Clinical Assistant Professor, Comparative Medicine
A Cross-sectional Survey on Rodent Environmental Health Monitoring Practices: Benchmarking, Associations, and Barriers.
Journal of the American Association for Laboratory Animal Science : JAALAS
2023; 62 (1): 64-73
Tens of thousands of rodents are used each year in Rodent Health Monitoring programs. However, Environment Health Monitoring (EHM) could replace sentinel rodent use while maintaining or even improving diagnostic quality. Despite its advantages, widespread implementation of EHM appears to be relatively low. To better understand EHM's prevalence and factors influencing its use, we surveyed research animal professionals. Our hypotheses were (1) EHM prevalence would be low and (2) EHM use would be associated with beliefs and knowledge about EHM. Participants were recruited via online promotion. A total of 158 individuals completed a mixed-methods survey about current practices, beliefs, and knowledge about EHM. Qualitative data were coded using thematic analysis and analyzed using generalized linear models. Results showed that current EHM implementation was low; only 11% of institutions used EHM exclusively. Across the 111 institutions surveyed, over 20,000 soiled bedding sentinels were used each year. However, most participants believed EHM to be advantageous in replacing sentinel animals (78% of participants). Some participants believed EHM could save time (31%), cost less (27%), and be highly accurate (15%). Conversely, some participants believed EHM would be difficult to use due to their current caging type (40%), higher costs (21%), lower accuracy (16%), and personnel attitudes/expertise (14%). Overall, respondents with higher planned EHM use also had more positive attitudes, norms, and control of EHM. We also identified several factors that could promote the implementation of EHM. Communication efforts should emphasize that EHM is compatible with various types of caging, can provide cost savings, has high accuracy, and is consistent with the 3Rs as a replacement. Efforts should also focus on improving attitudes, encouraging peers, and providing resources to facilitate implementation. Implementation in just the surveyed institutions could eliminate the need for well over 20,000 rodents each year, consistent with 3Rs goals.
View details for DOI 10.30802/AALAS-JAALAS-22-000086
View details for PubMedID 36755202
Efficacy of Supplemental Diet Gels for Preventing Postoperative Weight Loss in Mice (Mus musculus).
Journal of the American Association for Laboratory Animal Science : JAALAS
This study investigated whether the use of commercially available diet gels prevented the postoperative weight loss associated with major survival surgery in mice. C57BL/6 mice were divided into 3 groups (n = 9 per group) that received moistened chow pellets alone or with one of 2 commercially available diet gels. Mice began receiving the test diets 3 d before surgery (baseline) and were weighed daily for 7 d after surgery. On day 0, mice underwent ventral midline laparotomy, during which the intestines were manipulated for 2 min and a segment of jejunum was briefly clamped. Compared with the baseline value for the same group, body weights for the mice that received moistened chow only were significantly lower on all postoperative days (days 1 through 7). In contrast, body weights of mice that received both moistened chow and diet gel differed from baseline only on days 2 and 3 for one product and were never different from baseline for the other product. This study indicates that the combination of diet gel and moistened chow prevented or mitigated postoperative weight loss after a laparotomy procedure in mice.
View details for DOI 10.30802/AALAS-JAALAS22-000030
View details for PubMedID 36410729
Shotgun Immunoproteomics for Identification of Nonhuman Leukocyte Antigens Associated With Cellular Dysfunction in Heart Transplant Rejection.
2022; 106 (7): 1376-1389
The International Society for Heart and Lung Transplant consensus panel notes that too little data exist regarding the role of non-HLA in allograft rejection. We developed a novel shotgun immunoproteomic approach to determine the identities and potential roles non-HLA play in antibody-mediated rejection (AMR) in heart transplant recipients.Serum was collected longitudinally from heart transplant recipients experiencing AMR in the absence of donor-specific anti-HLA antibodies (n = 6) and matched no rejection controls (n = 7). Antidonor heart affinity chromatography columns were formed by recipient immunoglobulin G immobilization at transplantation, acute rejection, and chronic postrejection time points. Affinity chromatography columns were used to capture antigens from individual patient's donor heart biopsies collected at transplantation. Captured proteins were subjected to quantitative proteomic analysis and the longitudinal response was calculated.Overlap in antigen-specific response between AMR and non-AMR patients was only 8.3%. In AMR patients, a total of 155 non-HLAs were identified, with responses toward 43 high prevalence antigens found in ≥50% of patients. Immunofluorescence staining for representative high prevalence antigens demonstrated that their abundance increased at acute rejection, correlating with their respective non-HLA antibody response. Physiological changes in cardiomyocyte and endothelial cell function, following in vitro culture with patient immunoglobulin G, correlated with response toward several high prevalence antigens.This work demonstrates a novel high-throughput strategy to identify clinically relevant non-HLA from donor endomyocardial biopsy. Such a technique has the potential to improve understanding of longitudinal timing of antigen-specific responses and their cause and effect relationship in graft rejection.
