Further characterization of the human inducer T cell subset defined by monoclonal antibody.

Evidence is presented that the OKTA+ T cell subset in man, defined by a monoclonal hybridoma antibody, provides help for B lymphocyte differentiation in a PWM driven system. Both B cell proliferation and intracytoplasmic immunoglobulin synthesis are facilitated by OKT4+ and not by OKT4- T cells. Given earlier studies demonstrating that OKT4+ T cells were necessary for generation of T cytotoxic cells and the present study that OKT+ T cells are necessary for the differentiation of B cells, it would appear that the OKT+ population is the major human T helper (inducer) subset.