CYTOLYTIC T-LYMPHOCYTES FROM HUMAN RENAL-ALLOGRAFT BIOPSIES ARE TISSUE-SPECIFIC

The cytolytic activity of T lymphocytes infiltrating renal allografts from recipients undergoing episodes of acute cellular rejection was st udied. These T-cell populations, composed of both CD4+ and CD8+ cells, demonstrated significant cytolytic activity against both donor-derive d KCLs and B-LCLs. In five of 21 biopsy-derived lines greater cytolyti c activity was measured against donor KCLs compared to donor B-LCLs, s uggesting the presence of kidney antigen-specific, MHC-restricted clon es. Clones developed by stimulation with donor B-LCLs lysed both donor B-LCLs and KCLs while clones developed on donor KCLs as stimulator ce lls showed tissue specificity. Three of 26 clones recognized tissue-sp ecific antigens in the context of donor MHC class I antigens lysing do nor KCLs but not B-LCLs. These data demonstrate that a subpopulation o f T cells recognizing kidney-specific antigens are present in biopsies of renal allograft recipients undergoing acute cellular rejection. Th is subpopulation of tissue-specific cytotoxic T lymphocytes may prove to contribute significantly to the pathology of allograft rejection.