title: Metabolic and functional stimulation of lymphocytes and macrophages by an Escherichia coli extract (OM-89): in vitro studies.
abstract: OM-89, a proteinaceous extract from Escherichia coli with very low endotoxin content, was tested for its capacity to stimulate in vitro cells involved in the immune response. OM-89 induced a marked proliferation of mouse spleen cells; E. coli lipopolysaccharide (LPS) at the same concentration as present in OM-89 was totally ineffective. Passage through nylon wool strongly decreased the OM-89-induced effect, suggesting that the responding lymphocytes were of the B lineage. Exposure of bone marrow-derived macrophages to OM-89 promoted glucose oxidation through the hexose monophosphate shunt pathway and the capacity to generate superoxide upon phorbol myristate acetate (PMA) stimulation. These effects were not blocked by polymyxin B, whereas this compound completely prevented induction of similar metabolic activation by E. coli lipopolysaccharide. In addition, OM-89 treatment induced marked PMA-dependent superoxide and hydrogen peroxide release by macrophages from the LPS low responder mouse strain C3H/HeJ. Incubation with recombinant murine interferon-gamma and OM-89, but not with either compound alone, led to functional activation, as shown by the killing of tumor target cells, and by the destruction of the intracellular parasite Leishmania enrietti by macrophages of both LPS-responsive and unresponsive mouse strains. These experiments indicate that OM-89 can stimulate metabolic and functional activities of lymphocytes and macrophages that are important for host defense.
authors.affiliation: Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Van Pham
authors.forename: B
authors.initials: B
authors.lastname: Kreis
authors.forename: S
authors.initials: S
authors.lastname: Corradin-Betz
authors.forename: J
authors.initials: J
authors.lastname: Bauer
authors.forename: J
authors.initials: J
authors.lastname: Mauël
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000494:pharmacology*; D001854:Bone Marrow Cells; D003602:Cytotoxicity, Immunologic; D004926:Escherichia coli; D005260:Female; D006861:Hydrogen Peroxide / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D007894:Leishmania mexicana; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D010427:Pentose Phosphate Pathway; D010587:Phagocytosis; D011994:Recombinant Proteins; D013154:Spleen / Q000166:cytology; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D013481:Superoxides; D007371:Interferon-gamma; D006861:Hydrogen Peroxide; D013755:Tetradecanoylphorbol Acetate