1. ¹Gene Therapy Section, Department of Molecular Cell Biology, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands
2. ²Department of Genetics and Microbiology, University of Geneva, Geneva, Switzerland

Correspondence: Manuel A.F.V. Gonçalves, Fax: +31 71 5276180. E-mail: m.goncalves@lumc.nl

Received 11 July 2005; Revised 25 October 2005; Accepted 13 November 2005.

Abstract

Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene (DMD), making it amenable to gene- or cell-based therapies. Another possible treatment entails the combination of both principles by transplantation of autologous myogenic cells after their genetic complementation. This approach requires efficient and stable transduction of these cells with recombinant DMD. Recently, we generated a dual high-capacity (hc) adenovirus (Ad)–adeno-associated virus (AAV) hybrid vector (HV) that can deliver two full-length dystrophin-encoding modules into target cells. We showed that HV transduction of human cells containing AAV Rep proteins leads to the insertion of foreign DNA into the AAVS1 locus. Here, we improved HV entry into muscle cells from DMD patients. After having verified that these cells barely express the coxsackie B virus and Ad receptor (CAR), which constitutes the attachment molecule for Ad serotype 5 (Ad5) fibers, we equipped dual hcAd/AAV HV particles with Ad serotype 50 fiber domains to achieve CAR-independent uptake. These retargeted vectors complemented much more efficiently the genetic defect of dystrophin-defective myoblasts and myotubes than their isogenic counterparts with conventional Ad5 fibers. Importantly, the accumulation of -dystroglycan along the membranes of vector-treated DMD myotubes indicated proper assembly of dystrophin-associated glycoprotein complexes.