title: Potential therapeutic applications of recombinant, invasive E. coli.
abstract: An invasive Escherichia coli expressing the inv gene from Yersinia pseudotuberculosis was used as a vector for protein delivery to mammalian epithelial cells. Upon incubation with beta1-integrin-expressing mammalian cells, the bacteria are internalized, allowing bacteria-encoded proteins to function from within the mammalian cell. These bacteria are eventually processed in the host phagosome where they are destroyed. Expression of listeriolysin O from Listeria monocytogenes in the bacterium and its subsequent release into the phagosome triggers the breakdown of the membrane, allowing the release of the bacterial content into the cytosol of host cells. Using this vector, we demonstrate delivery of a gene and intact, functional proteins into mammalian cells in which beta1-integrin is expressed and accessible. At a ratio of bacteria/mammalian cells compatible with the survival of the mammalian cells, protein delivery can be observed in the entire cell population in vitro, while gene transfer is far less efficient. Protein delivery can also be achieved in vivo in mouse tumour models and can be detected at least 96 h after inoculation. Functional, natural E. coli proteins are delivered in the process and can provide therapeutic benefit in vivo, when associated with prodrugs. This therapeutic effect is associated with infiltration of neutrophils, eosinophils, macrophages and to a lesser extent dendritic cells in the tumour mass.
authors.affiliation: Cancer Research UK Molecular Oncology Unit, ICSM at Hammersmith Hospital, London, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Critchley
authors.forename: S
authors.initials: S
authors.lastname: Jezzard
authors.forename: K J
authors.initials: KJ
authors.lastname: Radford
authors.forename: S
authors.initials: S
authors.lastname: Goussard
authors.forename: N R
authors.initials: NR
authors.lastname: Lemoine
authors.forename: C
authors.initials: C
authors.lastname: Grillot-Courvalin
authors.forename: G
authors.initials: G
authors.lastname: Vassaux
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000378:metabolism; D018938:Caco-2 Cells; D002460:Cell Line; D003713:Dendritic Cells / Q000502:physiology; D004804:Eosinophils / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics*; D005472:Fluorouracil / Q000627:therapeutic use; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008546:Melanoma, Experimental / Q000628:therapy; D051379:Mice; D009369:Neoplasms / Q000276:immunology / Q000382:microbiology / Q000628:therapy*; D010586:Phagocytes / Q000502:physiology; D011355:Prodrugs / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage; D014169:Transformation, Bacterial
chemical_list: D018829:Adhesins, Bacterial; D000970:Antineoplastic Agents; D001426:Bacterial Proteins; D011355:Prodrugs; D011993:Recombinant Fusion Proteins; C053476:invasin, Yersinia; D005472:Fluorouracil