title: The Helicobacter heilmannii hofE and hofF Genes are Essential for Colonization of the Gastric Mucosa and Play a Role in IL-1β-Induced Gastric MUC13 Expression.
abstract: BACKGROUND
  Helicobacter heilmannii is a zoonotic bacterium associated with gastric disease in humans. We recently showed that H. heilmannii binds to human gastric mucins and epithelial cells and highlighted a potential role for the murine Muc13 mucin in gastric Helicobacter colonization. The aims of this study were to investigate the role of the H. heilmannii hof gene locus encoding HofH/F/E/G/C/D in adhesion to the gastric mucosa and induction of increased gastric Muc13 expression.
  
  
  METHODS
  Bacterial hof gene and host gene expression experiments, Helicobacter binding assays and experimental infection studies in mice were performed. H. pylori and its ΔhofF mutant were included for comparison.
  
  
  RESULTS
  Helicobacter heilmannii strains lacking HofE or HofF showed a clear decrease in binding to gastric mucins and epithelial cells as well as a lower gastric colonization level in the stomach of Balb/c mice at 4 and 9 weeks post-infection compared to the H. heilmannii wildtype strain. Interestingly, H. heilmannii ΔhofE and ΔhofF and H. pylori ΔhofF did not induce an increased expression of MUC13 in human gastric epithelial cells and of Muc13 in the stomach of mice. Finally, we demonstrated that IL-1β is induced in the stomach as a response to Helicobacter colonization which on its turn is involved in the expression of MUC13/Muc13 in the gastric epithelium.
  
  
  CONCLUSIONS
  These novel results in Helicobacter research identified H. heilmannii HofE and HofF as adhesins and suggest an important role of H. heilmannii HofE and HofF and H. pylori HofF in IL-1β-induced gastric MUC13/Muc13 expression.
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Liu
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Rossi
authors.initials: R
authors.lastname: Mirko
authors.affiliation: Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Lindén
authors.initials: L
authors.lastname: Sara
authors.affiliation: Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Padra
authors.initials: P
authors.lastname: Medea
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Blaecher
authors.initials: B
authors.lastname: Caroline
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Bauwens
authors.initials: B
authors.lastname: Eva
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Joosten
authors.initials: J
authors.lastname: Myrthe
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Flahou
authors.initials: F
authors.lastname: Bram
authors.affiliation: Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Van den Broeck
authors.initials: VD
authors.lastname: Wim
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Ducatelle
authors.initials: D
authors.lastname: Richard
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Haesebrouck
authors.initials: H
authors.lastname: Freddy
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Smet
authors.initials: S
authors.lastname: Annemieke
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis*; D001422:Bacterial Adhesion; D004815:Epidermal Growth Factor / Q000096:biosynthesis*; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology*; D018247:Helicobacter heilmannii / Q000472:pathogenicity / Q000502:physiology*; D054884:Host-Pathogen Interactions; D053583:Interleukin-1beta / Q000378:metabolism*; D008807:Mice, Inbred BALB C
chemical_list: D018829:Adhesins, Bacterial; D000954:Antigens, Surface; D053583:Interleukin-1beta; C063487:Ly64 protein, mouse; D004815:Epidermal Growth Factor
keywords: 
  Helicobacter heilmannii
  ; Hof outer membrane protein; MUC13; adhesion