title: Proteomics characterization of outer membrane vesicles from the extraintestinal pathogenic Escherichia coli DeltatolR IHE3034 mutant.
abstract: Extraintestinal pathogenic Escherichia coli are the cause of a diverse spectrum of invasive infections in humans and animals, leading to urinary tract infections, meningitis, or septicemia. In this study, we focused our attention on the identification of the outer membrane proteins of the pathogen in consideration of their important biological role and of their use as potential targets for prophylactic and therapeutic interventions. To this aim, we generated a DeltatolR mutant of the pathogenic IHE3034 strain that spontaneously released a large quantity of outer membrane vesicles in the culture supernatant. The vesicles were analyzed by two-dimensional electrophoresis coupled to mass spectrometry. The analysis led to the identification of 100 proteins, most of which are localized to the outer membrane and periplasmic compartments. Interestingly based on the genome sequences available in the current public database, seven of the identified proteins appear to be specific for pathogenic E. coli and enteric bacteria and therefore are potential targets for vaccine and drug development. Finally we demonstrated that the cytolethal distending toxin, a toxin exclusively produced by pathogenic bacteria, is released in association with the vesicles, supporting the recently proposed role of bacterial vesicles in toxin delivery to host cells. Overall, our data demonstrated that outer membrane vesicles represent an ideal tool to study Gram-negative periplasm and outer membrane compartments and to shed light on new mechanisms of bacterial pathogenesis.
authors.affiliation: Biochemistry and Molecular Biology Unit, Novartis Vaccines and Diagnostics, 53100 Siena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Berlanda Scorza
authors.forename: Francesco
authors.initials: F
authors.lastname: Doro
authors.forename: Manuel José
authors.initials: MJ
authors.lastname: Rodríguez-Ortega
authors.forename: Maria
authors.initials: M
authors.lastname: Stella
authors.forename: Sabrina
authors.initials: S
authors.lastname: Liberatori
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Taddei
authors.forename: Laura
authors.initials: L
authors.lastname: Serino
authors.forename: Danilo
authors.initials: D
authors.lastname: Gomes Moriel
authors.forename: Barbara
authors.initials: B
authors.lastname: Nesta
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Fontana
authors.forename: Angela
authors.initials: A
authors.lastname: Spagnuolo
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Pizza
authors.forename: Nathalie
authors.initials: N
authors.lastname: Norais
authors.forename: Guido
authors.initials: G
authors.lastname: Grandi
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000648:ultrastructure; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology* / Q000235:genetics* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000235:genetics*; D016680:Genome, Bacterial; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D010455:Peptides; D033903:Periplasmic Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D021122:Protein Subunits; D040901:Proteomics / Q000379:methods*; D012984:Software
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010455:Peptides; D033903:Periplasmic Proteins; D021122:Protein Subunits; C067044:cytolethal distending toxin; C060794:tolR protein, E coli