title: Structure and immunogenicity of the rough-type lipopolysaccharide from the periodontal pathogen Tannerella forsythia.
abstract: Tannerella forsythia is a Gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. It belongs to the so-called "red complex" of bacteria comprising species that are associated with periodontal disease. While the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (LPS) of this organism were available. In this study, the T. forsythia LPS structure was partially elucidated by a combined mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) approach and initial experiments to characterize its immunostimulatory potential were performed. The T. forsythia LPS is a complex, rough-type LPS with a core region composed of one 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) residue, three mannose residues, and two glucosamine residues. MS analyses of O-deacylated LPS proved that, in addition, one phosphoethanolamine residue and most likely one galactose-phosphate residue were present, however, their positions could not be identified. Stimulation of human macrophages with T. forsythia LPS resulted in the production of the proinflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha in a dose-dependent manner. The response to T. forsythia LPS was observed only upon stimulation in the presence of fetal calf serum (FCS), whereas no cytokine production was observed in the absence of FCS. This finding suggests that the presence of certain additional cofactors is crucial for the immune response induced by T. forsythia LPS.
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Vienna, Austria.
authors.forename: Gerald
authors.initials: G
authors.lastname: Posch
authors.forename: Oleh
authors.initials: O
authors.lastname: Andrukhov
authors.forename: Evgeny
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.forename: Paul
authors.initials: P
authors.lastname: Messner
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
authors.forename: Christina
authors.initials: C
authors.lastname: Schäffer
mesh_terms: D041963:Bacteroidetes / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010518:Periodontitis / Q000382:microbiology
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides