Nanotherapeutics-mediated tolerogenic Induction for Enabling Adeno-Associated Virus Vector Gene Therapy Re-administration by Overcoming Anti-drug antibodies

Recombinant adeno-associated virus (AAV) vectors have become the promising platform to deliver a therapeutic transgene for the treatment of monogenic disorders. However, anti-AAV antibodies that are released by B cells after AAV treatment create a substantial barrier to their long-lasting safe and effective therapy, making AAV gene therapy a “one shot” treatment. Here, we offered that tolerogenic nano-adjuvants (named RICP) composed of rapamycin (RAPA) and itaconate (ITA), to induce specific immune tolerance to overcome the anti-drug antibodies (ADAs). Such strategy blocked the feedback loops of follicular helper T （Tfh） cells and germinal center B cells by metabolic regulation, complementary to induction of regulatory T cells (Tregs) by mTORc1 inhibitor RAPA, consequently abolished the secretion of anti-AAV antibodies. The developed nano-adjuvants can also significantly increase expression of a transgene (such as luciferase, green fluorescent protein and human embryonic alkaline phosphatase reporter transgene) in the liver at re-dosing, compared to mice treated with AAV alone which showed almost no change in transgene expression. The emerging strategy provided AAV re-administration schedule available for not only mitigate toxicities with high vector doses, but re-storing therapeutic benefits in children in significant cell proliferation.