title: Factor IX expression in skeletal muscle of a severe hemophilia B patient 10 years after AAV-mediated gene transfer.
abstract: In previous work we transferred a human factor IX-encoding adeno-associated viral vector (AAV) into skeletal muscle of men with severe hemophilia B. Biopsy of injected muscle up to 1 year after vector injection showed evidence of gene transfer by Southern blot and of protein expression by IHC and immunofluorescent staining. Although the procedure appeared safe, circulating F.IX levels remained subtherapeutic (< 1%). Recently, we obtained muscle tissue from a subject injected 10 years earlier who died of causes unrelated to gene transfer. Using Western blot, IHC, and immunofluorescent staining, we show persistent factor IX expression in injected muscle tissue. F.IX transcripts were detected in injected skeletal muscle using RT-PCR, and isolated whole genomic DNA tested positive for the presence of the transferred AAV vector sequence. This is the longest reported transgene expression to date from a parenterally administered AAV vector, with broad implications for the future of muscle-directed gene transfer.
authors.affiliation: Division of Hematology and Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: George
authors.initials: G
authors.lastname: Buchlis
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Podsakoff
authors.forename: Antonetta
authors.initials: A
authors.lastname: Radu
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Hawk
authors.forename: Alan W
authors.initials: AW
authors.lastname: Flake
authors.forename: Federico
authors.initials: F
authors.lastname: Mingozzi
authors.forename: Katherine A
authors.initials: KA
authors.lastname: High
mesh_terms: D000328:Adult; D000229:Dependovirus / Q000235:genetics* / Q000502:physiology; D005164:Factor IX / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D002836:Hemophilia B / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009928:Organ Specificity / Q000235:genetics; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D005164:Factor IX