Functional analysis of human T cell subsets defined by monoclonal antibodies. I. Collaborative T-T interactions in the immunoregulation of B cell differentiation
Thomas, Y.; Sosman, J.; Irigoyen, O.; Friedman, S.M.; Kung, P.C.; Goldstein, G.; Chess, L.
Journal of Immunology 125(6): 2402-2408
1980
ISSN/ISBN: 0022-1767 PMID: 6968783 Document Number: 167439
T-B [T cell-B cell] and T-T interactions involved in the regulation of pokeweed mitogen-triggered human B cell differentiation were studied in vitro. Functionally distinct human T cell subsets were isolated by complement-mediated lysis by using the monoclonal antibodies OKT4 and OKT8. Graded numbers of untreated or irradiated T cell subsets were added to autologous B cells and total antibody synthesis was measured after 5-6 days of culture by using a highly sensitive reverse hemolytic plaque assay. Apparently the helper activity that is exclusively contained within the OKT4+ population is radiosensitive. Only at high T/B ratios can this radiosensitivity be overcome. The OKT8+ population contains radiosensitive cells important in suppressing B cell differentiation. The suppression induced with OKT8+ cells requires the presence of radiosenstive OKT4+ cells. OKT8+ cells added to cultures containing B cells and irradiated OKT4+ cells do not suppress the plaque-forming cell response. Addition of unirradiated OKT4+ cells to these cultures permits suppression reexpression by OKT8+ cells. Evidently, 2 radiosensitive cells one within the OKT4+ population and the other within the OKT8+ population, collaborate to induce suppression. Possible mechanism for this suppressive interaction including induction of suppressor precursor cells within the OKT4+ population or inhibition of OKT4+ helper cells by OKT8+ cells are discussed.