Signaling to a CD5+ B-cell clone through surface Ig and MHC class II molecules.
Cells of the CD5+ mouse B-cell clone CH12.LX are induced to become antibody-secreting cells by costimulatory signals delivered by binding of their surface Ig and MHC class II molecules. Class II-mediated signals can be delivered by the binding of either T cells or class II-specific monoclonal antibodies. Divalent, but not monovalent antigen-binding fragments of mAbs are effective in signalling, and cross-linking intact anti-class II mAbs with isotype-specific Ab enhance class II-mediated signaling. Class II-mediated signaling is accompanied by a rise in cAMP and is blocked by an adenyl cyclase inhibitor. The cAMP analogue dibutyryl cAMP, can partially but not completely substitute for the class II-mediated signal. The costimulatory Ig-mediated signal can be delivered by binding of either antigen or antiidiotype Ab, but anti-IgM Abs are much less effective. Antibodies specific for Ig constant regions are much more effective, however, if they engage both the mIgM and mIgD molecules; anti-kappa Abs or a combination of anti-IgM and anti-IgD Abs were more effective in signaling.
Bishop
G A
GA
Department of Microbiology, University of Iowa, Iowa City 52242.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D018956:CD5 Antigens; D002454:Cell Differentiation / Q000187:drug effects; D002999:Clone Cells; D000242:Cyclic AMP / Q000378:metabolism; D016048:Dideoxyadenosine / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000502:physiology*; D016393:Lymphoma, B-Cell / Q000276:immunology; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018956:CD5 Antigens; D000949:Histocompatibility Antigens Class II; D011947:Receptors, Antigen, B-Cell; D016048:Dideoxyadenosine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases