Preferential adenovirus-mediated transduction of cells at the sites of laser photocoagulation in the rat eye

Purpose. This study aimed to investigate the feasibility of recombinant ade novirus-mediated gene transfer into cells implicated in the development of choroidal neovascularization (CNV). Methods. A rat model of CNV which used laser photocoagulation was developed . Gene delivery into the laser spots was investigated following subretinal injection of recombinant adenoviruses, AdRSVlacZ, AdCMVlacZ or AdCMVgfp. Im munohistochemical analysis was performed using a proliferating cell nuclear antigen antibody and a cytokeratin-specific antibody to identify the cell types transduced by the recombinant adenoviruses. Results. At 7 days post-injection, lacZ expression was detected in 51.6 +/- 13.2% and 71.2 +/- 19.3% of laser spots in AdRSVlacZ- and AdCMVlacZ-inject ed eyes, respectively. By 28 days post-injection, lacZ expression was only present in AdCMVlacZ-injected eyes. In vivo fundus fluorescent photography of AdCMVgfp-injected eyes detected gfp expression in 79.9 +/- 12.7% and 35. 6% +/- 19.7% of laser spots at 4 and 7 days post-injection, respectively. A lthough fundus fluorescent photography did not detect the gfp signal at 10 days post-injection, fluorescent microscopy revealed a gfp signal in 81.3 /- 6.0% of laser spots. Immunohistochemical analysis detected retinal pigme nt epithelial (RPE) cells as the most predominant proliferating cell type i n the laser spots, although several other proliferating cell types were als o identified. X-gal staining showed that the majority of transduced cells w ere those present in the laser spots. Conclusions. It is proposed that following laser photocoagulation, prolifer ating RPE cells are susceptible to adenovirus-mediated gene delivery and th at they may be suitable targets for the delivery of anti-angiogenic factors by recombinant adenoviruses in order to inhibit developing CNV membranes.