title: Requirement for macrophages or for macrophage- or T cell-derived factors in the mitogenic stimulation of murine B lymphocytes by lipopolysaccharides.
abstract: Splenic B cells from a variety of mouse strains could be depleted of accessory cells by removal of large cells through velocity sedimentation, followed by adherence to plastic and by passage over Sephadex G-10. Such accessory cell removal abolished the reactivity of the splenic B cells to the mitogen lipopolysaccharide (LPS), as measured by their capacity to polyclonally proliferate and mature to IgM-secreting cells. Accessory cells from different sources, such as peritoneal exudate cells, irradiated spleen cells, cells of the macrophage line P388 D1 and macrophages from a single colony grown from bone marrow precursors in semi-solid media in the presence of colony-stimulating factor all reconstituted LPS reactivity of the accessory cell-depleted B cells. Limiting dilutions of the cells of a single macrophage colony indicated that as little as 30 to 1000 macrophages can reconstitute the polyclonal response of 3 X 10(4) B cells to LPS. Not only activated macrophages, but also activated long-term helper T cell lines and T cell hybridomas, produced supernatant factors which could also restore responsiveness of depleted B cells to LPS.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002448:Cell Adhesion; D006825:Hybridomas / Q000276:immunology; D007941:Leukemia P388 / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008819:Mice, Nude; D008934:Mitogens; D051381:Rats; D011917:Rats, Inbred Lew; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D008070:Lipopolysaccharides; D008934:Mitogens