title: Helicobacter pylori toxin VacA is transferred to host cells via a novel contact-dependent mechanism.
abstract: Helicobacter pylori is the causative agent of peptic ulcer disease. A major virulence factor of H. pylori is VacA, a toxin that causes massive vacuolization of epithelial cell lines in vitro and gastric epithelial erosion in vivo. Although VacA is exported over the outer membrane and is released from the bacteria, a portion of the toxin remains associated with the bacterial surface. We have found surface-associated toxin to be biologically active and spatially organized into distinct toxin-rich domains on the bacterial surface. Upon bacterial contact with host cells, toxin clusters are transferred directly from the bacterial surface to the host cell surface at the bacteria-cell interface, followed by uptake and intoxication. This contact-dependent transfer of VacA represents a cost-efficient route for delivery of VacA and potentially other bacterial effector molecules to target cells.
authors.affiliation: IRIS, Chiron srl, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Dag
authors.initials: D
authors.lastname: Ilver
authors.forename: Silvia
authors.initials: S
authors.lastname: Barone
authors.forename: David
authors.initials: D
authors.lastname: Mercati
authors.forename: Pietro
authors.initials: P
authors.lastname: Lupetti
authors.forename: John L
authors.initials: JL
authors.lastname: Telford
mesh_terms: D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D017353:Gene Deletion; D016480:Helicobacter pylori / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D018613:Microscopy, Confocal; D014617:Vacuoles
chemical_list: D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori