DECREASE PROGRESSIVELY IN HIV-INFECTED ADULTS
JOURNAL OF CLINICAL INVESTIGATION
1995; 95 (5): 2061-2066
Abstract
We show here that CD8 naive T cells are depleted during the asymptomatic stage of HIV infection. Although overall CD8 T cell numbers are increased during this stage, the naive CD8 T cells are progressively lost and fall in parallel with overall CD4 T cell counts. In addition, we show that naive CD4 T cells are preferentially lost as total CD4 cell counts fall. These findings, presented here for adults, and in the accompanying study for children, represent the first demonstration that HIV disease involves the loss of both CD4 T cells and CD8 T cells. Furthermore, they provide a new insight into the mechanisms underlying the immunodeficiency of HIV-infected individuals, since naive T cells are required for all new T cell-mediated immune responses. Studies presented here also show that the well-known increase in total CD8 counts in most HIV-infected individuals is primarily due to an expansion of memory cells. Thus, memory CD8 T cells comprise over 80% of the T cells in PBMC from individuals with < 200 CD4/microliter, whereas they comprise roughly 15% in uninfected individuals. Since the naive and memory subsets have very different functional activities, this altered naive/memory T cell representation has significant consequences for the interpretation of data from in vitro functional studies.
View details for Web of Science ID A1995QW20500015
View details for PubMedID 7738173
View details for PubMedCentralID PMC295794
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Development of the antibody repertoire as revealed by single-cell PCR of FACS-sorted B-cell subsets
Conference on Immunoglobulin Gene Expression in Development and Disease
NEW YORK ACAD SCIENCES. 1995: 224–227
View details for Web of Science ID A1995BE39E00034
View details for PubMedID 7486528
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REDOX REGULATION OF ACTIVATION OF NF-KAPPA-B TRANSCRIPTION FACTOR COMPLEX - EFFECTS OF N-ACETYLCYSTEINE
BIOTHIOLS, PT B
1995; 252: 168-174
View details for Web of Science ID A1995BE08C00017
View details for PubMedID 7476350
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HUMAN CD5+ B-LYMPHOCYTES (B-1 CELLS) DECREASE IN PERIPHERAL-BLOOD DURING PREGNANCY
JOURNAL OF REPRODUCTIVE IMMUNOLOGY
1995; 28 (1): 53-60
Abstract
Pregnancy is a unique immunologic state where a natural homeostasis exists between antigenically different tissues. Several earlier studies have addressed the fluctuations in the number and/or function of lymphocytes, including B cells during pregnancy, but changes within the subsets of B lymphocytes, conventional (CD5-) and B-1 (CD5+), have not been addressed. Here we demonstrate that the frequency of B-1 cells decreases dramatically during pregnancy, whereas the frequency of conventional B cells remains relatively constant. The missing B-1 cells return to pre-pregnancy levels 8-10 weeks after parturition. The polyreactive autoantibodies secreted by B-1 cells have been implicated in autoimmunity and immune regulation. The possible role of B-1 cells during pregnancy will be discussed in that context.
View details for Web of Science ID A1995QH79400005
View details for PubMedID 7537825
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DE-NOVO DEVELOPMENT AND SELF-REPLENISHMENT OF B-CELLS
INTERNATIONAL IMMUNOLOGY
1995; 7 (1): 55-68
Abstract
Previous studies distinguished two murine B cell lineages: the conventional lineage, which comprises the majority of B cells, and the Ly-1 B lineage (B-1a), which represents a small percentage of total adult B cells. A third subset, B-1b cells, shares many properties with B-1a cells, including the characteristic ability to self-replenish, but does not express Ly-1 (CD5). Reconstitution studies presented here show that (i) although the B220- population in adult spleen and bone marrow contains very little progenitor activity for B-1a cells, it can reconstitute roughly half the normal number of B-1b cells; (ii) B-1 progenitors present in adult bone marrow and spleen function at low levels in adult animals; (iii) peritoneal B-1 cells (principally B-1b) that develop following bone marrow transfer, like B-1 cells from normal animals, are capable of substantial self-replenishment; and (iv) conventional B cells do not expand (self-replenish) in adoptive recipients, although they can persist for long periods. Collectively, these progenitor and self-replenishment characteristics provide a developmental base for distinguishing B-1a, B-1b and conventional B cells.
View details for Web of Science ID A1995QD67400007
View details for PubMedID 7536467
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SEPARATION OF OXIDANT-INITIATED AND REDOX-REGULATED STEPS IN THE NF-KAPPA-B SIGNAL-TRANSDUCTION PATHWAY
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1994; 91 (24): 11527-11531
Abstract
Studies presented here show that overall NF-kappa B signal transduction begins with a parallel series of stimuli-specific pathways through which cytokines (tumor necrosis factor alpha), oxidants (hydrogen peroxide and mitomycin C), and phorbol ester (phorbol 12-myristate 13-acetate) individually initiate signaling. These initial pathways culminate in a common pathway through which all of the stimulating agents ultimately signal NF-kappa B activation. We distinguish the stimuli-specific pathways by showing that the oxidative stimuli trigger NF-kappa B activation in only one of two human T-cell lines (Wurzburg but not Jurkat), whereas tumor necrosis factor alpha and phorbol 12-myristate 13-acetate readily stimulate in both lines. We propose the common pathway as the simplest way of accounting for the common requirements and properties of the signaling pathway. We include a redox-regulatory mechanism(s) in this common pathway to account for the previously demonstrated redox regulation of NF-kappa B activation in Jurkat cells (in which oxidants don't activate NF-kappa B); we put tyrosine phosphorylation in the common pathway by showing that kinase activity (inhibitable by herbimycin A and tyrphostin 47) is required for NF-kappa B activation by all stimuli tested in both cell lines. Since internal sites of oxidant production have been shown to play a key role in the cytokine-stimulated activation of NF-kappa B, and since tyrosine kinase and phosphatase activities are known to be altered by oxidants, these findings suggest that intracellular redox status controls NF-kappa B activation by regulating tyrosine phosphorylation event(s) within the common step of the NF-kappa B signal transduction pathway.
View details for Web of Science ID A1994PU28500050
View details for PubMedID 7526398
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PATTERN SORTING - A COMPUTER-CONTROLLED MULTIDIMENSIONAL SORTING METHOD USING K-D TREES
CYTOMETRY
1994; 16 (4): 357-363
Abstract
Multidimensional binary trees provide a memory efficient and general method for computing sorting decisions in real time for a flow cytometer. Their fundamental advantage over conventional lookup table sorting techniques is that sort criteria in the full N-dimensional data space which cannot be described by projections onto two-dimensional parameter planes can be effectively implemented. This becomes particularly relevant when multidimensional analysis methods such as principal components or clustering are employed. We describe a prototype implementation of this method and point out other possible implementations.
View details for Web of Science ID A1994NY12100010
View details for PubMedID 7988296
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GLUTATHIONE PRECURSOR AND ANTIOXIDANT ACTIVITIES OF N-ACETYLCYSTEINE AND OXOTHIAZOLIDINE CARBOXYLATE COMPARED IN IN-VITRO STUDIES OF HIV REPLICATION
AIDS RESEARCH AND HUMAN RETROVIRUSES
1994; 10 (8): 961-967
Abstract
N-Acetyl-L-cysteine (NAC) and L-2-oxothiazolidine 4-carboxylate (OTC) are pro-GSH drugs that been proposed for AIDS therapy. In this article we compare the antiviral activities of these compounds in various in vitro HIV infection models. Although both compounds blocked cytokine induction of HIV in acute and chronic infection models, and in HIV-LTR reporter cell systems, NAC was far more effective than OTC, even at suboptimal doses. To test whether this difference is due to GSH conversion efficacies of these compounds, we measured GSH restoration by NAC or OTC in GSH-depleted peripheral blood mononuclear cells (PBMCs), using flow cytometry. In isolated PBMCs, NAC fully replenishes depleted intracellular GSH whereas OTC only minimally replenishes GSH. This ability to replenish GSH in vitro and its ability to scavenge free radicals directly explain why NAC has more potent antiviral activities in vitro.
View details for Web of Science ID A1994PE52200015
View details for PubMedID 7811547
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DNA METHYLATION PREVENTS THE AMPLIFICATION OF TROP1, A TUMOR-ASSOCIATED CELL-SURFACE ANTIGEN GENE
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1994; 91 (13): 5833-5837
Abstract
We tested the hypothesis that different genes can have different abilities to be amplified after transfection under comparable selection conditions. DNA from human lymphoid or choriocarcinoma cell lines was transfected into L cells. Transfectants for CD5, CD8A, TROP1, and TROP2, genes expressed on lymphocytes or trophoblast and carcinomas, were selected by fluorescence-activated cell sorting. To select for amplification of the transfected gene we cloned twice by fluorescence-activated cell sorting the transfectants with the highest expression. We analyzed a total of 38 families (1768 clones) derived from the original transfectants. We then analyzed by Southern blotting the clones with the highest increase in surface expression and determined the copy number of each transfected gene. CD5, CD8A, and TROP2 were amplified with high frequency and progressively, whereas TROP1 essentially was not amplified at all. We examined the hypothesis that DNA methylation prevents the amplification of the TROP1 gene by treating JAR choriocarcinoma cells with 5-azacytidine to decrease DNA methylation. DNA extracted at different times after the treatment was used for transfection. When DNA that showed demethylation of the TROP1 gene was used, 16 Trop-1 transfectants were obtained and 6 of them were found to contain up to 40 copies of the TROP1 gene per haploid genome. Thus, we showed that transfectants obtained from a demethylated TROP1 gene were amplified efficiently and progressively. We propose that DNA methylation affects DNA amplification either by altering the recognition of methylated DNA sequences or by changing the conformation of the chromatin of methylated segments. We speculate that DNA methylation is a determinant of gene amplification in vivo, for example in tumor cells.
View details for Web of Science ID A1994NT46100021
View details for PubMedID 8016075
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CONTRIBUTION OF A SINGLE HEAVY-CHAIN RESIDUE TO SPECIFICITY OF AN ANTIDIGOXIN MONOCLONAL-ANTIBODY
PROTEIN SCIENCE
1994; 3 (5): 737-749
Abstract
Two distinct spontaneous variants of the murine anti-digoxin hybridoma 26-10 were isolated by fluorescence-activated cell sorting for reduced affinity of surface antibody for antigen. Nucleotide and partial amino acid sequencing of the variant antibody variable regions revealed that 1 variant had a single amino acid substitution: Lys for Asn at heavy chain position 35. The second variant antibody had 2 heavy chain substitutions: Tyr for Asn at position 35, and Met for Arg at position 38. Mutagenesis experiments confirmed that the position 35 substitutions were solely responsible for the markedly reduced affinity of both variant antibodies. Several mutants with more conservative position 35 substitutions were engineered to ascertain the contribution of Asn 35 to the binding of digoxin to antibody 26-10. Replacement of Asn with Gln reduced affinity for digoxin 10-fold relative to the wild-type antibody, but maintained wild-type fine specificity for cardiac glycoside analogues. All other substitutions (Val, Thr, Leu, Ala, and Asp) reduced affinity by at least 90-fold and caused distinct shifts in fine specificity. The Ala mutant demonstrated greatly increased relative affinities for 16-acetylated haptens and haptens with a saturated lactone. The X-ray crystal structure of the 26-10 Fab in complex with digoxin (Jeffrey PD et al., 1993, Proc Natl Acad Sci USA 90:10310-10314) reveals that the position 35 Asn contacts hapten and forms hydrogen bonds with 2 other contact residues. The reductions in affinity of the position 35 mutants for digoxin are greater than expected based upon the small hapten contact area provided by the wild-type Asn. We therefore performed molecular modeling experiments which suggested that substitution of Gln or Asp can maintain these hydrogen bonds whereas the other substituted side chains cannot. The altered binding of the Asp mutant may be due to the introduction of a negative charge. The similarities in binding of the wild-type and Gln-mutant antibodies, however, suggest that these hydrogen bonds are important for maintaining the architecture of the binding site and therefore the affinity and specificity of this antibody. The Ala mutant eliminates the wild-type hydrogen bonding, and molecular modeling suggests that the reduced side-chain volume also provides space that can accommodate a congener with a 16-acetyl group or saturated lactone, accounting for the altered fine specificity of this antibody.
View details for Web of Science ID A1994NH62300003
View details for PubMedID 8061604
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REDOX REGULATION OF SIGNAL-TRANSDUCTION - TYROSINE PHOSPHORYLATION AND CALCIUM INFLUX
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1994; 91 (9): 3619-3622
Abstract
Studies presented here show that altering the intracellular redox balance by decreasing glutathione levels profoundly affects early signal transduction events in human T cells. In a T-cell receptor (TCR) signaling model, short-term pretreatment with buthionine sulfoximine, which specifically decreases intracellular glutathione, essentially abrogates the stimulation of calcium influx by anti-CD3 antibodies without significantly impairing other aspects of TCR-initiated signal transduction, such as overall levels of TCR-stimulated tyrosine phosphorylation. In an inflammatory-cytokine signaling model, the failure of tumor necrosis factor alpha to stimulate more than minimal tyrosine phosphorylation in lymphocytes is overcome by buthionine sulfoximine pretreatment--i.e., tumor necrosis factor alpha stimulates extensive tyrosine phosphorylation in glutathione-depleted lymphocytes. These redox-dependent changes in T-cell responsiveness suggest that the glutathione deficiency that we and others have demonstrated in human immunodeficiency virus-infected individuals may contribute significantly to the immunodeficiency and the increased inflammatory reactions in these individuals.
View details for Web of Science ID A1994NJ03400031
View details for PubMedID 7513425
View details for PubMedCentralID PMC43632
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BETA-GALACTOSIDASE ACTIVITY IN SINGLE DIFFERENTIATING BACTERIAL-CELLS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1993; 90 (17): 8194-8198
Abstract
Myxococcus xanthus strains containing transcriptional fusions to lacZ were analyzed and fractionated by differences in their levels of beta-galactosidase expression. The fluorogenic substrate for beta-galactosidase, fluorescein di-beta-galactopyranoside, was introduced into M. xanthus cells during a rapid decrease in osmolarity of the medium followed by a return to isoosmolarity. Fluorescein, the product of hydrolysis, was retained within the cells and their viability was preserved. Fluorescence increased linearly with time and was proportional to beta-galactosidase activity. beta-Galactosidase expression in most fusion strains, though beginning at different phases of growth or development, was distributed unimodally amongst cells. However, fusion strain Tn5 lac omega 4473 was shown to be heterogeneous at 9 hr of development. It was possible to separate physically cells that expressed beta-galactosidase at a high level from other, still viable, cells with no expression. The approach described here could be adapted to study differentiation in plants and animals as well, where transcriptional fusions and fluorogenic substrates for enzyme probes of gene expression also can be used.
View details for Web of Science ID A1993LV64400060
View details for PubMedID 8396263
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A HIGH-FREQUENCY OF HYBRIDOMAS FROM M54-MU HEAVY-CHAIN TRANSGENIC MICE INITIALLY COEXPRESS TRANSGENIC AND REARRANGED ENDOGENOUS MU GENES
INTERNATIONAL IMMUNOLOGY
1993; 5 (9): 1011-1022
Abstract
The M54 transgenic mouse line, which carries the 17.2.25 Ig mu heavy chain gene, rearranges Ig heavy chains and expresses both transgenic and endogenous mu. B cell lineage development is selectively impaired in these mice and cells that simultaneously express transgenic and endogenous mu ('double-producers') are common amongst the B cells and plasma cells that do develop. Weaver, Imanishi-kari, Baltimore and colleagues failed to obtain double-producing hybridomas from M54 mice; however, molecular and serologic studies presented here show that such hybridomas are readily generated. These hybridomas are extremely unstable and rapidly yield variants producing either transgenic or endogenous mu. Therefore the stable cloned lines we obtained, like Weaver et al., were almost all single or non-producers. We also found that the VH gene usage in our hybridomas was skewed towards the JH proximal (VHQ52, VH81X) families, supporting the idea that the expression of the M54 transgene alters the endogenous Ig repertoire.
View details for Web of Science ID A1993MA57700002
View details for PubMedID 8241050
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ANTIOXIDANTS INHIBIT STIMULATION OF HIV TRANSCRIPTION
AIDS RESEARCH AND HUMAN RETROVIRUSES
1993; 9 (4): 299-306
Abstract
In studies presented here, we demonstrate that antioxidants regulate NF-kappa B activation and signal transduction pathways leading to HIV expression. We show (1) that N-acetyl-L-cysteine (NAC), an antioxidant and an efficient glutathione (GSH) precursor, inhibits NF-kappa B activation and HIV expression under conditions in which GSH is depleted and NAC cannot be converted to GSH, (2) that the D-stereoisomer of NAC and a wide variety of chemically unrelated antioxidants also inhibit NF-kappa B activation and/or transcription directed by the HIV LTR, and (3) that depletion of GSH, the principal intracellular antioxidant, augments HIV production in an acute infection model. Taken together, these findings suggest direct antioxidant action as the mechanism for inhibition of HIV transcription by NAC. They also confirm that GSH, acting in its capacity as an antioxidant, regulates HIV expression and that exogenous antioxidants can potentiate this regulation.
View details for Web of Science ID A1993KY80800002
View details for PubMedID 8512745
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DISREGULATION OF LEUKOCYTE GLUTATHIONE IN AIDS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1993; 677: 113-125
View details for Web of Science ID A1993KX22500014
View details for PubMedID 8494201
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N-ACETYLCYSTEINE - POTENTIAL FOR AIDS THERAPY
PHARMACOLOGY
1993; 46 (3): 121-129
Abstract
The observations that people infected with HIV suffer not only from an inflammatory stress but also from depleted glutathione levels have led to a general hypothesis that these two are causally related, and that treatment of AIDS should include thiol-replenishment therapy. In particular, inflammatory stimulations are dependent on intracellular thiol levels, as they are potentiated at low glutathione levels (oxidative stress) and inhibited at high glutathione levels. Inflammatory stress may itself lead to decreased levels of glutathione. HIV has taken advantage of inflammatory signals to regulate its own replication; thus, the HIV infection is exacerbated by low levels of glutathione. We have shown that N-acetylcysteine can inhibit inflammatory stimulations, including that of HIV replication. Since N-acetylcysteine can replenish depleted glutathione levels in vivo, we suggest that it be used as an adjunct in the treatment of AIDS.
View details for Web of Science ID A1993KP55700001
View details for PubMedID 8441760
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B-CELL LINEAGES EXIST IN THE MOUSE
IMMUNOLOGY TODAY
1993; 14 (2): 79-83
View details for Web of Science ID A1993KL80100010
View details for PubMedID 8447936
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ORIGIN OF MURINE B-CELL LINEAGES
ANNUAL REVIEW OF IMMUNOLOGY
1993; 11: 501-538
Abstract
Until recently, the hematopoietic stem cells (HSC) that appear early in ontogeny were thought to constitute a homogeneous, self-replenishing population whose developmental potential remains constant throughout the life of the animal. Studies reviewed here, however, demonstrated clear differences in the developmental potential of fetal and adult progenitor populations (including FACS-sorted HSC). These studies, which chart the ability of various progenitor sources to reconstitute functionally distinct B cell populations, define three B cell lineages: B-1a cells (CD5 B cells), derived from progenitors that are present in fetal omentum and fetal liver but are largely absent from adult bone marrow; B-1b cells ("sister" population), derived from progenitors that are present in fetal omentum, fetal liver, and also in adult bone marrow; and conventional B cells, whose progenitors are missing from fetal omentum but are found in fetal liver and adult bone marrow. B-1a and B-1b cells share many properties, including self-replenishment and feedback regulation of development. These B cell studies, in conjunction with evidence for a similar developmental switch for T cells and erythrocytes, suggest that evolution has created a "layered" immune system in which successive progenitors (HSC) reach predominance during development and give rise to differentiated cells (B, T, etc) responsible for progressively more complex immune functions.
View details for Web of Science ID A1993KX30600018
View details for PubMedID 8476571
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DISREGULATION OF LEUKOCYTE GLUTATHIONE IN AIDS
CONF ON CLINICAL FLOW CYTOMETRY
NEW YORK ACAD SCIENCES. 1993: 113–125
View details for Web of Science ID A1993BX95P00014
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GLUTATHIONE AND IMMUNOPHENOTYPES OF LYMPHOCYTES-T AND LYMPHOCYTES-B IN HIV-INFECTED INDIVIDUALS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1992; 651: 453-463
View details for Web of Science ID A1992JM21900058
View details for PubMedID 1376062
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CHARACTERISTICS AND DEVELOPMENT OF THE MURINE B-1B (LY-1 B-SISTER) CELL-POPULATION
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1992; 651: 33-43
Abstract
In this paper we have outlined the evidence for two distinct branches of the B-1 cell lineage. The data show that phenotypically B-1a and B-1b cells are essentially identical, distinguished only by the presence or absence of the CD5 antigen. Functionally no differences between the two populations have yet been identified. Both produce anti-PtC antibodies, a specificity not observed in conventional B cells. Both produced high levels of IgM as measured in adoptive transfer experiments. Developmentally, B-1a and B-1b cells are indistinguishable with respect to generation from progenitors present in fetal liver and omentum, feedback regulation of new B-1a and B-1b cells from bone marrow, self-replenishment from Ig+ cells following adoptive transfer, and the generation of clonal populations. The major difference in the two populations is seen in the development of B-1a and B-1b cells from B220- progenitors in the adult bone marrow. Although B220- B-1a progenitors are rare in adult (greater than 6 weeks) bone marrow, the progenitors for B-1b cells persist well into adulthood. Our understanding of B-1b cell ontogeny is at a stage similar to that of B-1a cells five years ago. We have evidence from transfer experiments that strongly suggests the existence of two distinct progenitors for B-1a and B-1b, but we have yet to physically separate these progenitors as Solvansen et al. have done for B-1 and conventional B cells. Furthermore we must determine whether the B-1b cells that develop from fetal liver and bone marrow are functionally and developmentally equivalent to those that develop from adult bone marrow. As with B-1a cells, the role of B-1b cells in the immune system is unclear. Although we have not yet discerned functional differences between B-1a and B-1b, given the recent identification of CD72 (Lyb-2) as the ligand for CD5, it is tempting to speculate that B-1a cells are more involved in B-B cell interactions such as idiotype-anti-idiotype regulation of the early B-cell repertoire and that B-1b cells are more involved in B-T cell interactions. Whatever their function, it is clear that in trying to understand the role of the B-1 lineage it is important to consider both the B-1a and B-1b lineages.
View details for Web of Science ID A1992JM21900004
View details for PubMedID 1376053
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ADOPTIVE TRANSFER OF MURINE B-CELL LINEAGES
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1992; 651: 168-169
View details for Web of Science ID A1992JM21900023
View details for PubMedID 1376034
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LAYERED EVOLUTION IN THE IMMUNE-SYSTEM - A MODEL FOR THE ONTOGENY AND DEVELOPMENT OF MULTIPLE LYMPHOCYTE LINEAGES
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1992; 651: 1-9
View details for Web of Science ID A1992JM21900001
View details for PubMedID 1376026
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MOLECULAR-CLONING, RECONSTRUCTION AND EXPRESSION OF THE GENE ENCODING THE ALPHA-CHAIN OF THE BOVINE CD8 - DEFINITION OF 3 PEPTIDE REGIONS CONSERVED ACROSS SPECIES
IMMUNOLOGY
1992; 76 (1): 95-102
Abstract
We report the cloning of a cDNA encoding the alpha-chain of the bovine CD8 (BoCD8 alpha). A bovine thymus cDNA library was hybridized at low stringency with a human CD8 alpha cDNA clone. The first round of screening of 5 x 10(4) independent colonies yielded 12 clones containing incomplete BoCD8 alpha genes. Two further rounds of colony hybridization were conducted, each using as a probe the 5' fragment from the longest BoCD8 alpha clone previously isolated. The final screening yielded a clone containing a 2 kilobase (kb) insert. We mapped and sequenced the 2 kb BoCD8 alpha clone and compared it with the published sequences of the genes encoding the human, mouse and rat CD8 alpha. Sequence analysis confirmed that the clone under study encoded the BoCD8 alpha. The overall similarity of the BoCD8 alpha coding region with the human CD8 alpha coding sequence is 74.7% at the nucleotide level and 62.1% at the protein level. Lower levels of similarity are found with the mouse and rat CD8 alpha. Interestingly, three separate highly homologous regions are clearly defined at the peptide level in bovine versus human and mouse versus rat comparisons. Two of the regions are highly conserved among all species analysed, while the most 5' region is not. We speculate that the latter region may contain the binding site of CD8 alpha to the alpha 3 domain of major histocompatibility complex (MHC) class I molecules. Sequence analysis showed that the 2 kb BoCD8 alpha clone contains an incomplete coding region, i.e. lacks six bases corresponding to the first two amino acids of the leader region. To allow efficient translation and processing of the BoCD8 alpha gene, we constructed a chimeric gene containing the coding sequence of the BoCD8 alpha clone and synthetic sequences corresponding to the first two amino acids of the human CD8 alpha leader sequence. The chimeric gene was subcloned in the pKSV10 expression vector. The pKSV10-BoCD8 alpha construct is efficiently expressed both transiently in COS cells and stably in L cells, as determined by Northern blot and by FACS analysis, using the ILA-51 monoclonal antibody to BoCD8 alpha. The latter result formally proves that the ILA-51 antibody does indeed recognize the product of the BoCD8 alpha gene, as previously suggested on serological grounds.
View details for Web of Science ID A1992HV85200016
View details for PubMedID 1628904
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DIFFERENTIAL DEVELOPMENT OF PROGENITOR ACTIVITY FOR 3 B-CELL LINEAGES
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1992; 89 (8): 3320-3324
Abstract
Cell-transfer studies presented here distinguish three murine B cell lineages: conventional B cells, which develop late and are continually replenished from progenitors in adult bone marrow; Ly-1 B cells (B-1a), which develop early and maintain their numbers by self-replenishment; and Ly-1B "sister" (B-1b) cells, which share many of the properties of Ly-1 B cells, including self-replenishment and feedback regulation of development but can also readily develop from progenitors in adult bone marrow. The sequential emergence of these lineages, the time at which their progenitors function during ontogeny, and the distinctions among their repertoires and functions suggest that evolution has created a layered immune system in which the immune response potential of each successive lineage is adapted to its particular niche.
View details for Web of Science ID A1992HP04300033
View details for PubMedID 1565622
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GLUTATHIONE DEFICIENCY AND HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION
LANCET
1992; 339 (8798): 909-912
View details for Web of Science ID A1992HN48300013
View details for PubMedID 1348307
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THE ONTOGENY AND FUNCTIONAL-CHARACTERISTICS OF HUMAN B-1 (CD5+B) CELLS
INTERNATIONAL IMMUNOLOGY
1992; 4 (2): 243-252
Abstract
We demonstrate that, on average, greater than 90% of B lymphocytes in fetal spleen express CD5 at gestational ages of 17-23 weeks. Similarly, CD5+ B cells (B-1 cells) are the major B cell subset in umbilical cord blood. These findings depend on the optimization of fluorochrome conjugated anti-CD5 reagents for multiparameter fluorescent-activated cell sorter (FACS) analysis. From infancy through childhood the percentage of B-1 cells gradually diminishes in both spleen and peripheral blood. Stable adult levels, 25-35% of the total B cell population, are reached in late adolescence. The decrease in the percentage of B-1 cells in spleen is accompanied by an increase in conventional (CD5-) B cells, keeping the percentage of total B cells per mononuclear cells relatively constant. In contrast, in peripheral blood, the concentration of both B-1 cells and total B cells decreases, while T cells increase. At the functional level, we show that polyreactive IgM autoantibodies are produced by FACS-sorted CD5high B cells, but not by CD5- B cells from adolescent spleen. In contrast, fetal splenic CD5high and CD5- B cells appear functionally uniform, both producing IgM autoantibodies that are typical of B-1 cells. The apparent level of CD5- B cells in fetal spleen, on average 10% of total B cells, may still result from limitations of our reagent. The prominence of B-1 cells in fetal spleen and cord blood, the gradual reduction of B-1 cells with increasing age, and its characteristic repertoire, all suggest a role for this cell type in immunologically immature hosts.
View details for Web of Science ID A1992HF01700016
View details for PubMedID 1377947
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INTRACELLULAR GLUTATHIONE LEVELS IN T-CELL SUBSETS DECREASE IN HIV-INFECTED INDIVIDUALS
AIDS RESEARCH AND HUMAN RETROVIRUSES
1992; 8 (2): 305-311
Abstract
The authors have shown previously that intracellular glutathione (GSH) plays an important role in the regulation of human immunodeficiency virus (HIV) transcription and replication in vitro, through modulation of signal transduction by inflammatory cytokines. Moreover, intracellular GSH levels are known to regulate T-lymphocyte function. In multiparameter FACS studies presented here, we show that relative GSH levels in CD4+ and CD8+ T cells from HIV+ individuals are significantly lower than in corresponding subsets from uninfected controls. These studies define the relative intracellular glutathione (GSH) levels in CD4+ T cells, CD8+ T cells, B cells, and monocytes from 134 HIV-infected individuals and 31 uninfected controls. The greatest decreases in intracellular GSH occur in subsets of T cells in individuals in the later stages of the HIV infection. In AIDS patients, GSH levels are 63% of normal in CD4+ T cells (p less than 0.0001) and are 62% of normal in CD8+ T cells (p less than 0.0001). Similarly, in AIDS-related complex (ARC) patients, GSH levels are 66% of normal in CD4+ T cells (p less than 0.003) and are 69% of normal in CD8+ T cells (p less than 0.003). These findings suggest that low intracellular GSH levels may be an important factor in HIV infection and in the resulting immunodeficiency.
View details for Web of Science ID A1992HG48900025
View details for PubMedID 1540417
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N-ACETYLCYSTEINE - A NEW APPROACH TO ANTI-HIV THERAPY
AIDS RESEARCH AND HUMAN RETROVIRUSES
1992; 8 (2): 209-217
Abstract
Several investigators have implicated depletion of glutathione (GSH) and production of reactive oxygen intermediates (ROIs) in the regulation of the human immunodeficiency virus (HIV). We have shown directly that N-acetylcysteine (NAC) blocks HIV expression in chronic and acute infection models, and HIV replication in normal peripheral blood mononuclear cells. NAC is a cysteine prodrug which maintains intracellular thiol levels during oxidative stress and replenishes depleted GSH. The observed antiviral effect of NAC is due to inhibition of viral stimulation by ROIs, which are produced in response to inflammatory cytokines. We have also shown that HIV-infected individuals have decreased intracellular GSH levels in their circulating T cells. Since GSH is the major protection against the production of ROIs, we hypothesize that the observed decrease is due to a chronic oxidative stress induced by continual exposure to elevated levels of inflammatory cytokines. Together, these results provide a rationale for clinical trials testing the efficacy of GSH-replenishing drugs such as NAC in the treatment of AIDS. NAC is different than many other antiviral drugs in that it inhibits host-mediated stimulation of viral replication arising in normal immune responses, and may thereby extend latency. In addition, it inhibits the action of inflammatory cytokines which may mediate cachexia, thereby raising the possibility that it may alleviate the deleterious wasting that accompanies late stage AIDS.
View details for Web of Science ID A1992HG48900012
View details for PubMedID 1540408
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CD20 expression is increased on B lymphocytes from HIV-infected individuals.
Journal of acquired immune deficiency syndromes
1992; 5 (6): 627-632
Abstract
In studies presented here, we show that expression of the pan B cell marker CD20 is markedly increased on B lymphocytes from HIV-infected individuals and that this increase tends to be greater in individuals with more advanced disease. By using multiparameter FACS analyses to quantitate surface density of CD20 and intracellular glutathione (GSH) levels simultaneously, we further show that the distribution of intracellular glutathione (GSH) levels in B cells of HIV-infected individuals is more heterogeneous than in uninfected controls. Finally, we show that the intracellular GSH levels correlate with CD20 expression on a per-cell basis in all infected individuals. These findings suggest that CD20 expression, which can be precisely measured, may prove to be a useful surrogate marker for monitoring HIV infection.
View details for PubMedID 1375291
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ADOPTIVE TRANSFER OF MURINE B-CELL LINEAGES
CONF ON CD5 B-CELLS IN DEVELOPMENT AND DISEASE
NEW YORK ACAD SCIENCES. 1992: 168–169
View details for Web of Science ID A1992BW41S00023
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GLUTATHIONE AND IMMUNOPHENOTYPES OF LYMPHOCYTES-T AND LYMPHOCYTES-B IN HIV-INFECTED INDIVIDUALS
CONF ON CD5 B-CELLS IN DEVELOPMENT AND DISEASE
NEW YORK ACAD SCIENCES. 1992: 453–463
View details for Web of Science ID A1992BW41S00058
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CHARACTERISTICS AND DEVELOPMENT OF THE MURINE B-1B (LY-1 B-SISTER) CELL-POPULATION
CONF ON CD5 B-CELLS IN DEVELOPMENT AND DISEASE
NEW YORK ACAD SCIENCES. 1992: 33–43
View details for Web of Science ID A1992BW41S00004
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LAYERED EVOLUTION IN THE IMMUNE-SYSTEM - A MODEL FOR THE ONTOGENY AND DEVELOPMENT OF MULTIPLE LYMPHOCYTE LINEAGES
CONF ON CD5 B-CELLS IN DEVELOPMENT AND DISEASE
NEW YORK ACAD SCIENCES. 1992: 1–9
View details for Web of Science ID A1992BW41S00001
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THE INTERRELATIONSHIP OF TUMOR-NECROSIS-FACTOR, GLUTATHIONE, AND AIDS
3RD INTERNATIONAL CONF ON TUMOR NECROSIS FACTOR AND RELATED CYTOKINES
KARGER. 1992: 215–229
View details for Web of Science ID A1992BV28R00022
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HEPARIN ALTERS THE EXPRESSION OF DIFFERENT FORMS OF IMMUNOGLOBULIN-MU HEAVY-CHAINS AND THEIR ASSOCIATED PROTEINS BY PRE-B-CELL LINES AND NORMAL LY-1 (CD5+) B-CELLS
INTERNATIONAL IMMUNOLOGY
1991; 3 (11): 1117-1127
Abstract
Studies presented here show that heparin alters immunoglobulin expression by murine pre-B cell lines and normal Ly-1 (CD5+) B cells. Previous studies have shown that pre-B cell lines 70Z/3 and NFS-5.3 express mu heavy chains in the cytoplasm and a small amount on the cell surface. Both these cytoplasmic and surface mu are disulfide-linked to omega (lambda 5) surrogate light chains and are noncovalently associated with iota (Vpre-B) variable region-like proteins. We show that culturing 70Z/3 with heparin reduces the amount of the membrane-form mu (micron) on the cell surface. Culturing NFS-5.3 with heparin similarly decreases the membrane-form mu; however, it increases the surface level of a pentameric mu molecule containing secreted-form mu (microS) heavy chains, disulfide-linked omega (lambda 5) chains, and noncovalently associated proteins. Culturing peritoneal B cells with heparin also increases the production of the secreted-form microS, detectable in this case by the secretion of classical pentameric IgM. Similarly, injecting heparin intraperitoneally increases IgM secretion by peritoneal Ly-1 B cells. Thus heparin could influence pre-B cell and B cell differentiation and function.
View details for Web of Science ID A1991GQ76300008
View details for PubMedID 1722112
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CD4 AND CD8 T-CELLS WITH HIGH INTRACELLULAR GLUTATHIONE LEVELS ARE SELECTIVELY LOST AS THE HIV-INFECTION PROGRESSES
INTERNATIONAL IMMUNOLOGY
1991; 3 (11): 1195-?
View details for Web of Science ID A1991GQ76300017
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CD4 AND CD8 T-CELLS WITH HIGH INTRACELLULAR GLUTATHIONE LEVELS ARE SELECTIVELY LOST AS THE HIV-INFECTION PROGRESSES
INTERNATIONAL IMMUNOLOGY
1991; 3 (9): 933-937
Abstract
Maintenance of intracellular glutathione (GSH) levels has been implicated in blocking cytokine-stimulated HIV replication in vitro, in both acute and latent infection models. We demonstrate here that subsets of human peripheral blood mononuclear cells differ substantially in mean GSH levels, as measured on a cell-by-cell basis with the fluorescence-activated cell sorter (FACS): B cells have the lowest GSH levels; T cells are intermediate; and monocytes and macrophages have the highest levels. Furthermore, GSH levels subdivide the CD4 and CD8 T cell subsets into two classes each: high- and low-GSH cells, which cannot be distinguished by cell size or by currently known surface markers. Significantly, the high-GSH T cells are selectively depleted early during the HIV infection, and are effectively missing in all ARC and AIDS patients.
View details for Web of Science ID A1991GE61600010
View details for PubMedID 1681892
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N-ACETYLCYSTEINE INHIBITS LATENT HIV EXPRESSION IN CHRONICALLY INFECTED-CELLS
AIDS RESEARCH AND HUMAN RETROVIRUSES
1991; 7 (6): 563-567
Abstract
The progression of the human immunodeficiency virus (HIV) infection from its early latent (asymptomatic) stage to active, late-stage acquired immunodeficiency syndrome (AIDS) apparently begins with the production of inflammatory cytokines that stimulate the expression and replication of the latent virus. We have shown that N-acetylcysteine, a cysteine precursor that is converted intracellularly into glutathione, blocks cytokine-stimulated HIV replication in an acutely infected T-cell line and in acutely infected peripheral blood mononuclear cells from normal individuals. In this report, we show that N-acetylcysteine also inhibits stimulated HIV expression in chronically infected monocyte and T-cell lines which are used as models for latent infection in AIDS. Furthermore, we show that N-acetylcysteine blocks viral production in monocyte cell lines more effectively than it blocks viral production in T cells. Since monocytes are a major reservoir for HIV in infected individuals, these results suggest that N-acetylcysteine may slow the change from latency to the later stages of AIDS in HIV-infected individuals.
View details for Web of Science ID A1991FU36100010
View details for PubMedID 1931232
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ALTERED HAPTEN RECOGNITION BY 2 ANTIDIGOXIN HYBRIDOMA VARIANTS DUE TO VARIABLE REGION POINT MUTATIONS
JOURNAL OF BIOLOGICAL CHEMISTRY
1991; 266 (7): 4640-4647
Abstract
Two spontaneous variants of the murine anti-digoxin antibody-producing hybridoma cell line 26-10 were isolated by two-color fluorescence-activated cell sorting on the basis of altered hapten binding. The variable region sequences of the antibodies produced by the mutant lines revealed that each contains a single amino acid change in the heavy chain second complementarity determining region. A Tyr to His change at position 50 leads to a 40-fold reduction in affinity for digoxin. A Ser to Phe mutation at position 52 results in a 300-fold reduction in affinity for digoxin. A competition assay involving 33 digoxin analogues was used to examine the specificity of hapten binding of 26-10 and the two mutant antibodies. The position 50 mutant has a distinct specificity change; it exhibits a preference for digoxin congeners containing a hydroxyl group at the steroid 12 position, whereas the 26-10 parent does not. The affinities of all three antibodies for hapten are progressively lowered by substitutions of increasing size at the digoxin steroid D ring 16 position. Although 26-10 binds digoxin and its genin form equally, 12 and 16 steroid position substitutions which lower affinity also confer a preference for a sugar at the steroid 3 position. These results suggest that position 50 contributes to specificity of the antibody and that alterations of the hapten can lead to differences in recognition, possibly through a shift in hapten orientation within the binding site.
View details for Web of Science ID A1991FA69400094
View details for PubMedID 1999439
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WHOLE ANIMAL-CELL SORTING OF DROSOPHILA EMBRYOS
SCIENCE
1991; 251 (4989): 81-85
Abstract
Use of primary culture cells has been limited by the inability to purify most types of cells, particularly cells from early developmental stages. In whole animal cell sorting (WACS), live cells derived from animals harboring a lacZ transgene are purified according to their level of beta-galactosidase expression with a fluorogenic beta-galactosidase substrate and fluorescence-activated cell sorting. With WACS, incipient posterior compartment cells that express the engrailed gene were purified from early Drosophila embryos. Neuronal precursor cells were also purified, and they differentiated into neurons with high efficiency in culture. Because there are many lacZ strains, it may be possible to purify most types of Drosophila cells. The same approach is also applicable to other organisms for which germ-line transformation is possible.
View details for Web of Science ID A1991EQ60300032
View details for PubMedID 1898782
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IMPROVED FACS-GAL - FLOW CYTOMETRIC ANALYSIS AND SORTING OF VIABLE EUKARYOTIC CELLS EXPRESSING REPORTER GENE CONSTRUCTS
CYTOMETRY
1991; 12 (4): 291-301
Abstract
The previously reported FACS-Gal assay (Nolan et al., Proc Natl Acad Sci USA 85:2603-2607, 1988) measures E. coli lacZ-encoded beta-galactosidase activity in individual viable eukaryotic cells for a variety of molecular and cellular biological applications. Enzyme activity is measured by flow cytometry, using a fluorogenic substrate, which is hydrolyzed and retained intracellularly. In this system, lacZ serves both as a reporter gene to quantitate gene expression and as a selectable marker for the fluorescence-activated sorting of cells based on their lacZ expression level. This report details the following improvements of the original assay: 1) use of phenylethyl-beta-D-thiogalactoside, a competitive inhibitor, to inhibit beta-galactosidase activity; 2) reduction of false positives by two-color measurements; and 3) inhibition of interfering mammalian beta-galactosidases by the weak base chloroquine. We found an exponential relationship between fluorescence generated by beta-galactosidase in this assay and the intracellular concentration of beta-galactosidase molecules. Finally, we report conditions for optimal loading of the substrate (FDG) and retention of the product, fluorescein. Under these conditions, we found uniform loading of FDG in all cells of a clone in individual experiments. Together, these improvements make FACS-Gal an extremely powerful tool for investigation of gene expression in eukaryotic cells.
View details for Web of Science ID A1991FK38600001
View details for PubMedID 1905992
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Use of Escherichiu coli (E. coli) lacZ (ß-Galactosidase) as a Reporter Gene.
Methods in molecular biology (Clifton, N.J.)
1991; 7: 217-235
Abstract
Our understanding of the molecular mechanisms that govern gene expression has been facilitated by the ability to introduce recombinant DNA molecules into heterologous cellular systems both in vitro and in vivo. One approach to defining DNA sequences important in the regulation of gene expression is to place controlling elements (e.g., promoter/enhancer sequences) upstream of a DNA coding sequence, introduce these constructs into transgenic animals or cells in culture, and analyze the levels of gene product produced by the introduced construct. Ideally, such a reporter gene should encode a product that is stable, innocuous to the cell or organism in which it is being expressed, and should be readily detectable, even when present in small quantities.
View details for DOI 10.1385/0-89603-178-0:217
View details for PubMedID 21416358
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INSITU DETECTION OF STAGE-SPECIFIC GENES AND ENHANCERS IN B-CELL DIFFERENTIATION VIA GENE-SEARCH RETROVIRUSES
3RD INTERNATIONAL CONF ON LYMPHOCYTE ACTIVATION IMMUNE REGULATION
PLENUM PRESS DIV PLENUM PUBLISHING CORP. 1991: 187–200
Abstract
We demonstrate that infection of an LPS-responsive pre-B cell line with transcriptionally-defective retroviruses containing a reporter gene (lacZ) can result in viral integrations where expression of lacZ is differentiation stage-dependent. Because expression of lacZ is dependent upon flanking cellular sequences these retroviral integrations represent in situ gene fusions with cellular enhancers (Enhsr1) and genes (Gensr1) which are either induced or repressed during LPS-stimulated differentiation. One of the well-documented effects of LPS upon pre-B cells is the induction of kappa light chain transcription via NF-kappa B. The identification of LPS-stimulated gene repression during B cell differentiation indicates that LPS has multiple effects upon gene expression during the pre-B to B cell transition. The identification of cellular enhancers and genes which are downregulated during the transition from the pre-B to the B cell stage indicates that other transcription factors, in addition to NF-kappa B, are required for this step in differentiation. Finally, we present some initial experiments which indicate the gene-search retroviruses can introduce expression of lacZ into normal hematopoietic cells in vitro and in vivo.
View details for Web of Science ID A1991BT82R00021
View details for PubMedID 1950769
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INTRACELLULAR THIOLS REGULATE ACTIVATION OF NUCLEAR FACTOR KAPPA-B AND TRANSCRIPTION OF HUMAN-IMMUNODEFICIENCY-VIRUS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1990; 87 (24): 9943-9947
Abstract
The activation of nuclear factor kappa B (NF-kappa B) has been implicated in the regulation of transcription of a variety of genes and has been shown to be essential for the expression of genes controlled by the long terminal repeat of human immunodeficiency virus (HIV LTR). We show here that intracellular thiol levels play a key role in regulating this process. That is, stimulation with tumor necrosis factor alpha and/or phorbol 12-myristate 13-acetate activates NF-kappa B and markedly decreases intracellular thiols; N-acetyl-L-cysteine, an efficient thiol source, prevents this thiol decrease and blocks the activation of NF-kappa B; and the lack of activated NF-kappa B prevents the activation of the HIV LTR and the transcription of genes under its control. These findings reveal a previously unrecognized genetic regulatory mechanism in which cytokine-induced shifts in intracellular thiol levels are crucial in the control of NF-kappa B activity and thereby influence the spectrum of genes expressed by cytokine-stimulated cells.
View details for Web of Science ID A1990EN15900090
View details for PubMedID 2263644
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2 DISTINCT SIGNAL TRANSMISSION PATHWAYS IN LYMPHOCYTES-T ARE INHIBITED BY COMPLEXES FORMED BETWEEN AN IMMUNOPHILIN AND EITHER FK506 OR RAPAMYCIN
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1990; 87 (23): 9231-9235
Abstract
Proliferation and immunologic function of T lymphocytes are initiated by signals from the antigen receptor that are inhibited by the immunosuppressant FK506 but not by its structural analog, rapamycin. On the other hand, interleukin 2 (IL-2)-induced signals are blocked by rapamycin but not by FK506. Remarkably, these two drugs inhibit each other's actions, raising the possibility that both act by means of a common immunophilin (immunosuppressant binding protein). We find that the dissociation constant of rapamycin to the FK506 binding protein FKBP (Kd = 0.2 nM) is close to the dissociation constant of FK506 to FKBP (Kd = 0.4 nM) and to their effective biologic inhibitory concentrations. However, an excess of rapamycin is needed to revert FK506-mediated inhibition of IL-2 production, apoptosis, and transcriptional activation of NF-AT, a T-cell-specific transcription factor necessary for IL-2 gene activation. Similarly, an excess of FK506 is needed to revert rapamycin-mediated inhibition of IL-2-induced proliferation. The drug concentrations required for antagonism may be explained by the relative affinity of the drugs to, and by the abundance of, the immunophilin FKBP. FKBP has been shown to catalyze the interconversion of the cis- and trans-rotamers of the peptidyl-prolyl amide bond of peptide substrates; here we show that rapamycin, like FK506, is a potent inhibitor of the rotamase activity of FKBP (Ki = 0.2 nM). Neither FKBP binding nor inhibition of rotamase activity of FKBP alone is sufficient to explain the biologic actions of these drugs. Rather, these findings suggest that immunophilin bound to FK506 interferes with antigen receptor-induced signals, while rapamycin bound to the immunophilin interferes with IL-2-induced signals.
View details for Web of Science ID A1990EL36600033
View details for PubMedID 2123553
View details for PubMedCentralID PMC55138
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THE ACTIONS OF CYCLOSPORINE-A AND FK506 SUGGEST A NOVEL STEP IN THE ACTIVATION OF LYMPHOCYTES-T
EMBO JOURNAL
1990; 9 (13): 4425-4433
Abstract
Cyclosporin A and FK506 are immunosuppressive compounds that have similar inhibitory effects on the expression of several lymphokines produced by T lymphocytes. Despite their similar effects the drugs bind to two different cytosolic protein, cyclophilin and FKBP respectively, which raises the possibility that they have different modes of action. Using constructs in which mRNA production controlled by a specific transcription factor could be readily measured we found that both cyclosporin A and FK506 completely inhibited transcription activated by NF-AT, NFIL2 A, NFIL2 B and partially inhibited transcription activated by NF kappa B. Cyclosporin A and FK506 inhibited only transcriptional activation that was dependent on Ca2+ mobilization. However, cyclosporin A and FK506 did not inhibit Ca2+ mobilization dependent expression of c-fos mRNA indicating that only a subset of signalling pathways regulated by Ca2+ is sensitive to these drugs. Furthermore, we did not observe any qualitative differences between the effect of cyclosporin A and FK506 on six different transcription factors which suggests that these drugs may interfere with the activity of a novel Ca2+ dependent step that regulates several transcription factors.
View details for Web of Science ID A1990EN92100026
View details for PubMedID 1702384
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SINGLE CELL ASSAY OF A TRANSCRIPTION FACTOR REVEALS A THRESHOLD IN TRANSCRIPTION ACTIVATED BY SIGNALS EMANATING FROM THE T-CELL ANTIGEN RECEPTOR
GENES & DEVELOPMENT
1990; 4 (10): 1823-1834
Abstract
Stimulation of T lymphocytes through their antigen receptor leads to the appearance of several transcription factors, including NF-AT and NF-kappa B, which are involved in regulating genes required for immunologic activation. To investigate the activity of a single transcription factor in individual viable cells, we have applied an assay that uses the fluorescence-activated cell sorter to quantitate beta-galactosidase (beta-gal). We have analyzed the distribution of NF-AT transcriptional activity among T cells undergoing activation by using a construct in which three tandem copies of the NF-AT-binding site directs transcription of the lacZ gene. Unexpectedly, stimulation of cloned stably transfected Jurkat T cells leads to a bimodal pattern of beta-gal expression in which some cells express no beta-gal and others express high levels. This expression pattern cannot be accounted for by cell-cycle position or heritable variation. Further results, in which beta-gal activity is correlated with NF-AT-binding activity, indicate that the concentration of NF-AT must exceed a critical threshold before transcription initiates. This threshold likely reflects the NF-AT concentration-dependent assembly of transcription complexes at the promoter. Similar constructs controlled by NF-kappa B or the entire interleukin-2 enhancer show bimodal expression patterns during induction, suggesting that thresholds set by the concentration of transcription factors may be a common property of inducible genes.
