Single AAV-mediated mutation replacement genome editing in limited number of photoreceptors restores vision in mice

• Published in: Nature communications Vol. 11; no. 1; p. 482
• Main Authors: Nishiguchi, Koji M., Fujita, Kosuke, Miya, Fuyuki, Katayama, Shota, Nakazawa, Toru
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.01.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 13/1; 13/44; 13/51; 42/44; 45/22; 45/23; 45/29; 45/77; 631/61/201/2110; 64/60; 692/4017; 692/699/3161/3165; 82/80; Acuity; Animals; Cargo; CRISPR; CRISPR-Cas Systems; Cyclic Nucleotide Phosphodiesterases, Type 6 - deficiency; Cyclic Nucleotide Phosphodiesterases, Type 6 - genetics; Dependovirus - genetics; DNA End-Joining Repair; Eye Proteins - genetics; Gene Editing - methods; Genes; Genetic Therapy - methods; Genetic Vectors; Genome editing; Genomes; Hereditary diseases; Homology; Humanities and Social Sciences; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; multidisciplinary; Mutants; Mutation; Photoreception; Photoreceptor Cells, Vertebrate - physiology; Photoreceptors; Restoration; Retina; Retinal Dystrophies - genetics; Retinal Dystrophies - physiopathology; Retinal Dystrophies - therapy; Science; Science (multidisciplinary); Supplements; Targeted Gene Repair - methods; Transducin - deficiency; Transducin - genetics; Viruses; Visual acuity; Visual Acuity - genetics; Visual Acuity - physiology; Visual effects
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-14181-3

Supplementing wildtype copies of functionally defective genes with adeno-associated virus (AAV) is a strategy being explored clinically for various retinal dystrophies. However, the low cargo limit of this vector allows its use in only a fraction of patients with mutations in relatively small pathogenic genes. To overcome this issue, we developed a single AAV platform that allows local replacement of a mutated sequence with its wildtype counterpart, based on combined CRISPR-Cas9 and micro-homology-mediated end-joining (MMEJ). In blind mice, the mutation replacement rescued approximately 10% of photoreceptors, resulting in an improvement in light sensitivity and an increase in visual acuity. These effects were comparable to restoration mediated by gene supplementation, which targets a greater number of photoreceptors. This strategy may be applied for the treatment of inherited disorders caused by mutations in larger genes, for which conventional gene supplementation therapy is not currently feasible. Replacing mutant genes with wildtype copies using adeno-associated virus (AAV) has been explored for the treatment of inherited retinopathies, but the low cargo limit restricts its use. Here the authors describe a single AAV platform that allows local replacement of a mutated sequence with its wildtype counterpart, based on combined CRISPR-Cas9 and micro-homology-mediated end joining.