A transforming growth factor beta-like immunosuppressive factor in immunoglobulin G-binding factor.
Immunoglobulin G-binding factors (IgG-BF), which are produced by cells of the immune system, inhibit antibody production. In this paper, we show that transforming growth factor-beta (TGF-beta) suppresses secondary in vitro anti-sheep red blood cell responses of mouse splenocytes and lipopolysaccharide- or anti-IgM-stimulated mouse B cell responses in a way similar to, and with the same kinetics as, rodent IgG-BF. Moreover, the immunosuppressive activity of IgG-BF was totally neutralized by polyclonal and monoclonal anti-TGF-beta antibodies and it eluted with TGF-beta by gel exclusion chromatography, suggesting that a TGF-beta-like immunosuppressive factor is present in IgG-BF. We also show that TGF-beta behaves as an IgG-BF since it binds to insolubilized IgG, but not to insolubilized F(ab')2 or bovine serum albumin. Altogether, the data support the concept of a biological role for TGF-beta in the IgG-mediated negative feedback of antibody responses.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D006579:Heterozygote; D007166:Immunosuppressive Agents; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D029584:Prostatic Secretory Proteins; D017452:Receptors, IgG / Q000737:chemistry / Q000502:physiology*; D012995:Solubility; D013154:Spleen / Q000166:cytology; D016212:Transforming Growth Factor beta / Q000502:physiology*
D007166:Immunosuppressive Agents; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; D017452:Receptors, IgG; D016212:Transforming Growth Factor beta; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors