Expression of E10 antigen on functionally distinct human T-cell subpopulations: comparison with 3A1 defined subsets.

Using PWM-driven immunoglobulin synthesis, we studied the regulatory effects of the peripheral blood T-lymphocyte subpopulations defined by the E10 antigen. This previously described antigen (E10) is present on 60% of TPBL, of T4+, and of T8+ cells. The helper activity on PWM-driven B-cell differentiation appears to be highly increased in E10- T cells. This higher capacity does not apparently reflect a different susceptibility to suppressor influences as comparable results were obtained when such suppressor influences are minimized either by removal of T8+ cells from E10- and E10+ T cells, or by removal of monocytes from responding B-cell populations. In contrast, the relative function of T-cell subsets defined by the related antigen 3A1 are influenced by the presence of suppressor cells. It is only in the presence of both T8+ cells and monocytes that 3A1+ cells exhibit a higher inducer effect. Our results suggest that E10 and 3A1 antigens--although showing strong distribution homologies--define different regulatory T-cell populations.