title: Immunoglobulin M and immunoglobulin G secretion by human B cells exposed to RU 41.740, a glycoprotein extract from Klebsiella pneumoniae.
abstract: RU 41.740, a glycoprotein extract from Klebsiella pneumoniae, was seen to activate human B cells to immunoglobulin secretion in vitro. The effects of RU 41.740 on human B cells were compared to those induced by pokeweed mitogen, a T-cell-dependent polyclonal B-cell activator, and Epstein-Barr virus, a T-cell-independent polyclonal B-cell activator. Exposure of human B cells to all of these agents resulted in increased immunoglobulin M (IgM) and immunoglobulin G (IgG) secretion. IgM and IgG secretion induced by RU 41.740 appeared to be T cell dependent when B cells were isolated from human peripheral blood. However, this activity may have been T cell independent when B cells were isolated from human spleen. RU 41.740-induced IgM secretion by peripheral blood B cells was seen to peak after 6 days in culture; IgG secretion peaked after 7 days in culture. The optimal concentration of RU 41.740 for the induction of IgM and IgG secretion by human B cells in vitro was seen to be 200 micrograms/ml.
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D001426:Bacterial Proteins; D006023:Glycoproteins / Q000494:pharmacology*; D006462:Hemolytic Plaque Technique; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000096:biosynthesis; D007711:Klebsiella pneumoniae / Q000032:analysis; D008213:Lymphocyte Activation / Q000187:drug effects*; D008211:Lymphocyte Cooperation; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D006023:Glycoproteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C037567:glycoprotein, Klebsiella pneumoniae