Directed evolution of AAV accounting for long-term and enhanced transduction of cardiovascular endothelial cells in vivo

Y B Liu; B C Xu; Y T Chen; X Yuan; J Y Liu; T Liu; G Z Du; W Jiang; Y Yang; Y Zhu; L J Chen; B S Ding; Y Q Wei; L Yang

doi:10.1016/j.omtm.2021.05.015

Directed evolution of AAV accounting for long-term and enhanced transduction of cardiovascular endothelial cells in vivo

Mol Ther Methods Clin Dev. 2021 Jun 4:22:148-161. doi: 10.1016/j.omtm.2021.05.015. eCollection 2021 Sep 10.

Authors

Y B Liu¹, B C Xu², Y T Chen³, X Yuan², J Y Liu⁴, T Liu⁵, G Z Du⁵, W Jiang⁶, Y Yang⁷, Y Zhu⁸, L J Chen⁴, B S Ding³, Y Q Wei², L Yang¹

Affiliations

¹ Department of Cardiology and Laboratory of Gene Therapy for Heart Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, China.
² Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
³ Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, China.
⁴ State Key Laboratory of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, China.
⁵ Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
⁶ Molecular Medicine Research Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
⁷ State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, Sichuan, China.
⁸ Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.

Abstract

Cardiac endothelial cells (ECs) are important targets for cardiovascular gene therapy. However, the approach of stably transducing ECs in vivo using different vectors, including adeno-associated virus (AAV), remains unexamined. Regarding this unmet need, two AAV libraries from DNA shuffling and random peptide display were simultaneously screened in a transgenic mouse model. Cardiac ECs were isolated by cell sorting for salvage of EC-targeting AAV. Two AAV variants, i.e., EC71 and EC73, enriched in cardiac EC, were further characterized for their tissue tropism. Both of them demonstrated remarkably enhanced transduction of cardiac ECs and reduced infection of liver ECs in comparison to natural AAVs after intravenous injection. Significantly, persistent transgene expression was maintained in mouse cardiac ECs in vivo for at least 4 months. The EC71 vector was selected for delivery of the endothelial nitric oxide synthase (eNOS) gene into cardiac ECs in a mouse model of myocardial infarction. Enhanced eNOS activity was observed in the mouse heart and lung, which was correlated with partially improved cardiac function. Taken together, two AAV capsids were evolved with more efficient transduction in cardiovascular endothelium in vivo, but their endothelial tropism might need to be further optimized for practical application to cardiac gene therapy.

Keywords: adeno-associated virus; cardiac endothelial cells; cardiovascular gene therapy; directed evolution; transduction.