Comparison of adenovirus gene transfer to vascular endothelial cells in cell culture, organ culture, and in vivo

A replication-defective adenovirus 5 vector carrying the beta-galactosidase reporter gene was tested for its efficiency for gene delivery to vascular endothelial cells in various situations. Both porcine and human primary vascular endothelial cell cultures were very efficiently infected (>90%) at adenovirus concentrations of 10(10) pfu/ml or higher. Cultured rat fibroblasts and keratinocytes were even more readily infected, with >90% infection with adenovirus titers of 10(8) pfu/ml or higher. However, nondividing vascular endothelium in situ was very poorly transduced. Pieces of aorta from adult pigs, sheep, rabbit and rat, and pieces of human umbilical artery and vein were studied in organ culture. These showed only occasional positive vascular endothelial cells when exposed to the adenovirus vector at concentrations up to 5x10(11) pfu/ml. Kidney perfusion studies in rats and pigs gave similar results. The only exception to the above findings was in very young (3-4 day old) piglets, which showed excellent (>90%) infection of vascular endothelium with the adenovirus vector at titers of 10(10) pfu/ml. Our data suggest that adenovirus vectors will not be of value for gene delivery to uninjured vascular endothelium in situ, and are therefore unsuited for ex vivo genetic manipulation of vascular endothelium in organs for transplantation.