Role of endogenous peptides in murine allogenic cytotoxic T cell responses assessed using transfectants of the antigen-processing mutant 174xCEM.T2.

摘要: One model to explain the high frequency of alloreactive T cells proposes that allogeneic MHC molecules are recognized together with host cell-derived peptides. A system was developed investigate relevance this mechanism by expression H-2Dd or H-2Ld in 174xCEM.T2 (T2) cells. This human cell line contains a mutation its Ag-processing pathway should restrict association endogenous peptides surface class I molecules. CTL generated stimulating C57BL/6 (H-2b) responder transfectants B C1R murine lymphoma EL4 were assayed for their ability recognize alloantigenic determinants on these transfectants. The major fraction H-2Dd-specific response, MLC under clonal limiting dilution conditions, composed expressed cells, but failed molecule T2 Clonal analysis indicated approximately one-third unique stimulator whereas remainder also found Less than 10% H-2Dd-reactive transfectant, and clones killed C1R-Dd EL4-Dd. result suggests great majority formed complex absent significantly reduced Based recognition transfectants, exhibit some level specificity structure composition bound Examination specific revealed populations similar those described H-2Dd. In addition, new population present shared between C1R-Ld T2-Ld not EL4-Ld. These results consistent idea response is largely dependent presence peptide. However, they may indicate occupied one more other human, murine, significance current models alloreactivity discussed.