Drug Development

Abstract

Background: Our lab has developed a CRISPR-based, gene-editing strategy that targets the extreme C-terminus (C-term) of APP (amyloid precursor protein) - a gene with a central and indisputable role in AD. We have reported previously that APP C-terminus CRISPRs effectively attenuate APP β-cleavage and Alzheimer's pathology in vivo. Here, we present new data demonstrating the feasibility and efficacy of a clinically-viable, "all-in-one" therapeutic vector that has all the components needed for APP C-terminus editing (Cas enzyme / gRNAs / regulatory elements) packaged into a single AAV.

Method: APP C-terminus targeting gRNAs along with a SaCas9 expression cassette were cloned into AAV expression backbones and packaged into AAV-PHP.eB capsids. Resulting AAVs were injected into APP^NL-G-F mice and APP C-terminus editing along with amyloid beta (Aβ) plaque pathology were evaluated.

Result: AAV treated brain tissue showed wide-spread expression of APP CRISPRs and robust APP C-terminus editing. Both amyloid plaques and insoluble Aβ were decreased in APP CRISPR treated tissue.

Conclusion: These data demonstrate in vivo feasibility of our approach and advance our long-term goal of creating a "one-and-done", single injection CRISPR therapeutic for permanent treatment of AD in human patients.