title: Enhanced resistance to Gram-positive bacterium and increased susceptibility to bacterial endotoxin in mice sensitized with Propionibacterium acnes: involvement of Toll-like receptor.
abstract: Mice sensitized with Propionibacterium acnes showed an enhanced resistance against infection with Listeria monocytogenes in contrast to the increased susceptibility to LPS-induced endotoxin shock. The enhanced protection to L. monocytogenes was mediated by activated innate immunity but not by generation of Listeria-specific acquired immunity. After infection with L. monocytogenes, the elimination of bacteria was observed earlier in accordance with a higher level of endogenous cytokine production in P. acnes-sensitized mice than in control mice. Peritoneal cells from P. acnes-sensitized mice produced a larger amount of IL-12p70 and nitric oxide after stimulation with heat-killed L. monocytogenes or peptidoglycan purified from Staphylococcus aureus. RT-PCR analysis showed that the expression of TLR2 but not TLR1, TLR4 nor TLR6 was induced by injection of P. acnes in peritoneal cells. These results indicated that P. acnes-sensitization could induce the activation of innate immunity against L. monocytogenes through increased recognition of bacterial components by TLR2.
authors.affiliation: Department of Internal Medicine (II), Niigata University Graduate School of Medicine, Niigata 951-8510, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Takamasa
authors.initials: T
authors.lastname: Nomura
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kawamura
authors.forename: Masao
authors.initials: M
authors.lastname: Mitsuyama
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004198:Disease Susceptibility; D004731:Endotoxins / Q000633:toxicity*; D004927:Escherichia coli Infections / Q000276:immunology; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D018664:Interleukin-12 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity*; D008088:Listeriosis / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000502:physiology*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010457:Peptidoglycan / Q000276:immunology; D010587:Phagocytosis; D011425:Propionibacterium acnes / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000502:physiology*; D013211:Staphylococcus aureus / Q000737:chemistry; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D010457:Peptidoglycan; D011956:Receptors, Cell Surface; D051194:Toll-Like Receptor 1; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D018664:Interleukin-12; D009569:Nitric Oxide