Specific T helper cells that activate B cells polyclonally. In vitro enrichment and cooperative function.
C3H/HeJ T cells which specifically recognize B cell-surface antigens of the related, major histocompatibility complex-compatible C3H/Tif strain, can be substantially enriched in vitro by long-term exposure (2--6 wk) of primed lymph node cells to the relevant cellular antigens. These enriched T cells contain functional helper cells as demonstrated by their capacity to induce large numbers of Ig-secreting plaque-forming cells (PFC) in cultures of antigenic B cells. The cooperative interaction results in activation of a large fraction of all splenic B cells, with consequent exponential growth and maturation to high rate secretion of IgM, IgG1, and IgG2, but not IgG3. The IgM PFC response includes antibody specificities to a number of different antigens and can be considered, therefore, as polyclonal. The T helper cell-dependent B-cell response is insensitive to inhibition by anti-delta antibodies, and in contrast with lipopolysaccharide-induced PFC responses, is only partially sensitive to the inhibitory effects of anti-mu antibodies. Finally, B-cell activation to growth and maturation by helper T cells strictly required direct T-cell recognition of antigens on the surface of responding B cells, leading us to the conclusions that if any soluble factors are generated in the collaborative process, they are either antigen specific or incompetent to initiate B-cell growth.
D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000918:Antibody Specificity; D000954:Antigens, Surface; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D002999:Clone Cells / Q000276:immunology; D007148:Immunoglobulin mu-Chains; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008285:Major Histocompatibility Complex; D013601:T-Lymphocytes / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D000954:Antigens, Surface; D007148:Immunoglobulin mu-Chains