title: T lymphocytes mediate immunologic control of C3 gene expression.
abstract: Immunologic control of C3 gene expression by tissue macrophages can be accomplished by treatment of spleen fragments with anti-C3 antibody. We now demonstrate that suppression of C3 requires participation of T lymphocytes of both the CD4+ and CD8+ phenotypes. Pretreatment of splenic tissue with anti-Thy-1.2 monoclonal antibody blocks the ability of the anti-C3 antibody to induce C3 suppression. Reduction in either the CD4+ or CD8+ subpopulations of T lymphocytes also abrogates C3 suppression demonstrating that both T cell subsets are required in addition to the inducing antibody. Artificially elevating intracellular levels of cAMP with cholera toxin can partially substitute for the effects mediated by T cells in this reaction. Therefore, normal expression of the C3 gene can be suppressed by a regulatory network that requires the presence of a specific inducing antibody and T lymphocytes of both the CD4+ and CD8+ subsets. This regulatory network has many similarities to regulatory networks that have been well documented in suppression of specific murine immunoglobulin allotypes.
authors.affiliation: Department of Medicine, Pennsylvania State University College of Medicine, Hershey.
authors.forename: M B
authors.initials: MB
authors.lastname: Goldman
authors.forename: M A
authors.initials: MA
authors.lastname: Knovich
authors.forename: J N
authors.initials: JN
authors.lastname: Goldman
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002478:Cells, Cultured; D003176:Complement C3 / Q000096:biosynthesis / Q000235:genetics*; D000242:Cyclic AMP / Q000032:analysis; D005260:Female; D005786:Gene Expression Regulation; D007075:Immunoglobulin M / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D016176:T-Lymphocyte Subsets / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D003176:Complement C3; D007075:Immunoglobulin M; D000242:Cyclic AMP