Cardio-specific long-term gene expression in a porcine model after selective pressure-regulated retroinfusion of adeno-associated viral (AAV) vectors

Gene Ther. 2008 Jan;15(1):12-7. doi: 10.1038/sj.gt.3303035. Epub 2007 Oct 18.

Abstract

Cornerstone for an efficient cardiac gene therapy is the need for a vector system, which enables selective and long-term expression of the gene of interest. In rodent animal models adeno-associated viral (AAV) vectors like AAV-6 have been shown to efficiently transduce cardiomyocytes. However, since significant species-dependent differences in transduction characteristics exist, large animal models are of imminent need for preclinical evaluations. We compared gene transfer efficiencies of AAV-6 and heparin binding site-deleted AAV-2 vectors in a porcine model. Application of the AAVs was performed by pressure-regulated retroinfusion of the anterior interventricular cardiac vein, which has been previously shown to efficiently deliver genes to the myocardium (3.5 x 10(10) viral genomes per animal; n=5 animals per group). All vectors harbored a luciferase reporter gene under control of a cytomegalovirus (CMV)-enhanced 1.5 kb rat myosin light chain promoter (CMV-MLC2v). Expression levels were evaluated 4 weeks after gene transfer by determining luciferase activities. To rule out a systemic spillover peripheral tissue was analyzed by PCR for the presence of vector genomes. Selective retroinfusion of AAV serotype 6 vectors into the anterior cardiac vein substantially increased reporter gene expression in the targeted distal left anterior descending (LAD) territory (65 943+/-31 122 vs control territory 294+/-69, P<0.05). Retroinfusion of AAV-2 vectors showed lower transgene expression, which could be increased with coadministration of recombinant human vascular endothelial growth factor (1365+/-707 no vascular endothelial growth factor (VEGF) vs 38 760+/-2448 with VEGF, P<0.05). Significant transgene expression was not detected in other organs than the heart, although vector genomes were detected also in the lung and liver. Thus, selective retroinfusion of AAV-6 into the coronary vein led to efficient long-term myocardial reporter gene expression in the targeted LAD area of the porcine heart. Coapplication of VEGF significantly increased transduction efficiency of AAV-2.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Coronary Vessels
  • Dependovirus / genetics*
  • Gene Deletion
  • Gene Expression
  • Genetic Therapy / methods*
  • Genetic Vectors / administration & dosage*
  • Heart Diseases / therapy*
  • Heparin / analogs & derivatives
  • Heparin / genetics
  • Infusions, Intravenous / methods
  • Luciferases / analysis
  • Luciferases / genetics
  • Models, Animal
  • Myocardium / enzymology
  • Pressure
  • Proteoglycans / genetics
  • Swine
  • Transduction, Genetic / methods*
  • Transgenes
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Proteoglycans
  • Vascular Endothelial Growth Factor A
  • heparin proteoglycan
  • Heparin
  • Luciferases