Fc receptor-mediated inhibition of murine B-lymphocyte activation.
Immobilized antigen-antibody complexes are able to inhibit the mitogenic response of murine spleen cells to the B-cell mitogen 8-bromo-3',5'-cyclic guanosine monophosphoric acid. This this inhibition is dependent on intact Fc fragments in the immobilized complexes. Soluble complexes do not mediate this inhibition. When lipopolysaccharide (lps) activation of B cells was studied, it was found that the mitogenic response was inhibited at all times tested between 2 and 7 days of culture. Also, the LPS-induced mitogenesis of nude spleen cells was inhibited by immobilized complexes, indicating that suppressor T cells probably play no significant role in the inhibition. Immobilized complexes inhibit polyclonal antibody responses in a serum-free system and in the presence of normal mouse serum, but are unable to inhibit in the presence of fetal calf serum (FCS). If nu/nu spleen cells are used, however, the FCS does not block the ability of the complexes to inhibit the polyclonal response. It is suggested that that antigen-antibody complexes under appropriate conditions may bind to B lymphocytes via their Fc receptors and trigger a central "off" signal which blocks proliferation and consequently antibody production.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000936:Antigen-Antibody Complex; D001402:B-Lymphocytes / Q000276:immunology*; D006152:Cyclic GMP / Q000037:antagonists & inhibitors; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008934:Mitogens; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology
D000936:Antigen-Antibody Complex; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D008934:Mitogens; D006152:Cyclic GMP