Combined intraocular and intravenous gene delivery for therapy of gyrate atrophy of the choroid and retina.

Gyrate atrophy of the choroid and retina (GACR) is due to ornithine aminotransferase (OAT) deficiency, which causes hyperornithinemia, leading to retinal pigment epithelium, followed by choroidal and retinal degeneration. Adeno-associated virus serotype 8 (AAV8) vector-mediated OAT (AAV8-OAT) liver gene transfer reduces ornithinemia in the Oat mouse model of GACR and improves retinal function and structure. Since OAT is expressed in various tissues including the retina, we investigated the efficacy of restoration of OAT expression in either retina or liver or both tissues on the retinal phenotype of Oat mice.

Safe and effective liver-directed AAV-mediated homology-independent targeted integration in mouse models of inherited diseases.

Liver-directed adeno-associated viral (AAV) vector-mediated homology-independent targeted integration (AAV-HITI) by CRISPR-Cas9 at the highly transcribed albumin locus is under investigation to provide sustained transgene expression following neonatal treatment. We show that targeting the 3' end of the albumin locus results in productive integration in about 15% of mouse hepatocytes achieving therapeutic levels of systemic proteins in two mouse models of inherited diseases. We demonstrate that full-length HITI donor DNA is preferentially integrated upon nuclease cleavage and that, despite partial AAV genome integrations in the target locus, no gross chromosomal rearrangements or insertions/deletions at off-target sites are found.