title: IgM induction in murine B hybridomas with Ia-restricted T cell clones: a monoclonal model for T and B cell interactions in antibody response.
abstract: The mechanism of MHC-restricted T and B cell interactions in antibody response was studied with IgM-inducible B hybridomas and antigen-specific helper T cell clones. B hybridomas were prepared by fusion between splenic B cells from (CBA/N (H-2k) X BALB/c (H-2d)) F1 (NBF1) male mice and a B lymphoma cell line, M12.4.5. A B hybridoma clone, 1M70, which expressed I-Ad but not I-Ak determinants was chosen in the present study. IgM secretion was induced in 1M70 when it was cocultured with a "resting" KLH-specific and H-2d restricted helper T cell clone in the presence of KLH. A "resting" KLH-specific and H-2k restricted T cell clone did not induce IgM secretion in 1M70 even in the presence of KLH. However, when these KLH-specific T cell clones were activated by KLH and appropriate antigen presenting cells, both H-2d and H-2k restricted T cell clones induced IgM secretion in 1M70 even in the absence of KLH. A monoclonal anti-I-Ad antibody inhibited IgM secretion induced by a "resting" H-2d restricted T cell clone, but not by an "activated" T cell clone. These results indicated that T cell clones recognized antigens in the context of Ia molecules on B hybridomas in a MHC-restricted manner and were activated to produce B cell stimulatory factors which in turn acted on B hybridomas in a non-MHC-restricted manner and induced differentiation of B hybridomas into IgM secreting cells.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006825:Hybridomas / Q000276:immunology; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008954:Models, Biological; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D007075:Immunoglobulin M