Human C3a-mediated suppression of the immune response. II. Suppression of human in vitro polyclonal antibody responses occurs through the generation of nonspecific OKT8+ suppressor T cells.
C3a-mediated suppression of Ig secretion in human PBL cultures occurs through the activation of suppressor T cells. Incubation of T cell-enriched populations derived from peripheral blood or tonsil results in the activation of nonspecific OKT3+8+ suppressor T cells capable of inhibiting Fc fragment-induced Ig secretion in fresh autologous PBL cultures. Generation of OKT8+ suppressor T cells by C3a requires the interaction of T cells, adherent cells, and C3a. Activation of the suppressor-T-cell pathway is initiated early in culture. Incubation of the T-cell-enriched populations with C3a for 0.5 hr results in functional, transferable suppressor cells. Maximum suppression was achieved when C3a was allowed to interact with the cell population for 1-2 hr.
Morgan
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Thoman
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Hobbs
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Weigle
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Hugli
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D000917:Antibody Formation / Q000187:drug effects; D000938:Antigen-Presenting Cells / Q000276:immunology; D003176:Complement C3 / Q000494:pharmacology*; D015926:Complement C3a; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007136:Immunoglobulins / Q000378:metabolism; D007700:Kinetics; D008297:Male; D009000:Monocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D003176:Complement C3; D007136:Immunoglobulins; D015926:Complement C3a