Gene Transfer into Rat Renal Cells Using Adeno-Associated Virus Vectors

Abstract

Adeno-associated virus (AAV) vectors have a number of attractive features, including lack of cytotoxicity, ability to transduce nondividing cells, and long-term transgene expression. We investigated whether rat renal cells could be efficiently transduced with AAV vectors. Rat glomerular mesangial cells were transduced with AAV-lacZ vector containing β-galactosidase gene in vitro, and the expression of β-galactosidase was evaluated by X-gal staining and ELISA. For ex vivo experiments, sections of rat kidneys were incubated with AAV-lacZ, and then evaluated by X-gal histochemical staining. The level of β-galactosidase expression in cultured rat mesangial cells increased in a dose-dependent manner (ranging from 1 × 10⁵ to 5 × 10⁶ particles/cell). When transduced with 5 × 10⁶ vector particles/cell of AAV-lacZ, about 50% of mesangial cells were stained positively with X-gal, and the level of β-galactosidase expression reached 9.9 ± 1.5 ng/mg protein. Expression was detectable during the culture period for at least 7 days. X-gal histochemical examination of the ex vivo transduced renal tissue revealed tubular cell and interstitial tissue staining. However, gene transfer was not clearly observed in glomeruli. These findings suggest that AAV vectors have the potential for gene therapy of renal diseases.