title: Improved methods for producing outer membrane vesicles in Gram-negative bacteria.
abstract: Outer membrane vesicle formation occurs during Gram-negative bacterial growth. However, natural production of large amounts of outer membrane vesicles has only been described in a few bacterial genera. The purified vesicles of some bacterial pathogens have shown potential applications in vaccinology and in antibiotic therapy. This study focused on the development of a gene expression system able to induce production of large amounts of outer membrane vesicles. The Tol-Pal system of Escherichia coli, required to maintain outer membrane integrity, is composed of five cell envelope proteins, TolA, TolB, TolQ, TolR and Pal. Tol proteins are parasitized by filamentous bacteriophages and by colicins. The phage infection process and colicin import require, respectively, the N-terminal domain of the minor coat g3p protein and the translocation domain of colicins, with both domains interacting with Tol proteins. In this study, we show that the periplasmic production of either Tol, g3p or colicin domains was able to specifically destabilize the E. coli or Shigella flexneri cell envelope and to induce production of high amounts of vesicles. This technique was further found to work efficiently in Salmonella enterica serovar Typhimurium.
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, Parc scientifique de Luminy, case 906, 13288 Marseille 9, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Henry
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Pommier
authors.forename: Laure
authors.initials: L
authors.lastname: Journet
authors.forename: Alain
authors.initials: A
authors.lastname: Bernadac
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gorvel
authors.forename: Roland
authors.initials: R
authors.lastname: Lloubès
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology*; D003087:Colicins / Q000378:metabolism / Q000494:pharmacology; D003090:Coliphages / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000502:physiology*; D008828:Microbiological Techniques / Q000379:methods*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000502:physiology; D012763:Shigella flexneri / Q000187:drug effects / Q000502:physiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D003087:Colicins