title: In vivo administration of lentiviral vectors triggers a type I interferon response that restricts hepatocyte gene transfer and promotes vector clearance.
abstract: Liver gene transfer is a highly sought goal for the treatment of inherited and infectious diseases. Lentiviral vectors (LVs) have many desirable properties for hepatocyte-directed gene delivery, including the ability to integrate into nondividing cells. Unfortunately, upon systemic administration, LV transduces hepatocytes relatively inefficiently compared with nonparenchymal cells, and the duration of transgene expression is often limited by immune responses. Here, we investigated the role of innate antiviral responses in these events. We show that administration of LVs to mice triggers a rapid and transient IFNalphabeta response. This effect was dependent on functional vector particles, and in vitro challenge of antigen-presenting cells suggested that plasmacytoid dendritic cells initiated the response. Remarkably, when LVs were administered to animals that lack the capacity to respond to IFNalphabeta, there was a dramatic increase in hepatocyte transduction, and stable transgene expression was achieved. These findings indicate that, even in the setting of acute delivery of replication-defective vectors, IFNs effectively interfere with transduction in a cell-type-specific manner. Moreover, because disabling a single component of the innate/immune network was sufficient to establish persistent xenoantigen expression, our results raise the hope that the immunologic barriers to gene therapy are less insurmountable than expected.
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Brown
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sitia
authors.forename: Andrea
authors.initials: A
authors.lastname: Annoni
authors.forename: Ehud
authors.initials: E
authors.lastname: Hauben
authors.forename: Lucia Sergi
authors.initials: LS
authors.lastname: Sergi
authors.forename: Anna
authors.initials: A
authors.lastname: Zingale
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Roncarolo
authors.forename: Luca G
authors.initials: LG
authors.lastname: Guidotti
authors.forename: Luigi
authors.initials: L
authors.lastname: Naldini
mesh_terms: D000818:Animals; D003713:Dendritic Cells / Q000276:immunology; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000276:immunology; D022781:Hepatocytes / Q000276:immunology* / Q000821:virology*; D066298:In Vitro Techniques; D007370:Interferon Type I / Q000096:biosynthesis*; D016086:Lentivirus / Q000235:genetics* / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008819:Mice, Nude; D014161:Transduction, Genetic
chemical_list: D007370:Interferon Type I