Alvina Chu, MD, is an adjunct clinical faculty member within the Division of Immunology and Rheumatology. She has practiced rheumatology for more than 10 years, specializing in treatment of a wide range of chronic inflammatory conditions including rheumatoid arthritis, lupus, vasculitis, and gout.
She holds a longstanding scientific interest in immunology, especially the role of B-cell signaling mechanisms in lupus and other autoimmune diseases.
In addition to taking care of patients in clinic and in the hospital, Dr. Chu enjoys teaching and mentoring fellows, residents, and medical students.
Residency: University of Chicago Medical Center Internal Medicine Residency (2005) IL
Fellowship: Stanford University Rheumatology Fellowship (2007) CA
Medical Education: State University of New York - Buffalo (2002) NY
Board Certification: American Board of Internal Medicine, Rheumatology (2007)
Evaluation of 230 patients with relapsed/refractory deletion 17p chronic lymphocyticleukaemia treated with ibrutinib from 3 clinical trials
BRITISH JOURNAL OF HAEMATOLOGY
2018; 182 (4): 504–12
Patients with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) with deletion 17p [del(17p)] have poor outcomes with chemoimmunotherapy. Ibrutinib is indicated for the treatment of CLL/SLL, including del(17p) CLL/SLL, and allows for treatment without chemotherapy. This integrated analysis was performed to evaluate outcomes in 230 patients with relapsed/refractory del(17p) CLL/SLL from three ibrutinib studies. With a median of 2 prior therapies (range, 1-12), 18% and 79% of evaluable patients had del(11q) or unmutated IGHV, respectively. With a median follow-up of 28 months, overall response rate was 85% and estimated 30-month progression-free and overall survival rates were 57% [95% confidence interval (CI) 50-64] and 69% (95% CI 61-75), respectively. Patients with normal lactate dehydrogenase or no bulky disease had the most favourable survival outcomes. Sustained haematological improvements in haemoglobin, platelet count and absolute neutrophil count occurred in 61%, 67% and 70% of patients with baseline cytopenias, respectively. New onset severe cytopenias and infections decreased in frequency over time. Progression-free and overall survival with ibrutinib surpass those of other therapies for patients with del(17p) CLL/SLL. These results provide further evidence of the robust clinical activity of ibrutinib in difficult-to-treat CLL/SLL populations.
View details for PubMedID 29873072
Prognostic Factors for Complete Response to Ibrutinib in Patients With Chronic Lymphocytic Leukemia A Pooled Analysis of 2 Clinical Trials
2018; 4 (5): 712–16
Ibrutinib, a first-in-class Bruton tyrosine kinase inhibitor taken once daily, is approved in the United States for patients with chronic lymphocytic leukemia/small lymphocytic lymphoma and allows for treatment without chemotherapy. Extended treatment with ibrutinib has demonstrated increased complete response (CR) rates over time.To analyze baseline factors that predict CR in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma treated with ibrutinib.Univariate and multivariate analyses of pooled data from 2 clinical trials were used to assess the prognostic value of baseline factors associated with CR in 327 patients from the PCYC-1102 and PCYC-1112 studies treated with single-agent ibrutinib. Participants were followed up in academic and community medical centers in the United States, the United Kingdom, Australia, France, Italy, Ireland, Poland, Spain, and Austria.Odds ratio (OR) of CR rate.The 327 patients included in this analysis had a median age of 67 years (range, 30-86 years) and 227 (69.4%) were male. At baseline, 185 patients (56.6%) had bulky disease (lymph node ≥5 cm), 184 (56.3%) had advanced-stage disease, and 182 (55.7%) had an Eastern Cooperative Oncology Group performance status of 1 or higher. Thirty-one patients (9.5%) were in the first-line setting; 38 (11.6%) had undergone 1 previous therapy, 81 (24.8%) had undergone 2, and 177 (54.1%) had undergone 3 or more; patients with relapsed/refractory disease had undergone a median of 3 (range, 0-12) previous therapies. Median time on study was 26.4 months (range, 0.3-55.6 months). Thirty-two of the 327 patients (9.8%) treated with ibrutinib had a CR (PCYC-1102: relapsed/refractory, 12 of 101 [11.9%]; treatment-naive, 8 of 31 [25.8%]; and PCYC-1112: 12 of 195 [6.2%]). The median time to CR for these patients was 14.7 months (range, 4.6-47.1 months). Univariate analysis of baseline factors showed that bulky disease, clinical stage, number of previous therapies, and β2-microglobulin concentration had a significant effect on the odds of CR. The final multivariate model showed that patients with no previous therapy vs patients with at least 1 previous therapy (OR, 2.65; 95% CI, 1.01-6.95; P = .047) and patients without bulky disease (lymph node <5 cm) vs those with bulky disease (lymph node ≥5 cm [OR, 4.97; 95% CI, 1.91-12.91; P = .001]) had an increased likelihood of CR.Patients receiving ibrutinib as a first-line therapy for chronic lymphocytic leukemia and those without bulky disease had a better likelihood of CR to treatment. The CR rate with continued longer-term ibrutinib treatment was higher than in previous reports.clinicaltrials.gov Identifiers: NCT01105247 and NCT01578707.
