Glycobiology aspects of the oral bacterium Selenomonas sputigena - possible roles in periodontitis
Abstract
Periodontitis continues to afflict the majority of the world’s population as the major cause of tooth loss. It is an inflammatory disease of the periodontium triggered by a polymicrobial oral biofilm. Current efforts to unravel the still not fully understood etiology of periodontitis focus on the interplay that occurs among the numerous oral bacteria in the biofilm community. The structural, functional, and molecular properties of cell surface glycoconjugates support a key role of these molecules in inter-bacterial communication and recognition. Supported by own data on the glycobiology of the periodontopathogen Tannerella, and immunological research by others, we hypothesize that distinct oral bacteria possess a diverse, yet to be discovered, glycome and that their cell surface glycobiology is a hallmark of polymicrobial community inter-actions and relevant to the development and the properties of dental plaque. Despite its possible association with periodontitis, Selenomonas sputigena (Selspu), a Gram-negative, multi¬flagellated, motile, anaerobic rod, is almost uninvestigated. Based on recent findings from our laboratory we hypothesize that Selspu employs various glycobiology-based strategies for oral colonization and survival, because: (i) Selspu possesses a diverse glycoproteome as inferred from positive carbohydrate staining and lectin reactivity of whole cell extracts after separation by SDS-PAGE; (ii) There are indications that Selspu possesses glycosylated flagella; these might be important as both colonization and pathogenicity factor; (iii) Selspu is capable of co-aggregating with T. forsythia, pinpointing a possible association with the effects of the “red-complex” bacteria, and (iv) The Selspu genome provides rich glycobiology information. Especially the prediction of uncommon sugar residues such as L-fucose (an immunogenic sugar), pseudaminic acid (occurring on the flagella of pathogens and on T. forsythia proteins), -O-acetylglucosamine (rarely found on bacterial proteins), and 4-amino-arabinose (known as lipid A modification required for resistance to antimicrobial peptides) makes Selspu a prime glycobiology candidate. To get insight into the glycobiology of Selspu as a basis for assessing its role in the development of dental plaque, our research goals are: A) Identification of prominent Selspu glycoproteins and determination of their glycan composition and structure; B) Analysis of flagella glycosylation; C) Structural investigation of the Selspu lipopolysaccharide; and D) Analysis of the Selspu biofilm matrix focusing on a putative exo-poly¬saccharide. These work packages will be accompanied by transcription analysis of predicted genomic Selspu glycosylation loci and analysis of selected Selspu carbohydrate-active enzymes. This project contributes to deciphering glycobiology aspects of an oral bacterium associated with dental plaque and can inform about bacterial strategies relevant to the pathogenesis of periodontitis. In the future, these may constitute new targets for interfering with the oral microbial community’s ability to establish infection in periodontal disease.
keywords Glycobiology Selenomonas sputigena Flagellum Glycan structure Biofilm
Publikationen
Project staff
Christina Schäffer
Univ.Prof. Dipl.-Ing. Dr.nat.techn. Christina Schäffer
christina.schaeffer@boku.ac.at
Tel: +43 1 47654-80203
Project Leader
01.07.2014 - 31.01.2019
BOKU partners
External partners
National Research Council of Canada, Institute for Biological Sciences
Dr. Ian Schoenhofen
partner