View details for Web of Science ID A1990EC63000016
View details for PubMedID 2123468
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THE RAT B-CELL SYSTEM - THE ANATOMICAL LOCALIZATION OF FLOW CYTOMETRY-DEFINED B-CELL SUBPOPULATIONS
EUROPEAN JOURNAL OF IMMUNOLOGY
1990; 20 (7): 1527-1534
Abstract
Two-color flow cytometrical (FCM) analysis of rat peripheral lymphoid organs shows two distinct IgM/IgD-defined B cell subpopulations, similar to those of the mouse: a major population of cells expressing little IgM and high levels of IgD (population I) and a minor population of cells expressing high levels of IgM but little IgD (population III). In peripheral lymphoid organs population III cells are mainly found in spleen where they represent about 25% of the B cells; population III cells are almost absent from lymph nodes and Peyer's patches. In adult bone marrow and in neonatal spleen the majority of IgM/IgD-defined B cells (greater than 70%) are population III cells, similar to what is observed in the mouse. In contrast with mice, only a low proportion of the cells (1%) recovered from the peritoneal cavity are B cells, and most of them belong to population I. Previously defined monoclonal antibodies (HIS22 and HIS24) to B cell forms of the leukocyte common antigen (CD45R) in combination with staining for surface IgM and surface IgD demonstrates a further heterogeneity of rat B cells by three-color FCM analyses. HIS22 labels most population I cells; population III cells and a small subset (about one third) of population I express only very low levels of the HIS22 determinant. HIS24 reacts with population I cells and subdivides population III into two subsets: about one third of splenic population III cells are brightly stained with this antibody whereas fluorescence of the remaining two-thirds is lower. The HIS24bright population III cells likely are newly formed B cells since cells with this phenotype are the predominant surface Ig population found in adult bone marrow and neonatal spleen. In tissue sections of lymphoid organs, HIS22- and HIS24-positive cells are mainly found in lymphoid follicles; splenic marginal zones are almost unstained. Combining immunohistological analysis with the FCM data, we therefore conclude that the small follicular B cells are in population I and marginal zone B cells are found in the HIS24dull population III. The in situ localization of HIS24bright population III cells and the HIS22dull population I cells is not clear.(ABSTRACT TRUNCATED AT 400 WORDS)
View details for Web of Science ID A1990DV21200017
View details for PubMedID 2143728
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SURFACE-IMMUNOGLOBULIN LIGANDS AND CYTOKINES DIFFERENTIALLY AFFECT PROLIFERATION AND ANTIBODY-PRODUCTION BY HUMAN CD5+ AND CD5- LYMPHOCYTES-B
INTERNATIONAL IMMUNOLOGY
1990; 2 (7): 603-614
Abstract
Normal human peripheral blood B lymphocytes were separated into CD19+ CD5+ and CD19+ CD5- subsets by dual-color FACS sorting. In most experiments the cells were activated with Staphylococcus aureus Cowan I (SAC) and cultured in the absence or presence of recombinant human IL-1 alpha, IL-2, or IL-6, or combinations of these cytokines. Unstimulated CD5+ and CD5- B cells showed a comparable, low level of incorporation of [3H]thymidine into DNA. SAC stimulated proliferation of CD5+ and CD5- B cells, and this proliferation was augmented by IL-2 in the case of CD5- B cells. Anti-mu beads stimulated some proliferation of the CD5- subset and augmented SAC-induced proliferation of these cells. In contrast, anti-mu beads did not stimulate proliferation of the CD5+ subset and had no effect on SAC-induced proliferation of these cells. CD5+ B cells activated by anti-mu beads were stimulated to proliferate in the presence of IL-4, but not in the presence of IL-2. These observations support the interpretation that two signals are required for proliferation of CD5+ B cells. Using a two-step culture system, SAC activation itself did not induce Ig production by either subset of purified B cells. However, it primed the cells for antibody production in the presence of IL-2. IL-1 and IL-6 by themselves augmented antibody formation by these cells slightly, if at all. However, IL-6, and to a lesser extent IL-1, augmented antibody production in the presence of IL-2. Under the culture conditions used CD5- B cells produced IgM, IgG, and IgA whereas the CD5+ B cells produced almost exclusively IgM. The expression on B cells of surface activation markers was analyzed after culture for 2 days with SAC or anti-mu beads. In both subsets expression of Leu-23 and Leu-21 was increased, with some differences in intensity (Leu-23 greater in CD5+ cells, Leu-21 greater in CD5- cells). SAC increased IL-2R expression to a greater extent than anti-mu beads. In neither subset was expression of CD23 increased. These observations are discussed in the context of the possible role of the CD5+ subset of B lymphocytes as components of a system of natural immunity.
View details for Web of Science ID A1990DP33700002
View details for PubMedID 1703783
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DIFFERENCES IN GLYCOPROTEIN COMPLEXES ASSOCIATED WITH IGM AND IGD ON NORMAL MURINE B-CELLS POTENTIALLY ENABLE TRANSDUCTION OF DIFFERENT SIGNALS
EMBO JOURNAL
1990; 9 (7): 2117-2124
Abstract
Studies presented here demonstrate that IgM and IgD molecules on normal murine B lymphocytes exist in different, noncovalently associated molecular complexes containing distinct but potentially related glycoproteins. The glycoproteins in these complexes, particularly those associated with IgD, show striking differences in various lymphoid organs and in X-linked immunodeficient (Xid) mice. These differences are due in part to post-translational processing. They apparently reflect the differential expression of the Ig-associated glycoproteins in the various B cell subpopulations and lineages and the differential distribution of the subpopulations and lineages in the various lymphoid organs. In addition, they reflect structural differences in the IgM and IgD complexes which, we suggest, permit differential signal transduction by IgM and IgD on the same B cell.
View details for Web of Science ID A1990DL08100012
View details for PubMedID 2357960
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HEPARIN INHIBITS ECORI ENDONUCLEASE CLEAVAGE OF DNA AT CERTAIN ECORI SITES
NUCLEIC ACIDS RESEARCH
1990; 18 (11): 3255-3260
Abstract
Studies presented here demonstrate that heparin inhibits EcoRI endonuclease cleavage of DNA whereas related proteoglycans show no effect. The inhibition occurs at particular EcoRI sites that are near or overlap with palindromic sequences in the murine lambda 5 and Lyt-2 genes. Endogenous heparin from peritoneal mast cells co-isolates with DNA and inhibits digestion of peritoneal cell DNA at the inhibitable sites. Digestion of spleen DNA is inhibited at the same sites when commercial heparin is added prior to digestion. In both cases, the inhibition is abolished by pre-treating the DNA with heparinase. Thus, potential artifacts in restriction fragment length analyses could occur with DNA isolated either from cells that are naturally rich in heparin or from cells to which heparin has been added, e.g., as an anticoagulant.
View details for Web of Science ID A1990DJ27100016
View details for PubMedID 2356119
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CYTOKINE-STIMULATED HUMAN-IMMUNODEFICIENCY-VIRUS REPLICATION IS INHIBITED BY N-ACETYL-L-CYSTEINE
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1990; 87 (12): 4884-4888
Abstract
We show that the stimulation of human immunodeficiency virus (HIV) brought about by tumor necrosis factor alpha and phorbol 12-myristate 13-acetate can be inhibited by adding N-acetyl-L-cysteine (NAC). NAC, which replenishes intracellular glutathione, effectively inhibits the tumor necrosis factor alpha- or phorbol ester-stimulated replication of HIV in acutely infected cell cultures. NAC also inhibits the cytokine-enhanced HIV long terminal repeat-directed expression of beta-galactosidase in in vitro HIV model systems. These results show that intracellular thiol levels influence HIV production. Furthermore, because NAC reverses tumor necrosis factor alpha toxicity both in cells and in animals and is a well-known drug that can be administered orally without known toxicity in humans, these results suggest that NAC is a possible therapeutic agent in AIDS.
View details for Web of Science ID A1990DK27300100
View details for PubMedID 2112750
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LY-1 B-CELLS AND DISEASE-ACTIVITY IN (NEW-ZEALAND BLACK X NEW-ZEALAND WHITE) F1-MICE - EFFECT OF TOTAL LYMPHOID IRRADIATION
ARTHRITIS AND RHEUMATISM
1990; 33 (4): 553-562
Abstract
The treatment of female (New Zealand black x New Zealand white)F1 mice with total lymphoid irradiation resulted in a prolonged remission of autoimmune disease activity. Total lymphoid irradiation-treated mice also showed a marked reduction of Ly-1 B cells, which lasted up to 3 months. The subsequent return of Ly-1 B cells to preirradiation levels was not associated with a simultaneous return of disease when measured by parameters such as IgG anti-DNA antibodies and spontaneous secretion of IgG by splenic cells. In cell sorting experiments, most of the cells spontaneously secreting IgG were found within the Ly-1- (CD5-) splenic B cell population.
View details for Web of Science ID A1990CZ97400013
View details for PubMedID 2328033
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A NOVEL FLUORESCENCE-BASED SYSTEM FOR ASSAYING AND SEPARATING LIVE CELLS ACCORDING TO VDJ RECOMBINASE ACTIVITY
MOLECULAR AND CELLULAR BIOLOGY
1990; 10 (4): 1697-1704
Abstract
We describe two retroviral vector-based recombination substrate systems designed to assay for lymphoid VDJ recombinase activity in cultured cells. Both substrates incorporate a constitutive dominant marker gene (the simian virus promoter-driven neo gene) to allow selection of cells that stably integrate the substrate. Both substrates also include a second marker gene that becomes transcriptionally active only when inverted by a site-specific recombination event between flanking immunoglobulin variable-region gene segments. The first vector, similar in structure to previous retrovirus-based recombination substrates, utilizes the bacterial guanine-xanthine phosphoribosyltransferase gene (gpt) as its activatable marker; detection of inversion (VDJ recombinase activity) involves drug selection and Southern blotting analyses. We have used this vector to make a more extensive and quantitative survey of VDJ recombinase activity in B-lineage cell lines than has previously been performed with stable substrates, and we have compared our results with those of other studies that use transient recombination substrates. In the second vector, the activatable gene is the bacterial beta-galactosidase gene (lacZ). Detection for inversional activation of this gene is achieved by a fluorogenic assay, termed FACS-Gal, that detects beta-galactosidase activity in viable cells. The latter assay has the unique advantage of rapidly detecting cells that undergo recombination and also allows viable sorting of cells on the basis of the presence or absence of VDJ recombinase activity. We have used the lacZ vector to rapidly quantitate VDJ recombinase activity in B-lineage cell lines and compared the results with those obtained with the gpt vector. We have also used the lacZ vector to isolate variant pre-B-cell lines with low and high levels of VDJ recombinase activity.
View details for Web of Science ID A1990CW99600046
View details for PubMedID 2320007
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ZIDOVUDINE (AZIDO DIDEOXYTHYMIDINE) INHIBITS CHARACTERISTIC EARLY ALTERATIONS OF LYMPHOID-CELL POPULATIONS IN RETROVIRUS-INDUCED MURINE AIDS
JOURNAL OF IMMUNOLOGY
1990; 144 (5): 1705-1710
Abstract
Using flow cytometry technology and multiparameter analyses, we report early and characteristic alterations in lymphoid cell profile in spleen and lymph nodes due to LP-BM5 retrovirus disease (murine AIDS (MAIDS)) and the effect of azido dideoxythymidine, a nucleoside inhibitor, on these changes. MAIDS has been characterized by rapid and profound lymphoproliferation accompanied by hypergammaglobulinemia and immunosuppression. As early as 2 wk postinfection, there is a selective depletion of CD8+ cells whereas the total number of CD4+ cells increases throughout the first 8 wk of infection although the frequency is relatively stable. These population changes were partially delayed by oral AZT therapy for 6 wk postinfection. Ly-6C (AL-21) is expressed on roughly 50% of CD4+ and CD8+ cells in C57BL/6 mice. In MAIDS, the residual population of CD8+ cells is primarily Ly-6C+. The CD4+ cells have a transient increase in ratio of Ly-6C+/Ly-6C- cells at 2 wk postinfection but by 6 wk are primarily Ly-6C-. There was an increase in both the total number and percentage of Mac 1+ cells and a selective depletion of certain splenic B cell subpopulations. Azido dideoxythymidine delays these early population changes.
View details for Web of Science ID A1990CR42900022
View details for PubMedID 1968486
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TOWARD A LAYERED IMMUNE-SYSTEM
CELL
1989; 59 (6): 953-954
View details for Web of Science ID A1989CF97500002
View details for PubMedID 2688900
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ARE LY-1 B-CELLS IMPORTANT IN AUTOIMMUNE-DISEASE
JOURNAL OF AUTOIMMUNITY
1989; 2: 225-231
Abstract
Although Ly-1 B cells produce autoantibodies and are found at elevated frequencies in certain autoimmune strains, very little is known about the role of these cells, if any, in autoimmune disease. In this publication, we summarize some recent findings relevant to Ly-1 B-cell development, clonal expansion and antibody production. We then consider the idea that Ly-1 B cells constitute the most primitive B-cell lineage in mammals and that the evolutionary niche occupied by these cells requires that they produce a basic set of autoantibodies that cross-react with common bacterial antigens.
View details for Web of Science ID A1989AE29900024
View details for PubMedID 2673274
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PERMANENT ALTERATION OF THE MURINE LY-1-B REPERTOIRE DUE TO SELECTIVE DEPLETION OF LY-1-B CELLS IN NEONATAL ANIMALS
EUROPEAN JOURNAL OF IMMUNOLOGY
1989; 19 (3): 501-506
Abstract
Studies presented here demonstrate that paternal allotype Ly-1 B cells are permanently depleted following neonatal treatment with antibodies to the paternal IgM allotype. Paternal allotype conventional B cells, in contrast, are temporarily depleted by treatment with either anti-IgM or anti-IgD allotype antibodies and return rapidly to normal frequencies once the antibody treatment disappears. These differences are explained by basic developmental differences between Ly-1 B and conventional lineage B cells. That is, the conventional B cell population is replenished from Ig- precursors throughout life and, therefore, is only temporarily affected when depleted in neonates. The Ly-1 B cell population, in contrast, develops from Ig- progenitors during the prenatal and neonatal life but survives because it is exclusively self-replenishing in adults. Therefore, elimination of a population of Ly-1 B cells from neonates is tantamount to removing it forever. These findings suggest that while conventional B cells turn over rapidly and have an effectively unlimited repertoire, Ly-1 B cells express a repertoire whose composition is strongly influenced by neonatal conditions that favor or select against the retention of cells producing certain antibody molecules. Thus, Ly-1 B cells play a unique role in the immune system in that they retain indefinitely the history of the neonatal animal's immunological experience.
View details for Web of Science ID A1989U629900013
View details for PubMedID 2785045
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FEEDBACK-REGULATION OF MURINE LY-1-B CELL-DEVELOPMENT
EUROPEAN JOURNAL OF IMMUNOLOGY
1989; 19 (3): 507-513
Abstract
Studies presented here, conducted with allotype homozygotes, demonstrate the existence of a feedback mechanism that regulates development of Ly-1 B cells from immature progenitors. In the preceding study (P. A. Lalor et al., Eur. J. Immunol. 1989. 19:501), conducted with allotype heterozygotes, we showed that treating neonates with monoclonal antibody to the paternal allotype IgM depletes roughly half of the neonatal B cell population (i.e. those expressing the paternal IgM allotype) and that paternal allotype Ly-1 B cells specificically remain depleted for the life of the animal. Here we show that treating allotype homozygotes with the same antibody depletes all (rather than half) of the B cells and that, under these conditions, relatively normal numbers of Ly-1 B cells reappear shortly after the treatment antibody disappears. The recovery, we also show, is prevented by restoring allotype-congenic Ly-1 B cells to the treated homozygotes, i.e. by reconstituting treated neonates with allotype-congenic peritoneal cells, sorted Ly-1 B cells or a monoclonal population of Ly-1 B "tumor" cells. These findings in essence reveal a feedback mechanism through which mature Ly-1 B cells prevent further Ly-1 B cell development from Ig- precursors. This feedback regulation is independent of Ig secretion by the mature Ly-1 B cells, since the monoclonal Ly-1 B "tumor" population that prevents endogenous Ly-1 B development does not secrete Ig. Furthermore, it appears to be independent of Ly-1 B surface Ig specificity, since a monoclonal population is sufficient to block all Ly-1 B cell development. This mechanism appears to operate normally to fix the composition of the Ly-1 B population, which survives through self-replenishment in adults, in accord with conditions that influence Ly-1 B development during neonatal life.
View details for Web of Science ID A1989U629900014
View details for PubMedID 2785046
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INSITU DETECTION OF TRANSCRIPTIONALLY ACTIVE CHROMATIN AND GENETIC REGULATORY ELEMENTS IN INDIVIDUAL VIABLE MAMMALIAN-CELLS
IMMUNOLOGY
1989: 74-79
Abstract
Using a newly developed FACS method for quantifying the expression of the Escherischia coli lacZ reporter gene in viable mammalian cells, we have obtained cloned cell lines in which the expression of lacZ is under the control of native endogenous transcription elements. We infected the murine pre-B cell 70Z/3 with transcriptionally disabled retroviruses containing lacZ and employed the FACS-FDG technique to detect and sort rare lacZ+ cells in which we expect integration is near such endogenous transcription elements. After two rounds of enrichment we obtained a population of cells that was 80-90% positive for lacZ activity. Clones derived from the lacZ+ pool differ from each other with respect to their overall level of lacZ activity as well as in the pattern of lacZ expression among cells within an individual clone. Treatment of these lacZ+ 70Z/3 clones with lipopolysaccharide (LPS; which is known to stimulate differentiation of 70Z/3 from a pre-B cell to an IgM-expressing B cell) greatly decreased lacZ expression in one clone, 7e17. lacZ expression in this clone was 50-100 times lower within 24 hr of LPS addition and coincided with the acquisition of IgM kappa on the surface of 7e17. This suggests that a transcriptionally active domain of chromatin that harbors the lacZ construct is down-regulated during the transition induced by LPS stimulation.
View details for Web of Science ID A1989AR92700015
View details for PubMedID 2807403
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Many of the IgA producing plasma cells in murine gut are derived from self-replenishing precursors in the peritoneal cavity
INTERNATIONAL IMMUNOLOGY
1989; 1 (1): 75-84
Abstract
Long term B lineage chimeras are used here to study the origin of plasma cells in the mouse. Chimeric mice are constructed by reconstituting lethally irradiated mice with peritoneal cells (PerC) and bone marrow cells from congenic pairs of mice differing in Igh-C allotype. All conventional B cells in these mice express the allotype of the bone marrow donor and nearly all Ly-1 B lineage cells express the allotype of the PerC donor. FACS analysis and immunohistology of these mice shows that virtually all (sig+) B cells in peripheral lymphoid organs are derived from the bone marrow donor. However, despite this overwhelming number of bone marrow-derived B cells in these animals, immunohistological staining of lymphoid organs and gut shows that nearly half of the IgM, IgG, and IgA plasma cells derive from the PerC donor. These data demonstrate that the peritoneal cavity contains a major reservoir of self-replenishing cells that play a significant role in the mucosal immune response. The possibility that these are B cells that belong to the Ly-1 B lineage is discussed.
View details for DOI 10.1093/intimm/1.1.75
View details for Web of Science ID 000208919900010
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TRANSCRIPTIONALLY DEFECTIVE RETROVIRUSES CONTAINING LACZ FOR THE INSITU DETECTION OF ENDOGENOUS GENES AND DEVELOPMENTALLY REGULATED CHROMATIN
COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY
1989; 54: 767-776
View details for Web of Science ID A1989JX74600019
View details for PubMedID 2518010
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CONVENTIONAL AND LY-1 B-CELL LINEAGES IN NORMAL AND MU TRANSGENIC MICE
COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY
1989; 54: 219-225
View details for Web of Science ID A1989JX74500025
View details for PubMedID 2517920
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Many of the IgA producing plasma cells in murine gut are derived from self-replenishing precursors in the peritoneal cavity.
International immunology
1989; 1 (1): 75-84
Abstract
Long term B lineage chimeras are used here to study the origin of plasma cells in the mouse. Chimeric mice are constructed by reconstituting lethally irradiated mice with peritoneal cells (PerC) and bone marrow cells from congenic pairs of mice differing in Igh-C allotype. All conventional B cells in these mice express the allotype of the bone marrow donor and nearly all Ly-1 B lineage cells express the allotype of the PerC donor. FACS analysis and immunohistology of these mice shows that virtually all (sig+) B cells in peripheral lymphoid organs are derived from the bone marrow donor. However, despite this overwhelming number of bone marrow-derived B cells in these animals, immunohistological staining of lymphoid organs and gut shows that nearly half of the IgM, IgG, and IgA plasma cells derive from the PerC donor. These data demonstrate that the peritoneal cavity contains a major reservoir of self-replenishing cells that play a significant role in the mucosal immune response. The possibility that these are B cells that belong to the Ly-1 B lineage is discussed.
View details for PubMedID 2487677
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A MAJOR PERITONEAL RESERVOIR OF PRECURSORS FOR INTESTINAL IGA PLASMA-CELLS
IMMUNOLOGICAL INVESTIGATIONS
1989; 18 (1-4): 47-58
Abstract
Studies presented examine the origin of IgA plasma cells in B lineage chimeric mice constructed by reconstituting lethally irradiated mice with a mixture of syngeneic bone marrow cells and peritoneal cells from Ig heavy chain allotype congenic donors. In these mice, essentially all B cells in spleen and Peyer's patches are derived from the bone marrow donor; however Ly-1 B lineage cells which have been mainly detected in the peritoneum are derived from the peritoneal cell donor. Surprisingly, roughly half of the IgA plasma cells in the lamina propria of the gut are also derived from the peritoneal cell donor, suggesting an important role for peritoneally-derived B cells in the mucosal immune response.
View details for Web of Science ID A1989U349300008
View details for PubMedID 2786500
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MURINE SUPPRESSOR T-CELLS - MIRAGE OR CLOUDY REALITY
RESEARCH IN IMMUNOLOGY
1989; 140 (3): 337-338
View details for Web of Science ID A1989AC35900017
View details for PubMedID 2474188
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REPETITIVE USAGE OF IMMUNOGLOBULIN VH-GENE AND D-GENE SEGMENTS IN CD5+LY-1B CLONES OF (NZB X NZW)F1 MICE
EMBO JOURNAL
1988; 7 (12): 3705-3710
Abstract
The usually small Ly-1 B cell population is markedly increased in older mice by expansion of certain clones. This results in a cellular picture very similar to human B chronic lymphocytic leukemia. Here we report a molecular analysis of the immunoglobulin gene rearrangements of the Ly-1 B cell populations in (NZB x NZW)F1 females. We find that (i) the number of clones found in the peritoneum (a major tissue source of Ly-1 B cells) decreases with age till mono- or biclonality is common by approximately 6 months, (ii) many clones from different mice show the same size rearrangements at both the Ig heavy and light chain loci and (iii) the IgH rearrangements found in a clone isolated from the spleen of one mouse are a subset of those found in the peritoneum of the same mouse, implying migration occurs from the peritoneum to the spleen. Molecular cloning and sequencing of the IgH rearrangements from the peritoneal clones of one B/W mouse revealed that all productive rearrangements used the identical unmutated VH and D elements joined to different JHS. Indeed, two VDJH4 rearrangements were recovered which were identical but for six junctional (N region) nucleotides. The conservation of VH and D segment usage in the rearrangements of these Ly-1 B cell clones could indicate some strong selective pressure for clonal expansion (for example antigen selection) operates via the immunoglobulin molecules of these cells. Southern analyses of other (NZB x NZW)F1 mice with this cloned VH and the usage of the same or similar VH genes among a number of Ly-1 B origin tumors in other mouse strains indicate the generality of this repetitive VH gene usage in individual mice.
View details for Web of Science ID A1988Q990600010
View details for PubMedID 2463165
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LY-6C IS A MONOCYTE MACROPHAGE AND ENDOTHELIAL-CELL DIFFERENTIATION ANTIGEN REGULATED BY INTERFERON-GAMMA
EUROPEAN JOURNAL OF IMMUNOLOGY
1988; 18 (11): 1819-1826
Abstract
Using a new Ly-6C-specific antibody (Monts-1) we show that this class of antigens are differentially expressed on monocytes/macrophages and endothelial cells. Recently elicited peritoneal exudate Mac-1+ mononuclear cells, as well as Mac-1+ mononuclear cells in the bone marrow and in the peripheral blood, express high levels of Ly-6C. Ly-6C+ mononuclear Mac-1+ cells are absent in normal uninflamed skin, but are present in high numbers in skin lesions 3 days after the s.c. injection of lipopolysaccharide, concanavalin A or complete Freund's adjuvant. In addition, large Ly-6C+ mononuclear cells are predominant in chronic granulomas induced by complete Freund's adjuvant. Resident macrophages in a variety of tissues express low levels or in many cases do not express Ly-6C. Two out of three monocyte-like cell lines are Ly-6C+, whereas macrophage-like cell lines are negative. Ly-6C+ monocytes/macrophages lose the Ly-6C antigen within 24 h after in vitro culture. Ly-6C- cultured monocytes and Ly-6C- monocyte-like cell lines, but not fully differentiated macrophages and macrophage-like cell lines, can be induced to express the Ly-6C antigen by interferon-gamma. A population of small vessel endothelial cells in diverse tissues also express high levels of Ly-6C. The present findings suggest that the Ly-6C antigen family, shown by others to be involved in T cell activation, may have more general importance in immune responses and cellular differentiation than previously appreciated.
View details for Web of Science ID A1988R780600024
View details for PubMedID 2849552
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DNA METHYLATION PREVENTS TRANSFECTION OF GENES FOR SPECIFIC SURFACE-ANTIGENS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1988; 85 (22): 8391-8394
Abstract
Sperm and trophoblast are among the few nucleated human cells that do not express HLA class I antigens. DNA methylation, which is proposed to be a tight mechanism of regulation, may be necessary to turn off these genes. We have investigated the transfectability of HLA class I genes and of the genes for the T-cell differentiation antigens Leu-1 (CD5) and Leu-2 (CD8) in mouse L cells by using human sperm cells and choriocarcinoma cell lines, tumors of trophoblastic origin, as sources of DNA. It was found that DNA from one choriocarcinoma line (JAR) does not transfect genes for HLA, Leu-1, or Leu-2 and that DNA from two other choriocarcinoma lines (BeWo and Ima) transfects only some of the surface markers. Sperm DNA transfects genes for all the surface antigens tested except Leu-1. DNA from control cells and from the line SCH transfects all the markers studied. Southern blots show that all cell types contain apparently intact genes encoding HLA, Leu-1, and Leu-2 and reveal differences in the DNA methylation patterns of genes from different sources of DNA. We treated JAR (the cell line with the lowest transfecting ability) with 5-azacytidine and obtained demethylation of its DNA. This demethylated DNA transfects genes for both HLA class I antigens and Leu-2. Further culture of JAR cells in the absence of 5-azacytidine results in remethylation of their DNA and decreased ability to transfect these surface antigens. These findings indicate that DNA methylation affects the efficiency of transfection of surface antigen genes in L cells.
View details for Web of Science ID A1988Q990500005
View details for PubMedID 3054885
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LY-1 B-CELL CLONES SIMILAR TO HUMAN CHRONIC LYMPHOCYTIC LEUKEMIAS ROUTINELY DEVELOP IN OLDER NORMAL MICE AND YOUNG AUTOIMMUNE (NEW ZEALAND BLACK-RELATED) ANIMALS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1988; 85 (19): 7312-7316
Abstract
Studies presented here demonstrate that individually expanded clones of murine Ly-1 B cells, perhaps analogous to the expanded neoplastic Leu-1 B-cell clones in human chronic lymphocytic leukemias, are universally detectable in young New Zealand Black (NZB)-related autoimmune mice and in senescent normal mice (greater than 18 months old). These clones are visible as phenotypically homogeneous cell populations in multiparameter fluorescence-activated cell sorter analyses of peritoneal and splenic B cells; they show unique immunoglobulin heavy- and light-chain gene rearrangements in Southern gel analyses of peritoneal and splenic DNA; and, like the self-replenishing Ly-1 B-cell population from which they are drawn, they tend to grow readily in irradiated or unirradiated syngeneic or allotype congenic hosts. Furthermore, they develop and generalize in primary and secondary hosts in a characteristic pattern (peritoneum much greater than spleen greater than lymph node greater than bone marrow) that suggests that their initial growth is controlled by the mechanisms that normally control Ly-1 B-cell distribution in lymphoid organs. The universal emergence of these clones within the Ly-1 B-cell lineage may be explained by the substantially greater opportunity for hyperplastic and neoplastic transformation events in this long-lived self-replenishing Ly-1 B-cell population, which must divide relatively frequently to maintain its normal size throughout adulthood. Repeated exposure to internal or environmental antigens (with which Ly-1 B cells are known to react) may also play a role in driving the development of these clones.
View details for Web of Science ID A1988Q358500058
View details for PubMedID 3262873
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SEGMENTAL FLEXIBILITY AND COMPLEMENT-FIXATION OF GENETICALLY ENGINEERED CHIMERIC HUMAN, RABBIT AND MOUSE ANTIBODIES
EMBO JOURNAL
1988; 7 (7): 1989-1994
Abstract
We generated a family of chimeric immunoglobulin G (IgG) molecules having identical antigen-combining sites for the dansyl (DNS) hapten, in conjunction with nine heavy chain constant (CH) regions. This family of antibody molecules allows comparison of CH dependent properties independent of possible variable region contributions to IgG function. The segmental flexibility and complement fixation activity were measured of six genetically engineered molecules (the four human IgG isotypes, mouse IgG3 and rabbit IgG) and the remaining three mouse IgG isotypes, (IgG1, IgG2a and IgG2b), isolated previously by somatic cell genetic techniques. These properties of antibody molecules each correlate with the length of the immunoglobulin hinge region which separate the first and second CH (CH1 and CH2) domains. These results attribute a structural basis for two critical properties of antibody molecules.
View details for Web of Science ID A1988P074100009
View details for PubMedID 3138110
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REARRANGEMENT AND EXPRESSION OF ENDOGENOUS IMMUNOGLOBULIN GENES OCCUR IN MANY MURINE B-CELLS EXPRESSING TRANSGENIC MEMBRANE IGM
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1988; 85 (10): 3546-3550
Abstract
Transgenic mice carrying immunoglobulin genes coding for mu heavy chain and kappa light chain have been used to study the mechanisms involved in allelic and isotypic exclusion. We report here that individual cells from transgenic mice carrying a functionally rearranged mu heavy chain gene (capable of generating both membrane and secreted forms of IgM) can rearrange an endogenous mu heavy chain gene and simultaneously produce both transgenic and endogenous IgM. These "double-producing" cells express both endogenous and transgenic IgM in the cytoplasm (detected by immunohistology) and on the cell surface (detected by multiparameter fluorescence-activated cell sorter analysis). In addition, they secrete mixed IgM molecules containing both transgenic and endogenous mu heavy chains (detected in serum by radioimmune assay). The transgenic mice studied also have relatively large numbers of cells that produce endogenous immunoglobulin in the absence of detectable transgenic immunoglobulin ("endogenous-only cells"). The mechanisms that generate double-producing cells and endogenous-only cells appear to be under genetic control because the frequencies of these B-cell populations are characteristic for a given transgenic line. Thus, our findings indicate that more is involved in triggering allelic exclusion than the simple presence or absence of membrane mu heavy chains (as has been previously postulated).
View details for Web of Science ID A1988N475300062
View details for PubMedID 3130629
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VARIABLE REGION FRAMEWORK DIFFERENCES RESULT IN DECREASED OR INCREASED AFFINITY OF VARIANT ANTI-DIGOXIN ANTIBODIES
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1988; 85 (9): 3080-3084
Abstract
Rare spontaneous variants of the anti-digoxin antibody-producing hybridoma 40-150 (Ko = 5.4 x 10(9) M-1) were selected for altered antigen binding by two-color fluorescence-activated cell sorting. The parent antibody binds digoxin 890-fold greater than digitoxin. The variant 40-150 A2.4 has reduced affinity for digoxin (Ko = 9.2 x 10(6) M-1) and binds digoxin 33-fold greater than digitoxin. A second-order variant, derived from 40-150 A2.4 (designated 40-150 A2.4 P.10), demonstrated partial regain of digoxin binding (Ko = 4.4 x 10(8) M-1). The altered binding of the variant 40-150 A2.4 was accounted for by a point mutation resulting in substitution of arginine for serine at position 94 in the heavy chain variable region. Antibody 40-150 A2.4 P.10 also contains this arginine but owes its enhanced antigen binding to deletion of two amino acids from the heavy chain amino terminus. This unusual sequence alteration in an immunoglobulin framework region confers increased affinity for antigen.
View details for Web of Science ID A1988N304400042
View details for PubMedID 3129726
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FLUORESCENCE-ACTIVATED CELL ANALYSIS AND SORTING OF VIABLE MAMMALIAN-CELLS BASED ON BETA-D-GALACTOSIDASE ACTIVITY AFTER TRANSDUCTION OF ESCHERICHIA-COLI LACZ
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1988; 85 (8): 2603-2607
Abstract
We demonstrate that individual cells infected with and expressing a recombinant retrovirus carrying the Escherichia coli beta-galactosidase gene (lacZ) can be viably stained, analyzed, sorted, and cloned by fluorescence-activated cell sorting based on the levels of lacZ expressed. To accomplish this we have devised a method to enzymatically generate and maintain fluorescence in live mammalian cells. Accumulation of fluorescent products in cells is linear with time, with a direct correlation of fluorescence to enzymatic activity. This technology for beta-galactosidase detection is more sensitive than other available cytochemical or biochemical methods. We have used this procedure to show that the expression of psi-2-MMuLVSVnlsLacZ in the T-cell lymphoma BW5147 and the B-cell hybridoma SP2/0 is not completely stable and that subclones selected by the fluorescence-activated cell sorter for low lacZ activity demonstrate distinctly lower average expression of LacZ. These findings indicate the utility of beta-galactosidase as a reporter molecule at the single-cell level for studies of gene regulation, including studies of promoter efficacy, enhancer activity, trans-acting factors, and other regulatory elements.
View details for Web of Science ID A1988N023400040
View details for PubMedID 3128790
View details for PubMedCentralID PMC280046
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TRANSFECTION OF GENES ENCODING LYMPHOCYTE DIFFERENTIATION ANTIGENS - APPLICATIONS IN VETERINARY IMMUNOLOGY
VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY
1987; 17 (1-4): 291-302
Abstract
The work conducted so far in this laboratory has demonstrated the application of the use of genes encoding lymphocyte differentiation molecules, in the isolation of homologous genes from other mammalian species, by the technique of cross-species DNA hybridization. The studies have also highlighted the use of transfection as a means of obtaining expression of genes, either from total genomic DNA or cloned in plasmids, which encode lymphocyte antigens. Preliminary work presented in this paper demonstrates the application of these technologies in the isolation and expression of genes for lymphocyte antigens from species in which the gene products have not been fully defined. We favour this approach because it may allow isolation and definition of important immunological molecules independently of the existence of specific antibodies. It therefore seems the most direct way to avoid the frustrating randomness in production of anti lymphocyte subset-specific monoclonal antibodies, and to shorten the time and effort needed to define the specificities of such reagents. Furthermore, the cDNA clones isolated from alternate species (in this case the bovine) have a use in classical immunological studies apart from the application of antibodies made to their products in veterinary immunology. That is, comparisons of the DNA sequences of lymphocyte differentiation antigens from different species provide much important information about structural or functional elements of evolutionarily conserved proteins involved in generation of immune responses.
View details for Web of Science ID A1987L817900028
View details for PubMedID 3324465
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IMPORTANCE OF IMMUNOGLOBULIN ISOTYPE IN THERAPY OF EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS WITH MONOCLONAL ANTI-CD4 ANTIBODY
JOURNAL OF IMMUNOLOGY
1987; 139 (11): 3660-3664
Abstract
Experimental allergic encephalomyelitis (EAE) is an autoimmune disease mediated by CD4+ T cells. Prior studies have established that monoclonal anti-CD4 antibodies can reverse EAE. To determine whether immunoglobulin isotype plays a role in the therapy of EAE with anti-CD4 antibody, an isotype switch variant family of the mouse IgG1 anti-rat CD4 antibody W3/25 was isolated with the fluorescence-activated cell sorter. The IgG1, IgG2b, and IgG2a W3/25 isotype variants all had identical binding capacities for rat CD4+ T cells. Although all three W3/25 isotypes showed some beneficial effects in the amelioration of EAE, the IgG1 and IgG2a W3/25 antibodies were superior to the IgG2b W3/25 in the treatment of EAE. Multiparameter fluorescence-activated cell sorter analysis of T cell subpopulations from treated rats showed that none of the antibodies of the W3/25 isotype switch variant family substantially depleted CD4+ target cells in vivo. These experiments demonstrate that immunoglobulin isotype is important in the monoclonal antibody therapy of autoimmune disease. They indicate that therapy of EAE may be successful without a major depletion of CD4+ lymphocytes. Immunotherapy may be optimized by selecting an appropriate isotype of a monoclonal antibody.
View details for Web of Science ID A1987L166500017
View details for PubMedID 3500226
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DEPLETION OF THE PREDOMINANT B-CELL POPULATION IN IMMUNOGLOBULIN-MU HEAVY-CHAIN TRANSGENIC MICE
NATURE
1987; 329 (6134): 71-73
Abstract
The transgenic mouse line M54 was generated by introducing a functionally-rearranged immunoglobulin mu heavy-chain gene into the germ line of a C57B1/6 inbred mouse. Previous examination of the antibodies produced by B-cell hybridomas derived from transgenic M54 mice showed that the presence of the mu transgene grossly altered the immunoglobulin repertoire of unimmunized animals, suggesting that these mice suffer from a serious immunoregulatory perturbation. Studies presented here introduce a new perspective on this functional defect. We show that the lymphoid tissues from these transgenic mice lack virtually all conventional bone-marrow-derived B cells, which constitute the predominant B-cell population in normal mice and which typically produce primary and secondary antibody responses to T-cell-dependent antigens. Moreover, the bone marrow from transgenic M54 mice is depleted of pre-B lymphocytes, indicating a serious defect in early B-cell lymphopoiesis. In contrast, CD5 (Ly-1) B cells, a second B-cell population displaying a characteristic set of cell surface markers which are derived from distinct precursors in the peritoneum, are represented at normal frequencies in these transgenic mice. Thus, the presence of the rearranged immunoglobulin heavy-chain transgene in M54 mice results in an unexpected selective developmental defect that impairs the development of bone-marrow-derived pre-B and B cells without affecting Ly-1 B cells.
View details for Web of Science ID A1987J846700058
View details for PubMedID 3114639
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ISOLATION AND CHARACTERIZATION OF THE GENE FOR THE MURINE T-CELL DIFFERENTIATION ANTIGEN AND IMMUNOGLOBULIN-RELATED MOLECULE, LYT-2
NUCLEIC ACIDS RESEARCH
1987; 15 (10): 4337-4347
Abstract
We present here the sequence of the 5310 base pair Hind III-cleaved genomic DNA segment that includes the gene for the Lyt-2, a murine differentiation antigen expressed on most immature T lymphocytes as well as the cytotoxic suppressor T cell subset. We also present the complete intron/exon structure of Lyt-2. There are five exons: a fused leader and immunoglobulin variable region like exon, a hinge region exon, a transmembrane exon and two alternatively spliced intracytoplasmic exons (alternative splicing of these exons yields the 38 kDa alpha and 34 kDa alpha' Lyt-2 polypeptides). The promotor region contains a "TATA" box and sequences homologous to the putative immunoglobulin transcriptional control elements cd/pd. S1 protection analysis reveals that thymocytes, T cells from lymph nodes, and a Lyt-2 transfectant obtained by introduction of total genomic DNA have the same initiation site. In the 3' region, there is a polyadenylation signal sequence after a 700 bp long 3' untranslated region.
View details for Web of Science ID A1987H489600029
View details for PubMedID 3495785
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INTERLEUKIN-1 MODULATES MESSENGER-RNA LEVELS OF LYMPHOKINES AND OF OTHER MOLECULES ASSOCIATED WITH T-CELL ACTIVATION IN THE T-CELL LYMPHOMA LBRM33-1A5
JOURNAL OF IMMUNOLOGY
1987; 138 (8): 2514-2519
Abstract
We have investigated the mechanism of action of IL 1 on T cell activation. For this purpose, we analyzed the content of specific messenger RNA for lymphokines and other genes that are associated with T cell activation in the murine IL 1-dependent T cell lymphoma LBRM33-1A5. Using cloned genes for IL 2, IL 3, TGF-beta, TY5, IL 2 receptor, Ly-1, c-myc, and p53 as probes in the S1 nuclease protection assay, we compared the amount of specific transcripts among total RNA prepared from unstimulated cells, IL 1 alpha or PHA-stimulated cells, and PHA plus IL 1 alpha-stimulated cells. IL 1 alpha augmented the PHA-induced accumulation of IL 2 mRNA with a magnitude comparable to the amount of IL 2 produced, suggesting that IL 1 alpha modulates IL 2 gene expression at the RNA level. Similar results were obtained with IL 3. We also observed that Ly-1 mRNA appears after PHA treatment and its accumulation was augmented by IL 1 alpha addition. On the basis of the effects of IL 1 alpha and/or PHA treatments on gene expression, we classified these genes into four groups. In all cases, IL 1 alpha seemed to affect mRNA levels quantitatively. These observations support previously described characteristics of this cytokine as a co-stimulator of T cell activation.
View details for Web of Science ID A1987G768100022
View details for PubMedID 3494073
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A SINGLE LASER METHOD FOR SUBTRACTION OF CELL AUTOFLUORESCENCE IN FLOW-CYTOMETRY
CYTOMETRY
1987; 8 (2): 114-119
Abstract
In flow cytometry cell autofluorescence often interferes with efforts to measure low levels of bound fluorescent antibody. We have developed a way to correct for autofluorescence on a cell-by-cell basis. This results in improved estimates of real staining and better separation of the fluorescence histograms of stained and non-stained cells. Using a single laser, two-color fluorescence measurement system and two-color compensation electronics, autofluorescence and one fluorescent reagent are measured (rather than two fluorescent reagents). With fluorescein-conjugated antibodies the signal in the 515 to 555 nm range (green fluorescence) includes both fluorescein emission and part of the cellular autofluorescence. In the cases we have investigated, autofluorescence collected at wavelengths above 580 nm ("red") is well correlated with the green autofluorescence of the cells. A fraction of this red fluorescence is subtracted from the green fluorescence to produce an adjusted fluorescein output on which unstained cells have zero average signal. Use of this method facilitates the selection of rare cells transfected with surface antigen genes. Culture conditions affect the level of autofluorescence and the balance between red and green autofluorescence. When applied with fluorescein-conjugated reagents, the technique is compatible with the use of propidium iodide for live/dead cell discrimination.
View details for Web of Science ID A1987G699400002
View details for PubMedID 3556100
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GENE-TRANSFER AND MOLECULAR-CLONING OF THE RAT NERVE GROWTH-FACTOR RECEPTOR
NATURE
1987; 325 (6105): 593-597
View details for Web of Science ID A1987F973500045
View details for PubMedID 3027580
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MOLECULAR-CLONING OF LY-1, A MEMBRANE GLYCOPROTEIN OF MOUSE LYMPHOCYTES-T AND A SUBSET OF B-CELLS - MOLECULAR HOMOLOGY TO ITS HUMAN COUNTERPART LEU-1/T1 (CD5)
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1987; 84 (1): 204-208
Abstract
We report the isolation of cDNA clones of the mouse lymphocyte differentiation antigen Ly-1. One of these cDNA clones was confirmed to be full-length by DNA sequencing and by expression of Ly-1 by L cells transfected with this clone. Analysis of the predicted amino acid sequence indicated that the Ly-1 polypeptide is synthesized with a 23 amino acid leader and that the mature protein consists of an amino-terminal region of 347 amino acids, a transmembrane sequence of 30 residues, and a carboxyl-terminal region of 94 amino acids. The amino-terminal region appears to be divided into two subregions by a threonine- and proline-rich sequence of 23 amino acids that is highly conserved between Ly-1 and its human homologue Leu-1 (CD5) in position and amino acid composition. The first amino-terminal subregion of 111 amino acids is predicted to be arranged in a beta-pleated sheet structure of six strands. The entire amino-terminal region is rich in cysteine, with all of its 22 cysteine residues conserved between Ly-1 and Leu-1. The carboxyl-terminal region has no cysteines. Ly-1 and Leu-1 are 63% identical, with a gradient of identical residues from 43% for the first amino-terminal subregion to 58% for the second amino-terminal subregion and 90% for the carboxyl-terminal region. The predicted secondary structure of the first amino-terminal subregion and identities of certain conserved residues among most members of the immunoglobulin gene superfamily suggest that Ly-1 and Leu-1 are distant members of this family.
View details for Web of Science ID A1987F667900043
View details for PubMedID 3025855
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AN RFLP ASSOCIATED WITH PCDLEU2-14, A HUMAN T-CELL DIFFERENTIATION ANTIGEN CD8 (LEU2) CDNA MAPPED TO 2P12
NUCLEIC ACIDS RESEARCH
1986; 14 (19): 7817-7817
View details for Web of Science ID A1986E404600031
View details for PubMedID 2877435
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ISOLATION OF COMPLEMENTARY-DNA CLONES ENCODING THE HUMAN-LYMPHOCYTE GLYCOPROTEIN-T1 LEU-1
NATURE
1986; 323 (6086): 346-349
Abstract
The T1/Leu-1/CD5 molecule, a human T-cell surface glycoprotein of relative molecular mass (Mr) 67,000, has been implicated in the proliferative response of activated T cells and in T-cell helper function. A similar involvement in T-cell proliferation has been reported for Ly-1, the murine homologue of T1. Here we report the complete amino-acid sequence of the T1 precursor molecule deduced from complementary DNA clones. The protein contains a classical signal peptide; a 347-amino-acid extracellular segment; a transmembrane region; and a 93-amino-acid intracellular segment. The extracellular segment contains many cysteine residues and is composed of two related structural domains separated by a proline/threonine-rich region. The T1 molecule has structural features characteristic of other receptor molecules.
View details for Web of Science ID A1986E137100050
View details for PubMedID 3093892
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RECOMBINATION BETWEEN AN EXPRESSED IMMUNOGLOBULIN HEAVY-CHAIN GENE AND A GERMLINE VARIABLE GENE SEGMENT IN A LY-1+ B-CELL LYMPHOMA
NATURE
1986; 322 (6082): 843-846
Abstract
The early stages of murine B-cell differentiation are characterized by a series of immunoglobulin gene rearrangements which are required for the assembly of heavy(H) and light(L)-chain variable regions from germline gene segments. Rearrangement at the heavy-chain locus is initiated first and consists of the joining of a diversity (DH) gene segment to a joining (JH) gene segment. This forms a DJH intermediate to which a variable (VH) gene segment is subsequently added. Light-chain gene rearrangement follows and consists of the joining of a VL gene segment to a JL gene segment: once a productive light-chain gene has been formed the cell initiates synthesis of surface immunoglobulin M (sIgM) receptors (reviewed in ref. 1). These receptors are clonally distributed and may undergo further diversification either by somatic mutation or possibly by continued recombinational events. Such recombinational events have been detected in the Ly 1+ B-cell lymphoma NFS-5, which has been shown to rearrange both lambda and H-chain genes subsequent to the formation of sIgM (mu kappa) molecules. Here we have analysed a rearrangement of the productive allele of NFS-5 and found that it is due to a novel recombination event between VH genes which results in the replacement of most or all of the coding sequence of the initial VHQ52 rearrangement by a germline VH7183 gene. Embedded in the VH coding sequence close to the site of the cross-over is the sequence 5' TACTGTG 3', which is identical to the signal heptamer found 5' of many DH gene segments. This embedded heptamer is conserved in over 70% of known VH genes. We suggest that this heptamer mediates VH gene replacement and may play an important part in the development of the antibody repertoire.
View details for Web of Science ID A1986D782300064
View details for PubMedID 3092106
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THERAPY OF AUTOIMMUNE-DISEASES WITH ANTIBODY TO IMMUNE-RESPONSE GENE-PRODUCTS OR TO T-CELL SURFACE-MARKERS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1986; 475: 274-284
View details for Web of Science ID A1986D835500026
View details for PubMedID 3098154
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LY-1 B-CELLS AND AUTOANTIBODIES
ANNALES DE L INSTITUT PASTEUR-IMMUNOLOGY
1986; D137 (1): 173-176
View details for Web of Science ID A1986D234700019
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PRODUCTION OF IMMUNOGLOBULIN ISOTYPES BY LY-1+ B-CELLS IN VIABLE MOTH-EATEN AND NORMAL MICE
SCIENCE
1986; 232 (4756): 1423-1425
Abstract
Almost all B cells in autoimmune mice with the viable motheaten (mev) mutation express the Ly-1 cell surface antigen, which marks a minor population of B cells constituting a separate lineage in normal mice. Immunoglobulins primarily of the M and G3 classes, which in both normal and mev mice contain high levels of lambda light chain, are produced in excess in mev mice. These and other observations suggest that the development of B cells that express Ly-1 is regulated independently from the development of B cells that do not express Ly-1. B cells bearing the Ly-1 surface antigen may play specialized roles in the normal immune system and in autoimmunity by regulating other B cells via lymphokines, by producing antibodies to self and certain foreign antigens, and by preferentially secreting immunoglobulin M and immunoglobulin G3.
View details for Web of Science ID A1986C602400041
View details for PubMedID 3487115
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FORMAL PROOF THAT DIFFERENT-SIZE LYT-2 POLYPEPTIDES ARISE FROM DIFFERENTIAL SPLICING AND POSTTRANSCRIPTIONAL REGULATION
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1986; 83 (10): 3422-3426
Abstract
We recently isolated the gene and a cDNA clone for the mouse T-cell surface antigen Lyt-2 and showed that Lyt-2 is homologous to the human Leu-2 (T8) antigen and that the gene encoding it is a member of the immunoglobulin gene superfamily. By screening a mouse thymus cDNA library with the Lyt-2 cDNA clone, we isolated two classes of cDNA clones, alpha and alpha', which differ by 31 base pairs. Comparison of the alpha cDNA with genomic sequence data indicates that there are five exons encoding Lyt-2: a fused leader/immunoglobulin variable region-like exon, a spacer region exon, a transmembrane exon, and two cytoplasmic exons. The alpha' cDNA clones lack the first of the two cytoplasmic exons and have a direct splice from the donor splice site of the transmembrane exon to the acceptor of the second cytoplasmic exon. This splice changes the reading frame for the second cytoplasmic exon, causing a stop codon shortly after the splice so that the alpha' cDNA clone codes for a peptide 25 residues shorter than the alpha cDNA-encoded peptide. We have constructed expression vectors with alpha and alpha' cDNAs and have shown that L-cell transfectants of these produce Lyt-2 polypeptides of the predicted sizes and that these associate as homodimers on the cell membranes. We found the two species of mRNA corresponding to alpha and alpha' cDNAs at equal levels in thymus RNA by using S1 nuclease analysis. Although lymph node T cells have only the alpha form of Lyt-2 protein, S1 nuclease analysis shows that lymph nodes have about 20% alpha' mRNA relative to alpha. Thus, Lyt-2 is regulated at RNA processing, translational, and/or post-translational steps.
View details for Web of Science ID A1986C379200078
View details for PubMedID 3085089
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PERITONEAL LY-1 B-CELLS - GENETIC-CONTROL, AUTOANTIBODY PRODUCTION, INCREASED LAMBDA LIGHT CHAIN EXPRESSION
EUROPEAN JOURNAL OF IMMUNOLOGY
1986; 16 (4): 450-456
Abstract
Previous studies demonstrate that Ly-1 B cells and their progenitors are clearly detectable in peritoneum in normal mice. In this publication, we show (a) that peritoneal Ly-1 B cells resemble splenic Ly-1 B cells with respect to surface marker expression and functional activity (autoantibody production); (b) that Ly-1 B frequencies in peritoneum are considerably higher than in spleen; and (c) that genetic mechanisms reduce peritoneal Ly-1 B frequencies to minimal levels in SJL-related mice and to below detectability in CBA/N and other mice with the X-linked immunodeficiency (Xid). In addition, we show that that peritoneal (and perhaps splenic) Ly-1 B populations demonstrate an unique bias in immunoglobulin commitment. That is, they are selectively enriched for cells that express IgM heavy chains in association with lambda light chains. Thus, as a whole, evidence presented here defines the peritoneum as a tightly regulated lymphocyte compartment that normally houses a large population of mature Ly-1 B cells with distinctive functional properties.
View details for Web of Science ID A1986C242800022
View details for PubMedID 3084283
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FREQUENT LAMBDA-LIGHT CHAIN GENE REARRANGEMENT AND EXPRESSION IN A LY-1 B-LYMPHOMA WITH A PRODUCTIVE KAPPA-CHAIN ALLELE
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1986; 83 (5): 1438-1442
Abstract
We describe here a murine Ly-1-bearing pre-B-cell tumor that, when induced for kappa light chain expression with bacterial lipopolysaccharide, also gives rise spontaneously to a few percent of cells expressing surface lambda light chains. These lambda-positive cells have undergone DNA rearrangements involving either V lambda 1 or V lambda 2 genes. Nearly all clones of lambda-bearing cells express mu and lambda on their surface (but not kappa). However, all these lambda-positive clones continue to transcribe kappa mRNA and synthesize internal kappa chains. Further, surface lambda-positive clones show JH rearrangements on one or both heavy chain chromosomes.
View details for Web of Science ID A1986A426100056
View details for PubMedID 3081897
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HOMOLOGOUS CHROMOSOME RECOMBINATION GENERATING IMMUNOGLOBULIN ALLOTYPE AND ISOTYPE SWITCH VARIANTS
EMBO JOURNAL
1986; 5 (2): 263-268
Abstract
We investigated whether spontaneous isotype switching in monoclonal antibody-producing hybridomas always occurs with genes on the same chromosome. Spleen cells of (BAB/ 25 X AKR/J) F1 mice, immunized with dansyl-keyhole limpet hemocyanin (DNS-KLH), were hybridized with NS-1 to generate hybridomas producing monoclonal anti-DNS antibodies of either the b or d haplotype of the BAB/25 or AKR/J parent, respectively. We selected isotype switch variants of such hybridomas using the fluorescence-activated cell sorter (FACS). Although in most cases the allotypic haplotype expressed by the parent and switch-variant hybridomas are the same, in one family of variants we noted a switch in haplotype along with the switch in isotype. This was noted in the selection of IgG2a switch variants from an IgG1 switch variant originally derived from an IgG3-producing parent. Biochemical and molecular studies confirm that the allotype switch variant expresses the same heavy-chain variable region gene complex as its parent hybridomas. As such, the allotype switch represents an example of spontaneous mitotic recombination between immunoglobulin heavy-chain genes, generating a single actively transcribed gene from loci previously positioned on different chromosomes.
View details for Web of Science ID A1986A347600008
View details for PubMedID 3519208
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FURTHER-STUDIES ON THE EPITOPES OF HLA-B7 DEFINED BY MURINE MONOCLONAL-ANTIBODIES
HUMAN IMMUNOLOGY
1986; 15 (1): 44-67
Abstract
Monoclonal antibodies reactive with polymorphic epitopes of HLA-B7 were analyzed by direct and indirect cytotoxicity assays on established panels of HLA typed lymphocytes. This permitted further refinement of their specificity and the identification of various novel reactions. The topographic relationship of polymorphic epitopes on the surface of the B7 molecule was assessed with various serological assays using cell surface B7 or papain solubilized B7 as the antigenic target. These studies focused on monoclonal antibodies recognizing B27 and B7. The results, in combination with those of previously published studies, are used to provide a current assessment of the epitope map of HLA-B7 as defined with mouse monoclonal antibodies. This is compared to the results obtained with alloantisera.
View details for Web of Science ID A1986AWL1100004
View details for PubMedID 2419285
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THE LY-1 B-CELL LINEAGE
IMMUNOLOGICAL REVIEWS
1986; 93: 81-102
View details for Web of Science ID A1986E650700005
View details for PubMedID 3096879
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REVERSAL OF EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS WITH MONOCLONAL-ANTIBODY TO A T-CELL SUBSET MARKER
SCIENCE
1985; 227 (4685): 415-417
Abstract
Administration of a monoclonal antibody (GK1.5) that recognizes the L3T4 marker present on helper T cells prevented the development of experimental allergic encephalomyelitis (EAE) in mice. Furthermore, treatment with GK1.5 reversed EAE when the antibody was given to paralyzed animals. In vivo injection of GK1.5 selectively reduced the number of L3T4+ cells in the spleen and the lymph nodes. These results suggest that manipulation of the human equivalent of the murine L3T4+ T-cell subset with monoclonal antibodies may provide effective therapy for certain autoimmune diseases.
View details for Web of Science ID A1985AAB2300027
View details for PubMedID 3155574
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MOLECULAR-CLONING OF LYT-2, A MEMBRANE GLYCOPROTEIN MARKING A SUBSET OF MOUSE LYMPHOCYTES-T - MOLECULAR HOMOLOGY TO ITS HUMAN COUNTERPART, LEU-2/T8, AND TO IMMUNOGLOBULIN VARIABLE REGIONS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1985; 82 (15): 5126-5130
Abstract
The sequence of Lyt-2 cDNA shows that it is a new member of the immunoglobulin super gene family. Analysis of the predicted amino acid sequence indicates that the Lyt-2 polypeptide is synthesized with a 27-amino acid leader, and that the mature protein has an immunoglobulin variable region (Ig V)-related sequence of approximately 100 amino acids, an extracellular spacer of 43, a transmembrane region of 38, and an intracytoplasmic region of 27 amino acids. Lyt-2 and its human analogue Leu-2 are 56% homologous; analysis indicates that the Ig V-related domains of the two molecules have evolved away from each other faster than the carboxyl-terminal half of the proteins.
View details for Web of Science ID A1985ANN3100056
View details for PubMedID 3927298
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ASSIGNMENT OF GENE FOR HUMAN CELL-SURFACE MEMBRANE ANTIGEN TROP-4 TO CHROMOSOME-11
SOMATIC CELL AND MOLECULAR GENETICS
1985; 11 (3): 257-265
Abstract
The gene (named MF16) for a surface membrane antigen, Trop-4, is assigned to human chromosome 11 on the basis of studies using a mouse monoclonal antibody, immunofluorescence, fluorescence-activated cell sorting (FACS), immunoprecipitation, and mouse-human lymphocyte hybrids. The Trop-4 antigen is present on all human cell lines tested, on peripheral blood monocytes and granulocytes, and on a small fraction of peripheral blood lymphocytes, but is absent from erythrocytes. The Trop-4 monoclonal antibody precipitates an 85,000-dalton glycopolypeptide from hybrid cells containing human chromosome 11. However, in a human cell line expressing this antigen, a larger-molecular-weight species, 100-105,000 daltons was coprecipitated with the 85,000-dalton glycopeptide, and under nonreducing conditions a larger compound of 110-125,000 daltons was obtained. Although the Trop-4 antigen is of similar molecular weight to the Mab-4 and F10.44.2 antigens previously assigned to chromosome 11, it is shown to be different from them.
View details for Web of Science ID A1985AJY7900007
View details for PubMedID 3923630
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THE HUMAN T-CELL ANTIGEN LEU-2 (T8) IS ENCODED ON CHROMOSOME-2
HUMAN GENETICS
1985; 70 (4): 311-314
Abstract
The locus encoding the human T lymphocyte cell surface antigen Leu-2 has been assigned to chromosome 2 with a DNA mapping panel derived from somatic cell hybrids. The two genomic components identified by a cDNA clone for Leu-2 segregated with human chromosome 2 in all 24 independent hybrid clones examined. The cosegregation of the Leu-2 and immunoglobulin kappa (IgK) loci in hybrids with spontaneous rearrangements of chromosome 2 is consistent with the possibility that the Leu-2 locus is on proximal human 2p near IgK. In the mouse, a locus for a T lymphocyte cell surface antigen with properties similar to Leu-2 is closely linked to the IgK locus on mouse chromosome 6. Hence the syntenic relationship of a gene implicated in T cell killing with the immunoglobulin kappa locus would then be conserved in the mouse and human genomes.
View details for Web of Science ID A1985APB2200003
View details for PubMedID 3926629
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PROGENITORS FOR LY-1 B-CELLS ARE DISTINCT FROM PROGENITORS FOR OTHER B-CELLS
JOURNAL OF EXPERIMENTAL MEDICINE
1985; 161 (6): 1554-1568
Abstract
Data from previous multiparameter fluorescence-activated cell sorter (FACS) analysis and sorting studies define a subset of murine B cells that expresses the Ly-1 surface determinant in conjunction with IgM, IgD, Ia, and other typical B cell markers. These Ly-1 B cells are physically and functionally distinct. They express more IgM and less IgD than most other B cells; they are not normally found in lymph node or bone marrow; they are always present at low frequencies (1-5%) in normal spleens, and, as we show here, they comprise about half of the B cells (10-20% of total cells) recovered from the peritoneal cavity in normal mice. Furthermore, most of the commonly studied IgM autoantibodies in normal and autoimmune mice are produced by these Ly-1 B cells, even though they seldom produce antibodies to exogenous antigens such as trinitrophenyl-Ficoll or trinitrophenyl-keyhole limpet hemocyanin. Cell transfer studies presented here demonstrate that the progenitors of Ly-1 B cells are different from the progenitors of the predominant B cell populations in spleen and lymph node. In these studies, we used FACS analysis and functional assays to characterize donor-derived (allotype-marked) B cells present in lethally irradiated recipients 1-2 mo after transfer. Surprisingly, adult bone marrow cells typically used to reconstitute B cells in irradiated recipients selectively failed to reconstitute the Ly-1 B subset. Liver, spleen, and bone marrow cells from young mice, in contrast, reconstituted all B cells (including Ly-1 B), and peritoneal "washout" cells (PerC) from adult mice uniquely reconstituted Ly-1 B. Bone marrow did not block Ly-1 B development, since PerC and newborn liver still gave rise to Ly-1 B when jointly transferred with marrow. These findings tentatively assign Ly-1 B to a distinct developmental lineage originating from progenitors that inhabit the same locations as other B cell progenitors in young animals, but move to unique location(s) in adults.
View details for Web of Science ID A1985AKB7800021
View details for PubMedID 3874257
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IMPORTANCE OF IMMUNOGLOBULIN ISOTYPE IN HUMAN ANTIBODY-DEPENDENT, CELL-MEDIATED CYTO-TOXICITY DIRECTED BY MURINE MONOCLONAL-ANTIBODIES
JOURNAL OF EXPERIMENTAL MEDICINE
1985; 161 (1): 1-17
Abstract
Using the fluorescence activated cell sorter to select rare IgG2a- and IgG2b-producing variants, we developed switch variant families of hybridomas from IgG1-producing hybridomas, ME1 and MA2.1. The IgG2a and IgG2b antibodies produced by such switch variants have the same binding activities for HLA as the IgG1 antibodies produced by the parent hybridomas. Using these antibodies, we directly compared the IgG1, IgG2a, and IgG2b murine Ig isotypes for their capacities to direct human peripheral blood lymphocytes (PBL) in antibody-dependent cell-mediated cytotoxicity (ADCC) against a B lymphoblastoid cell line. We demonstrate that, for antibodies of identical binding affinity and specificity, the murine IgG2a isotype is the most effective in directing ADCC by human effector cells. The murine IgG2b directs intermediate levels of ADCC activity while IgG1 is inactive. We identified the effector cells in human PBL that mediate IgG2a or IgG2b ADCC as nonadherent killer (K) cells. These cells express the C3bi receptor and have cytolytic activity which is specifically blocked by a monoclonal antibody (anti-Leu-11a) that binds the Fc receptor (FcR) of such cells. Finally, FcR-bearing K cells bind to target cell-bound, rather than free, IgG2a or IgG2b molecules.
View details for Web of Science ID A1985AAV9200001
View details for PubMedID 3918141
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ISOLATION OF THE GENE ENCODING THE HUMAN LYMPHOCYTE-T DIFFERENTIATION ANTIGEN LEU-2 (T8) BY GENE-TRANSFER AND CDNA SUBTRACTION
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1984; 81 (24): 7688-7692
Abstract
We report the isolation of genomic and cDNA clones encoding the human T-lymphocyte cell-surface differentiation antigen, Leu-2 (T8), by use of a combination of transfection, fluorescence-activated cell-sorting, and subtractive cDNA hybridization. We constructed a cDNA library with mRNA from a mouse L-cell transfectant in which the human Leu-2 gene is expressed and amplified. We identified Leu-2 cDNA clones by screening with a selected cDNA probe from a second amplified Leu-2 transfectant. This probe contained cDNA species not removed by hybridization with L-cell mRNA. A Leu-2 cDNA clone was used to isolate a genomic clone. Transfection with DNA from this clone resulted in a high number of Leu-2 transfectants. This approach can be used to clone genes coding for other cell-surface molecules.
View details for Web of Science ID A1984AAK5100005
View details for PubMedID 6440142
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CELL-SURFACE ANTIGENS EXPRESSED ON L-CELLS TRANSFECTED WITH WHOLE DNA FROM NON-EXPRESSING AND EXPRESSING CELLS
NATURE
1984; 312 (5989): 68-69
Abstract
We have shown previously that transfection of mouse L-cells with DNA from JM, a human T-cell line expressing certain T-cell differentiation antigens, yields stable transfectants expressing one or another of these antigens. The identities of the antigens were confirmed by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. We now report that our procedure--co-transfection with the chicken thymidine kinase gene (tk) and whole cellular DNA, selection with hypoxanthine-aminopterin-thymidine (HAT), and staining of the cells with fluorochrome-conjugated monoclonal antibodies and fluorescence-activated cell-sorter (FACS) selection--yields transfectants expressing a variety of cell-surface molecules (19 of 21 investigated), most at a frequency of about one per 10(3) Tk+ transformants. Of these, 9 of 12 were transferred and expressed as readily using DNA from cells which did not express the cell-surface antigens as from tissues or cells that did express them.
View details for Web of Science ID A1984TQ42600048
View details for PubMedID 6333643
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EPITOPE-SPECIFIC REGULATION .4. INVITRO STUDIES WITH SUPPRESSOR T-CELLS INDUCED BY CARRIER HAPTEN-CARRIER IMMUNIZATION
CELLULAR IMMUNOLOGY
1984; 86 (2): 327-336
Abstract
Sequential immunization with a carrier molecule and a new epitope (hapten) conjugated to the carrier (carrier/hapten-carrier immunization) induces specific suppression for IgG antibody production to the new epitope (hapten) on the carrier. Once induced, this "epitope-specific" suppression persists and specifically suppresses subsequent in vivo IgG antibody responses to the hapten presented on the same or on an unrelated carrier molecule. In vitro studies presented here characterize the surface markers and specificity of suppressor T cells generated in carrier/hapten-carrier-immunized animals. Thus we show (1) that spleen cells from these donors suppress in vitro IgG anti-hapten antibody production by cocultured hapten-primed spleen cells; (2) that some but not all of the suppressor cells carry surface Lyt-2; (3) that at least some of the suppressor cells have receptors for the inducing hapten (DNP); and (4) that, unlike the suppression obtained in vivo, the in vitro suppression extends to IgG responses to unrelated carrier protein epitopes presented in association with the inducing hapten.
View details for Web of Science ID A1984TA33400007
View details for PubMedID 6203650
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LY-1 B-CELLS - FUNCTIONALLY DISTINCT LYMPHOCYTES THAT SECRETE IGM AUTOANTIBODIES
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1984; 81 (8): 2494-2498
Abstract
Studies presented here introduce another perspective on the mechanisms responsible for IgM autoantibody production. A unique subpopulation of B lymphocytes (Ly-1 B) that concomitantly expresses IgM, IgD, Ia, and Ly-1 membrane glycoproteins is present at higher frequencies in NZB and NZB-related mice. The Ly-1 B subpopulation in these autoimmune animals is responsible for the "spontaneous" IgM secretion demonstrated with cultured NZB spleen cells and contains the cells that secrete typical NZB IgM autoantibodies to single-stranded DNA and to thymocytes. In addition, the Ly-1 B population in normal mouse strains (and in NZB) contains virtually all of the spleen cells that secrete IgM autoantibodies reactive with bromelain-treated mouse erythrocytes. Since a different B-cell subpopulation (IgM+, IgD-, Ly-1) secretes most of the IgM antibodies produced in responses to exogenous antigens, we conclude that Ly-1 B cells constitute a functionally distinct B-cell population important in certain kinds of autoimmunity.
View details for Web of Science ID A1984SR28800048
View details for PubMedID 6609363
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LY-1 AS A DIFFERENTIATION ANTIGEN ON NORMAL AND NEOPLASTIC-B CELLS
CURRENT TOPICS IN MICROBIOLOGY AND IMMUNOLOGY
1984; 113: 231-236
View details for Web of Science ID A1984TH34500039
View details for PubMedID 6332718
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FLUORESCENCE-ACTIVATED CELL SORTING - THEORY, EXPERIMENTAL OPTIMIZATION, AND APPLICATIONS IN LYMPHOID-CELL BIOLOGY
METHODS IN ENZYMOLOGY
1984; 108: 197-241
View details for Web of Science ID A1984AAB8200020
View details for PubMedID 6396481
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MURINE B-CELL DIFFERENTIATION LINEAGES
JOURNAL OF EXPERIMENTAL MEDICINE
1984; 159 (4): 1169-1188
Abstract
Subpopulations of mouse B cells express different amounts of two antigens (BLA-1 and BLA-2) recognized by rat monoclonal antibodies (53-10.1 and 30-E2). Two-color immunofluorescence analysis on the fluorescence-activated cell sorter (FACS) shows that the 53-10.1 monoclonal antibody reacts with a similar proportion of splenic B cells from normal and CBA/N (xid) mice, whereas 30-E2 reacts with most CBA/N B cells but with only a fraction of normal B cells. Data from three- and four-color immunofluorescence analyses with xid, athymic (nude), and normal mice suggest that the order in which these antigens are lost during B cell differentiation distinguishes two B cell lineages: immature B cells express both antigens, intermediate-stage B cells of one or the other lineage express only BLA-1 or only BLA-2, respectively, and mature resting B cells express neither. CBA/N mice lack one of the putative intermediate populations (BLA-1+,2-); thus, this population apparently gives rise to the predominant mature B cell population, which is present in normal adult spleen and lymph node but is missing in CBA/N. The other putative intermediate population (BLA-1-,2+) is decreased by two- to threefold in spleens from nude mice compared with strain-matched controls. Both BLA-1 and BLA-2 antigens rapidly reappear after specific (antigen) or nonspecific (lipopolysaccharide) B cell activation. IgM plaque-forming cells (PFC) derived from such activated cells continue to express both antigens while IgG PFC express only BLA-1.
View details for Web of Science ID A1984SL63900015
View details for PubMedID 6423764
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DETECTION OF FETAL ERYTHROCYTES IN MATERNAL BLOOD POST PARTUM WITH THE FLUORESCENCE-ACTIVATED CELL SORTER
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
1984; 148 (3): 290-295
Abstract
A study was made of the frequency and amount of fetal hemorrhage into maternal blood during labor and delivery as evidenced by the number of fetal cells present in the maternal circulation immediately after spontaneous vaginal delivery. A sensitive, indirect immunofluorescence was used with fluorescence-activated cell sorter analysis of erythrocytes. All of the 16 Rh-negative mothers studied after vaginal delivery of Rh-positive infants had circulating Rh-positive cells. The mean Rh-positive to Rh-negative erythrocyte ratio was 1:14, 100 in maternal blood, which corresponds to a mean fetal hemorrhage of 156 microliters. The test described is sufficiently sensitive to be used for the study of primary Rh isoimmunization and could be clinically applicable for antepartum screening to determine which patients require Rh immune globulin treatment before delivery.
View details for Web of Science ID A1984SC45400010
View details for PubMedID 6421161
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3-COLOR IMMUNOFLUORESCENCE ANALYSIS OF MOUSE B-LYMPHOCYTE SUBPOPULATIONS
CYTOMETRY
1984; 5 (2): 159-168
Abstract
We have modified a fluorescence-activated cell sorter (FACS) to make three independent immunofluorescence measurements on each cell and used this system to study mouse B-lymphocyte subpopulations. An argon-ion laser (emitting at 488 nm) excites fluorescein- and phycoerythrin-labeled reagents, and a tunable dye laser charged with rhodamine 6G (emitting at 615 nm) excites an allophycocyanin-labeled reagent. We report simultaneous measurements of IgM, IgD, and the recently-defined mouse B lymphocyte antigens BLA-1 and BLA-2 on splenic lymphocytes of CBA/J mice and mice of the congenic strain CBA/N (which have an X-linked immunodeficiency [xid]). These data provide information on relationships among the B-cell populations in CBA/J "normal" mice and the defective CBA/N that could not be derived from one- or two-color immunofluorescent measurements. We believe this is the first use of allophycocyanin as an immunofluorescence label.
View details for Web of Science ID A1984SK18400009
View details for PubMedID 6370630
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TRANSFECTION AND CLONING OF GENES FOR MEMBRANE-ANTIGENS USING THE FACS
MEDICAL ONCOLOGY AND TUMOR PHARMACOTHERAPY
1984; 1 (4): 219-224
Abstract
In order to facilitate cloning of genes for cell surface molecules, we cotransfected LTK- mouse fibroblasts with thymidine kinase (TK) genes and total human or mouse DNA. TK+ cells, selected by growth in HAT medium, were stained with fluorochrome conjugated monoclonal antibodies or other fluorescent ligands which bind to one or another membrane differentiation antigen or receptor. We isolated fluorescent transfectants expressing these molecules using a fluorescence activated cell sorter (FACS). For some antigens, spontaneous gene amplification occurred. By repeated cycles of FACS sorting and regrowth we obtained high expressing clones. We then isolated cDNA and genomic clones using selected cDNA probes to screen phage with cDNA inserts. DNA from virtually any tissue source transfected equally well for the various molecules except for DNA from a trophoblast derived choriocarcinoma cell line which did not transfect for Leu-2.