View details for PubMedID 29470582
View details for PubMedCentralID PMC5885180
Single-agent ibrutinib in treatment-naive and relapsed/refractory chronic lymphocytic leukemia: a 5-year experience
2018; 131 (17): 1910–19
We previously reported durable responses and manageable safety of ibrutinib from a 3-year follow-up of treatment-naïve (TN) older patients (≥65 years of age) and relapsed/refractory (R/R) patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We now report on long-term efficacy and safety with median follow-up of 5 years in this patient population with TN (N = 31) and R/R (N = 101) CLL/SLL. With the current 5-year follow-up, ibrutinib continues to yield a high overall response rate of 89%, with complete response rates increasing over time to 29% in TN patients and 10% in R/R patients. The median progression-free survival (PFS) was not reached in TN patients. The 5-year PFS rate was 92% in TN patients and 44% in R/R patients. Median PFS in R/R patients was 51 months; in those with del(11q), del(17p), and unmutated IGHV, it was 51, 26, and 43 months, respectively, demonstrating long-term efficacy of ibrutinib in some high-risk subgroups. Survival outcomes were less robust for R/R patients with del(17p) and those who received more prior therapies. The onset of grade ≥3 cytopenias, such as neutropenia and thrombocytopenia, decreased over time. Treatment--limiting adverse events were more frequent during the first year compared with subsequent periods. These results demonstrate sustained efficacy and acceptable tolerability of ibrutinib over an extended time, providing the longest experience for Bruton tyrosine kinase inhibitor treatment in patients with CLL/SLL. These trials were registered at www.clinicaltrials.gov as #NCT01105247 and #NCT01109069.
View details for PubMedID 29437592
View details for PubMedCentralID PMC5921964
Ibrutinib for patients with relapsed or refractory chronic lymphocytic leukaemia with 17p deletion (RESONATE-17): a phase 2, open-label, multicentre study
2016; 17 (10): 1409-1418
The TP53 gene, encoding tumour suppressor protein p53, is located on the short arm of chromosome 17 (17p). Patients with 17p deletion (del17p) chronic lymphocytic leukaemia have poor responses and survival after chemoimmunotherapy. We assessed the activity and safety of ibrutinib, an oral covalent inhibitor of Bruton's tyrosine kinase, in relapsed or refractory patients with del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma.We did a multicentre, international, open-label, single-arm study at 40 sites in the USA, Canada, Europe, Australia, and New Zealand. Patients (age ≥18 years) with previously treated del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma received oral ibrutinib 420 mg once daily until progressive disease or unacceptable toxicity. The primary endpoint was overall response in the all-treated population per International Workshop on Chronic Lymphocytic Leukaemia 2008 response criteria modified for treatment-related lymphocytosis. Preplanned exploratory analyses were progression-free survival, overall survival, sustained haematological improvement, and immunological improvement. Patient enrolment is complete, but follow-up is ongoing. Treatment discontinuation owing to adverse events, unacceptable toxicity, or death were collected as a single combined category. This study is registered with ClinicalTrials.gov, number NCT01744691.Between Jan 29, 2013, and June 19, 2013, 145 patients were enrolled. The all-treated population consisted of 144 patients with del17p chronic lymphocytic leukaemia or small lymphocytic lymphoma who received at least one dose of study drug, with a median age of 64 years (IQR 57-72) and a median of two previous treatments (IQR 1-3). At the prespecified primary analysis after a median follow-up of 11·5 months (IQR 11·1-13·8), 92 (64%, 95% CI 56-71) of 144 patients had an overall response according to independent review committee assessment; 119 patients (83%, 95% CI 76-88) had an overall response according to investigator assessment. In an extended analysis with median follow-up of 27·6 months (IQR 14·6-27·7), the investigator-assessed overall response was reported in 120 patients (83%, 95% CI 76-89). 