Genomic Editing of Stem Cells for Modeling and Therapy of Genetic Diseases

Abstract

The application of advanced genome editing technologies, when combined with induced pluripotent stem cells (iPSC), presents a unique opportunity to develop unprecedented patient‐specific in vitro models of disease‐in‐a‐dish that can be used for the development of more effective and universal stem cell therapies. Towards this aim, we have corrected SCID‐X1 patient‐derived iPSC using TALENs, resulting in the rescue of defective IL2RG expression and in the recovered generation of lymphoid cells derived from these iPSC. We have also corrected the common ΔF508 mutation of CFTR in cystic fibrosis patient‐derived iPSC using a novel, efficient, footprint‐free CRISPR‐mediated approach, and shown the subsequent functional recovery of CFTR function in airway epithelium derived from the corrected iPSC.However, the inability to derive truly transplantable cell types from iPSC limits the long‐term clinical and therapeutic potential of this approach. To address this we have carried out direct CRISPR‐mediated gene correction of CD34+ hematopoietic stem cells (HSC) from the FoxP3 mutant scurfy (sf) NOD mouse, which is defective for the development of regulatory T‐cells. These directly gene‐edited FoxP3sf HSC can then be evaluated for their potential for long‐term engraftment and regeneration of regulatory T‐cells by transplantation into lethally irradiated recipient mice. The ultimate goal is to establish novel pre‐clinical models for stem cell‐based therapy for a variety of genetic disorders.