Recognition of MOPC-460 variable region determinants by polyclonally distributed triggering receptors on B lymphocytes.
Purified M460 protein-induced untreated and anti-Thy 1.2 and complement-treated murine spleen cells to proliferate and differentiate in vitro. Fc receptor complexing was not responsible for the phenomenon, since M460 Fab fragments retained the B cell triggering activity. Activation was inhibitable by the addition of DNP-glycine to cultures and could also be detected by using spleen cells from various strains of mice, including the C3H/HeJ, which is genetically nonresponding to LPS. Hybrid molecules were constructed between the M460 proteins and the products of 2 myelomas that do not activate B cells, namely, X25 and X24. The only hybrid molecules that retained triggering activity were (L460-Hx25)2. Interestingly, the same molecule was also the only one recognized by an anti-M460 monoclonal antibody (F6(51)) that has been previously shown to induce B cells to proliferate and differentiate. The data suggest the existence on B lymphocytes of a network of polyclonally distributed mitogen receptors that share determinants cross-reacting with immunoglobulin idiotypes.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009194:Myeloma Proteins / Q000276:immunology*; D011961:Receptors, Fc; D011975:Receptors, Mitogen
D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D007135:Immunoglobulin Variable Region; D008070:Lipopolysaccharides; D009194:Myeloma Proteins; D011961:Receptors, Fc; D011975:Receptors, Mitogen