Autologous transplantation of genetically modified induced pluripotent stem cells for rescue of autosomal dominant retinal disorders

About This Grant

PROJECT SUMMARY Gene therapy for the treatment of autosomal recessive disorders by supplementation with wild-type (WT) copies of the affected gene has been tested in FDA-approved trials. However, strategies for treating autosomal dominant (ad) disorders, which require the removal of a gain-of-function allele through precise genomic repair, have been tested preclinically but have not been evaluated in human subjects. In this proposal, we aim to overcome long standing obstacles to the treatment of RPE65 D477G dominant disorders using autologous induced pluripotent stem cell (iPSC) transplantation. The central hypothesis is that patient-derived iPSC RPE (iRPE) grafts repaired by CRISPR in vitro are a therapeutic option to treat RPE disorders. We will use allele- specific CRISPR-edited RPE65 D477G iRPE to confirm functional repair and differentiation in Aim 1a, and the genomic integrity will be validated via WGS in Aim 1b. The therapeutic potential of iRPE transplantation will be assessed when transplanted into a retinitis pigmentosa preclinical mouse model, Rpe65rd12;Prdcscid. By comparing phenotypes induced by transplantation of repaired iRPE vs. control RPE lines, we will assess whether in vitro CRISPR-repaired iRPE halts disease development in the context of an ad disorder. Our objective is to identify ways to leverage patient stem cells as a tissue source for regenerative medicine. Aim 2 will determine whether patient iRPE repaired in vitro functionally integrate into the retinal circuitry of live mice and rescue vision. Lastly, Aim 3 will determine whether transplanted iRPE is safe and nontumorigenic through long-term analysis.