Surface Lyt phenotype of suppressor cells in C57BL/6 mice infected with Mycobacterium lepraemurium.

C57BL/6 were infected intravenously with 10(7) Mycobacterium lepraemurium (MLM). At increasing time intervals after infection different isolated splenic cell subpopulations were tested for their ability to suppress the mixed lymphocyte reaction (MLR) of normal syngeneic mouse splenocytes. During the first 6 months after infection neither T depleted nor plastic adherent spleen cells from infected mice exerted a suppressive activity on the normal mouse allogeneic proliferative response. Conversely, splenic T cells from MLM infected mice exhibited suppressive activity as early as 2 months after infection. Attempts to characterize the Lyt phenotype of splenic suppressor T cells from 6 months infected mice showed that both Lyt 1+ 2- and Lyt 2+ enriched cell subsets possessed the ability to suppress the MLR of the normal mouse spleen cells and Lyt 1+ 2- T cells were shown to be more efficient suppressors than Lyt 2+ cells.