Background: Hereditary retinal disease is currently known to involve nearly 200 different genetic loci. There has been remarkable recent progress in the treatment of retinal disease via gene therapy in animal models using virus-based vectors. The majority of retinal diseases affect one of several cell types. In order to target expression of a rescue transgene specifically to the cells in need of therapy, it is necessary to employ a cis-regulatory element (CRE) to drive expression of the transgene specifically in those cells.
Objective/methods: This review discusses the repertoire of CREs currently available for use in gene therapy vectors for treatment of retinal disease and outlines the issues that must be taken into consideration in the development of novel CREs for the purpose of gene therapy in the retina.
Conclusion: There have been a number of important recent advances in the identification and characterization of retinal CREs and their utilization in gene therapy vectors. Nevertheless, future efforts to rationally manipulate existing CREs and design novel synthetic CREs for therapeutic purposes will require a better understanding of the cis-regulatory rules that govern CRE activity in vivo.