Human Blue-Opsin Promoter Preferentially Targets Reporter Gene Expression to Rat S-Cone Photoreceptors

Abstract

AAV5.HB.GFP vector injected into the subretinal space of Sprague-Dawley rats targeted gene expression to photoreceptor cells with an efficiency approximately 20-fold higher than that for AAV2.HB.GFP. Transgene expression regulated by the human blue cone-promoter persisted at least for 20 months. Cones coexpressing S-opsin and the GFP transgene appeared to prevail, confirming that in addition to having properties of the AAV serotype, the promoter choice is key to fine-tuning transgene delivery and expression in specific retinal cells. The system described here may be effective in a therapeutic setting in which strong S-cone transgene expression is required.