T lymphocytes mediate immunologic control of C3 gene expression. Journal   European journal of immunology. Citation   Eur J Immunol. 22(12):3103-9 Publication date   1992 Dec Authors   Goldman MB Knovich MA Goldman JN Investigators   John N. Goldman Grant agencies   Public Health Service Grants   PHS RO1 A1 25775 MeSH headings   Complement C3 Gene Expression Regulation T-Lymphocytes MeSH qualifiers   genetics physiology 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. Medline ID   93076840