title: Relaxation of DNA supercoiling leads to increased invasion of epithelial cells and protein secretion by Campylobacter jejuni.
abstract: Invasion of intestinal epithelial cells by Campylobacter jejuni is a critical step during infection of the intestine by this important human pathogen. In this study we investigated the role played by DNA supercoiling in the regulation of invasion of epithelial cells and the mechanism by which this could be mediated. A significant correlation between more relaxed DNA supercoiling and an increased ability of C. jejuni strains to penetrate human epithelial cells was demonstrated. Directly inducing relaxation of DNA supercoiling in C. jejuni was shown to significantly increase invasion of epithelial cells. Mutants in the fibronectin binding proteins CadF and FlpA still displayed an increased invasion after treatment with novobiocin suggesting these proteins were not essential for the observed phenotype. However, a large increase in protein secretion from multiple C. jejuni strains upon relaxation of DNA supercoiling was demonstrated. This increase in protein secretion was not mediated by outer membrane vesicles and appeared to be dependent on an intact flagellar structure. This study identifies relaxation of DNA supercoiling as playing a key role in enhancing C. jejuni pathogenesis during infection of the human intestine and identifies proteins present in a specific invasion associated secretome induced by relaxation of DNA supercoiling.
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Eoin
authors.initials: E
authors.lastname: Scanlan
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Laura
authors.initials: L
authors.lastname: Ardill
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Matthew V X
authors.initials: MV
authors.lastname: Whelan
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.|National Childrens Research Centre, Our Ladys Hospital for Sick Children, Crumlin, Dublin 12, Ireland.
authors.forename: Claire
authors.initials: C
authors.lastname: Shortt
authors.affiliation: School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Jarlath E
authors.initials: JE
authors.lastname: Nally
authors.affiliation: National Childrens Research Centre, Our Ladys Hospital for Sick Children, Crumlin, Dublin 12, Ireland.|School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Billy
authors.initials: B
authors.lastname: Bourke
authors.affiliation: School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.|National Childrens Research Centre, Our Ladys Hospital for Sick Children, Crumlin, Dublin 12, Ireland.
authors.forename: Tadhg
authors.identifier: 0000-0003-1966-204X
authors.initials: T
authors.lastname: Ó Cróinín
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002169:Campylobacter Infections / Q000378:metabolism / Q000382:microbiology; D016123:Campylobacter jejuni / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000235:genetics; D004247:DNA / Q000378:metabolism; D004278:DNA, Superhelical / Q000235:genetics* / Q000378:metabolism*; D004847:Epithelial Cells / Q000382:microbiology; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D009675:Novobiocin / Q000378:metabolism; D000069284:Protein Translocation Systems; D021381:Protein Transport; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C107872:CadF protein, Campylobacter jejuni; D002352:Carrier Proteins; D004278:DNA, Superhelical; D005353:Fibronectins; C119770:FlpA protein, bacteria; D000069284:Protein Translocation Systems; D014157:Transcription Factors; D009675:Novobiocin; D004247:DNA