title: TNF-alpha hyper-responses to Gram-negative and Gram-positive bacteria in Propionibacterium acnes primed or Salmonella typhimurium infected mice.
abstract: IFN-gamma-dependent hypersensitivity to LPS is inducible in mice by infection or pre-treatment with killed bacteria. Hypersensitive mice exhibit enhanced inflammatory responses to LPS, including the overproduction of TNF-alpha. Using Lps(n) BALB/c and Lps(d) BALB/c/l mice, primed with Propionibacterium acnes or infected with Salmonella typhimurium, we show that concurrently to hypersensitivity to LPS, a hypersensitivity to other constituents of killed Gram-negative or Gram-positive bacteria and to staphylococcal enterotoxin B (SEB) develops. The TNF-alpha hyper-responses in sensitized mice induced by different Gram-positive bacteria, are generally weaker than those by Gram-negative bacteria and vary significantly, due to the absence of a common, LPS-equivalent component. Using IFN-gamma R(-/-) and the respective wild-type mice, we demonstrate that although sensitization to LPS and killed Listeria monocytogenes is exclusively IFN-gamma-dependent, an IFN-gamma-independent, moderate sensitization to certain TNF-alpha-inducing constituents in bacteria may develop in parallel.
authors.affiliation: Max-Planck-Institut für Immunbiologie, Freiburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Merlin
authors.forename: M
authors.initials: M
authors.lastname: Gumenscheimer
authors.forename: C
authors.initials: C
authors.lastname: Galanos
authors.forename: M A
authors.initials: MA
authors.lastname: Freudenberg
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000276:immunology / Q000633:toxicity; D016908:Gram-Positive Bacterial Infections / Q000378:metabolism*; D006967:Hypersensitivity / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology / Q000633:toxicity; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D011425:Propionibacterium acnes / Q000472:pathogenicity*; D012481:Salmonella Infections, Animal / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000472:pathogenicity*; D013047:Specific Pathogen-Free Organisms; D018089:Superantigens / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics
chemical_list: D001427:Bacterial Toxins; D008070:Lipopolysaccharides; D018089:Superantigens; D014409:Tumor Necrosis Factor-alpha