title: B cell stimulatory factor-1 enhances the IgE response of lipopolysaccharide-activated B cells.
abstract: Supernatants from some mouse helper T cell (TH) lines contain an activity that can enhance IgE production by lipopolysaccharide (LPS)-stimulated B cells by at least two orders of magnitude. During purification, this activity could not be resolved from B cell stimulatory factor-1 (BSF-1). Highly purified BSF-1 from a different source, the T lymphoma cell line EL-4, enhanced IgE production to the same extent as TH supernatants, which suggests that BSF-1 is responsible for this increase in IgE production. Monoclonal antibody to BSF-1 totally inhibits the IgE-enhancing activity of a TH supernatant, lending further support to this conclusion. The effects of BSF-1 on LPS-stimulated B cells are specific for IgE and, as previously reported, IgG1 and IgG3, because the levels of IgM, IgG2a, IgG2b, and IgA in the cultures change relatively little when BSF-1 is added.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D001667:Binding, Competitive; D002460:Cell Line; D006133:Growth Substances / Q000302:isolation & purification / Q000502:physiology*; D007073:Immunoglobulin E / Q000096:biosynthesis*; D015847:Interleukin-4; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000302:isolation & purification / Q000502:physiology*; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D029584:Prostatic Secretory Proteins
chemical_list: D000911:Antibodies, Monoclonal; D006133:Growth Substances; D008070:Lipopolysaccharides; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D015847:Interleukin-4; D007073:Immunoglobulin E