ELSEVIER zyxwvutsrq Cytolytic T Lymphocytes from Human Renal Allograft Biopsies Are Tissue Specific Nancy J. Poindexter, Nancy S. Steward, Surendra Shenoy, Martin D. Jendrisak, M . W ayne Flye, Todd K. Howard, and ‘I’. Mohanakumar ABSTRACT: The cytolytic activity of T lymphocytes infiltrating renal allografts from recipients undergoing episodes of acute cellular rejection was studied. These T-cell populations, composed of both CD4 + and CD8 + cells, demonstrated significant cytolytic activity against both donor-derived KCLs and B-LCLs. In live of 21 bi- opsy-derived lines greater cytolytic activity was measured against donor KCLs compared to donor B-LCLs, suggest- ing the presence of kidney antigen-specific, MHC- restricted clones. Clones developed by stimulation with donor B-LCLs lysed both donor B-LCLs and KCLs while ABBREVIATIONS B-LCL B lymphoblastoid cell line CTL cytolytic T lymphocyte E:T effector-to-target ratio IL-2 interleukin 2 KCL kidney cell line INTRODUCTION Despite improved immunosuppression therapy, allograft rejection remains a serious problem in renal transplanta- tion. The diagnosis of rejection often depends on histo- logic analysis of renal biopsies. Infiltration by mononu- clear cells is characteristic of rejection but the relation- ship between lymphocyte subpopulations and graft rejection has yet to be completely understood. Renal grafts undergoing acute rejection show both CD8 + and CD4 + [ 1, 21 infiltrating T-lymphocyte populations. These cells have been cultured in low concentrations of interleukin 2 (IL-2) and their functional activities char- zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE From the Departments of Surgwy and Pathology, W ashington University Medical School, St. Louis, Missouri, USA. Address reprint requests to Dr. T. Mohanakumar, Department of Sur- gery, Box 8109-CSRB 4449, W ashington Univwsity School of Medicine, 4939 Children’s Place, St. Louis, MO 63110, USA. Received November I, 1994; acceptedApril 11, 1995. Human Immunology 44, 43-49 (1995) 0 American Society for Histocompacibility and Immunogenetics, 1995 clones developed on donor KCLs as stimulator cells showed tissue specificity. Three of 26 clones recognized tissue-specific antigens in the context of donor MHC class I antigens lysing donor KCLs but not B-LCLs. These data demonstrate that a subpopulation of T cells recognizing kidney-specific antigens are present in biopsies of renal allograft recipients undergoing acute cellular rejection. This subpopulation of tissue-specific cytotoxic T lympho- cytes may prove to contribute significantly to the pathol- ogy of allograft rejection. Human Immunology 44, 43-- 49 (199s) MHC MLR PBL PHA major histocompatibility complex mixed lymphocyte reaction peripheral blood lymphocyte phytohemagglutinin acterized [3, 41. Expansion and cloning against donor B-lymphoblastoid cell lines (B-LCLs) have allowed the further characterization of infiltrating T lymphocytes. The results of these experiments have revealed that graft infiltrating CD8 + or CD4 + T lymphocytes are either cytolytic or proliferate in response to donor HLA class I or II antigens, depending on the functional assays and selection processes used ~3-61. Stimulation with donor B-LCLs has proven that CD8 + infiltrating cells are di- rected against HLA class I antigens and CD4 + cells are directed against HLA class II antigens 137. CD8 + cytolytic T lymphocytes (CTLs) recognize en- dogenous peptide bound to major histocompatibility complex (MHC) class I molecules on the surface of their target or stimulator cell 17, 81. Characterization of the peptides eluted from MHC class I molecules has uncov- ered sequence motifs for those peptides bound by MHC 0198~8859/95/%9.50 SSDI 0198-8859(95)00058-C