title: Monocyte-T-cell interactions in the regulation of polyclonal B-cell response.
abstract: Human peripheral blood monocyte subsets with and without Fc receptor for human IgG are known to suppress (FcR+) and enhance (FcR-) pokeweed mitogen-induced polyclonal immunoglobulin synthesis in vitro. The ability of these subsets to modulate immunoglobulin production in the presence or absence of OKT8+ T cells and under conditions where suppressor T-cell activation was blocked by irradiation or mitomycin C was studied. It was shown that, regardless of the presence or absence of suppressor T cells, FcR+ monocytes can suppress immunoglobulin production if their number in culture exceeds 20%. However, at lower numbers this monocyte subset was suppressive only when suppressor T cells were activated. The suppressor T-cell activation was shown to be independent of the predominant presence of the FcR+ or FcR- monocyte subset. Moreover, the enhancing effect of FcR- monocytes was not caused by their interference with suppressor T-cell activation.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D007136:Immunoglobulins / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology; D009000:Monocytes / Q000145:classification / Q000276:immunology*; D010641:Phenotype; D011043:Pokeweed Mitogens / Q000494:pharmacology; D011961:Receptors, Fc; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D007136:Immunoglobulins; D008937:Mitomycins; D011043:Pokeweed Mitogens; D011961:Receptors, Fc; D016685:Mitomycin