title: T-cell influence on the B-cell differentiation process induced by Klebsiella.
abstract: Klebsiella pneumoniae K43 cell membrane preparations (Klebs M) have been characterized previously as a human polyclonal B cell activator (PBA) that stimulates purified B cells to differentiate into immunoglobulin (Ig) secreting cells with negligible prior or parallel proliferation and in the absence of T cells. The aim of the present study was to define the cellular interactions in the regulation of Klebs M induced B-cell differentiation. For this purpose OKT4+ and OKT8+ cell populations were negatively selected with reasonable purity by means of a panning technique or by complement-mediated cytolysis using monoclonal OKT4 and OKT8 antibodies. The resulting cell populations were added to purified autologous B cells exposed to Klebs M or, as a control, pokeweed mitogen (PWM). In the Klebs M system both the OKT4+ and the OKT8+ cell subsets markedly enhanced IgM production; however, the helper effect of the OKT4+ cell subset was much more intense than that of the OKT8+ subset. In the PWM system only the OKT4+ cells provided help for B-cell differentiation. The OKT8+ subset demonstrated suppressor activity in the presence of an adequate helper cell (OKT4+ subset) function. These results indicate that Klebs M behaves like a "relatively T cell-independent PBA".
authors.forename: W L
authors.initials: WL
authors.lastname: Gross
authors.forename: I
authors.initials: I
authors.lastname: Sieg
authors.forename: D
authors.initials: D
authors.lastname: Steppat
mesh_terms: D000955:Antigens, T-Independent / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D006801:Humans; D007711:Klebsiella pneumoniae / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000955:Antigens, T-Independent; D011043:Pokeweed Mitogens