PREFERENTIAL POSITIVE SELECTION OF V-ALPHA-2+CD8+ T-CELLS IN MOUSE STRAINS EXPRESSING BOTH H-2K AND T-CELL RECEPTOR V-ALPHA-A HAPLOTYPES - DETERMINATION WITH A V-ALPHA-2-SPECIFIC MONOCLONAL-ANTIBODY

A monoclonal antibody, B20.1, was generated by fusing spleen cells from a Lou rat immunized with a soluble alpha/beta-T cell receptor (TcR; V(alpha)2/V(beta)2) to mouse myeloma cells. Analysis of a panel of V(alpha)2 mRNA-expressing T cell lines, hybridomas and transfectants revealed that the B20.1 antibody was specific for murine TcR V(alpha)2 chains. The V(alpha)2+ T cell population was examined in various inbred strains by two-color immunofluorescence using B20.1 and CD4- and CD8-specific antibodies with the following results: (a) the B20.1 antibody detected most members of the TcR V(alpha)2 subfamily in the four TcR V(alpha) haplotypes tested; (b) in most strains examined, TcR V(alpha)2 expression was biased to the CD4 subset (7.4%-17.4% V(alpha)2+ T cells) as compared to the CD8 compartment (3.8%-13.3%); (c) TcR V(alpha)2 expression was not influenced by Mls gene products and (d) increased positive selection of V(alpha)2+ CD8+ T cells by H-2k major histocompatibility complex molecules occurred in all murine strains tested of the TcR V(alpha)a, but not in those bearing the TcR V(alpha)b haplotype.