Systemic gene therapy using an AAV44.9 vector rescues a neonatal lethal mouse model of propionic acidemia

作者：Randy J. Chandler, Giovanni Di Pasquale, Eun-Young Choi, David K. Chang, Stephanie Smith, Jennifer L. Sloan, Victoria Hoffmann, Lina Li, John A. Chiorini, Charles P. Venditti · 发表于：Molecular Therapy — Methods & Clinical Development · 年份：2023 · DOI：10.1016/j.omtm.2023.06.008 · 被引用次数：10 · 研究领域：Metabolism and Genetic Disorders、Mitochondrial Function and Pathology、Virus-based gene therapy research

Propionic acidemia (PA) is rare autosomal recessive metabolic disorder caused by defects in the mitochondrially localized enzyme propionyl-coenzyme A (CoA) carboxylase. Patients with PA can suffer from lethal metabolic decompensation and cardiomyopathy despite current medical management, which has led to the pursuit of gene therapy as a new treatment option for patients. Here we assess the therapeutic efficacy of a recently described adeno-associated virus (AAV) capsid, AAV44.9, to deliver a therapeutic PCCA transgene in a new mouse model of propionyl-CoA carboxylase α (PCCA) deficiency generated by genome editing. Pcca −/− mice recapitulate the severe neonatal presentation of PA and manifest uniform neonatal lethality, absent PCCA expression, and increased 2-methylcitrate. A single injection of the AAV44.9 PCCA vector in the immediate newborn period, systemically delivered at a dose of 1e11 vector genome (vg)/pup but not 1e10 vg/pup, increased survival, reduced plasma methylcitrate, and resulted in high levels of transgene expression in the liver and heart in treated Pcca −/− mice. Our studies not only establish a versatile and accurate new mouse model of PA but further demonstrate that the AAV44.9 vectors may be suitable for treatment of many metabolic disorders where hepato-cardiac transduction following systemic delivery is desired, such as PA, and, by extension, fatty acid oxidation defects and glycogen storage disorders.