title: Helicobacter pylori HopQ outer membrane protein attenuates bacterial adherence to gastric epithelial cells.
abstract: Helicobacter pylori genomes contain about 30 hop genes that encode outer membrane proteins. Helicobacter pylori hopQ alleles exhibit a high level of genetic diversity, and two families of hopQ alleles have been described. Type I hopQ alleles are found more commonly in cag-positive H. pylori strains from patients with peptic ulcer disease than in cag-negative strains from patients without ulcer disease. In this study, we mutated hopQ in four H. pylori strains that each contained a type I hopQ allele, and then analyzed interactions of the wild-type and hopQ mutant strains with AGS cells. In comparison with the wild-type strains, two of the hopQ mutant strains exhibited increased adherence to AGS cells and two hopQ mutants did not exhibit any detectable differences in adherence. Higher levels of tyrosine-phosphorylated CagA were detected when AGS cells were cocultured with a hyperadherent hopQ mutant strain than when cocultured with the corresponding wild-type strain. These data indicate that in some strains of H. pylori, the HopQ protein can attenuate bacterial adherence to gastric epithelial cells.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Loh
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Torres
authors.forename: Holly M Scott
authors.initials: HM
authors.lastname: Algood
authors.forename: Mark S
authors.initials: MS
authors.lastname: McClain
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Cover
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism; D001422:Bacterial Adhesion / Q000187:drug effects; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000382:microbiology*; D005753:Gastric Mucosa / Q000166:cytology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics / Q000502:physiology*; D006801:Humans; D020382:Interleukin-18 / Q000378:metabolism; D009154:Mutation; D010957:Plasmids; D013045:Species Specificity
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D020382:Interleukin-18; C080866:cagA protein, Helicobacter pylori