INCREASED FREQUENCY OF 2,4,6-TRINITROPHENYL (TNP)-SPECIFIC, H-2B-RESTRICTED CYTOTOXIC LYMPHOCYTE-T PRECURSORS IN TRANSGENIC MICE EXPRESSING A T-CELL RECEPTOR BETA-CHAIN GENE FROM AN H-2B-RESTRICTED, TNP-SPECIFIC CYTOLYTIC T-CELL CLONE

T cell antigen receptors (TcR) expressing V(alpha)10/J(alpha)BBM142 genes in association with beta-chains containing J(beta)2.6 elements were found to be predominant among 2,4,6-trinitrophenyl (TNP)-specific, H-2b-restricted cytolytic T cell lines (CTL). To assess the relative contribution of the TcR beta-chain to the TNP specificity as well as to the selection of the respective TcR alpha-chain elements we generated transgenic mice expressing the TcR beta-chain of the H-2b/TNP-specific CTL clone BT7.4.1. The TcR of this clone does not belong to the type predominant among H-2b/TNP-specific CTL, as it consists of an alpha-chain encoded by a V(alpha)8/J(alpha)DO gene rearrangement and a V(beta)2/J(beta)1.1-containing beta-chain. In the transgenic mice almost all T cells exclusively express the transgenic V(beta)2 gene, as a result of allelic exclusion. TNP-specific, H-2b-restricted precursors were found at 7- to 8-fold higher frequency in these mice as compared with non-trangenic littermates. In H-2b/d heterozygous transgenic mice, an increased frequency of TNP-specific precursors was found only in H-2b, but not in H-2d-restricted CTL. Analysis of H-2b/TNP-specific CTL lines derived from V(beta)2-transgenic mice indicated a preferential association of the transgenic TcR beta-chain with endogenous alpha-chains encoded by V(alpha)8 and J(alpha)BBM142 genes. This suggests that the hapten TNP is recognized like typical peptide antigens by combinatorial TcR-alpha and beta-contact sites.