Recombinant Adeno-Associated Virus Vector Genomes Take the Form of Long-Lived, Transcriptionally Competent Episomes in Human Muscle

摘要: Gene augmentation therapy as a strategy to treat alpha-1 antitrypsin (AAT) deficiency has reached phase 2 clinical testing in humans. Sustained serum levels of AAT have been observed beyond one year after intramuscular administration recombinant adeno-associated virus (rAAV) vector expressing the gene. In this study, sequential muscle biopsies obtained at 3 and 12 months injection were examined for presence rAAV genomes. Each biopsy sample contained readily detectable DNA, majority which existed double-stranded supercoiled open circular episomes. Episomes persisted through months, although slightly lower than months. There was clear dose response when comparing low- mid-vector-dose groups high-dose group. The highest absolute copy numbers found subject, confirmed that group also had sustained levels. Sequence analysis revealed vast episomes double-D inverted terminal repeats ranging from fully intact severely deleted. Molecular clones genomes derived directly transcriptionally active, potentially identifying them source trial subjects.