Covalently linked adenovirus-AAV complexes as a novel platform technology for gene therapy

Abstract

Adeno-associated virus (AAV) has found immense success as a delivery system for gene therapy, yet the small 4.7 kb packaging capacity of the AAV sharply limits the scope of its application. In addition, high doses of AAV are frequently required to facilitate therapeutic effects, leading to acute toxicity issues. While dual and triple AAV approaches have been developed to mitigate the packaging capacity problem, these necessitate even higher doses to ensure that co-infection occurs at sufficient frequency. To address these challenges, we herein describe a novel delivery system consisting of adenovirus (Ad) covalently linked to multiple adeno-associated virus capsids as a new way of more efficiently co-infecting cells with lower overall amounts of AAVs. We utilize the DogTag-DogCatcher (DgT-DgC) molecular glue system to construct our AdAAVs and we demonstrate that these hybrid virus complexes achieve enhanced co-transduction of cultured cells, including physiologically relevant primary cells. On this basis, AdAAV technology may eventually facilitate therapeutic co-delivery of multiple transgenes at low virus doses for treating complex ailments.