View details for Web of Science ID A1984TT15100003
View details for PubMedID 6443577
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CHIMERIC HUMAN-ANTIBODY MOLECULES - MOUSE ANTIGEN-BINDING DOMAINS WITH HUMAN CONSTANT REGION DOMAINS
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1984; 81 (21): 6851-6855
Abstract
We have created mouse-human antibody molecules of defined antigen-binding specificity by taking the variable region genes of a mouse antibody-producing myeloma cell line with known antigen-binding specificity and joining them to human immunoglobulin constant region genes using recombinant DNA techniques. Chimeric genes were constructed that utilized the rearranged and expressed antigen-binding variable region exons from the myeloma cell line S107, which produces an IgA (kappa) anti-phosphocholine antibody. The heavy chain variable region exon was joined to human IgG1 or IgG2 heavy chain constant region genes, and the light chain variable region exon from the same myeloma was joined to the human kappa light chain gene. These genes were transfected into mouse myeloma cell lines, generating transformed cells that produce chimeric mouse-human IgG (kappa) or IgG (kappa) anti-phosphocholine antibodies. The transformed cell lines remained tumorigenic in mice and the chimeric molecules were present in the ascitic fluids and sera of tumor-bearing mice.
View details for Web of Science ID A1984TU89100061
View details for PubMedID 6436822
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CORRELATION BETWEEN SEGMENTAL FLEXIBILITY AND EFFECTOR FUNCTION OF ANTIBODIES
NATURE
1984; 307 (5947): 136-140
Abstract
Mouse monoclonal anti-dansyl antibodies with the same antigen-binding sites but different heavy chain constant regions were generated. The extent of segmental flexibility in times of nanoseconds and the capacity to fix complement were greatest for IgG2b, intermediate for IgG2a, and least for IgG1 and IgE. Hence, the effector functions of immunoglobulin isotypes may be controlled in part by the freedom of movement of their Fab arms.
View details for Web of Science ID A1984RY26500041
View details for PubMedID 6690993
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LIMITATION OF DIFFERENTIAL EXPRESSION OF HLA-A,B,C ANTIGENS ON CHORIOCARCINOMA CELL-LINES BY MESSENGER-RNA FOR HLA HEAVY-CHAIN BUT NOT BY BETA-2-MICROGLOBULIN
CANCER RESEARCH
1984; 44 (9): 4011-4016
Abstract
The relative amounts of HLA-A,B,C antigens, beta 2-microglobulin (beta 2m), and trophoblast antigens (Trop-1 and Trop-2) were determined on nine choriocarcinoma cell lines including seven lines of gestational origin and two lines of nongestational origin (from ovary and stomach) by quantitative immunofluorescence analysis using a fluorescence-activated cell sorter. Most of these lines expressed surface HLA to variable extents, but one had none detectable. However, all lines secreted readily measurable amounts of beta 2m. We analyzed total RNA extracted from these lines using northern blot molecular hybridization with HLA-A,B,C- and beta 2m-specific complementary DNA probes. We found no messenger RNA species which hybridized with the HLA probe in cells with no detectable HLA surface antigen and only small amounts of HLA-specific RNA in cells with low levels of HLA membrane antigen. Cells exhibiting surface HLA levels greater than about 30% of that on lymphocytes had much higher amounts of HLA-specific RNA than did choriocarcinoma cells with no or low HLA antigen expression. In contrast, RNA hybridizing with beta 2m-specific probes was present at the 20% level or higher (relative to lymphocytes) in all the cell lines tested. Thus, the expression of HLA-A,B,C is apparently limited in choriocarcinoma cells by the level of HLA heavy-chain RNA and not by the level of beta 2m RNA. We discuss these findings in relation to the normal trophoblastic or other origins of this tumor type and with respect to the regulation and function of HLA in trophoblasts.
View details for Web of Science ID A1984TF39800062
View details for PubMedID 6204750
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TRANSCRIPTIONAL CONTROL OF HLA-A,B,C ANTIGEN IN HUMAN PLACENTAL CYTOTROPHOBLAST ISOLATED USING TROPHOBLAST-SPECIFIC AND HLA-SPECIFIC MONOCLONAL-ANTIBODIES AND THE FLUORESCENCE-ACTIVATED CELL SORTER
JOURNAL OF EXPERIMENTAL MEDICINE
1984; 160 (3): 633-651
Abstract
Human placental cell suspensions prepared by trypsin digestion were analyzed with several monoclonal antibodies on a multiparameter fluorescence-activated cell sorter (FACS). Five distinct cell populations were isolated on the basis of size and quantitative differences in the coordinate expression of cell surface antigens detected by monoclonal antibodies against an HLA-A,B,C monomorphic determinant (MB40.5) and against human trophoblasts (anti-Trop-2). By FACS analysis and after sorting we clearly identified the major cell population as cytotrophoblasts based on several independent criteria, including presence of trophoblast-specific surface antigens, Trop-1, and Trop-2; absence of all HLA class I, class II, and beta 2-microglobulin (beta 2m) antigens; absence of the pan-leucocyte and monocyte antigens, HLe1 and LeuM1, respectively; presence of Y-chromatin in a male placenta; presence of placental and not liver alkaline phosphatase; and a large, mononuclear morphology. These procedures provide a reproducible method for obtaining highly purified human cytotrophoblast populations for further studies. We measured by molecular hybridization (RNA or Northern blots) the HLA-A,B,C and beta 2m mRNA in total RNA extracted from sorted cytotrophoblasts. We find that normal human cytotrophoblasts have extremely small amounts of HLA-A,B,C mRNA: approximately 300 times less than that in the lymphoid cell line LCL-721 or normal lymphocytes. In contrast, they have approximately 11% the level of beta 2m mRNA present in LCL-721 cells. Thus, HLA-A,B,C antigen expression on human cytotrophoblasts is limited by the level of HLA heavy chain mRNA.
View details for Web of Science ID A1984TH18400001
View details for PubMedID 6206184
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EPITOPE-SPECIFIC REGULATION
ANNUAL REVIEW OF IMMUNOLOGY
1983; 1: 609-632
View details for Web of Science ID A1983QP21000021
View details for PubMedID 6085788
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HUMAN-IMMUNOGLOBULIN ALLOTYPES - PREVIOUSLY UNRECOGNIZED DETERMINANTS AND ALLELES DEFINED WITH MONOCLONAL-ANTIBODIES
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1983; 80 (12): 3762-3766
Abstract
The highly polymorphic system of serologically defined genetic markers on human IgG heavy chains (Gm allotypes) is second only to the HLA complex in terms of the large number of determinants, alleles, and haplotypes that can be used for analyses of disease associations and other genetic studies. However, present typing methods are based on the use of anti-Gm antisera that are derived mainly from fortuitously immunized human donors, often requiring processing before use, and must be used in a hemagglutination-inhibition assay that cannot be used in typing for isoallotypic determinants (currently termed "non-markers"). In studies presented here, we describe an allotyping system that utilizes monoclonal antibodies in a "sandwich" modification of the solid-phase radioimmunoassay, which is capable of reliable quantitative typing of allotypic, isoallotypic, and isotypic immunoglobulin determinants. We show that these highly reproducible, easily disseminated, and essentially inexhaustible reagents can be used for rapid, sensitive, and quantitative Gm typing. Using this system we define two previously unrecognized Gm determinants, one of which, found to date only in Caucasians, is different from all known Gm markers and thus defines previously unrecognized alleles and haplotypes. The other determinant co-segregates with the conventional G3m(b1) marker but is distinct from that marker on serological grounds. The successful preparation of mouse monoclonal antibodies that detect human Gm allotypic differences and the development of an assay system capable of typing isoallotypic as well as allotypic determinants opens the way to further dissection and application of this rich genetic system.
View details for Web of Science ID A1983QV20800047
View details for PubMedID 6190180
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AMPLIFICATION OF A GENE CODING FOR HUMAN T-CELL DIFFERENTIATION ANTIGEN
NATURE
1983; 306 (5941): 385-387
Abstract
Using previously isolated mouse L-cell transferents for the human T-cell differentiation antigen Leu-2, we now report the first example of spontaneous gene amplification for membrane antigens. The Leu-2 (or T8) antigen is normally expressed on T lymphocytes that have cytotoxic or suppressor functions. Cells of a Leu-2 transfected clone were stained with fluorescein-tagged monoclonal anti-Leu-2, and the brightest 0.1-0.3% of cells were viably separated using a fluorescence activated cell sorter (FACS). After growth of these selected cells, sorting and regrowth was repeated six times, resulting in a population of cells that, compared with the starting population, stains 40 times brighter for Leu-2 and whose DNA transforms 20 times more efficiently for Leu-2. In addition, these cells have 10- to 50-fold amplified human DNA sequences and numerous double minute chromosome fragments, a common indicator of gene amplication in mouse cells.
View details for Web of Science ID A1983RS29500053
View details for PubMedID 6417545
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LYMPHOCYTE SUBSETS IN SJOGRENS SYNDROME - A QUANTITATIVE-ANALYSIS USING MONOCLONAL-ANTIBODIES AND THE FLUORESCENCE-ACTIVATED CELL SORTER
JOURNAL OF CLINICAL & LABORATORY IMMUNOLOGY
1983; 10 (2): 63-69
Abstract
Lymphocyte subsets in the peripheral blood of 18 patients with Sjogren's syndrome (SS) were studied using monoclonal antibodies and the fluorescence-activated cell sorter (FACS). The percentage of T cells was decreased when compared to normal controls. In primary SS, there was a proportional decrease in both suppressor/cytotoxic (anti-Leu-2a reactive) and helper/inducer (anti-Leu-3a reactive) T cells with an unchanged helper/suppressor ratio (1.8 vs. 1.7 for normals). In SS with an associated connective tissue disorder, there was a significant decrease only in the suppressor/cytotoxic subset. There was increase in B cells and null cells in primary SS compared to controls. Quantitative immunofluorescence allowed the calculation of determinant density per cell. Cells expressing low antigen density Leu-2a were increased in 8 patients (4 with primary SS and 4 with SS with an associated disorder). Thus, in addition to quantitative changes in lymphocyte subsets, we found changes in Leu-2a expression suggesting abnormal differentiation of the suppressor/cytotoxic subset. These changes may contribute to the immunoregulatory disturbance in Sjogren's syndrome.
View details for Web of Science ID A1983QC41600001
View details for PubMedID 6601716
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HUMAN LYMPHOCYTE-T DIFFERENTIATION ANTIGENS - EFFECTS OF BLOOD-SAMPLE STORAGE ON LEU ANTIBODY-BINDING
CYTOMETRY
1983; 3 (6): 453-455
Abstract
Current studies of human T lymphocytes and their subsets often use quantitative immunofluorescence analysis with monoclonal antibodies against cell surface antigens. With storage of whole blood or separated mononuclear cells for more than a few hours we have found marked changes in lymphocyte analysis using a fluorescence activated cell sorter (FACS). Experiments were done to determine if these lymphocyte changes were influenced by storage temperature and if lymphocytes could be made more stable by addition of culture media RPMI 1640 to whole blood. Optimal conditions found for blood storage were with with addition of 50% RPMI 1640 and with samples held at room temperature (22 degrees C). With these storage conditions, delay on FACS analysis up to 24 hours did not result in spurious results. When blood samples are collected in places remote from the laboratory or when batch analysis of serially collected samples is desirable, excessive storage times should be avoided.
View details for Web of Science ID A1983QP61600011
View details for PubMedID 6406196
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STABLE TRANSFORMATION OF MOUSE L-CELLS FOR HUMAN MEMBRANE T-CELL DIFFERENTIATION ANTIGENS, HLA AND BETA-2-MICROGLOBULIN - SELECTION BY FLUORESCENCE-ACTIVATED CELL SORTING
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1983; 80 (2): 524-528
Abstract
We isolated stable transformants of mouse L cells expressing human cell surface differentiation antigens by using immunofluorescence with monoclonal antibodies and selection with a fluorescence-activated cell sorter (FACS). Mouse L cells (TK-) were cotransformed with human cellular DNA and the herpes simplex virus thymidine kinase (TK) gene. TK+ transformants were first selected. The TK+ populations were stained with various fluorescent antibodies to membrane antigens, and positive cells were sorted and cloned by using a FACS. Transformants for HLA class I antigens, for beta 2-microglobulin, and for the T-cell differentiation antigens Leu-1 and Leu-2 were isolated. The frequency of antigen transformants among the TK+ transformants was about 0.5 X 10(-3). The sizes of the HLA, Leu-1, and Leu-2 molecules expressed by the transformants were the same as those of the proteins present on DNA-donor cells.
View details for Web of Science ID A1983PZ62700044
View details for PubMedID 6188154
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TRANSIENT IMMUNOLOGICAL EFFECTS OF BETAMETHASONE IN HUMAN-PREGNANCY AFTER SUPPRESSION OF PRETERM LABOR
AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY
1983; 4 (2): 83-87
Abstract
Maternal immune suppression is a potentially significant adverse effect when betamethasone is used to hasten lung maturation of the fetus at risk for preterm delivery. However, increased incidence of infection has not been observed consistently after betamethasone treatment of pregnant women. This study was designed to determine if the cellular immune response to steroids may be modified during pregnancy in a way that would diminish the infection risk associated with steroid treatment. The effect of betamethasone on immunocytes among patients with preterm labor or in nonpregnant subjects were determined following administration of 12 mg of betamethasone intramuscularly. We measured serially the circulating leukocytes, lymphocytes, T lymphocytes, and their subsets. Measurements were also made of localized leukocyte mobilization to serum-filled skin chambers covering experimental inflammatory sites. Patients in preterm labor had increased WBC counts prior to treatment with betamethasone but no additional leukocytosis was induced nor was mobilization of leukocytes to the skin chambers decreased. Lymphopenia and depression of T cells was more transient among pregnant patients compared to nonpregnant. Thus, the pregnant patients studied had diminished or more transient potentially adverse immunocyte responses to betamethasone as compared to nonpregnant subjects.
View details for Web of Science ID A1983RK66800005
View details for PubMedID 6650712
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FLUORESCENCE-ACTIVATED CELL SORTING OF MOUSE-HUMAN HYBRID-CELLS AIDS IN LOCATING THE GENE FOR THE LEU-7 (HNK-1) ANTIGEN TO HUMAN CHROMOSOME-11
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
1983; 80 (11): 3421-3424
Abstract
Leu 7 (HNK-1) is a membrane antigen expressed on human natural killer cells and some other lymphoid cells. Starting with two clones of mouse-human hybrid lymphoid cells that had 1.6% and 35% Leu 7-positive cells, respectively, we viably sorted Leu 7-positive and -negative cells using a fluorescence-activated cell sorter (FACS). Short-term progeny of the sorted cells were then karyotyped. Chromosome 11 was the only human chromosome that was absent from the Leu 7-negative population and present in nearly all of the progeny of the Leu 7-positive selected cells. Thus, we assigned the Leu 7 gene to chromosome 11.
View details for Web of Science ID A1983QT04900060
View details for PubMedID 6344083
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B-CELL SUB-POPULATIONS IDENTIFIED BY 2-COLOR FLUORESCENCE ANALYSIS
NATURE
1982; 297 (5867): 589-591
View details for Web of Science ID A1982NT76200041
View details for PubMedID 7045679
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ANALYSIS OF LY-6.2-BEARING MURINE LYMPHOCYTE SUB-POPULATIONS IN RELATION TO THE LYMPHOCYTE-T MARKERS, THY-1, LYT-1, AND LYT-2
CELLULAR IMMUNOLOGY
1982; 69 (1): 91-100
View details for Web of Science ID A1982NR22900009
View details for PubMedID 7049403
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MOLECULAR-WEIGHT DETERMINATION OF 2 GENETICALLY LINKED CELL-SURFACE MURINE ANTIGENS - THB AND LY-6
IMMUNOGENETICS
1982; 15 (6): 591-599
Abstract
Various murine tumor lines were screened by FACS analysis for the surface antigens ThB and Ly-6.2. Positive cell lines were used for immunoprecipitation studies. A monoclonal ThB-specific antibody immunoprecipitated a unique acidic protein of approximately 16 000 daltons from several positive tumors and from concanavalin A (Con-A) and LPS activated splenic lymphocytes. Monoclonal Ly-6.2-specific antibody was used to immunoprecipitate a 33 500 dalton protein that was shown to exist in four similarly sized forms with different basic charges. In the course of these studies, the apparent molecular weight of the surface antigen T 30, immunoprecipitated with a monoclonal T 30-specific antibody from the cell line EL4, was found to be approximately 25 000 daltons.
View details for Web of Science ID A1982NW25200006
View details for PubMedID 7106866
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NEW IMMUNOGLOBULIN IGG ALLOTYPES AND HAPLOTYPES FOUND IN WILD MICE WITH MONOCLONAL ANTI-ALLOTOPE ANTIBODIES
JOURNAL OF IMMUNOLOGY
1982; 128 (2): 661-667
Abstract
Sera from 156 wild mice (Mus musculus L.) collected from parts of Eurasia, Northern Africa, and the Americas were tested in solid-phase radioimmunoassays for reactivity with 20 monoclonal anti-allotope antibodies directed against gene products of the Igh-1, Igh-3, and Igh-4 loci. Most of the wild mice have Igh phenotypes similar to those of inbred strains or heterozygotes thereof, but frequently the wild mice showed unique combinations of allotypes on a given chromosome (haplotypes) not seen in inbred strains. We found new allotypes of the Igh-1 and Igh-4 loci. Mice from three regions (Poland, Taiwan, and Japan) possess combinations of allotypes indicating that recombination, gene conversion, or other gene duplication events have occurred in portions of the Igh constant region gene complex. Most interestingly, sera of three mice from Egypt possess immunoglobulin molecules appearing to result from an intragenic recombination event involving either Igh-1d or Igh-3d with Igh-1b. Two mice from Pakistan and one from Seychelles Island in the Indian Ocean also showed similar unusual phenotypes. These mice possess two CH2 IgH-1b and two CH2 Igh-1a/CH2 Igh-1d determinants, suggesting that these variant immunoglobulin arose from recombinations within the CH2 domain.
View details for Web of Science ID A1982MZ49700026
View details for PubMedID 7054292
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EPITOPE-SPECIFIC REGULATION .1. CARRIER-SPECIFIC INDUCTION OF SUPPRESSION FOR IGG ANTIHAPTEN ANTIBODY-RESPONSES
JOURNAL OF EXPERIMENTAL MEDICINE
1982; 155 (6): 1730-1740
Abstract
The epitope-specific regulatory system selectively controls IgG antibody production to the individual (haptenic) determinants on a complex antigen. This system can be specifically induced to suppress primary and secondary IgG antibody responses to dinitrophenyl hapten (DNP) without interfering with antibody responses to epitopes on the carrier molecule on which the DNP is presented. Furthermore, once induced, it will specifically suppress responses to DNP presented on unrelated carrier molecules. Results summarized here obtained using widely different immunization conditions, and a variety of haptens and carrier molecules indicate that this regulatory system controls antibody production in most T-dependent antibody responses. Carrier-specific suppressor T cells (CTs) that arise shortly after priming with a carrier molecule such as keyhole limpet hemocyaninin (KLH) induce the epitope-specific system to suppress in situ and adoptive antibody responses to epitopes (e.g., DNP) presented subsequently on the priming carrier. These well-known regulatory T cells are commonly believed to regulate antibody production by interfering with carrier-specific help; however, by repeating the original CTs transfer experiments with additional controls that define the specificity of the mechanism mediating suppression in CTs recipients, we show that KLH-specific CTs regulate responses by inducing typical isotope- specific suppression for anti-DNP responses when the recipients are immunized with DNP-KLH. Thus, whether KLH-primed animals are immunized directly with DNP-KLH (KLH/DNP-KLH immunization sequence) or whether T cells from these animals are challenged with DNP-KLH in (nonirradiated)recipients, anti-DNP responses are persistently suppressed while anti-carrier responses proceed normally. The aqueous KLH-priming protocols usually used to generate CTs are marginally more effective in priming for in situ suppression-induction than the alum KLH-priming protocols commonly used to generate KLH-specific helper T cells and used here in KLH/DNP-KLH immunizations. Thus, studies presented show that priming with an antigenic (carrier) molecule simultaneously prepares the animal for the production of typical secondary (anamnestic) antibody responses to epitopes on the priming antigen and for the induction of epitope-specific suppression for antibody production to determinants presented subsequently on the same antigenic molecule. We discuss the mechanism(s) responsible for this duality and its significance for antibody responses in an accompanying publication that describes the bistable regulatory capabilities of the epitope-specific system.
View details for Web of Science ID A1982NR65400012
View details for PubMedID 6176665
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EPITOPE-SPECIFIC REGULATION .3. INDUCTION OF ALLOTYPE-RESTRICTED SUPPRESSION FOR IGG ANTIBODY-RESPONSES TO INDIVIDUAL EPITOPES ON COMPLEX ANTIGENS
EUROPEAN JOURNAL OF IMMUNOLOGY
1982; 12 (10): 814-818
View details for Web of Science ID A1982PR24900003
View details for PubMedID 6184234
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B-CELL SUBPOPULATIONS IDENTIFIABLE BY 2-COLOR FLUORESCENCE ANALYSIS USING A DUAL-LASER FACS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1982; 399 (DEC): 112-121
View details for Web of Science ID A1982PY68800009
View details for PubMedID 6984600
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RAPID ISOLATION OF CLONED ISOTYPE SWITCH VARIANTS USING FLUORESCENCE ACTIVATED CELL SORTING
CYTOMETRY
1982; 2 (6): 395-401
Abstract
We have used highly specific, directly fluorescein-conjugated heterologous (conventional) and monoclonal antibodies directed against mouse immunoglobulin isotypes in conjunction with the fluorescence activated cell sorter (FACS) to enrich and clone hybridoma cells producing new immunoglobulin heavy chain constant regions. Each variant retains the parental heavy chain variable region and the parental immunoglobulin light chain; thereby each variant binds the same dansyl (DNS) hapten. These isotype switch variants occur at frequencies of approximately 10-5 to 10-6. We were able to isolate the variants by first sorting for an approximate 1000-fold enrichment of the desired immunoglobulin-producing cells, growing these cells for five to nine days, followed by a second 1000-fold enrichment and direct cell cloning into 96 well culture trays. Clones were screened only 3-5 weeks after the original selection for secretion of dansyl-binding immunoglobulin of the selected isotype. Judicious combination of existing methods permits improved analytical techniques using the cell sorter. These include: first, "red" fluorescence staining of dead cells with ethidium bromide or propidium iodide and using the red fluorescence measurement to exclude dead cells from the green fluorescence selection; and second, the use logarithmic amplification of fluorescence signals, allowing for more succinct selection of fluorescence parameters for sorting.
View details for Web of Science ID A1982NQ30900006
View details for PubMedID 6804196
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SELECTION OF HYBRIDOMAS AND HYBRIDOMA VARIANTS USING THE FLUORESCENCE ACTIVATED CELL SORTER
JOURNAL OF IMMUNOLOGICAL METHODS
1982; 52 (1): 1-14
View details for Web of Science ID A1982NX16800001
View details for PubMedID 6811662
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LACK OF IMMUNE-RESPONSE GENE-CONTROL FOR INDUCTION OF EPITOPE-SPECIFIC SUPPRESSION BY TGAL ANTIGEN
NATURE
1982; 295 (5847): 329-331
View details for Web of Science ID A1982MZ66100041
View details for PubMedID 6977095
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PRIMARY AND SECONDARY INSITU ANTIBODY-RESPONSE - ABNORMAL AFFINITY MATURATION PATTERN IN MICE CARRYING THE XID GENE
EUROPEAN JOURNAL OF IMMUNOLOGY
1981; 11 (5): 353-357
Abstract
The xid gene in mice controls a recessive defect resulting in the absence of a late maturing subset of B cells. Whereas the responsiveness pattern of these mice have been clearly defined in terms of their ability or inability to make antibodies to certain classes of thymus-independent antigens, there are conflicting reports in regard to affinity maturation of the antibody response to thymus-dependent antigens. To resolve this controversial issue, the two major isotypes of the IgG response, namely IgG1 and IgG2a were examined with a highly sensitive radioimmunoassay that measures both the magnitude and affinity of the anti-2,4-dinitrophenyl antibody of each isotype in individual serum samples. It was found that the xid gene reduced the amount but not affinity of the IgG1 antibody produced, whereas it impaired the whole IgG2a responses severely. In fact, mice carrying the defective gene were unable to mount a secondary IgG2a response, measured either quantitatively or qualitatively in terms of increased affinity. To test the possibility that Lyb3, an isogenic B cell-triggering receptor lacking in xid-mutant mice, plays a direct role in the maturation of the immune response, the antibody profile in normal mice immunized eigher with antigen alone or in combination with anti-Lyb3 receptor substantially elevated and accelerated the primary IgG2a response, whereas it had little effect on the IgG1 response.
