title: Requirement for BSF-1 in the induction of antigen-specific B cell proliferation by a thymus-dependent antigen and carrier-reactive T cell line.
abstract: We report here a role of B cell stimulatory factor 1 (BSF-1) in the induction of antigen-specific proliferation of affinity-purified small B lymphocytes by a thymus-dependent antigen and a carrier-reactive T cell line. By using an ovalbumin-reactive T cell line (designated Hen-1), which does not produce BSF-1 following activation, it was possible to demonstrate that the antigen-specific proliferative response of trinitrophenyl (TNP)-binding B cells to TNP-ovalbumin required exogenous BSF-1 in addition to direct interaction with irradiated Hen-1 T cells. The activation obtained under these conditions was highly efficient, being sensitive to antigen doses as low as 0.001 microgram/ml. The addition of saturating amounts of BSF-1 did not alter the antigen-specificity or the requirements for hapten-carrier linkage or major histocompatibility complex-restricted T-B interaction in this system. The involvement of BSF-1 was confirmed by the ability of 11B11 anti-BSF-1 antibody to specifically suppress the response of TNP-binding B cells to TNP-ovalbumin, BSF-1, and irradiated Hen-1 T cells. Finally, this response was augmented by addition of the monokine interleukin 1. These data indicate that the proliferative response of small B cells to the thymus-dependent antigen and carrier-reactive T cell line used in our experiments can be regulated by the same factors that govern B cell proliferation induced by thymus-independent type 2 antigens or anti-IgM antibodies.
mesh_terms: D000818:Animals; D000955:Antigens, T-Independent / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology*; D002460:Cell Line; D006133:Growth Substances / Q000502:physiology*; D007375:Interleukin-1 / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000502:physiology*; D051379:Mice; D010047:Ovalbumin / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000955:Antigens, T-Independent; D006133:Growth Substances; D007375:Interleukin-1; D007376:Interleukin-2; D008222:Lymphokines; D014301:Trinitrobenzenes; D015847:Interleukin-4; D010047:Ovalbumin