Hapten reactive inducer T cells. II. Evidence that a secreted form of the T cell receptor induces antibody production.
The biologic activity of molecules synthesized and secreted by hapten-specific inducer T cells was examined. After activation, a single inducer clone secretes both antigen-specific inducer peptides as well as nonspecific factors. The nonspecific factors augment the in vitro response of B cells to sheep erythrocytes (SRBC) and Type 2 T-independent antigens. The antigen-specific molecules (ABM) induce plaque-forming cell (PFC) responses in cultures containing ABM, B cells, and antigen that links the epitope recognized by ABM with the B cell epitope. Induction of B cells by ABM is limited to B cells expressing the same I-A allele as the source of the ABM and this reflects binding by ABM to I-A products on B lymphocytes. The data reported here strongly support the view that inducer cells can activate at least some B cells by secretion of a modified form of the T cell surface receptor.
D000818:Animals; D000917:Antibody Formation; D000950:Antigens, Ly / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D000939:Epitopes; D006462:Hemolytic Plaque Technique; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008211:Lymphocyte Cooperation; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
D000950:Antigens, Ly; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell; D014301:Trinitrobenzenes