View details for Web of Science ID A1981LY82200001
View details for PubMedID 6973472
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HYBRIDOMS AND THEIR APPLICATIONS
RECHERCHE
1981; 12 (125): 952-961
View details for Web of Science ID A1981MC19500004
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EVOLUTIONARY CONSERVATION OF SURFACE MOLECULES THAT DISTINGUISH LYMPHOCYTE-T HELPER-INDUCER AND CYTOTOXIC-SUPPRESSOR SUB-POPULATIONS IN MOUSE AND MAN
JOURNAL OF EXPERIMENTAL MEDICINE
1981; 153 (2): 310-323
Abstract
We describe the biochemical properties and cell surface distributions of three human T cell antigens (Leu-1, Leu-2a, and Leu-2b) which we postulate to be the homologues of the Lyt-1, Lyt-2, and Lyt-3 antigens that distinguish functional T cell subsets in the mouse. Leu-l, like Lyt-1, is on all thymocytes and peripheral T cells and is present in greater amounts on the helper/inducer subset than on the cytotoxic/suppressor subset. Both antigens increase in parallel fashion during T cell maturation in the thymus and each antigen is carried on a single 67,000-molecular weight (relative) (M(r)) polypeptide chain. Surprisingly, Leu-1 and Lyt-1 each are also expressed in readily detectable amounts on some B celI Ieukemias but not detectably so on normal B cells. Leu-2a and Leu-2b are antigens found only on suppressor/cytotoxic cells in the human and are very similar to the murine Lyt-2 and Lyt-3 antigens. In both species, the two antigens are on the same disulfide- linked multimeric molecules. Disulfide-bond reduction in both species yields subunits of similar size and charge. Lyt-3 and Leu-2b are extremely sensitive to trypsin digestion on viable cells whereas Lyt-2 and Leu-2a are much less so. A different membrane antigen, Leu-3, is an exclusive marker of the helper/inducer subset in man. No mouse homologue for this 55,000-M(r) protein is known. The maintenance of the homologous molecules on functionally distinct T cell subpopulations in two evolutionarily distant species suggests that the Lyt and Leu antigens perform essential functions for the cells on which they are found.
View details for Web of Science ID A1981LB84500008
View details for PubMedID 6165796
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LYT-2 AND LYT-3 ANTIGENS ARE ON 2 DIFFERENT POLYPEPTIDE SUBUNITS LINKED BY DISULFIDE BONDS - RELATIONSHIP OF SUBUNITS TO T-CELL CYTOLYTIC ACTIVITY
JOURNAL OF EXPERIMENTAL MEDICINE
1981; 153 (6): 1503-1516
Abstract
Lyt-2 and Lyt-3 antigens are carried on separate disulfide-bonded subunits of the same cell surface macromolecules. These are present on thymocytes in a variety of multimeric forms consisting of disulfide-bonded dimers, tetramers, and hexamers of pairwise combinations of three subunits (30,000, 34,000, and 38,000 Mr). From reduced and alkylated Nonidet-P40 thymus extracts, a monoclonal anti-Lyt-3 precipitates only the 30,000 Mr subunit, but not the 30,000 Mr subunit. Almost all of the Lyt-2 and Lyt-3 subunits on the cell are covalently linked by disulfide bonds. However, small amounts of free Lyt-3 subunit was seen in some experiments. Similarly, small amounts of Lyt-2-3- material, consisting of dimers of the 38,000 and 34,000 Mr subunits were identified. Each of the three subunits migrated with a basic charge (pI greater than 8) on two-dimensional gels. Cytotoxic effector cells that are blocked by anti-Lyt-2 and anti-3 can be treated with trypsin and other arginine-specific proteases to remove these antigens. At low concentrations of these proteases, Lyt-3 antigens are selectively removed. After selective removal of Lyt-3 antigens, cytotoxic effector cells are still active and blocking of activity by anti-Lyt-3 is significantly reduced, whereas blocking of activity by anti-Lyt-2 is significantly increased. Neither Lyt-2 nor Lyt-3 is allelically excluded on thymocytes or T cells. These results suggested that the Lyt-2, Lyt-3 macromolecules are associated with but do not serve as the T cell antigen receptor.
View details for Web of Science ID A1981LU17300010
View details for PubMedID 6166718
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A MONOCLONAL MOUSE ANTI-ALLOTYPE ANTIBODY REACTS WITH CERTAIN HUMAN AND OTHER VERTEBRATE IMMUNOGLOBULINS - GENETIC AND PHYLOGENETIC FINDINGS
IMMUNOGENETICS
1981; 12 (3-4): 207-219
Abstract
A new mouse monoclonal antibody, 18.1, recognizes an allotypic determinant on mouse IgG1 of the "a" allotype. We found that this alloantibody reacts with immunoglobulins of evolutionarily distant vertebrate species including man, and with only certain isotypes or allotypes in some of these species. Most mammalian sera are reactive, except those from lagomorphs, marsupials, and monostremes. Avian and reptilian sera are also positive, while the amphibian and fish sera tested were negative. In human sera, 18.1 detects the isotypic marker on IgG2 and an allotypic marker on IgG3. This reactivity parallels the distribution of the Gm non-g determinant. These findings are discussed in relation to the phylogeny of IgG and its subclasses.
View details for Web of Science ID A1981LC73800001
View details for PubMedID 6782018
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A HUMAN LYMPHOCYTE-T DIFFERENTIATION MARKER DEFINED BY MONOCLONAL-ANTIBODIES THAT BLOCK E-ROSETTE FORMATION
JOURNAL OF IMMUNOLOGY
1981; 126 (6): 2117-2122
Abstract
A new human T cell surface antigen, Leu-5, has been defined using a set of monoclonal antibodies that block rosette formation between T lymphocytes and sheep erythrocytes (SRBC). Four antibodies obtained from 2 different fusions using 2 immunized mouse strains all reacted with the same antigen. All these antibodies gave identical quantitative immunofluorescence (FACS) profiles, all gave the same staining profiles and intensities when used singly or in combinations, and all precipitated the same molecule. The antigen is a single polypeptide chain, 40,000 to 50,000 Mr, and is found on all thymocytes, peripheral T cells, and some null cells, but not on B cells. Leu-5 is a differentiation antigen that decreases in density as thymocytes mature to peripheral T lymphocytes. Thus, the Leu-5+ subpopulations ranked in order of decreasing Leu-5 density are: a subpopulation of subcapsular thymocytes greater than cortical and medullary thymocytes greater than peripheral T cells (cytotoxic/suppressor subset) greater than peripheral T cells (helper/inducer subset). The density distribution pattern of Leu-5 parallels the relative affinity of thymocytes and peripheral T lymphocytes for SRBC. We suggest that Leu-5 is either identical to or closely associated with the human T lymphocyte receptor for SRBC.
View details for Web of Science ID A1981LR85800010
View details for PubMedID 6785348
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SURFACE-ANTIGENS ON MOUSE NATURAL-KILLER CELLS - USE OF MONOCLONAL-ANTIBODIES TO INHIBIT OR TO ENRICH CYTO-TOXIC ACTIVITY
JOURNAL OF IMMUNOLOGY
1981; 127 (3): 982-986
Abstract
In studies using monoclonal antibodies to cell-surface antigens we have identified 2 new antigens (H11 and 7.2) expressed on mouse NK cells. These are shared with T cells but not B cells. We have also shown that NK cells express T200 but lack detectable ThB or Lyt-1. The T200 and H11 surface molecules were implicated in the mediation or regulation of natural killing; monoclonal antibodies to T200 and H11 inhibited natural killing when added to the cytotoxicity assay but did not interfere with T cell cytotoxicity against the same target. The inhibitory effect of anti-T200 is consistent with recent evidence showing that antibodies to the Ly-5 polymorphic determinant on T200 block natural killing. The H11 determinants is on a different molecule. The absence of Lyt-1 and ThB on NK cells permitted development of a rapid and simple method for separating NK cells from T cells and B cells. Spleen cells incubated with rat monoclonal antibodies to Lyt-1 (on all T cells) and ThB (on all B cells) were 95% removed by adherence to Petri dishes coated with antiserum to rat immunoglobulin. The natural killer activity in the nonadherent population was enriched 16-fold.
View details for Web of Science ID A1981MC71000034
View details for PubMedID 6790624
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DETECTION AND ISOLATION OF FETAL CELLS FROM MATERNAL BLOOD USING THE FLUORESCENCE-ACTIVATED CELL SORTER (FACS)
PRENATAL DIAGNOSIS
1981; 1 (1): 61-73
Abstract
The presence of fetal cells in the maternal circulation during pregnancy has been suggested by repeated observations of small numbers of cells containing Y chromatin or a Y chromosome in the blood of pregnant women. With the fluorescence-activated cell sorter (FACS), we have used antibodies to a paternal cell surface (HLA) antigen, not present in the mother, to select fetal cells from the lymphocyte fractions of a series of maternal blood samples, collected as early as 15 weeks of gestation. These sorted cells have been examined for a second paternal genetic marker, Y chromatin. Y chromatin-containing cells were found among the sorted cells from prenatal maternal blood specimens in 8 pregnancies subsequently producing male infants whose lymphocytes reacted with the same antibodies to paternal antigen used for sorting with the FACS. In each of 17 pregnancies resulting in male infants who failed to inherit the antigen detected by the antibodies used for cell sorting, Y chromatin-containing cells were not found prenatally. The use of two paternal genetic markers, a cell surface antigen and nuclear Y chromatin, to identify fetal cells in maternal blood permits us to conclude that these cells are present in the mother's circulation, as early as 15 weeks gestation. Further development of the techniques reported here could lead to widespread screening of maternal blood samples during pregnancy for detection of fetal genetic abnormalities.
View details for Web of Science ID A1981MS91900009
View details for PubMedID 7050957
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CARRIER-SPECIFIC INDUCTION OF HAPTEN-SPECIFIC SUPPRESSION
IMMUNOLOGY TODAY
1981; 2 (3): 40-46
View details for Web of Science ID A1981LL21900004
View details for PubMedID 25291107
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CARRIER-PRIMING LEADS TO HAPTEN-SPECIFIC SUPPRESSION
NATURE
1980; 285 (5767): 664-667
View details for Web of Science ID A1980JX38700044
View details for PubMedID 6967189
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A RAPID METHOD FOR THE DETECTION OF ANTIBODIES TO CELL-SURFACE ANTIGENS - A SOLID-PHASE RADIOIMMUNOASSAY USING CELL-MEMBRANES
JOURNAL OF IMMUNOLOGICAL METHODS
1980; 38 (1-2): 75-84
Abstract
Cell membranes isolated from murine lymphocytes or ascites tumors bind tightly to the surface of flexible plastic microtiter plates in the absence of additional proteins. This allows the detection of membrane associated molecules by specific antibodies and thus forms the basis for a rapid and sensitive radioimmunoassay for antibodies to membrane-bound components. The assay compares favorably with a variety of methods currently used to detect antibodies to cell surface antigens. The assay detects a variety of well characterized murine cell surface antigens (H-2, I-A, T-200, Thy-1.2, Ig). The level of antibody binding to membranes on plates correlates well with antigen density on intact cells. A modification of the assay involving competition between cross-reacting antibodies allows detection and resolution of closely spaced antigenic determinants.
View details for Web of Science ID A1980KS18800006
View details for PubMedID 6161193
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T-CELL SUBSETS DEFINED BY EXPRESSION OF LYT-1,2,3 AND THY-1 ANTIGENS - 2-PARAMETER IMMUNOFLUORESCENCE AND CYTO-TOXICITY ANALYSIS WITH MONOCLONAL-ANTIBODIES MODIFIES CURRENT VIEWS
JOURNAL OF EXPERIMENTAL MEDICINE
1980; 152 (2): 280-295
Abstract
Using monoclonal antibodies and multiparameter fluorescence analyses, we show that the expression of Lyt-1, Lyt-2, and Lyt-3 on T cell subpopulations is more complex than was originally recognized by the cytotoxic depletion studies with conventional reagents that defined the Lyt-1+2+3+, Lyt-1+2-3-, and Lyt-1-2+3+ populations. We detect at least some Lyt-1 on all T (Thy-1-bearing) lymphocytes; however, in agreement with previous studies, we find that Lyt-2+3+ cells are more difficult to depelete with anti-Lyt-1 than Lyt-1+2-3- cells. Surprisingly, we found a small subpopulation of cells carrying relatively large amounts of Lyt-1 and no Thy-1 detectable by fluorescence-activated cell sorter analysis. We also detect cells with this phenotype histologically in B cell zones (primary follicles) and germinal centers in spleen and lymph nodes. In general, the Lyt-1 only population represents approximately 2% of spleen cells. The relative quantitative expression of Thy-1, Lyt-1, Lyt-2, and Lyt-3 changes systematically during T cell maturation. Among Lyt-1+2+3+ cells in the thymus, Thy-1 and Lyt-2 are high, whereas Lyt-1 is low. Among splenic T cells, in contrast, Thy-1 is low, Lyt-1 is high, and Lyt-2 and Lyt-3 are a little higher than in thymus. In general, Thy-1 expression is negatively correlated with Lyt-1. Thus, even among splenic and lymph node T cells subpopulations exist that tend to be either high Thy-1 and low Lyt-1 or vice versa. Lyt-2+3+ cells represent approximately 85% of thymocytes but only approximately 35% of splenic or lymph node T cells. The Lyt-2+3+ cells are found predominantly in the low Lyt-1, high Thy-1 subpopulation.
View details for Web of Science ID A1980KC43300003
View details for PubMedID 6156984
View details for PubMedCentralID PMC2185937
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FETAL CELLS IN THE BLOOD OF PREGNANT-WOMEN - DETECTION AND ENRICHMENT BY FLUORESCENCE-ACTIVATED CELL SORTING
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1979; 76 (3): 1453-1455
Abstract
Fetal cells, potentially usable for prenatal diagnosis, were sorted from maternal blood samples taken as early as 15 weeks of gestation. Immunogenetic and cytogenic criteria established the fetal origin of the observed cells: Y-chromatin-containing (male) cells were detected in the sorted sample if and only if the newborn proved to be male and carried cell-surface antigens detected by the fluorescent-labeled antibody used for sorting with the fluorescence-activated cell sorter.
View details for Web of Science ID A1979GP42700095
View details for PubMedID 286330
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XENOGENEIC MONOCLONAL ANTIBODIES TO MOUSE LYMPHOID DIFFERENTIATION ANTIGENS
IMMUNOLOGICAL REVIEWS
1979; 47: 63-90
View details for Web of Science ID A1979HX75900002
View details for PubMedID 398327
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Immunoglobulin isoantigens (allotypes) in the mouse : V. Characterization of IgM allotypes.
Immunogenetics
1978; 7 (1): 213-230
Abstract
Murine antisera raised against allogeneic lymphoid cells often contain antibodies to IgM allotypes. Rarely, allotypic antibodies to IgM have been found after immunization withB. pertussis anti-B. pertussis conjugates. Using both types of antibodies, we have defined a new constant-region locus for both secreted and membrane-bound μ chains. This locus,Ig-6, is closely linked to the previously described H-chain constant-region loci (Ig-1 throughIg-5) and is subject to allelic exclusion. We have identified three alleles and four antigenic specificities ofIg-6.
View details for DOI 10.1007/BF01844009
View details for PubMedID 21302076
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T-CELL LINES PRODUCING ANTIGEN-SPECIFIC SUPPRESSOR FACTOR
NATURE
1978; 274 (5670): 477-480
View details for Web of Science ID A1978FJ84900043
View details for PubMedID 307689
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IMMUNOGLOBULIN ISOANTIGENS (ALLOTYPES) IN THE MOUSE .5. CHARACTERIZATION OF IGM ALLOTYPES
IMMUNOGENETICS
1978; 7 (3): 213-230
View details for Web of Science ID A1978GH01000003
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Properties of monoclonal antibodies to mouse Ig allotypes, H-2, and Ia antigens.
Current topics in microbiology and immunology
1978; 81: 115-120
View details for PubMedID 567555
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T cell hybrids with T cell functions.
Current topics in microbiology and immunology
1978; 81: 195-202
View details for PubMedID 80303
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Surface markers and functional relationships of cells involved in murine B-lymphocyte differentiation.
Cold Spring Harbor symposia on quantitative biology
1977; 41: 33-45
View details for PubMedID 408094
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FC RECEPTOR ON THYMUS-DERIVED LYMPHOCYTES .4. INHIBITION OF BINDING OF ANTIGEN-ANTIBODY COMPLEXES TO FC RECEPTOR POSITIVE T CELLS BY ANTI-IA SERA
JOURNAL OF EXPERIMENTAL MEDICINE
1977; 145 (1): 187-203
Abstract
Treatment of splenic T lymphocytes with anti-Ia antiserum inhibits the binding of antigen-antibody (AgAb) complexes to the majority (less than 50%) of Fc receptor-positive (FcR+) T cells. A similar inhibition was observed with anti-H-2D and anti-H-2K sera but not with anti-Thy 1.2. Despite the presence of Ia determinants on peripheral T cells, as established by the inhibition of AgAb binding, Ia could not be detected on peripheral T cells by immunofluorescence assays. Data obtained with the AgAb-binding inhibition assay indicate that determinants controlled by loci mapping in the I-A and I-C, S, or G regions are present on the FcR+ T cells. Evidence is presented that subpopulations of T cells within the FcR+ T-cell population may be distinguishable on the basis of which I-region-controlled determinant is expressed. The data are discussed in terms of phenotypic and functional heterogeneity of T lymphocytes.
View details for Web of Science ID A1977CQ67900016
View details for PubMedID 63534
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ISOLATION OF ANTIGEN-BINDING CELLS FROM UNPRIMED MICE .2. EVIDENCE FOR MONOSPECIFICITY OF ANTIGEN-BINDING CELLS
EUROPEAN JOURNAL OF IMMUNOLOGY
1976; 6 (4): 288-292
Abstract
Spleen cells from unimmunized mice were exposed to two contrastingly fluorescent antigens simultaneously. Antigen-binding cells of either specificity were isolated using a fluorescence-activated cell sorter (FACS). Purified cells binding one or the other of the antigens were then examined by fluorescence microscopy for the presence of bound antigen of the alternate specificity. No double binding cells were seen. If cells bear receptors of two or more specificities and these receptors are randomly distributed among antigen-binding cells, then of the 13 000 binding cells examined 82 were expected to bind both antigens. These results strongly suggest that antigen-binding cells bear receptors of only one specificity. In addition, by inference from the functional correlation between antigen-binding cells and precursor cells, the data support the contention that precursors of antibody-forming cells are monospecific.
View details for Web of Science ID A1976BS55500009
View details for PubMedID 62666
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T-CELL REGULATION OF ANTIBODY-RESPONSES - DEMONSTRATION OF ALLOTYPE-SPECIFIC HELPER T CELLS AND THEIR SPECIFIC REMOVAL BY SUPPRESSOR T CELLS
JOURNAL OF EXPERIMENTAL MEDICINE
1976; 144 (2): 330-344
Abstract
Allotype suppressor T cells (Ts) generated in SJL X BALB/c mice specifically suppress production of antibodies marked with the Ig-1a allotype. The studies presented here show that allotypes Ts suppress by specifically removing helper T cell (Th) activity required to facilitate differentiation and expansion of B cells to Ig-1b antibody-forming cells. We show first that Ts and Th belong to different T-cell subclasses as defined by Ly surface antigens. Ts are Ly2+Lyl- and thus belong to the same subclass as cytotoxic precursor and effector cells; Th are Lyl+Ly2- cells and thus belong to the subclass containing cells which can exert helper functions and initiate delayed hypersensitivity reactions. Placing these cells in these two subclasses shows that Th are different from Ts and suggests that they play different roles in regulating antibody responses. The difference in these roles is defined by the evidence presented here showing that Ts attack Th and regulate the antibody response by specifically regulating the availability of Th activity. We show that in allotype suppressed mice, Ts which suppress Ig-1b antibody production have completely removed the Th activity of helping Ig-1b cells without impairing Th activity which helps other IgB B cells. These findings imply the existence of allotype-specific Th for Ig-1b cells (Ig-1b Th). We directly establish that Ig-1b cells require such help by showing that carrier-primed spleen cells from Iga/Iga congenic hybrids help Ig-1a B cells from hapten-primed Igb/Iga donors but do not help Ig-1b B cells from the same donor in the same adoptive recipient.
View details for Web of Science ID A1976BZ72800003
View details for PubMedID 1085324
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2 STAGES OF B-CELL MEMORY DEVELOPMENT WITH DIFFERENT T-CELL REQUIREMENTS
JOURNAL OF EXPERIMENTAL MEDICINE
1976; 144 (2): 345-357
Abstract
We present evidence here for two stages in B-memory cell development, the first of which is T independent and the second T dependent. For these studies, we use a new type of T-deficient mouse (allotype suppressed) which specifically lacks T-helper activity (Th) for a subset of memory B cells responsible for approximately 10% of the overall IgG antibody response. We have shown elsewhere that these mice (SJL X BALB/c hybrids suppressed for Ig-1b) lack Th capable of helping Ig-1b memory cells, although they have normal Th activity for all other IgG memory B cells. This selective Th deficiency allows study of the effects of T depletion on memory development and avidity maturation of one population of B cells under conditions where the bulk of the immune response in the animal is proceeding normally, thus obviating environmental problems due to secondary effects of T depletion. With this sytem, we show that after a single priming dose of 2,4-dinitrophenyl-keyhole limpet hemocyanin, the memory B-cell pool in suppressed and nonsuppressed donors is indistinguishable with respect to magnitude and avidity of the response for all IgG antibodies produced, including Ig-1b antibody, despite the fact that expression of Ig-1b memory cells is prevented in intact Ig-1b-suppressed mice by the absence of Th capbale of cooperating with these memory cells. We have shown elsewhere that virtually all of the Ig-1b memory is carried by Ig-1b bearing cells. In contrast with the lack of suppressor T-cell effect on initial Ig-1b memory cell development, our data show that continued Ig-1b memory development is selectively impaired in suppressed mice. When primed mice are boosted repeatedly with the priming antigen, the average avidity of most of the IgG memory cells increases over 100-fold while there is no avidity increase in the Ig-1b component. To explain these data, we suggest that the development of high avidity memory occurs in two stages. The first stage, which occurs as a result of primary antigenic exposure, is the creation of a pool of IgG-bearing memory cells with a relatively low average avidity for the antigen. The appearance of these first stage memory cells does not require help from (post-thymic) Th, although Th are required for the expression of these memory cells (antibody production). The second stage of B-memory development requires both further antigenic stimulation and B-memory cell interaction with competent Th. This is a continuing process in which the number of memory cells in the pool remains relatively constant but the average avidity of these cells increases with continued antigenic exposure.
View details for Web of Science ID A1976BZ72800004
View details for PubMedID 1085325
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IDENTIFICATION AND SEPARATION OF PRE T-CELLS FROM NU-NU MICE - DIFFERENTIATION BY PRE-CULTURE WITH THYMIC RETICULOEPITHELIAL CELLS
CELLULAR IMMUNOLOGY
1976; 24 (1): 173-185
View details for Web of Science ID A1976BV81800017
View details for PubMedID 132991
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FURTHER-STUDIES ON TH-B, A CELL-SURFACE ANTIGENIC DETERMINANT PRESENT ON MOUSE B CELLS, PLASMA-CELLS AND IMMATURE THYMOCYTES
CELLULAR IMMUNOLOGY
1976; 23 (1): 140-157
View details for Web of Science ID A1976BQ35700012
View details for PubMedID 57834
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FC RECEPTOR ON THYMUS-DERIVED LYMPHOCYTES .3. MIXED LYMPHOCYTE-REACTIVITY AND CELL-MEDIATED LYMPHOLYTIC ACTIVITY OF FC- AND FC+ T-LYMPHOCYTES
JOURNAL OF EXPERIMENTAL MEDICINE
1976; 144 (1): 54-68
Abstract
The involvement of Fc- and Fc+ T cells, separated on the fluorescence-activated cell sorter, in proliferative and cytotoxic responses to alloantigens was examined. The cytotoxic lymphocytes generated by in vivo exposure to allogeneic tumor cells were shown to express the Fc receptor. The proliferative responses to alloantigen exposure in mixed lymphocyte cultures was equivalent in intensity for unseparated T cells, the Fc+ T-cell fraction, and the Fc- T-cell fraction isolated from nonsensitized spleen cells. In contrast, the cytotoxic responses generated by the Fc- T-cell fraction (less than 1% Fc+) were much weaker than the cytotoxic responses generated by the Fc+ T-cell fraction (80-90% Fc+), and the responses of the Fc+ T-cell fraction were generally weaker than, or equal to the responses of unseparated T cells (Fc- T less than Fc+ T less than or equal to unseparated T). Mixtures of the Fc- and Fc+ T-cell fractions mounted stronger cytotoxic responses than the sum of the responses of either fraction alone. Examination of the Ly phenotypes of the synergizing populations revealed that the CL precursor activity (Ly-2+ T cells) resided in the Fc- T-cell population, and that the amplifier T-cell activity (Ly-1+ T cells) resided in the Fc+ T-cell population. The data are discussed in terms of T-cell heterogeneity, differentiation, and intercellular interaction.
