PRODUCTION OF MINOR LYMPHOCYTE STIMULATORY-1(A) ANTIGENS FROM T-CELL SUBSETS

T cell subsets that produce minor lymphocyte stimulatory (Mis) antigens were analyzed using mixed lymphocyte reaction (MLR) in vitro or clonal elimination assay in vivo. When lymph node T cells from B10.BR(Mls-l(b)) mice were stimulated with various T cell subsets from AKR (Mls-1(2)) mice in the presence of B10.BR antigen presenting cells (APC), proportions of Mls-1(2) reactive T cell blasts (V beta 6(+), V beta 8.1(+)) increased. The stimulatory potency of CD8(+) T cells was higher than that of CD4(+) T sells. Furthermore, among either CD8(+) or CD4(+) T cell subset, CD44(+) T cells appeared to produce larger amounts of Mls-1(2) antigens than CD44(-) T cells. More marked difference was demonstrated, when stimulator AKR T cells were bring activated by immobilized anti-T cell antigen receptor (TCR) antibody during MLR. Thus, AKR T cells appeared to produce large amounts of Mls-1(a)) antigens on appropriate stimulations. These findings were confirmed by the semiquantitative analysis of mRNA levels of MTV-7 in the AKR T cell subsets. When CD8(+)CD44(+) T cells from (AKR x B10.BR)F-1 mice were injected intravenously into [B10.BR --> B10.BR] syngeneic bone marrow (BM) chimeras 1 week after BM reconstitution and proportions of V beta 6(+) T cells were quantitated 7 weeks later, significant clonal elimination of V beta 6(+) T cells was induced among both thymocyte population and lymph node T cell population in a dose-dependent manner of the inoculated F-1 T cells. Inoculation of CD8(+)CD44(-)F(1) T cells eliminated V beta 6(+) T cells less efficiently from lymph node T cells and inoculation of CD4(+) F-1 T cells induced no significant clonal elimination of the V beta 6(+) T cells. The present findings demonstrate clearly that CD8(+)CD44(+) T cells represent the cells producing large amounts of Mls-1(a) antigens and inducing clonal elimination of V beta 6(+) T cells in vivo.