View details for DOI 10.1097/TP.0000000000004012
View details for PubMedID 34923540
- Immunoproteomic Identification of Noncarbohydrate Antigens Eliciting Graft-Specific Adaptive Immune Responses in Patients with Bovine Pericardial Bioprosthetic Heart Valves. Proteomics. Clinical applications 2021; 15 (4): e2170034
Chronic graft-specific cell-mediated immune response toward candidate xenogeneic biomaterial.
2018; 66 (2): 288-298
Despite rabbits becoming an increasingly popular animal model, a flow cytometry panel that combines T cell markers (CD3, CD4, CD8, CD25, FOXP3) with a method for monitoring proliferation is lacking in this species. It has been shown that the rabbit model can be used to identify xenoantigens within bovine pericardium (BP), a common biological heart valve replacement material; however, these methods rely on monitoring the humoral immune response. The development of a rabbit T cell proliferation assay has utility in monitoring graft-specific cell-mediated immune responses toward bovine pericardium. Isolation and culture conditions were optimized to avoid cell death, red blood cell contamination, and non-specific proliferation. Effect of cell culture and stimulation on distribution and intensity of T cell markers was analyzed and compared between cells isolated from naïve and BP-immunized rabbits. Submaximal levels (0.25 μg/mL) of concavalin A were used to stimulate proliferation toward BP extract, with resultant proliferation compared between naïve and BP-immunized rabbits. Density stratification followed by ammonium potassium chloride (ACK) lysis yielded the greatest number of viable peripheral blood mononuclear cells with the least amount of erythrocyte contamination. Flat-bottomed plates were necessary to reduce non-specific proliferation in culture. T cells responded appropriately to maximal mitogenic stimulation (5 μg/mL concavalin A). Interestingly, immunization increased the intensity of FOXP3 in T regulatory cells compared to cells from naïve animals. With addition of submaximal levels of concavalin A, T cells from immunized rabbits proliferated in response to BP protein extract, while cells from naïve rabbits did not. In immunized rabbits, not only did more CD4+ T cells proliferate in response to BP re-stimulation, but the intensity of CD25 was increased indicating cell activation. This research provides a functional cell-mediated screening assay for assessment of BP-based biomaterials in rabbits, overcoming the limitations of previous humoral immune system-based assessments of biomaterial antigenicity in this important experimental animal species.
View details for DOI 10.1007/s12026-018-8985-8
View details for PubMedID 29446013
Cardiac Non-Human Leukocyte Antigen Identification: Techniques and Troubles.
Frontiers in immunology
2017; 8: 1332
Historically efforts have focused on the human leukocyte antigen (HLA) as the major cause for acute and chronic rejection following cardiac transplantation. However, rising evidence indicates that non-HLA antibodies can be both primary initiators and modifiers of antibody-mediated rejection (AMR) and cardiac allograft vasculopathy (CAV). The purpose of this review is to assess currently available technologies for non-HLA identification and leveraging such responses toward antibody quantification. Several techniques have been used to identify antigenic determinants of recipient graft-specific non-HLA humoral immune responses, but each comes with its own set of benefits and caveats. Improving our ability to detect non-HLA humoral immune response will aid in our understanding of the underlying antigenic determinants of AMR and CAV, as well as improve patient outcomes.
View details for DOI 10.3389/fimmu.2017.01332
View details for PubMedID 29093713
View details for PubMedCentralID PMC5651233
Antigenicity of Bovine Pericardium Determined by a Novel Immunoproteomic Approach.
2017; 7 (1): 2446
Despite bovine pericardium (BP) being the primary biomaterial used in heart valve bioprostheses, recipient graft-specific immune responses remain a significant cause of graft failure. Consequently, tissue antigenicity remains the principal barrier for expanding use of such biomaterials in clinical practice. We hypothesize that our understanding of BP antigenicity can be improved by application of a combined affinity chromatography shotgun immunoproteomic approach to identify antigens that have previously been overlooked. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) analysis of affinity chromatography purified antigens resulted in identification of 133 antigens. Most importantly, antigens were identified from all subcellular locations, including 18 integral membrane protein antigens. Critically, isoforms of several protein families were found to be antigenic suggesting the possibility that shared epitope domains may exist. Furthermore, proteins associated with immune, coagulation, and inflammatory pathways were over-represented, suggesting that these biological processes play a key role in antigenicity. This study brings to light important determinants of antigenicity in a clinically relevant xenogeneic biomaterial (i.e. BP) and further validates a rapid, high-throughput method for immunoproteomic antigen identification.
View details for DOI 10.1038/s41598-017-02719-8
View details for PubMedID 28550302
View details for PubMedCentralID PMC5446425