title: Legionella pneumophila induced tumor necrosis factor production in permissive versus nonpermissive macrophages.
abstract: The ability of an opportunistic intracellular bacterial pathogen, Legionella pneumophila, to induce tumor necrosis factor (TNF) in macrophages from susceptible A/J or resistant BDF1 and BALB/c mice was determined. Cultures of peritoneal elicited macrophages from these mouse strains produced TNF in response to the Legionella. The TNF levels produced by the macrophages stimulated with either heat-killed Legionella vaccine or lipopolysaccharide were similar and dose dependent, although the amount of TNF produced by macrophages from permissive A/J mice was 2- to 4-fold higher than that produced by macrophages from the nonpermissive mice. Similar differences in TNF levels occurred when macrophages from either permissive or non-permissive mice were infected with viable Legionella. The TNF levels produced by the A/J mouse macrophages increased as a function of time after infection, with a peak of activity on Day 1 or 2, depending upon the initial concentration of the bacteria. Infection of the A/J mouse macrophages with avirulent Legionella resulted in induced levels comparable to those induced by a virulent strain. Although it is widely believed that TNF production by mouse macrophages is related to resistance to infections, the results of this study did not show a relationship between TNF production by macrophages in vitro and resistance versus susceptibility of the macrophage donor mouse strain to Legionella infection.
authors: Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa 33612.
authors: S
authors: S
authors: Arata
authors: C
authors: C
authors: Newton
authors: T W
authors: TW
authors: Klein
authors: Y
authors: Y
authors: Yamamoto
authors: H
authors: H
authors: Friedman
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli; D016952:Legionella pneumophila / Q000276:immunology*; D008070:Lipopolysaccharides / Q000633:toxicity*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D013045:Species Specificity; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D001428:Bacterial Vaccines; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha