title: Ability of antigen-specific helper cells to effect a class-restricted increase in total Ig-secreting cells in spleens after immunization with the antigen.
abstract: Immunization with antigens stimulates not only B lymphocytes secreting specific antibody but, in addition, results in the generation of very large numbers of splenic Ig-secreting cells which lack specificity for that antigen. The present report examined the nature of the antigens capable of eliciting this effect and the mechanisms whereby B cells could be nonspecifically activated. It is shown that the ability of T-dependent, but not T-independent antigens, to induce such increases requires the participation of T helper cells specific for the antigen so that any one antigen results in the activation of only a proportion of total B cells. Analysis of this nonspecific plaque-forming-cell response reveals that B cell activation is not random but occurs in a class-restricted manner. The magnitude of the increase and the isotype produced are shown to be characteristic of the immunizing antigen. Based on the data presented, the apparent nonspecific T-B collaboration can best be explained by invoking a second Ig-specific helper mechanism in which helper cells capable of recognizing determinants on Ig molecules, e.g. isotype or idiotype, cause the stimulation of B cells of any specificity providing they express that determinant.
mesh_terms: D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D001402:B-Lymphocytes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006462:Hemolytic Plaque Technique; D007136:Immunoglobulins / Q000096:biosynthesis*; D008211:Lymphocyte Cooperation; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D013154:Spleen / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D000941:Antigens; D007136:Immunoglobulins; D005719:gamma-Globulins