A Novel Hybrid Viral Vector for Therapeutic CRISPR Insertion of Multiple Transgenes

PROJECT SUMMARY Existing delivery systems for CRISPR-Cas gene editing machinery have very little capacity for making multigenic insertions. As such, the scope of existing gene therapies has been limited primarily to monogenic diseases. Yet multigenic insertions could facilitate treatment of a much broader range of conditions. To address this challenge, I am developing a chimeric AdAAV gene editing delivery system by physically linking multiple adeno-associated viruses (AAVs) to the surface of adenovirus (Ad). I am using the SpyTag-SpyCatcher technology for site-specific covalent conjugation. In my design, the Ad will encode the Cas9 protein and the gRNAs while the AAVs will provide a single-stranded DNA template. To enable multigenic genetic insertions, I will conjugate a mixture of AAVs (with distinct genetic cargos) onto the Ads. Each AAV cargo sequence will undergo programmable insertion into a unique genomic target site via the Cas9 and gRNAs encoded in the Ad. I anticipate that the strong and targetable transduction of the Ad will efficiently drive the uptake of AdAAV particles into cells. I also anticipate that greater in vivo gene editing efficiencies may occur using this design because of the known benefits of single- stranded DNA templates for homology-directed repair (HDR). My fully novel AdAAV vector will act as an efficacious and versatile platform for multigenic gene therapy. AdAAVs will be particularly suited for treating aging and aging-related conditions, especially Alzheimer’s disease.