title: Comparative studies on the actions of antigen and polyclonal B-cell activator in differentiation and proliferation of B-cells and B memory cells.
abstract: Using the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) as a polyclonal B-cell activator (PBA) and sheep red blood cells (SRBC) as a T cell-dependent antigen, we compared the ability of PBA and antigen to differentiate (generate antibody-forming cells, AFC) and proliferate (generate immunological memory) virgin B cells and B memory cells. In vitro CPS-K induced the differentiation of IgM virgin B cells, IgM B memory cells and IgG B memory cells to AFC, as well as or better than SRBC. The differentiation of B memory cells to AFC by CPS-K did not require the participation of macrophages or T cells, whereas the action of SRBC depended strictly upon the helper actions of these cells. The responsiveness to CPS-K and SRBC of normal and antigen-primed spleen cells as judged by anti-SRBC PFC responses in vitro was markedly decreased after stimulation of virgin B cells and B memory cells in vivo by CPS-K injection into normal or primed mice but greatly increased after the injection of SRBC. The decrease in the responsiveness to CPS-K of spleen cells from mice treated with CPS-K appeared principally due to exhaustion of the functions of B cells and B memory cells. From the present data it has been concluded that the signals required for the differentiation and proliferation of B cells of B memory cells are different from each other, the signal for differentiation being provided by either antigen (SRBC) or PBA (CPS-K), while the signal for proliferation only by antigen.
mesh_terms: D000818:Animals; D000941:Antigens; D000961:Antilymphocyte Serum; D001402:B-Lymphocytes / Q000276:immunology*; D002448:Cell Adhesion; D002454:Cell Differentiation; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006462:Hemolytic Plaque Technique; D007114:Immunization; D007156:Immunologic Memory; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000276:immunology; D051379:Mice; D008954:Models, Biological; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D000941:Antigens; D000961:Antilymphocyte Serum; D011135:Polysaccharides, Bacterial