title: Lipid A-associated proteins from periodontopathogenic bacteria induce interleukin-6 production by human gingival fibroblasts and monocytes.
abstract: The aim of this study was to determine whether lipid A-associated proteins (LAP) from two periodontopathogenic species of bacteria were able to stimulate interleukin-6 (IL-6) release from human gingival fibroblasts and myelomonocytic cells. LAP and lipopolysaccharide (LPS) were extracted from Porphyromonas gingivalis and Prevotella intermedia and added to cultures of human gingival fibroblasts and mono-mac-6 monocytic cells. Release of IL-6 into the culture supernatants was determined by ELISA. LAP and LPS from Por. gingivalis, but not from Prev. intermedia, stimulated IL-6 release from both cell types in a dose-dependent manner although LPS was less potent than LAP in inducing IL-6 release from the fibroblasts. IL-6 was detectable in cultures of both cell types following stimulation with LAP from Por. gingivalis at a concentration as low as 10 ng/ml. In response to LAP from Prev. intermedia, IL-6 was produced by mono-mac-6 cells but not by fibroblasts. Our results show that bacterial cell wall components other than LPS can induce IL-6 release from cells of the periodontium in vitro. The production of such potent immunomodulatory agents in vivo may contribute to the connective tissue breakdown characteristic of chronic periodontitis.
authors.affiliation: Department of Microbiology, Eastman Dental Institute for Oral Health Care Sciences, University of London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Reddi
authors.forename: S
authors.initials: S
authors.lastname: Poole
authors.forename: S
authors.initials: S
authors.lastname: Nair
authors.forename: S
authors.initials: S
authors.lastname: Meghji
authors.forename: B
authors.initials: B
authors.lastname: Henderson
authors.forename: M
authors.initials: M
authors.lastname: Wilson
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005347:Fibroblasts / Q000276:immunology; D005881:Gingiva / Q000166:cytology / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008050:Lipid A / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000302:isolation & purification / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology; D016966:Porphyromonas gingivalis / Q000276:immunology*; D018713:Prevotella intermedia / Q000276:immunology*
chemical_list: D001426:Bacterial Proteins; D004731:Endotoxins; D015850:Interleukin-6; D008050:Lipid A; D008070:Lipopolysaccharides; C027315:lipid A-associated protein, Bacteria