title: Polyclonal B-cell activation by bacteria that induce nonsuppurative sequelae.
abstract: The polyclonal B cell activation (PBA) process induced by Klebsiella pneumoniae K34 (klebs) and Yersinia enterocolitica 03 (yers) was investigated. Both heat-inactivated bacteria and their cell wall biostructures (klebsM, muriene, protein I etc.) stimulate human blood B cells to differentiate into immunoglobulin-secreting cells without prior proliferation and without T cells. Klebs-activated B cells secrete mainly IgM and to a lesser degree IgG (mainly IgG2). The PBA process was regulated by CD4+ cells and monocytes, but not by CD8+ cells. While interleukin 2 is able both to induce proliferation and to enhance differentiation in klebs-activated B cell cultures, the low-molecular-weight B cell growth factor (BCGF) did not lead to a significant amount of 3H-thymidine uptake. In addition, in klebs-activated B cell cultures various anti-polynucleotide autoantibodies and the 16/6 idiotype were detectable. Thus, bacteria that induce nonsuppurative sequelae (e.g. klebs, yers) can use several mechanisms to overcome tolerance in their host.
authors.affiliation: I. Medizinische Universitäts-Klinik, Kiel, Federal Republic of Germany.
authors.forename: W L
authors.initials: WL
authors.lastname: Gross
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001323:Autoantibodies / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D007711:Klebsiella pneumoniae / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000032:analysis
chemical_list: D001323:Autoantibodies; D001425:Bacterial Outer Membrane Proteins; D015375:Receptors, Interleukin-2