title: The MSHA pilus of Vibrio parahaemolyticus has lectin functionality and enables TTSS-mediated pathogenicity.
abstract: Vibrio parahaemolyticus is a seafood-borne pathogen which causes acute inflammatory gastroenteritis--a process which is mediated by the translocation of type three secretion system effector proteins. The molecular interactions governing colonization of the intestinal epithelium by this pathogen remain poorly understood. The mannose-sensitive haemagglutinin (MSHA) pilus was identified in this study as a significant factor in bacterial-host cell adherence and subsequent pathogenesis towards Caco-2 human intestinal epithelial cells. Deletion of essential components of the MSHA pilus resulted in a 60% decrease in adherence and a similar reduction in bacterial uptake by human intestinal cells. The diminished adherence of MSHA mutants correlated with significant decreases in V. parahaemolyticus-induced Caco-2 cell lysis, cell rounding and IL-8 secretion. Glycan array comparison between the V. parahaemolyticus wild type and MSHA deficient mutants identified lectin functionality for the MSHA pilus with specificity towards the fucosylated blood group oligosaccharide antigens Lewis A and X and blood groups A and B. The MSHA pilus also exhibited high affinity for the structurally related asialo-GM1 ganglioside, lacto-N-fucopentaose I and lacto-N-difucohexaose I. We hypothesize that these glycans act as receptors for the MSHA pilus in the gastrointestinal tract, thereby facilitating efficient colonization of the intestinal epithelium by V. parahaemolyticus.
authors: Pathogenic Mechanisms Research Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
authors: Nicky
authors: N
authors: O'Boyle
authors: Benoit
authors: B
authors: Houeix
authors: Michelle
authors: M
authors: Kilcoyne
authors: Lokesh
authors: L
authors: Joshi
authors: Aoife
authors: A
authors: Boyd
mesh_terms: D001422:Bacterial Adhesion; D058947:Bacterial Secretion Systems; D001789:Blood Group Antigens / Q000378:metabolism; D018938:Caco-2 Cells; D004252:DNA Mutational Analysis; D004847:Epithelial Cells / Q000382:microbiology; D036781:Fimbriae Proteins / Q000378:metabolism*; D006388:Hemagglutinins / Q000378:metabolism*; D006801:Humans; D037601:Mannose-Binding Lectin / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D011485:Protein Binding; D014736:Vibrio parahaemolyticus / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D058947:Bacterial Secretion Systems; D001789:Blood Group Antigens; D006388:Hemagglutinins; D037601:Mannose-Binding Lectin; D011134:Polysaccharides; D037521:Virulence Factors; D036781:Fimbriae Proteins
keywords: Adhesin; Cytotoxicity; Glycan; Lectin; Type IV pili; Type three secretion system