As usual, this was a great team effort. Many thanks to lead author Ming Cheng, PhD as well as Demitri de la Cruz, Adam Crain, Carrie Ng and Paula Espinoza in the lab. Also, I am grateful to the Asokan lab and Zachary Elmore for the MAAP part of the study.

-AAV MAAP (membrane associated accessory protein) expression in trans during production increase yields of EV-AAV (and standard AAV).
These findings should be very useful for the further development of the EV-AAV platform!

-Intraluminal AAV (capsids on the inside of EVs) are functional at transduction in vitro and in vivo and have the best resistance to anti-AAV antibody neutralization.

Our main findings:
-The capsid is necessary for robust transduction of EV-AAV. AAV genomes devoid of capsid in EVs do not mediate efficient transduction of cultured cells

We also wanted to better understand the nature of antibody evasion of EV-AAV, components of the system necessary for its robust transduction, and also potential strategies to increase yield (critical for scaling up the system for commercial production).

In particular, we set out to understand the yield of EV-AAV compared to free (conventional) AAV in the media of producer cells.

This resulted in:
• >40-fold increase in the ratio of EV-AAV over free AAV in the media of engineered producer cells
• 300-fold decrease in free AAV in the media
• Increased transduction of mEV-AAV over EV-AAV and standard AAV in cultured cells
• Robust transduction of murine brain