title: In vivo model of adeno-associated virus vector persistence and rescue.
abstract: Gene therapy vectors based on human DNA viruses could be mobilized or rescued from individuals who are subsequently infected with the corresponding wild-type (wt) helper viruses. This phenomenon has been effectively modeled in vitro with both adenovirus (Ad) and adeno-associated virus (AAV) vectors but has not previously been studied in vivo. In the current study, we have developed an in vivo model to study the interactions of a recombinant AAV vector (AAV-CFTR) with wt AAV type 2 (AAV2) and a host range mutant Ad (Ad2HR405) for which monkey cells are permissive (D.E.Brough, S.A.Rice, S.Sell, and D.F.Klessig, J. Virol. 55:206-212, 1985). AAV-CFTR was administered to the respiratory epithelium of the nose or lung of rhesus macaques. Primary cells were harvested from the infusion site at time points up to 3 months after vector administration to confirm vector DNA persistence. Vector DNA was present in episomal form and could be rescued in vitro only by addition of wt AAV2 and Ad. In in vivo rescue studies, vector was administered before or after wt-AAV2 and Ad2HR405 infection, and the shedding of AAV-CFTR was examined. Ad2HR405 and wt-AAV2 infections were established in the nose with concomitant administration. wt-AAV2 replication occurred in the lung when virus was administered directly at a high titer to the lower respiratory tract. AAV-CFTR vector rescue was also observed in the latter setting. Although these studies were performed with small numbers of animals within each group, it appears that AAV-CFTR DNA persists in the primate respiratory tract and that this model may be useful for studies of recombinant AAV vector rescue.
authors.affiliation: Eudowood Division of Pediatric Respiratory Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Afione
authors.forename: C K
authors.initials: CK
authors.lastname: Conrad
authors.forename: W G
authors.initials: WG
authors.lastname: Kearns
authors.forename: S
authors.initials: S
authors.lastname: Chunduru
authors.forename: R
authors.initials: R
authors.lastname: Adams
authors.forename: T C
authors.initials: TC
authors.lastname: Reynolds
authors.forename: W B
authors.initials: WB
authors.lastname: Guggino
authors.forename: G R
authors.initials: GR
authors.lastname: Cutting
authors.forename: B J
authors.initials: BJ
authors.lastname: Carter
authors.forename: T R
authors.initials: TR
authors.lastname: Flotte
mesh_terms: D000256:Adenoviridae / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D001980:Bronchi / Q000166:cytology / Q000821:virology; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D002460:Cell Line; D002478:Cells, Cultured; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis; D017931:DNA Primers; D000229:Dependovirus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D004847:Epithelial Cells; D004848:Epithelium / Q000821:virology; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D006367:HeLa Cells; D006378:Helper Viruses / Q000502:physiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D017201:Virus Shedding
chemical_list: C505032:CFTR protein, human; D017931:DNA Primers; D019005:Cystic Fibrosis Transmembrane Conductance Regulator