The Role of LAG3 in Antibody Responses to Kidney Transplantation
1Inflammation and Immunity, Cleveland Clinic, Lerner Research Institute, Cleveland, OH, 2Cardiovascular and Metabolic Science, Cleveland Clinic, Lerner Research Institute, Cleveland, OH, 3Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL
Meeting: 2022 American Transplant Congress
Abstract number: 197
Keywords: Antibodies, Kidney transplantation, Mice
Topic: Basic Science » Basic Science » 04 - B-cell / Antibody /Autoimmunity
Session Information
Session Time: 8:10am-9:15am
Presentation Time: 9:00am-9:15am
Location: Hynes Veterans Auditorium
*Purpose: The functions of coinhibitory receptor lymphocyte activation gene-3 (LAG3) in T cells are well studied, however its role in humoral immune responses remains poorly characterized. The goal of this study was to test the role of recipient LAG3 in a mouse model of renal allograft rejection.
*Methods: Murine kidney transplant surgeries were performed from C3H (H-2Dk) donors to B6 WT, LAG3-/-, CD4CreLAG3fl/fl & CD19CreLAG3fl/fl recipients (H-2Db) after bilateral nephrectomy. Grafts were evaluated by immunistochemistry. WT recipients were treated with anti-mCD20 or anti-CD8 mAbs to deplete B cells or CD8 T cells, respectively. Immune responses were assessed by flow cytometry, ELISPOT assay, and serum levels of MHC-I and MHC-II-reactive IgG donor specific antibody (DSA) were determined by ELISA.
*Results: Compared to WT animals, naïve B6.LAG3-/- mice have elevated numbers of CD44hi memory T cells, CXCR5hi follicular T cells, and B220+CD138+ plasma cells, and increased frequencies of memory T cells reactive to H-2Dd, H-2Ds, H-2Dq and H-2Dk alloantigens. All C3H kidney allografts survived for > 60d (n=5) in WT recipients, whereas recipient LAG3 deficiency led to rapid allograft rejection (MST of 14d, n=5) and elevated serum creatinine levels at d14 posttransplant. Graft histology at rejection revealed minimal T cell infiltration, diffuse C4d staining, atrophic peritubular capillaries, endothelial swelling and edema characteristic of antibody mediated rejection (AMR). Compared to WT, LAG3-/- recipients had elevated frequencies of anti-donor IFNγ producing T cells and increased levels of DSA against MHC-I and MHC-II. Recipient CD8 T cell depletion did not alter rejection kinetics in LAG3-/- recipients (MST of 16d), while B cell depletion significantly extended C3H kidney allograft survival (MST of >30d), suggesting the predominant role of alloantibody rather than T cell mediated rejection in these mice. However, neither T nor B cell conditional knockout recipients rejected the allograft demonstrating LAG3 expression on both cell types is necessary to mediate rejection.
*Conclusions: These findings demonstrate that LAG3 regulates both T and B cell functions in response to kidney allografts, and is an attractive therapeutic target for the prevention of AMR.
To cite this abstract in AMA style:
Nicosia M, Fan R, Lee J, Gorbacheva V, Beavers AM, Dvorina N, III WBaldwin, Fairchild RL, Min B, Valujskikh A. The Role of LAG3 in Antibody Responses to Kidney Transplantation [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/the-role-of-lag3-in-antibody-responses-to-kidney-transplantation/. Accessed December 13, 2024.« Back to 2022 American Transplant Congress