View details for Web of Science ID A1976BX01400005
View details for PubMedID 132509
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QUANTITATIVE SEPARATION OF ANTIGEN-SPECIFIC MURINE ANTIBODIES BY ANTI-ALLOTYPE CHROMATOGRAPHY
SCANDINAVIAN JOURNAL OF IMMUNOLOGY
1975; 4 (5-6): 479-485
Abstract
The use of Sepharose-conjugated murine anti-Iga or anti-Igb allo-antisera allowed the quantitative separation of immunoglobulins of the two allotypes. After fractionation of mixtures of anti-(T,G)-A--L antisera obtained from congenic strains differing in immunoglobulin allotype, it was possible to measure the antigen-binding capacity of specific anti-(T,G)-A--L antibodies in each allotype fraction. Analysis of artificial mixtures of immune sera obtained from homozygous Iga and Igb animals showed that this method is quantitative and internally consistent. This method of affinity chromatography was used in the analysis of specific anti (T,G)-A--L antisera from tetraparental mice.
View details for Web of Science ID A1975AQ35200008
View details for PubMedID 52179
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SURFACE MEMBRANE DETERMINANT SHARED BY SUBPOPULATIONS OF THYMOCYTES AND B-LYMPHOCYTES
JOURNAL OF IMMUNOLOGY
1975; 115 (2): 508-512
Abstract
Utilizing a quantitative fluorescence assay with the fluorescence-activated cell sorter (FACS), we have demonstrated that a rabbit antiserum obtained by immunization with cells of a mouse IgM-producing plasma cell tumor (MOPC104E) is reactive with at least two surface determinants, designated Th-B and ML2, on subpopulations of normal murine lymphocytes. The ML2 determinant is restricted to B lymphocytes. The Th-B determinant is shared by splenic B lymphocytes and a large subpopulation of thymocytes, the latter of which express a 3-fold higher density of Th-B on their surface than do the B lymphocytes. Neither Th-B nor ML2 were found on peripheral T cells or on brain, liver, or kidney cells. The available evidence suggesting that Th-B may be a stem cell determinant that is lost upon maturation is discussed.
View details for Web of Science ID A1975AL49100035
View details for PubMedID 50365
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FC RECEPTOR ON THYMUS-DERIVED LYMPHOCYTES .2. MITOGEN RESPONSIVENESS OF T LYMPHOCYTES BEARING FC RECEPTOR
JOURNAL OF EXPERIMENTAL MEDICINE
1975; 142 (5): 1041-1051
Abstract
The responsiveness of purified Fc- and Fc+ T lymphocytes, isolated from normal spleen cell populations by cell sorting on the fluorescence activated cell sorter, has been examined. Although both Fc- and Fc+ T cells responded to phytohemagglutinin, the response to concanavalin A (Con A) was found to be a characteristic of the Fc+ T lymphocyte. The poor responsiveness of the Fc- T cells to Con A was shown not to be due to a requirement of either different concentrations of Con A or for adherent cells. The addition of Fc+ T cells to the Fc- T cells in a ratio of 1:3 resulted in a mitotic response not significantly different from that observed with the purified Fc+ T cells alone and up to 15-fold greater than that of Fc- T cells alone. It is suggested that the Fc T cells can be recruited into mitosis as a result of Con A stimulation of the Fc+ T cells.
View details for Web of Science ID A1975AV25500001
View details for PubMedID 1081574
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CHARACTERIZATION OF SUBPOPULATIONS OF T-LYMPHOCYTES .1. SEPARATION AND FUNCTIONAL STUDIES OF PERIPHERAL T-CELLS BINDING DIFFERENT AMOUNTS OF FLUORESCENT ANTI-THY 1.2 (THETA) ANTIBODY USING A FLUORESCENCE-ACTIVATED CELL SORTER (FACS)
CELLULAR IMMUNOLOGY
1975; 15 (1): 180-196
View details for Web of Science ID A1975V156100016
View details for PubMedID 1088903
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FC RECEPTOR ON THYMUS-DERIVED LYMPHOCYTES .1. DETECTION OF A SUBPOPULATION OF MURINE T-LYMPHOCYTES BEARING FC RECEPTOR
JOURNAL OF EXPERIMENTAL MEDICINE
1975; 142 (3): 611-621
Abstract
Utilizing the fluorescence-activated cell sorter (FACS) and washed murine antibody-antigen complexes formed in antibody excess, we have demonstrated the presence of the Fc receptor on the surface of a distinct subpopulation of murine T lymphocytes. No differences in intensity of labeling with the complexes was observed when the Fc+ T lymphocytes were compared with Fc+ B lymphocytes. The majority of Fc+ T lymphocytes are small lymphocytes determined by light-scattering characteristics on the FACS. Separating Fc+ from Fc- T lymphocytes from spleens of mice primed 1 wk or 1 mo previously with keyhole limpet hemocyanin (KLH) revealed that the T cells capable of cooperating with DNP-KLH primed B cells to give an adoptive anti-DNP PFC response do not bear the Fc receptor.
View details for Web of Science ID A1975AN64100006
View details for PubMedID 1100762
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GENETIC-CONTROL OF ANTIBODY-RESPONSE TO POLY-L(TYR,GLU)-POLY-D,L-ALA--POLY-L-LYS IN C3H [--]CWB TETRAPARENTAL MICE
JOURNAL OF EXPERIMENTAL MEDICINE
1974; 140 (6): 1660-1675
Abstract
In order to further delineate the mechanisms underlying genetic unresponsiveness, tetraparental mice were constructed from immune response-1A gene high responder and low responder parental genotypes, then were immunized with poly-L-(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys ((T,G)-A--L). An analysis of the total serum allotype mixture and of the antigen-binding capacity of the separated allotypes demonstrated that in the milieu of a tetraparental mouse, both high and low responder B cells could be stimulated equally to produce identical high titered anti-(T,G)-A--L responses. Furthermore, these studies show that effective stimulation could occur across a histocompatibility disparity.
View details for Web of Science ID A1974U967100017
View details for PubMedID 4139235
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RESTRICTION OF GENE-EXPRESSION IN B-LYMPHOCYTES AND THEIR PROGENY .1. COMMITMENT TO IMMUNOGLOBULIN ALLOTYPE
JOURNAL OF EXPERIMENTAL MEDICINE
1974; 139 (3): 581-599
Abstract
Lymphocytes from b(5)/b(9) rabbits were stained in suspension with fluorescent antiallotype antibody reagents to selectively label with fluorescent molecules those cells bearing membrane immunoglobulin (Ig) of the b5 or b9 allotype. After staining, the cells were separated by the fluorescence-activated cell sorter into populations markedly enriched in cells bearing b5 or b9 membrane Ig or totally depleted of cells with detectable membrane Ig. The potential of these separated cells to give rise to Ig-synthesizing plasma cells either in vivo after transfer into irradiated recipients or in vitro during culture in the presence of phytohemagglutinin or pokeweed mitogen was assessed by immunofluorescence. The relative proportion of b5 and b9 cytoplasmic Ig-stained cells (CSC) arising from the separated cells was determined to test directly whether B lymphocytes and their progeny are committed to the synthesis of Ig of one allotype. It was found that b5- and b9-bearing cells gave rise almost exclusively to b5- and b9-producing plasma cells, respectively, in both the in vivo and in vitro assay systems. Most of these CSC were probably not derived from previously existing CSC but arose as the result of the differentiation of lymphocytes with membrane Ig. When cell populations totally depleted of Ig-bearing lymphocytes were cultured, very few CSC were found, indicating that the majority of immediate precursors of CSC have membrane Ig. These results suggest that individual B cell clones are phenotypically restricted to the expression of immunoglobulin genes on one chromosome; the significance of this clonal allelic exclusion is discussed.
View details for Web of Science ID A1974S408900009
View details for PubMedID 4591172
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RESTRICTION OF GENE-EXPRESSION IN B LYMPHOCYTES AND THEIR PROGENY .2. COMMITMENT TO IMMUNOGLOBULIN HEAVY-CHAIN ISOTYPE
JOURNAL OF EXPERIMENTAL MEDICINE
1974; 140 (2): 452-469
Abstract
To determine whether or not B lymphocytes are committed to the synthesis of a single immunoglobulin heavy chain isotype during their differentiation into plasma cells, rabbit lymph node and Peyer's patch cells were separated into populations with and without membrane IgM, using a fluorescence-activated cell sorter (FACS). The potential of the micro-bearing (micro+) and non-micro-bearing (micro-) cells to give rise to plasma cells both in vivo after transfer into irradiated recipients and in vitro in the presence of pokeweed mitogen was assessed by immunofluorescence techniques, and the relative proportions of the cytoplasmic Ig-stained cells (CSC) synthesizing each class of heavy chains were determined. Most of the CSC arising in vitro from micro-bearing lymph node and Peyer's patch cells contained IgM; all IgM CSC appeared to be derived from micro+ cells. Peyer's patch lymphocytes, however, did not generate IgM CSC after cell transfer and thus may be functionally different from lymph node micro+ cells. It was found also that nearly all of the many IgA CSC generated by Peyer's patch lymphocytes either in culture or after transfer were derived from micro- cells. Further fractionation of these micro- cells with the FACS after they had been membrane stained with anti-b locus allotype reagents revealed that the precursors of IgA CSC belong to a minor population of cells which do have b locus light chain determinants on their membranes, although they do not have detectable micro-chains. These cells are not found in lymph nodes. Although the majority of Peyer's patch and lymph node cells were found to be precommitted to the synthesis of a single heavy chain isotype, a small proportion of cells may not be similarly restricted. Some of the CSC with membrane IgM were found to contain cytoplasmic IgA or IgG. In addition, micro+ populations did give rise to low numbers of IgA and IgG CSC. The implications of these results, obtained under experimental conditions, on the normal differentiation of B lymphocytes in situ are discussed.
View details for Web of Science ID A1974T838500012
View details for PubMedID 4603013
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IDENTIFICATION AND QUANTITATION OF THYMUS-DERIVED LYMPHOCYTES IN HUMAN PERIPHERAL-BLOOD
JOURNAL OF IMMUNOLOGY
1974; 112 (2): 520-527
View details for Web of Science ID A1974S040600011
View details for PubMedID 4130690
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ISOLATION OF ANTIGEN-BINDING CELLS FROM UNPRIMED MICE - DEMONSTRATION OF ANTIBODY-FORMING CELL PRECURSOR ACTIVITY AND CORRELATION BETWEEN PRECURSOR AND SECRETED ANTIBODY AVIDITIES
JOURNAL OF EXPERIMENTAL MEDICINE
1974; 140 (4): 904-920
Abstract
Cells binding DNP groups conjugated to fluoresceinated mouse gamma globulin ((F)DNP-MGG) were isolated from spleens of unprimed mice using a fluorescence-activated cell sorter (FACS). The isolated cells were specifically enriched at least 100-fold for anti-DNP precursor activity in an adoptive transfer assay as compared to unfractionated spleen. The fraction depleted of binding cells, although depleted of anti-DNP precursor activity, responded as well as unfractionated spleen when assayed for anticarrier (keyhole limpet hemocyanin [KLH]) precursor activity. High avidity binding cells were stained using low concentrations of (F)DNP-MGG. Medium and low avidity binding cells were stained using high concentrations of (F)DNP-MGG in the presence of free hapten which selectively blocked staining of the high avidity binding cells. Cells were supplemented with an excess of carrier-primed (KLH), nylon-purified splenic T cells and transferred to irradiated recipients. DNP-KLH was given at transfer and 5 days later. The anti-DNP plaque-forming cell (DNP-PFC) response and the avidities of the DNP-PFC in the irradiated recipients were measured by hapten inhibition of direct PFC plaque formation 12 days after transfer. At this time, very few indirect PFC were found. There was a positive correlation between the avidity of the DNP-binding cells and the avidity of the anti-DNP antibody secreted by their progeny. High avidity DNP-binding cells gave rise to predominantly high avidity anti-DNP-PFC. Medium and low avidity binding cells gave rise to medium and low avidity DNP-PFC.
View details for Web of Science ID A1974U366800003
View details for PubMedID 4139227
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LYMPHOCYTE COMMITMENT TO IG ALLOTYPE AND CLASS
ANNALES D IMMUNOLOGIE
1974; C125 (1-2): 271-276
View details for Web of Science ID A1974R968600029
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MOUSE IMMUNOGLOBULIN ALLOTYPES - CHARACTERIZATION AND USE IN CELLULAR IMMUNOLOGY
ANNALES D IMMUNOLOGIE
1974; C125 (1-2): 71-83
View details for Web of Science ID A1974R968600008
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IMMUNOGLOBULIN (IG) ALLOTYPE MARKERS ON RABBIT LYMPHOCYTES - SEPARATION OF CELLS BEARING DIFFERENT ALLOTYPES AND DEMONSTRATION OF BINDING OF IG TO LYMPHOID-CELL MEMBRANES
JOURNAL OF IMMUNOLOGY
1973; 111 (5): 1334-1348
View details for Web of Science ID A1973R254000004
View details for PubMedID 4126772
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RABBIT ANTISERUM TO A THYMUS EXTRACT SPECIFIC FOR MOUSE THYMUS-DERIVED CELLS
JOURNAL OF IMMUNOLOGY
1973; 110 (5): 1222-1232
View details for Web of Science ID A1973P988200004
View details for PubMedID 4633295
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ACTIVE SUPPRESSION OF IMMUNOGLOBULIN ALLOTYPE SYNTHESIS .3. IDENTIFICATION OF T CELLS AS RESPONSIBLE FOR SUPPRESSION BY CELLS FROM SPLEEN, THYMUS, LYMPH-NODE, AND BONE-MARROW
JOURNAL OF EXPERIMENTAL MEDICINE
1973; 137 (6): 1311-1324
Abstract
Thymus-derived cells (T cells) that actively suppress production of IgG2a immunoglobulins carrying the Ig-1b allotype have been found in adult (SJL x BALB/c)F(1) mice exposed to anti-Ig-1b early in life. The suppression is specific for Ig-1b. The allelic product, Ig-1a, is unaffected. Spleen, lymph node, bone marrow, or thymus cells from suppressed mice suppress production of Ig-1b by syngeneic spleen cells from normal F(1) mice. When a mixture of suppressed and normal cells is transferred into lethally irradiated BALB/c mice, there is a short burst of Ig-1b production after which Ig-1b levels in the recipient fall rapidly below detectability. Pretreatment of the cells from the suppressed mice with antiserum specific for T cells (anti-Thy-1b) plus complement before mixture destroys the suppressing activity. Similar results with suppressor cells were obtained in vitro using Mishell-Dutton cultures. Mixture of spleen cells from suppressed animals with sheep erythrocyte (SRBC)-primed syngeneic normal spleen before culture suppresses Ig-1b plaque-forming cell (PFC) formation while leaving Ig-1a PFC unaffected. Treatment of the suppressed spleen with anti-Thy-1b before transfer removes the suppressing activity.
View details for Web of Science ID A1973P838500001
View details for PubMedID 4541122
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ANALYSIS OF ANTI(T,G)-A--L ANTIBODY IN TETRAPARENTAL MICE
TRANSPLANTATION PROCEEDINGS
1973; 5 (1): 167-171
View details for Web of Science ID A1973P413100032
View details for PubMedID 4695941
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RAPID METHOD FOR ISOLATION OF FUNCTIONAL THYMUS-DERIVED MURINE LYMPHOCYTES
EUROPEAN JOURNAL OF IMMUNOLOGY
1973; 3 (10): 645-649
View details for Web of Science ID A1973R496800010
View details for PubMedID 4587740
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Active suppression of immunoglobulin allotype synthesis. II. Transfer of suppressing factor with spleen cells.
journal of experimental medicine
1972; 135 (5): 1163-1176
Abstract
The mechanism of chronic allotype suppression in (SJL x BALB/c)F(1) mice has been investigated by means of cell transfer studies. These mice are phenotypically negative for serum Ig-1b, the paternal allotype determinant on gammaG(2a) immunoglubulin, as a result of perinatal exposure to maternal anti-Ig-1b. When spleen or bone marrow (B) cells from suppressed mice were injected into irradiated BALB/c "indicator" hosts, detectable levels of Ig-1b were demonstrated in the sera of a majority of the recipients early after transfer. These results indicate that Ig-1b-producing cells or their precursors are present in the lymphoid tissues of suppressed mice, even though they are not expressed. Within 5-7 wk, it was no longer possible to detect Ig-1b in the sera of these hosts, although cells producing another paternal allotype (Ig-4b) were shown to persist. Control BALB/c mice, injected with spleen and B cells from normal mice, continued to produce high levels of immunoglobulin carrying this allotype. The disappearance of serum, Ig-1b occurred most frequently in the recipients of suppressed spleen cells. Similar results were obtained using a mixture of spleen cells from normal and suppressed mice. Ig-1b production in the recipient mice ceased within a few weeks, even though the majority of cells in the mixture were obtained from normal (nonsuppressed) donors. The data are interpreted as evidence that chronic allotype suppression in mice is actively maintained by cells which are resident in the lymphoid tissues, splenic cells being the most effective. These cells are capable of proliferating in a new host and exerting their suppressive influence on Ig-1b-producing cells and/or their precursors.
View details for PubMedID 4623317
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DEMONSTRATION THAT ANTIGEN-BINDING CELLS ARE PRECURSORS OF ANTIBODY-PRODUCING CELLS AFTER PURIFICATION WITH A FLUORESCENCE-ACTIVATED CELL SORTER
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1972; 69 (7): 1934-?
Abstract
We have obtained viable and functional populations of antigen-binding cells enriched up to 500-fold from primed spleen-cell suspensions by fluorescent labeling and by a new electronic cell sorter that sorts viable cells according to fluorescence. Concomitantly, populations largely depleted of antigen-binding cells were obtained. While neither population alone is capable of a full adoptive secondary response when injected into irradiated recipients, a reconstituted mixture restores the full response of the unfractionated spleen cells. Admixture of sources of unprimed thymus-derived cells (T-cells) with the purified antigen-binding cells (B-cells) restores much of the full response.
View details for Web of Science ID A1972N026000065
View details for PubMedID 4114858
View details for PubMedCentralID PMC426835
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ACTIVE SUPPRESSION OF IMMUNOGLOBULIN ALLOTYPE SYNTHESIS .2. TRANSFER OF SUPPRESSING FACTOR WITH SPLEEN-CELLS
JOURNAL OF EXPERIMENTAL MEDICINE
1972; 135 (5): 1163-?
View details for Web of Science ID A1972YY84000012
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Chronic allotype suppression in mice: an active regulatory process.
Annals of the New York Academy of Sciences
1971; 190: 212-220
View details for PubMedID 5290015
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CHRONIC ALLOTYPE SUPPRESSION IN MICE - ACTIVE REGULATORY PROCESS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1971; 190: 212-?
View details for Web of Science ID A1971L715600017
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MOUSE LYSOZYME PRODUCTION BY A MONOCYTOMA - ISOLATION AND COMPARISON WITH OTHER LYSOZYMES
SCIENCE
1970; 168 (3939): 1595-?
Abstract
A transplantable mouse tumor, GPC-11, produces large amounts of lysozyme. The tumor is a reticulum cell sarcoma, type A, and is a neoplasm of monocytes. The lysozyme was purified from mouse urine in quantities sufficient for structural analysis. Comparison of mouse lysozyme with lysozymes from; chicken egg white and patients with monocytic leukemia reveals similarities in size and electrophoretic mobility and, with human lysozyme, in functional properties; but considerable differences are found in antigenic characteristics and amino acid composition.
View details for Web of Science ID A1970G609400031
View details for PubMedID 4911872
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IMMUNOGLOBULIN SYNTHESIS IN MICE - SUPPRESSION BY ANTI-ALLOTYPE ANTIBODY
JOURNAL OF EXPERIMENTAL MEDICINE
1967; 126 (4): 701-?
Abstract
In the mouse, antibody directed against an immunoglobulin allotype, Ig-1b, passed from mother to offspring or injected into neonates, suppresses synthesis of immunoglobulin carrying Ig-1b. In allotype homozygotes as well as heterozygotes the allotype suppression is manifested both by a delay of several weeks in attaining initial detectable allotype levels and a reduction in allotype level continuing into adulthood. A possible mechanism for the differentiation of the immune system consistent with both the kinetics of suppression reported here for the mouse and the comparatively longer lived and more complete allotype suppression described for the rabbit is discussed. Evidence for a strong intralitter (as opposed to interlitter) correlation of age of onset of immunoglobulin allotype synthesis is presented.
View details for Web of Science ID A19679972400010
View details for PubMedID 4168099
View details for PubMedCentralID PMC2138387
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IMMUNOGLOBULIN ISOANTIGENS ( ALLOTYPES ) IN MOUSE .I. GENETICS AND CROSS-REACTIONS OF 7S GAMMA2A-ISOANTIGENS CONTROLLED BY ALLELES AT IG-1 LOCUS
JOURNAL OF EXPERIMENTAL MEDICINE
1965; 121 (3): 415-?
Abstract
Eight antigens of 7S gamma(2)-immunoglobulins controlled by alleles at a single locus Ig-1, have been identified in mice. This locus has previously been shown to determine antigenic specificities on the F fragments of 7S gamma(2a)-globulins. The reactions of these antigens with various isoantisera have shown that the antigens all cross react with one another. New methods for the analysis of antigenic specificities of soluble proteins are presented in detail. A sensitive method for detecting in the order of 0.01 microg of these isoantigens has been developed, based on the quantitative inhibition of precipitation of I(125)-labeled antigen. Cross-reactions of the antigens were analysed in inhibition assays and the data is compatible with the existence of a minimum of eight antigenic specificities. Each of the antigens is composed of different combinations of these specificities, with only one antigen having a specificity not present in any other. Sixty-eight mouse strains have been tested with specific isoantisera, and on the basis of the results, have been placed into the eight allele groups. Evidence for close genetic linkage of the Ig-1 locus and 11 chromosome markers has been sought and not found.
View details for Web of Science ID A19656206100007
View details for PubMedCentralID PMC2137960
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ISOIMMUNIZATION ASSOCIATED WITH CESAREAN SECTION IN MOUSE
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
1964; 90 (6): 776-?
View details for Web of Science ID A19643203A00009
View details for PubMedID 14233667
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PREGNANCY INDUCED HEMAGGLUTININS TO PATERNAL H-2 ANTIGENS IN MULTIPAROUS MICE
TRANSPLANTATION
1964; 2 (3): 357-361
View details for Web of Science ID A1964WM64600004
View details for PubMedID 14144347
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GENETICS OF A GAMMA GLOBULIN ISOANTIGEN (ALLOTYPE) IN MOUSE
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
1963; 49 (5): 592-?
View details for Web of Science ID A19639818B00032
View details for PubMedID 16591071
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IN VITRO STUDIES OF MAMMALIAN SOMATIC CELL VARIATION .2. ISOIMMUNE CYTOTOXICITY WITH A CULTURED MOUSE LYMPHOMA AND SELECTION OF RESISTANT VARIANTS
JOURNAL OF EXPERIMENTAL MEDICINE
1963; 117 (2): 267-?
Abstract
When long term cultures of mouse lymphoma cells, known to possess the isoantigenic phenotype determined by the H-2(d) allele, are incubated with anti H-2d isoantibody and guinea pig complement, slightly more than 99 per cent of cells are killed under optimal conditions. Growth in mass culture and colony formation by single cells after incubation with isoantibody and complement are employed to assess the cytotoxic effect. The cytotoxic action of isoantibody is complement-dependent, for viability of cells exposed to antibody alone is unaltered. When excess isoantibody and optimum concentrations of complement are used, killing begins as soon as these reagents are mixed with the cells, and no further killing occurs after 5 to 15 minutes at 37 degrees C. About 80 per cent of cells are killed with an isoantiserum containing antibody to two isoantigenic components of the H-2d complex. That the cytotoxic action is mediated through the H-2 isoantigen is shown by (a) isoantiserum containing only anti H-2d antibody produces maximal cell killing, and (b) isoantiserum from which anti H-2d antibody has been removed by absorption loses all cytotoxic activity. Variant cells resistant to the cytotoxic action of anti H-2d isoantibody were isolated from lymphoma cell populations surviving multiple exposures to isoantibody and complement. These variants can be distinguished morphologically from the isoantibody-sensitive parent cell line. Although variants are resistant to anti H-2d isoantibody, these cells possess H-2d isoantigen but in a lower concentration than found in cells of the parent line. The basis for resistance to cytotoxic isoantibody is discussed.
View details for Web of Science ID A19634832B00002
View details for PubMedID 14018309
View details for PubMedCentralID PMC2137607
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IN VITRO STUDIES OF MAMMALIAN SOMATIC CELL VARIATION .1. DETECTION OF H-2 PHENOTYPE IN CULTURED MOUSE CELL LINES
JOURNAL OF EXPERIMENTAL MEDICINE
1963; 117 (2): 259-?
Abstract
The isoantigenic phenotype of the H-2 locus has been detected by isohemagglutinin absorption in a line of mouse lymphoma cells growing continuously in culture for 6 years and in two established lines of fibroblastic mouse cells growing continuously in culture for 1 year. Quantitative absorption studies suggest that the concentration of H-2 isoantigens is higher in the cultured lymphoma cells than in the other two fibroblastic cell lines.
View details for Web of Science ID A19634832B00001
View details for PubMedID 14018308
View details for PubMedCentralID PMC2137608