Cooney, A.; Chen, Y. H.; Lewandowski, B. C.; Lamer, S.; Boysen, G.; Kulhankova, K.; Vu, A.; Newase, P.; Sinn, P.; Davidson, B.; McCray, P. B.

Gene therapies have demonstrated transformative potential for a range of genetic disorders, including immunodeficiencies, hematopoietic conditions, and neuromuscular diseases. However, the application of these approaches to cystic fibrosis (CF) and other airway diseases remains constrained by the challenge of efficient gene delivery to target epithelial cells. Adeno-associated virus (AAV) vectors are widely used for in vivo gene delivery due to their favorable safety profile and capacity for long-term transgene expression in non-dividing cells. Nonetheless, current AAV capsids require high doses to achieve therapeutic efficacy in the airways, raising safety concerns. Here we report the development of novel AAV capsid variants with markedly enhanced transduction efficiency of airway epithelial cells. Using unbiased peptide-modified AAV libraries and round-over-round screening in well-differentiated primary cultures of human airway epithelia (HAE), we identified 20 novel capsids that efficiently transduced cells at doses 10- to 100-fold lower than those required by existing vectors (termed AAV-AE). These variants demonstrated high transgene expression in HAE, primary human basal cells, tracheal explants from nonhuman primates, and murine airways in vivo. These optimized AAV capsids represent a significant advancement in pulmonary gene therapy, offering a versatile platform for the delivery of gene addition and editing reagents to treat CF and other respiratory diseases.