Herpes simplex virus as a model vector system for gene therapy in renal disease

The past decade has been marked by significant advances in the application of gene transfer into living cells of animals and humans. These approaches have been tested in a few animal models of inherited and acquired renal diseases, including carbonic anhydrase II deficiency [1] and experimental glomerulonephritis [2, 3]. Gene transfer into proximal tubular cells has been successfully accomplished by intrarenal arterial infusion of a liposomal complex [4] or an adenoviral vector [5]. Tubular cells from the papilla and medulla have been selectively transduced by retrograde infusion into the pelvi-calyceal system of an adenoviral vector containing a reporter for beta-galactosidase [5]. Although the results of these initial studies are promising, further studies to optimize viral vectors, maximize gene delivery, minimize side-effects, and develop cell-specific and long-term regulated gene expression are critical to the success of gene therapy targeted to specific compartments of the kidney. Our recent efforts have focused on defining the cellular pathways responsible for viral entry and infection into renal epithelial cells using herpes simplex virus (HSV) as a model vector. We anticipate that a solid understanding of the basic scientific principles underlying viral entry and gene expression into specific populations of renal cells will facilitate the design of successful therapeutic viral-based gene transfer strategies.