T lymphocyte-mediated suppression of myeloma function in vitro. III. Regulation of antibody production in hybrid myeloma cells by T lymphocytes.
To investigate the mechanisms by which T lymphocytes regulate myeloma function in vitro, the effects of regulatory T cells on antibody secretion by a hybrid myeloma cell line were examined. Suppressor T cells (Ts) specific for idiotypic determinants on M315 (IgA, lambda 2 anti-2,4-dinitrophenol and anti-2,4,6-trinitrophenol [TNP]) and MPC 11 (IgG2b, kappa) myeloma proteins inhibit antibody secretion by the appropriate parental myeloma cells. When cocultured with a hybrid cell line derived by fusion of MOPC 315 and MPC 11 myelomas, the idiotype-reactive Ts inhibit secretion of only the immunoglobulin (Ig) bearing the relevant idiotype. In contrast, syngeneic TNP-reactive cytolytic T lymphocytes (CTL) inhibit antibody secretion by TNP-binding MOPC 315 cells but not by MPC 11 cells in the presence of soluble TNP-keyhole limpet hemocyanin (KLH), and this inhibition probably represents a prelytic effect of the CTL. Such TNP-reactive CTL, in the presence of TNP-KLH, inhibit both IgA and IgG secretion by the MOPC 315-MPC 11 hybrid, which is consistent with a prelytic effect. Thus, myeloma hybrids are a useful tool for investigating the effector function of regulatory T cells. These results are discussed with reference to the mechanisms of action of regulatory T cells and their relevance to modulation of physiologic humoral immune responses.
D000818:Animals; D000917:Antibody Formation; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology; D006822:Hybrid Cells / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009101:Multiple Myeloma / Q000276:immunology*; D009374:Neoplasms, Experimental / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D007074:Immunoglobulin G; D007130:Immunoglobulin Idiotypes