Subpopulations of human T cells identified by receptors for immunoglobulins and mitogen responsiveness

Human T lymphocytes in peripheral blood have been shown to have receptors for IgG (Tγ) or IgM (Tμ). Cultured Tγ cells do not express receptors for IgM and purified Tμ cells do not have receptors for IgG, thus they appear to be distinct T cell populations. Although the two subpopulations show similar response patterns to concanavalin A, Tμ and Tγ cells exhibit different dose response curves to phytohemagglutinin. The normal response pattern to phytohemagglutinin requires a mixture of T cell subpopulations suggesting that synergistic interactions may occur.