title: Induction of human immunoglobulin secretion. I. Synergistic effect of B cell mitogen Cowan I plus T cell mitogens or factors.
abstract: Synergistic effects of B cell mitogen Staphylococcus bacteria strain Cowan I (Cowan I) plus T cell mitogens in generating immunoglobulin-secreting cells (ISC) from human peripheral blood mononuclear cells (MNC) were investigated. ISC were assayed by reverse plaque-forming cells with protein A-coated red blood cells. Low concentrations of pokeweed mitogen (PWM) plus Cowan I gave superadditive effects on ISC induction, generating 3 to 10 times as many ISC as optimal amounts of either mitogen alone. The mitogens together and separately showed similar kinetics of ISC; synergy was observed at every day tested. Plaque-forming cells of IgM, IgG, and IgA classes all showed strong synergy, together routinely representing 20% of initial MNC. At day 7 of culture, over 80% of non-E-rosetting cells were ISC. Cell donors tested gave these strong responses even if they were low responders to either mitogen alone. Cowan I plus other T cell mitogens, PHA, Con A, and protein A, also provided good signals for B cell activation. Cowan I induced marked proliferation of purified B cells, but T cell-helper signals were required for differentiation to ISC. T cell-helper factor, induced by PWM or PHA, also showed synergistic effects with Cowan I in induction of ISC. Purified B cells did not respond to T cell-helper factor(s) alone to proliferate or differentiate to ISC. These results indicate that optimal ISC induction occurs with a B cell mitogen plus T cell signals acting synergistically.
mesh_terms: D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D004357:Drug Synergism; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis*; D007700:Kinetics; D008934:Mitogens / Q000494:pharmacology*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012995:Solubility; D013210:Staphylococcus / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D008934:Mitogens; D011043:Pokeweed Mitogens