The helper-dependent adenoviral (HD-Ad) vector is the latest generation of Ad vectors. It ameliorates the vector-associated immunogenic problems with increased capacity for carrying DNA because all viral coding genes are removed. I hypothesize that HD-Ad vectors can be effective vehicles for retinal gene delivery. The objectives of this study are to determine if HD-Ad vectors can deliver reporter genes, GFP or lacZ, driven by a CMV or a MOPS promoter, into specific retinal layers. Subretinal injections were performed and eyes removed at time points from 1 week to 3 months, processed for fluorescent microscopy, X-gal staining, and H&E staining. Transgene expression was detected for at least 3 months. A dose dependent relationship was revealed between the level of transgene expression and viral vector dose. Distinctively, the MOPS promoter drove photoreceptor cell specific expression. Notably, no sign of inflammation or tissue toxicity was detected, demonstrating the benefits of the HD-Ad vector.

The helper-dependent adenoviral (HD-Ad) vector is the latest generation of Ad vectors. It ameliorates the vector-associated immunogenic problems with increased capacity for carrying DNA because all viral coding genes are removed. I hypothesize that HD-Ad vectors can be effective vehicles for retinal gene delivery. The objectives of this study are to determine if HD-Ad vectors can deliver reporter genes, GFP or lacZ, driven by a CMV or a MOPS promoter, into specific retinal layers. Subretinal injections were performed and eyes removed at time points from 1 week to 3 months, processed for fluorescent microscopy, X-gal staining, and H&E staining. Transgene expression was detected for at least 3 months. A dose dependent relationship was revealed between the level of transgene expression and viral vector dose. Distinctively, the MOPS promoter drove photoreceptor cell specific expression. Notably, no sign of inflammation or tissue toxicity was detected, demonstrating the benefits of the HD-Ad vector.