title: Role of interleukin 1 in anti-immunoglobulin-induced B cell proliferation.
abstract: In this report we describe conditions for polyclonal activation of small numbers of highly purified mouse B lymphocytes. Three signals are required for induction of DNA synthesis by the particular subset of small B lymphocytes investigated: a signal delivered by antibodies specific for the IgM receptor expressed on the B cell membrane; a signal delivered by a T cell-derived factor (B cell growth factor [BCGF]); and a signal delivered by the macrophage-derived factor interleukin 1 (IL-1). The conclusion that IL-1 has B cell co-stimulator activity is based on the findings that highly purified preparations of mouse and human IL-1 have the capacity to cause proliferation in B cells treated with anti-IgM and BCGF. Such cultures show an absolute dependence on exogenously added IL-1 when 2-mercaptoethanol is omitted from the medium. BCGF and IL-1 each act in a non-antigen-specific, non-H-2-restricted, synergistic manner. Their requirement is not observed when B cells are cultured at high density, presumably reflecting accessory cell contamination and endogenous factor production under these conditions. The B cell activation induced by these three signals is restricted to proliferation without the production of antibody-forming cells.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D006133:Growth Substances / Q000502:physiology; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007375:Interleukin-1 / Q000302:isolation & purification / Q000502:physiology*; D015847:Interleukin-4; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008970:Molecular Weight; D015846:Monokines; D011506:Proteins / Q000502:physiology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D006133:Growth Substances; D007075:Immunoglobulin M; D007375:Interleukin-1; D015846:Monokines; D011506:Proteins; D015847:Interleukin-4