Directed Evolution of AAV for Efficient Gene Delivery to Canine and Primate Retina - Raw counts of variants from deep sequencing

Efficient AAV-mediated gene delivery remains a significant obstacle to
effective retinal gene therapies. Here, we apply the process of directed
evolution – guided by deep sequencing and followed by direct in vivo
secondary selection of high-performing vectors with a GFP-barcoded library
– to create AAV viral capsids with new capabilities to deliver genes to
the outer retina in large animals. The resulting vectors resulted in
efficient targeting of photoreceptors, bipolar cells, and RPE cells in dog
retina and substantially increased efficiency of gene delivery to primate
outer retina. In addition, direct comparison of gene delivery across
animals revealed emergent species specificities in vector performance.
These new viral vectors will enable long-term and pan-retinal gene
therapies targeting outer retina cell types in large preclinical animal
models and establish deep sequencing-guided directed evolution as a
powerful approach for developing AAV vectors specialized for a multitude
of physical barriers and cellular targets.