Human T cell colony formation in microculture: analysis of growth requirements and functional activities.
A microculture method in methylcellulose has been developed for the study of human T cell colony formation. The technique is simple, reliable, does not require preincubation with lectin and requires small numbers of cells. Colony formation was dependent on the presence of phytohemagglutin-conditioned medium, a T colony precursor cell (TCPC), and a "helper" or accessory T cell. Plating efficiency was increased 10-fold in the presence of irradiated feeder cells. Progenitors of the T colony cells were identified in peripheral blood, tonsil, and spleen but not in thymus or thoracic duct. They were isolated in the E-rosetting, theophylline-resistant, Fc-IgG-negative cell populations. In peripheral blood the frequency of TCPC and accessory cells, the T colony forming unit, was estimated to be 8 X 10(-3). Colony cells proliferated in response to lectins and allogeneic cells. Forty to 80% of the cells were Ia-positive and stimulated both autologous and allogeneic mixed lymphocyte responses. They were incapable of mediating antibody-dependent cytotoxicity. In contrast, they were effective in assays of spontaneous cytotoxicity but only against certain target cells. This method for the analysis of T colony formation should prove valuable in the functional analysis of T cell subsets in immunodeficiency states or the transplant recipient.
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D003176:Complement C3; D004307:Dose-Response Relationship, Radiation; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007700:Kinetics; D011951:Receptors, Complement; D011961:Receptors, Fc; D012756:Sheep; D013601:T-Lymphocytes / Q000276:immunology*
D003176:Complement C3; D011951:Receptors, Complement; D011961:Receptors, Fc