title: Klebsiella pneumoniae stimulate highly purified human blood B cells to mature into plaque forming cells without prior proliferation.
abstract: The plaque forming cell (PFC) and proliferative responses of human peripheral blood lymphocytes and highly purified blood B cells induced by pokeweed mitogen (PWM) and group A streptoccocal cell membranes (A-ScM) were compared with the responses triggered by various cell preparations of Klebsiella pneumoniae K 43 (Klebs). The number of PFC was determined by a protein A plaque assay, and lymphoproliferation was measured by 3H-thymidine incorporation. In cell cultures stimulated with PWM and A-ScM, lymphocyte proliferation appeared to be associated with the generation of PFC. Klebs caused development of PFC without measurable prior proliferation. Whereas the response to PWM and A-ScM was absolutely T cell-dependent, highly purified B cells generated PFC when incubated with Klebs. Moreover, restitution of T cells to the B cell fraction did not augment (or diminish) the number of plaques. These studies establish that Klebs cell envelope structures contain a T cell-independent polyclonal B cell activator for human B lymphocytes in a high stage of differentiation. Use of this probe should provide further insight into the cellular interactions involved in the differentiation of antibody forming cells in humans.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002455:Cell Division; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D006462:Hemolytic Plaque Technique; D006801:Humans; D007711:Klebsiella pneumoniae / Q000276:immunology*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D013205:Staphylococcal Protein A; D013210:Staphylococcus / Q000276:immunology; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D000511:alpha-Macroglobulins / Q000276:immunology
chemical_list: D013205:Staphylococcal Protein A; D000511:alpha-Macroglobulins; C032306:polyclonal B cell activator; D013936:Thymidine