24-month progression-free survival was 63% (95% CI 54-70) and 24-month overall survival was 75% (67-81). Sustained haematological improvement was noted in 72 (79%) of 91 patients with any baseline cytopenia. No clinically relevant changes were noted from baseline to 6 months or 24 months in IgA (median 0·4 g/L at baseline, 0·6 g/L at 6 months, and 0·7 g/L at 24 months), IgG (5·0 g/L, 5·3 g/L, and 4·9 g/L), or IgM (0·3 g/L at each timepoint) concentrations. Common reasons for treatment discontinuation were progressive disease in 34 (24%) patients and adverse events, unacceptable toxicity, or death in 24 (17%) patients. Major bleeding occurred in 13 (9%) patients (11 [8%] grade 3-4). Grade 3 or worse infections occurred in 43 (30%) patients, including pneumonia in 19 (13%) patients. In the extended analysis, 38 patients died, 18 as a result of adverse events (four pneumonia, three chronic lymphocytic leukaemia, two Richter's syndrome, two sepsis, and one each of acute myocardial infarction, septic shock, encephalopathy, general deterioration in physical health, abnormal hepatic function, myocardial infarction, and renal infarction).A high proportion of patients had an overall response to ibrutinib and the risk:benefit profile was favourable, providing further evidence for use of ibrutinib in the most difficult subset of patients with chronic lymphocytic leukaemia or small lymphocytic lymphoma. Ibrutinib represents a clinical advance in the treatment of patients with del17p chronic lymphocytic leukaemia and has been incorporated into treatment algorithms as a primary treatment for these patients.Pharmacyclics LLC, an AbbVie Company.
View details for DOI 10.1016/S1470-2045(16)30212-1
View details for Web of Science ID 000387055800042
View details for PubMedID 27637985
Development of Th17-Associated Interstitial Kidney Inflammation in Lupus-Prone Mice Lacking the Gene Encoding STAT-1
ARTHRITIS & RHEUMATOLOGY
2016; 68 (5): 1233-1244
Type I interferon (IFN) signaling is a central pathogenic pathway in systemic lupus erythematosus (SLE), and therapeutics targeting type I IFN signaling are in development. Multiple proteins with overlapping functions play a role in IFN signaling, but the signaling events downstream of receptor engagement are unclear. This study was undertaken to investigate the roles of the type I and type II IFN signaling components IFN-α/β/ω receptor 2 (IFNAR-2), IFN regulatory factor 9 (IRF-9), and STAT-1 in a mouse model of SLE.We used immunohistochemical staining and highly multiplexed assays to characterize pathologic changes in histology, autoantibody production, cytokine/chemokine profiles, and STAT phosphorylation in order to investigate the individual roles of IFNAR-2, IRF-9, and STAT-1 in MRL/lpr mice.We found that STAT-1(-/-) mice, but not IRF-9(-/-) or IFNAR-2(-/-) mice, developed interstitial nephritis characterized by infiltration with retinoic acid receptor-related orphan nuclear receptor γt-positive lymphocytes, macrophages, and eosinophils. Despite pronounced interstitial kidney disease and abnormal kidney function, STAT-1(-/-) mice had decreased proteinuria, glomerulonephritis, and autoantibody production. Phosphospecific flow cytometry revealed shunting of STAT phosphorylation from STAT-1 to STAT-3/4.We describe unique contributions of STAT-1 to pathology in different kidney compartments in a mouse model, and provide potentially novel insight into tubulointerstitial nephritis, a poorly understood complication that predicts end-stage kidney disease in SLE patients.
