Preferential restriction of minor alloantigen-specific suppressor T cells to I-E rather than I-A molecules.

Suppressor T (Ts) cells specific for minor alloantigens can be generated by intravenous administration of high doses (10(8) cells) of alloantigenic spleen cells. Such Ts cells have previously been shown to inhibit the in vivo induction of CTL responses and are now shown to suppress in vitro proliferative responses to specific minor antigens. This report demonstrates that the activity of such antigen-specific Ts cells in four different strain combinations involving two haplotypes is blocked by anti-I-E antibody. The proliferative helper T cells (Th) in the same strain combinations are restricted to I-A molecules. Whether our results reflect a more general bias of suppressor T cells to be restricted to I-E molecules is discussed.