title: Responses of B cells with or without C3 receptors to polyclonal B cell activators.
abstract: Responses of B cells with or without receptors for C3 (CR) to polyclonal B cell activators (PBA) were studied. Mouse spleen cells were incubated with sheep red blood cells (SRBC) coated with antibody and complement to form rosettes, and they were separated by Ficoll-Hypaque density sedimentation into populations depleted of and enriched with lymphocytes bearing CR (CRL). These 2 populations were cultured with lipopolysaccharide (LPS), purified protein derivative of tuberculin (PPD), or dextran sulfate (DxS) and assayed for anti-TNP PFC. The CRL-depleted population responded well to LPS, poorly to PPD, and it showed practically no response to DxS, whereas the CRL-enriched population seemed to respond poorly to LPS but well to both PPD and DxS. The low responsiveness of the cRL-depleted population to PPD and DxS could not be explained by a shift of time-kinetics, by the dose-response profile of the responding cells, or by the depletion of adherent cells. Suppressor T cells did not take part in the reduced responses, since the treatment of the population with anti-Thy 1.2 plus complement could not restore the responses. These results indicate that B cells with CR [CR(+) B cells] respond well both to PPD and DxS, whereas the cells without CR [CR(-) B cells] respond poorly to PPD and DxS. It was difficult to evaluate the low responsiveness of CR(+) B cells to LPS because of the high background PFC of the cRL-enriched population.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002448:Cell Adhesion; D003176:Complement C3 / Q000276:immunology*; D003911:Dextrans / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011951:Receptors, Complement; D012756:Sheep; D013154:Spleen / Q000276:immunology; D014373:Tuberculin / Q000276:immunology
chemical_list: D003176:Complement C3; D003911:Dextrans; D008070:Lipopolysaccharides; D011951:Receptors, Complement; D014373:Tuberculin