Factor IX expression in skeletal muscle of a severe hemophilia B patient 10 years after AAV-mediated gene transfer

Abstract

<jats:title>Abstract</jats:title><jats:p>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 (&lt; 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.</jats:p>

Life-Long Correction of Hyperbilirubinemia with a Neonatal Liver-Specific AAV-Mediated Gene Transfer in a Lethal Mouse Model of Crigler–Najjar Syndrome

“…As mentioned above, targeting the skeletal muscle for gene therapy offers a series of advantages over a liver-directed gene therapy approach (Mingozzi and High, 2011;Buchlis et al, 2012). However, when we treated in parallel mutant mice with CMV-hUGT1A1 and AAT-hUGT1A1 AAV vectors, plasma bilirubin levels were much higher in CMVhUGT1A1-treated mice than in AAT-hUGT1A1-treated ones, despite of the 4-6-fold higher muscle expression of hUGT1a1.…”

“…Third, viral vectors are currently available that transduce skeletal muscle fibers at very high efficiency. Fourth and final, AAV-mediated gene transfer to human skeletal muscle persists and is transcriptionally active for a period of at least 10 years (Buchlis et al, 2012), and probably longer periods. Because of these favorable characteristics, it is not surprising that several of the clinical trials for liver metabolic diseases performed to date have entailed intramuscular gene delivery (Mingozzi and High, 2011).…”

Intravenous Adeno-Associated Virus Serotype 8 Encoding Urocortin-2 Provides Sustained Augmentation of Left Ventricular Function in Mice

“…Clinical trials of systemic delivery of genes are underway for hemophilia B (Nathwani et al, 2011;Buchlis et al, 2012) and a 1 -antitrypsin deficiency (Flotte et al, 2011). However, systemic delivery of paracrine-based transgenes has not been performed in clinical CHF trials, and is relatively uncommon in preclinical studies (Rivera et al, 1999;Lai et al 2012).…”

Waking the Sleeping Giant: Gene Therapy in Decline?

“…AAV also displays long term stability whether as an integrated or episomal provirus. AAV2-based gene expression has been shown to be maintained for many months, as long as ten years, in our and others' laboratories [1,[4][5][6]. There is also a plethora of AAV capsid types which can be used to customize their uptake in liver, lungs, kidney, blood vessels, and other sites with a single intravenous injection.…”

“…These include recombinant adenoassociated virus (AAV) [1][2][3][4][5][6], retrovirus/lentivirus (Lenti) [7][8][9][10] and adenovirus (Ad) [11][12][13]. These are described in Table 1, and all of these have shown their usefulness and power since the pioneer years of 1983-1984.…”