Structural characterization of a novel human adeno-associated virus capsid with neurotropic properties

Recombinant adeno-associated viruses (rAAVs) are currently considered the safest and most reliable gene delivery vehicles for human gene therapy. Three serotype capsids, AAV1, AAV2, and AAV9, have been approved for commercial use in patients, but they may not be suitable for all therapeutic contexts. Here, we describe a novel capsid identified in a human clinical sample by high-throughput, long-read sequencing. The capsid, which we have named AAVv66, shares high sequence similarity with AAV2. We demonstrate that compared to AAV2, AAVv66 exhibits enhanced production yields, virion stability, and CNS transduction. Unique structural properties of AAVv66 visualized by cryo-EM at 2.5-angstrom resolution, suggest that critical residues at the three-fold protrusion and at the interface of the five-fold axis of symmetry likely contribute to the beneficial characteristics of AAVv66. Our findings underscore the potential of AAVv66 as a gene therapy vector. Adeno-associated viruses (AAVs) are vehicles for gene therapy in humans, but currently only a limited amount of AAV serotypes is available. Here, the authors identify a novel AAV, AAVv66, and demonstrate enhanced production yields, virion stability, and CNS transduction compared to the clinically approved serotype AAV2.