Phenotypic identification of suppressor‐effector, suppressor‐amplifier and suppressor‐inducer T cells of B cell differentiation in man

Abstract
Using monoclonal anti-Leu 8 antibody to isolate subpopulations of human helper/inducer (CD4+) and suppressor/cytotoxic (CD8+) T cells, we have investigated the role of these subpopulations in the regulation of B cell differentiation in the human autologous mixed leukocyte reaction (AMLR). Whereas AMLR-activated CD8+,Leu8 cells were capable of suppressing fresh AMLR cultures in the absence of fresh CD8+ cells, CD8+, Leu8+ cells suppressed only those cultures containing fresh CD8+ cells. On the other hand, CD8+, Leu8 cells became suppressor cells only when cultured in the presence of CD8+,Leu8+ cells. Finally, the development of CD8+ suppressor cells was dependent on the presence of CD4+,Leu8+ cells; CD4+,Leu8 cells were incapable of acting as suppressor-inducer cells, but have been shown previously to mediate T cell help for B cell differentiation. Thus, at least 3 phenotypically distinct subsets of T cells interact sequentially to generate suppression of B cell differentiation induced in the AMLR: CD4+,Leu8+ suppressor/inducer cells, CD8+,Leu8+ suppressor-amplifier cells and CD8+Leu8 suppressor-effector cells.