title: Suppression of the polyclonal B-cell responses by concanavalin A-treated bone marrow B cells in vitro.
abstract: A suppressor cell that inhibits the development of a polyclonal antibody response of splenic B cells to lipopolysaccharide is generated in the bone marrow cell culture in response to a mitotic dose (10 micrograms/ml) of concanavalin A (Con A). The Con A-responding suppressor cell is radioresistant and found in a bone marrow B (BM-B) cell population of normal as well as athymic mice. The suppressor activity of Con A-treated BM-B cells was consistently higher (P less than 0.01-0.0001) than those of untreated BM-B and fresh BM cells. The BM-B cell population recovered from short-term (3-day) cultures with Con A contained about 65% surface immunoglobulin (Ig)-positive cells, about 6% T cells, and less than 0.5% plastic-adherent cells, the latter two of which did not contribute to the suppressive activity. Thus, cytolytic treatment with various anti-T-cell antibodies could not eliminate the suppressive activity of the Con A-treated BM-B cells, and the Con A-treated macrophage population provided no significant suppression. The Con A-treated BM-B cells adherent to anti-Ig or anti-Con A dishes exhibited highly enriched suppressive activity. It was therefore concluded that an immature B-cell population of bone marrow could develop in response to stimulation with Con A into surface Ig-positive suppressor cells, contributing to the regulation of nonspecific B-cell responses.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL / Q000276:immunology; D008808:Mice, Inbred CBA / Q000276:immunology; D008819:Mice, Nude / Q000276:immunology
chemical_list: D003208:Concanavalin A