View details for DOI 10.1002/art.39535
View details for Web of Science ID 000375551600023
View details for PubMedID 26636548
View details for PubMedCentralID PMC4848130
A phase 2, randomised, placebo-controlled clinical trial of blisibimod, an inhibitor of B cell activating factor, in patients with moderate-to-severe systemic lupus erythematosus, the PEARL-SC study
ANNALS OF THE RHEUMATIC DISEASES
2015; 74 (9): 1667-1675
To evaluate the efficacy and safety of subcutaneous blisibimod, an inhibitor of B cell activating factor, in patients with systemic lupus erythematosus (SLE) in a dose-ranging Phase 2b clinical trial.547 patients with SLE with anti-double stranded DNA or antinuclear antibodies and Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) score ≥6 at baseline were randomised to receive placebo or blisibimod at one of 3 dose levels. The primary end point, measured at Week 24, was the SLE Responder Index-5 (SRI-5, meeting established SRI criteria but with ≥5 point improvement in SELENA-SLEDAI).Although SRI-5 response rates were not significantly improved in the pooled blisibimod groups compared with placebo, they were higher in subjects randomised to the highest dose of blisibimod (200 mg once-weekly (QW)) compared with pooled placebo, from Week 16 to Week 24, reaching statistical significance at Week 20 (p=0.02). SRI response rates compared with placebo were higher still in subjects who attained SELENA-SLEDAI improvements of ≥8, and in a subgroup of patients with severe disease (SELENA-SLEDAI ≥10 and receiving corticosteroids at baseline). In subjects with protein:creatine ratios of 1-6 at baseline, significant reductions in proteinuria were observed with blisibimod. Significant (p<0.01) changes in anti-double stranded DNA antibodies, complement C3 and C4, and reductions in B cells were observed with blisibimod.No imbalances in serious adverse events or infections (4/280 and 3/266), deaths (4/280 and 3/266) and malignancies (2/280 and 2/266) were reported for blisibimod compared with placebo.This study successfully identified a safe, effective and convenient dose, study population and end point for evaluation of blisibimod effect in Phase 3.NCT01162681.
View details for DOI 10.1136/annrheumdis-2013-205144
View details for Web of Science ID 000359378100014
View details for PubMedID 24748629
Tetramers reveal IL-17-secreting CD4+ T cells that are specific for U1-70 in lupus and mixed connective tissue disease.
Proceedings of the National Academy of Sciences of the United States of America
2015; 112 (10): 3044-3049
Antigen-specific CD4(+) T cells are implicated in the autoimmune disease systemic lupus erythematosus (SLE), but little is known about the peptide antigens that they recognize and their precise function in disease. We generated a series of MHC class II tetramers of I-E(k)-containing peptides from the spliceosomal protein U1-70 that specifically stain distinct CD4(+) T-cell populations in MRL/lpr mice. The T-cell populations recognize an epitope differing only by the presence or absence of a single phosphate residue at position serine(140). The frequency of CD4(+) T cells specific for U1-70(131-150):I-E(k) (without phosphorylation) correlates with disease severity and anti-U1-70 autoantibody production. These T cells also express RORγt and produce IL-17A. Furthermore, the U1-70-specific CD4(+) T cells that produce IL-17A are detected in a subset of patients with SLE and are significantly increased in patients with mixed connective tissue disease. These studies provide tools for studying antigen-specific CD4(+) T cells in lupus, and demonstrate an antigen-specific source of IL-17A in autoimmune disease.
View details for DOI 10.1073/pnas.1424796112
View details for PubMedID 25713364
View details for PubMedCentralID PMC4364210
Ibrutinib versus ofatumumab in previously treated chronic lymphoid leukemia.
