1. ¹Gene Therapy Center, Columbus Children's Research Institute, Columbus Children's Hospital, Columbus, OH, USA
2. ²Integrated Biomedical Graduate Program and Medical Scientist Program, The Ohio State University, Columbus, OH, USA
3. ³Department of Molecular Virology, Immunology, and Medical Genetics, College of Medicine and Public Health, The Ohio State University, Columbus, OH, USA
4. ⁴Division of Molecular Medicine, Department of Pediatrics, College of Medicine and Public Health, The Ohio State University, Columbus, OH, USA

Correspondence: Dr JS Bartlett, Gene Therapy Center, Columbus Children's Research Institute, 700 Children's Drive, Columbus, OH 43205, USA. E-mail: bartletj@pediatrics.ohio-state.edu

Received 12 August 2005; Revised 30 November 2005; Accepted 1 January 2006; Published online 16 February 2006.

Abstract

Vascular-targeted gene therapies have the potential to treat many of the leading causes of mortality in the western world. Unfortunately, these therapies have been ineffective due to poor vascular gene transfer. The use of alternative virus serotypes and the incorporation of vascular targeting ligands into vectors has resulted in only modest increases in vascular gene transfer. Adeno-associated virus (AAV) 1 has shown the most promise among the AAV vectors for the transduction of vascular endothelial cells. However, no straightforward small-scale purification strategy exists for AAV1 as it does for AAV2 making it difficult to quickly produce AAV1 vector for analysis. Here we have combined two AAV1 capsid protein modifications to enhance vascular gene transfer and allow easy purification of vector particles. Mosaic vector particles have been produced comprised of capsid proteins containing the well-characterized RGD4C modification to target integrins present on the vasculature, and capsid proteins containing a modification that permits metabolic biotinylation and efficient purification of mosaic particles by avidin affinity chromatography. We show that the RGD modification results in a 50–100-fold enhancement in endothelial cell gene transfer that is maintained in biotinylated mosaic AAV1 particles. These results suggest that mosaic virions hold significant promise for targeted gene delivery to the vasculature.