title: Suppression of mitogen-induced peripheral B cell differentiation by soluble Fc gamma receptors released from lymphocytes.
abstract: Soluble receptors for FcIgG released from unstimulated human peripheral blood lymphocytes were isolated by affinity chromatography on Sepharose 4B-IgG. This material was shown to interfere with the differentiation of peripheral blood B cells into Ig-secreting cells in cultures stimulated with pokeweek or Nocardia opaca extracts. Neither cell viability nor [3H]thymidine incorporation were altered, but the number of Ig-containing cells and that of Ig-secreting cells were decreased. These effects were dose-related. They were found to be associated with Fc IgG-binding soluble material, since absorption on Sepharose 4B-IgG but not on pepsin-digested F(ab')2 fragments removed the inhibitory activity. This suppressor factor, released by unstimulated lymphocytes, may represent a human analogue of murine immunoglobulin-binding factor (IBF) produced by alloactivated T cells.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D001665:Binding Sites; D002454:Cell Differentiation; D002470:Cell Survival; D006462:Hemolytic Plaque Technique; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D011043:Pokeweed Mitogens / Q000494:pharmacology*; D011817:Rabbits; D011961:Receptors, Fc; D012995:Solubility
chemical_list: D007136:Immunoglobulins; D011043:Pokeweed Mitogens; D011961:Receptors, Fc