New England journal of medicine
2014; 371 (3): 213-223
In patients with chronic lymphoid leukemia (CLL) or small lymphocytic lymphoma (SLL), a short duration of response to therapy or adverse cytogenetic abnormalities are associated with a poor outcome. We evaluated the efficacy of ibrutinib, a covalent inhibitor of Bruton's tyrosine kinase, in patients at risk for a poor outcome.In this multicenter, open-label, phase 3 study, we randomly assigned 391 patients with relapsed or refractory CLL or SLL to receive daily ibrutinib or the anti-CD20 antibody ofatumumab. The primary end point was the duration of progression-free survival, with the duration of overall survival and the overall response rate as secondary end points.At a median follow-up of 9.4 months, ibrutinib significantly improved progression-free survival; the median duration was not reached in the ibrutinib group (with a rate of progression-free survival of 88% at 6 months), as compared with a median of 8.1 months in the ofatumumab group (hazard ratio for progression or death in the ibrutinib group, 0.22; P<0.001). Ibrutinib also significantly improved overall survival (hazard ratio for death, 0.43; P=0.005). At 12 months, the overall survival rate was 90% in the ibrutinib group and 81% in the ofatumumab group. The overall response rate was significantly higher in the ibrutinib group than in the ofatumumab group (42.6% vs. 4.1%, P<0.001). An additional 20% of ibrutinib-treated patients had a partial response with lymphocytosis. Similar effects were observed regardless of whether patients had a chromosome 17p13.1 deletion or resistance to purine analogues. The most frequent nonhematologic adverse events were diarrhea, fatigue, pyrexia, and nausea in the ibrutinib group and fatigue, infusion-related reactions, and cough in the ofatumumab group.Ibrutinib, as compared with ofatumumab, significantly improved progression-free survival, overall survival, and response rate among patients with previously treated CLL or SLL. (Funded by Pharmacyclics and Janssen; RESONATE ClinicalTrials.gov number, NCT01578707.).
View details for DOI 10.1056/NEJMoa1400376
View details for PubMedID 24881631
- Assessing disease activity and outcome in systemic lupus erythematosus Rheumatology Elsevier. 2014; 6
- B-cell kinase inhibitors in rheumatoid arthritis Open Access Arthritis 2013; 1 (2): 17
- Design of clinical trials in rheumatology Oxford Textbook of Rheumatology Oxford University Press. 2013; 4
- Generic Versus Disease-specific Measures of Health-related Quality of Life in Systemic Lupus Erythematosus JOURNAL OF RHEUMATOLOGY 2011; 38 (9): 1821-1823
Measuring outcomes in systemic lupus erythematosus clinical trials
EXPERT REVIEW OF PHARMACOECONOMICS & OUTCOMES RESEARCH
2011; 11 (4): 455-468
The recent approval of the biologic therapy, belimumab, for treatment of systemic lupus erythematosus (SLE) by the US FDA has shifted the developmental landscape of therapeutics for this autoimmune disease. Promising therapies are currently in development for the treatment of SLE, with trials designed to emphasize clinically relevant end points. This article will discuss outcome measures that have been utilized including disease activity indices, definitions of flare, measures of damage, global assessments of disease activity and measures of health-related quality of life. Application of these outcome measures in recent trials are highlighted as illustrative examples. Contributions to the recent success of randomized controlled trials in SLE have included use of evidence-based responder indices, clear definitions of treatment failure, predefined management strategies for use of immunosuppressive agents and corticosteroids, sufficient sample sizes and efforts to identify responsive patient populations. Each completed study in SLE promises to better inform trial design and offer further opportunities for success in a field with a continuing unmet therapeutic need.
View details for DOI 10.1586/ERP.11.38
View details for Web of Science ID 000297021300018
View details for PubMedID 21831027
Natural Killer Cells From Children With Type 1 Diabetes Have Defects in NKG2D-Dependent Function and Signaling
2011; 60 (3): 857-866
Natural killer (NK) cells from NOD mice have numeric and functional abnormalities, and restoration of NK cell function prevents autoimmune diabetes in NOD mice. However, little is known about the number and function of NK cells in humans affected by type 1 diabetes. Therefore, we evaluated the phenotype and function of NK cells in a large cohort of type 1 diabetic children.Peripheral blood mononuclear blood cells were obtained from subjects whose duration of disease was between 6 months and 2 years. NK cells were characterized by flow cytometry, enzyme-linked immunosorbent spot assays, and cytotoxicity assays. Signaling through the activating NK cell receptor, NKG2D, was assessed by immunoblotting and reverse-phase phosphoprotein lysate microarray.NK cells from type 1 diabetic subjects were present at reduced cell numbers compared with age-matched, nondiabetic control subjects and had diminished responses to the cytokines interleukin (IL)-2 and IL-15. Analysis before and after IL-2 stimulation revealed that unlike NK cells from nondiabetic control subjects, NK cells from type 1 diabetic subjects failed to downregulate the NKG2D ligands, major histocompatibility complex class I-related chains A and B, upon activation. Moreover, type 1 diabetic NK cells also exhibited decreased NKG2D-dependent cytotoxicity and interferon-γ secretion. Finally, type 1 diabetic NK cells showed clear defects in NKG2D-mediated activation of the phosphoinositide 3-kinase-AKT pathway.These results are the first to demonstrate that type 1 diabetic subjects have aberrant signaling through the NKG2D receptor and suggest that NK cell dysfunction contributes to the autoimmune pathogenesis of type 1 diabetes.
View details for DOI 10.2337/db09-1706
View details for Web of Science ID 000288060300020
View details for PubMedID 21270236
View details for PubMedCentralID PMC3046846
Active and Latent Tuberculosis in Patients With Systemic Lupus Erythematosus Living in the United States
JCR-JOURNAL OF CLINICAL RHEUMATOLOGY
2009; 15 (5): 226-229
The prevalence and clinical course of tuberculosis infection have not been well described in patients with systemic lupus erythematosus (SLE) in the United States.This study documents the demographic, clinical, and laboratory characteristics and outcomes of patients with SLE and latent tuberculosis infection (LTBI) or active TB in an ethnically diverse clinic.We conducted a retrospective review of clinical records of patients with SLE followed during 2005 in a county community hospital rheumatology clinic, with a large immigrant population. Clinical characteristics were analyzed according to the patients' ethnicity, tuberculin skin test (TST) results, and history of treatment for latent or active TB.Data regarding a history of active TB or TST status were available for 187 of 220 patients seen in 2005 (85%). The prevalence of TB infection was highest in patients from TB endemic areas. Fourteen patients (7%) had active TB and 33 patients (18%) had LTBI. Among the 6 patients who developed active TB after the onset of SLE, 2 had pulmonary, 1 had extrapulmonary, and 3 had disseminated TB. Laboratory features and treatment regimens for SLE were similar in patients with a history of TB infection and in patients with a negative TST.A significant number of patients with SLE in a county clinic population in the United States had LTBI or TB. Treatment of active TB and latent TB yielded good outcomes with no deaths. US clinicians should consider screening SLE patients for LTBI, especially those from TB endemic areas.
View details for DOI 10.1097/RHU.0b013e3181b0c85d
View details for Web of Science ID 000268826800004
View details for PubMedID 19590444
IRF9 and STAT1 are required for IgG autoantibody production and B cell expression of TLR7 in mice
JOURNAL OF CLINICAL INVESTIGATION
2008; 118 (4): 1417-1426
A hallmark of SLE is the production of high-titer, high-affinity, isotype-switched IgG autoantibodies directed against nucleic acid-associated antigens. Several studies have established a role for both type I IFN (IFN-I) and the activation of TLRs by nucleic acid-associated autoantigens in the pathogenesis of this disease. Here, we demonstrate that 2 IFN-I signaling molecules, IFN regulatory factor 9 (IRF9) and STAT1, were required for the production of IgG autoantibodies in the pristane-induced mouse model of SLE. In addition, levels of IgM autoantibodies were increased in pristane-treated Irf9 -/- mice, suggesting that IRF9 plays a role in isotype switching in response to self antigens. Upregulation of TLR7 by IFN-alpha was greatly reduced in Irf9 -/- and Stat1 -/- B cells. Irf9 -/- B cells were incapable of being activated through TLR7, and Stat1 -/- B cells were impaired in activation through both TLR7 and TLR9. These data may reveal a novel role for IFN-I signaling molecules in both TLR-specific B cell responses and production of IgG autoantibodies directed against nucleic acid-associated autoantigens. Our results suggest that IFN-I is upstream of TLR signaling in the activation of autoreactive B cells in SLE.
View details for DOI 10.1172/JCI30065
View details for Web of Science ID 000254588600035
View details for PubMedID 18340381
View details for PubMedCentralID PMC2267033
Tissue specificity of E- and P-selectin ligands in Th1-mediated chronic inflammation
JOURNAL OF IMMUNOLOGY
1999; 163 (9): 5086-5093
The demonstrated role of E- and P-selectin ligands in the recruitment of Th1 cells raises the question of tissue specificity determination by pathogenic T cells. We took advantage of the fact that chronic Th1-mediated inflammation in the scid/scid CD4+CD45RBhigh T cell transfer model can occur at multiple tissue sites, resembling inflammatory bowel disease in the colon and psoriasis in the skin. We show that the majority of infiltrating effector T cells from psoriatic skin expresses high levels of functional P-selectin ligand (87 +/- 3%), detected by P-selectin-Ig (PIg), while a significantly smaller subset of T cells from colitic lesions expresses this ligand (24 +/- 2%). Similarly, E-selectin ligand is preferentially expressed on CD4+ T cells infiltrating the skin (24 +/- 2%), but only on very few CD4+ T cells infiltrating the colon (CIT; 1.3 +/- 0.8%). In contrast, CD4+ T cells infiltrating the skin express alpha4beta7 at a significantly lower level than CIT (mean fluorescence intensity, 28 vs 61, respectively), although, interestingly, alphaEbeta7 was expressed at high levels on both populations. Analysis of the disease-inducing potential of PIg+ and PIg- CD4+ CIT cells revealed that both populations not only express similar levels of the gut-homing molecule alpha4beta7 (mean fluorescence intensity, 50 vs 56, respectively), but do not differ in their capacity to express IFN-gamma. Furthermore, CIT depleted of cells expressing functional P-selectin ligand were able to induce colitis upon transfer, suggesting that induction of colitis in this model may be independent of E- and P-selectin. These results indicate that adhesion molecule expression and the homing pattern of inflammatory T cells are regulated by the local environment independently of their inflammatory capacity.
View details for Web of Science ID 000083256000059
View details for PubMedID 10528215
IL-12, independently of IFN-gamma, plays a crucial role in the pathogenesis of a murine psoriasis-like skin disorder
JOURNAL OF IMMUNOLOGY
1999; 162 (12): 7480-7491
The onset of acute psoriasis and the exacerbation of chronic psoriasis are often associated with a history of bacterial infection. We demonstrate that while only few scid/scid mice develop disease when CD4+CD45Rbhigh T cells are transferred alone, coadministration of LPS plus IL-12 or staphylococcal enterotoxin B into scid/scid mice 1 day after CD4+CD45Rbhigh T cell transfer greatly enhances disease penetrance and severity. Most importantly, the skin lesions induced by this method exhibit many of the histologic hallmarks observed in human psoriasis. Skin infiltrating CD4+ T cells were predominantly memory/effector cells (CD45Rblow) and exhibited a highly polarized Th1 phenotype. To test whether the development of pathogenic T cells was dependent on their production of IFN-gamma, we transferred IFN-gamma-/- CD4+CD45Rbhigh T cells into scid/scid or into T, B and NK cell-deficient scid/beige mice. Surprisingly, the incidence of psoriasis was similar to scid/scid animals that received IFN-gamma+/+ T cells, although acanthosis of the skin was attenuated. In contrast, the development of psoriasis was abolished if anti-IL-12 mAb was administered on day 7 and 35 after T cell transfer. Skin-derived IFN-gamma-/- inflammatory cells, but not cells from anti-IL-12-treated animals, secreted substantial amounts of TNF-alpha, suggesting that the inflammatory effect of IFN-gamma-/- T cells may be partly exerted by TNF-alpha and that the therapeutic effect of anti-IL-12 may depend on its ability to down-regulate both TNF-alpha and IFN-gamma. Overall, these results suggest that IL-12, independently of IFN-gamma, is able to induce pathogenic, inflammatory T cells that are able to induce psoriasiform lesions in mice.
View details for Web of Science ID 000080802000072
View details for PubMedID 10358203