(SD2022-222) Optimized CAG repeat‐targeting CRISPR/cas13d designs

Abstract

Reseachers from UC San Diego demonstrated a proof of principle for a CAGEX RNA-targeting CRISPR–Cas13d system as a potential allele-sensitive therapeutic approach for HD, a strategy with broad implications for the treatment of other neurodegenerative disorders.

Technology Description

Researchers from UC San Diego leveraged the advantageous compact nature of Ruminococcus flavefaciens XPD3002 (Rfx) CRISPR/Cas13d and engineered a CRISPR/Cas13d‐based gene therapy vector packaged into a single vector in both lentiviral and adeno‐associated viral delivery vehicles, that silences mutant toxic CAG‐expanded (CAGEX) RNA in both human patient iPSC models and an established mouse model of HD.

Applications

1) Research tool. To target, locate, and track intracellular or extracellular CAG expansion‐containing RNA transcripts in fixed or living cells and/or in vivo.

2) Biomarker. Can serve as a pharmacodynamic biomarker to assess efficacy of potential therapies that target CAG expansions including small molecules or natural/synthetic compounds and/or any DNA or RNA‐targeting gene therapy approach.

Advantages

State Of Development

The UCSD researchers have collected extensive preclinical data in two established models of HD for a new gene therapy strategy that effectively eliminates CAG‐expanded pre‐mRNA with the use of RNA‐targeting CRISPR/Cas13d technology. Specifically, they engineered a potent gene therapy vector that encases Ruminococcus flavefaciens Cas13d, an RNA‐targeting enzyme only 2.4 kb in size, and a CAG‐expansion RNA‐targeting gRNA in a single viral delivery vehicle. They utilized multiple established preclinical models of HD including the Q175/+ mouse model which harbors one human allele of HTT with 175 CAG repeats in exon 1, and a series HD patient iPSC‐derived striatal neurons to show both efficacy and safety of the new gene therapy approach both in vivo and in a humanized preclinical model.

Further details are in the manuscript.

Intellectual Property Info

University is securing US patent rights, see: https://patents.google.com/patent/WO2023154843A2/en?oq=US2023%2f062352

 Please contact UCSD is you are interested in licensing this technology for commercial development.

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• Morelli KH, Wu Q, Gosztyla ML, Liu H, Yao M, Zhang C, Chen J, Marina RJ, Lee K, Jones KL, Huang MY, Li A, Smith-Geater C, Thompson LM, Duan W, Yeo GW. An RNA-targeting CRISPR-Cas13d system alleviates disease-related phenotypes in Huntington's disease models. Nat Neurosci. 2023 Jan;26(1):27-38 - 12/12/2022