title: Effect of Staphylococcus aureus Cowan i bacteria on the mitogenic response of human B-cell subsets.
abstract: We have made a detailed investigation to determine which of the B-cell subsets could be stimulated by Staphylococcus aureus Cowan I bacterium (SpA CoI). B-cell subsets were separated from peripheral blood and tonsil lymphocytes by means of rosette formation with E, EAIgG, anti-immunoglobulin (Ig) conjugated OE (OE-Pro A) or by separation on a bovine serum albumin (BSA) discontinuous density gradient. The cells responding to SpA CoI included E receptor negative (E-), C3 receptor positive (C3R+), and surface Ig positive (SIg+) B-cell subsets. Among these B-cell subsets, FcR-n cells were more responsive than FcR+ cells. These B-cell subsets responded alone to SpA CoI and significantly proliferated, although, they failed to respond alone to pokeweed mitogen (PWM) and Protein A of S. aureus (Protein A). Among the SIg+ B-cell subsets stimulated with SpA CoI, IgM+ and IgG+ B cells showed much less response. Both Protein A receptor positive (Pro A . R+) and negative (Pro A . R-) cells responded well to SpA CoI. Fractionation of B cells on a BSA gradient revealed that comparatively small sized and denser B-cell subsets responded well to SpA CoI. From these criteria, it is suggested that B cells responding to SpA CoI are capable of stimulating not only mature B cells, but can also stimulate immature B cells.
mesh_terms: D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology*; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D003176:Complement C3; D006801:Humans; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D011951:Receptors, Complement / Q000032:analysis; D011961:Receptors, Fc / Q000032:analysis; D012397:Rosette Formation; D013205:Staphylococcal Protein A / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D003176:Complement C3; D008934:Mitogens; D011947:Receptors, Antigen, B-Cell; D011951:Receptors, Complement; D011961:Receptors, Fc; D013205:Staphylococcal Protein A