Adeno-associated virus (AAV)-7 and -8 poorly transduce vascular endothelial cells and are sensitive to proteasomal degradation

• Published in: Gene therapy Vol. 12; no. 20; pp. 1534 - 1538
• Main Authors: DENBY, L, NICKLIN, S. A, BAKER, A. H
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.10.2005
• Subjects: Adeno-associated virus; Adeno-associated virus 7; Adeno-associated virus 8; Adenoviruses; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Aorta, Thoracic - virology; Applied cell therapy and gene therapy; Biological and medical sciences; Biotechnology; Blood vessels; Cell Line; Cells, Cultured; Degradation; Dependovirus - genetics; DNA, Viral - analysis; Endothelial cells; Endothelial Cells - metabolism; Endothelial Cells - virology; Endothelium; Expression vectors; Extracellular matrix; Fundamental and applied biological sciences. Psychology; Gene therapy; Genetic aspects; Genetic Therapy - methods; Genetic Vectors - administration & dosage; Genetic Vectors - genetics; Genetic Vectors - metabolism; Health aspects; Health. Pharmaceutical industry; Humans; Industrial applications and implications. Economical aspects; Infectivity; Leupeptins - therapeutic use; Medical sciences; Methods; Mice; Muscle, Smooth, Vascular - metabolism; Muscle, Smooth, Vascular - virology; Nuclear transport; Phage display; Physiological aspects; Proteasome Endopeptidase Complex - metabolism; Proteasome Inhibitors; Proteasomes; Rats; Rats, Inbred WKY; Saphenous Vein; Serotypes; Serotyping; Skeletal muscle; Smooth muscle; Transduction; Transduction, Genetic - methods; Transfusions. Complications. Transfusion reactions. Cell and gene therapy; Ubiquitin-proteasome system; Virions; United Kingdom; Multicatalytic endopeptidase complex; proteasome; Endothelial cell; AAV serotypes; Enzyme; vascular gene therapy; adeno-associated virus; Dependovirus; Endothelium; Virus; Degradation; Peptidases; Parvoviridae; Hydrolases; Serotype; Gene therapy; Vector; Parvovirinae
• ISSN: 0969-7128; 1476-5462
• DOI: 10.1038/sj.gt.3302564

Transduction of the vascular endothelium by adeno-associated virus (AAV) vectors would have broad appeal for gene therapy. However, levels of transduction by AAV serotype-2 are low, an observation linked to deficiencies in endothelial cell binding, sequestration of virions in the extracellular matrix and/or virion degradation by the proteasome. Strategies to improve transduction of endothelial cells include AAV-2 capsid targeting using small peptides isolated by phage display or the use of alternate serotypes. Previously, we have shown that AAV serotypes-3 through -6 transduce endothelial cells with poor efficiency. Recently, AAV serotypes-7 and -8 have been shown to mediate efficient transduction of the skeletal muscle and liver, respectively, although their infectivity profile for vascular cells has not been addressed. Here, we show that AAV-7 and -8 also transduce endothelial cells with poor efficiency and the levels of transgene expression are markedly enhanced by inhibition of the proteasome. In both cases proteasome blockade enhances the nuclear translocation of virions. We further show that this is vascular cell-type selective since transduction of smooth muscle cells is not sensitive to proteasome inhibition. Analysis in intact blood vessels corroborated these findings and suggests that proteasome degradation is a common limiting factor for endothelial cell transduction by AAV vectors.