CONTRIBUTION OF THE TCR ALPHA-CHAIN TO THE DIFFERENTIAL RECOGNITION OF BACTERIAL AND RETROVIRAL SUPERANTIGENS

The TCR alpha-chain has been implicated in superantigen recognition by some T cells. In this study, recognition of a retroviral (minor lymph ocyte stimulating Ag-l, Mls-1) and a bacterial (staphylococcal enterot oxin B, SEE) superantigen by T cells expressing an identical (transgen ic) V beta 8.1 beta-chain and either a V alpha 2(+) or V alpha 11(+) a lpha-chain have been compared. Individual hybridomas were found to var y in their recognition of the two superantigens. Whereas some T cell h ybridomas recognized both superantigens comparably, other hybridomas p referentially recognized either Mls-1 or SEE, indicating that the cont ribution of the TCR alpha-chain to recognition of these superantigens is not equivalent. The degree of heterogeneity in recognition varied b etween the V alpha 2(+) and V alpha 11(+) hybridomas, although there w ere individual hybridomas within each group with distinct patterns of reactivity that varied only in CDR3 alpha. These data are consistent w ith recent evidence that recognition of Mls-1 and SEE involves distinc t TCR/MHC interactions.