» Articles » PMID: 39655309

Comprehensive Analysis of Off-target and On-target Effects Resulting from Liver-directed CRISPR-Cas9-mediated Gene Targeting with AAV Vectors

Overview
Publisher Cell Press
Date 2024 Dec 10
PMID 39655309
Authors
Affiliations
Soon will be listed here.
Abstract

Comprehensive genome-wide studies are needed to assess the consequences of adeno-associated virus (AAV) vector-mediated gene editing. We evaluated CRISPR-Cas-mediated on-target and off-target effects and examined the integration of the AAV vectors employed to deliver the CRISPR-Cas components to neonatal mice livers. The guide RNA (gRNA) was specifically designed to target the factor IX gene (F9). On-target and off-target insertions/deletions were examined by whole-genome sequencing (WGS). Efficient F9-targeting (36.45% ± 18.29%) was apparent, whereas off-target events were rare or below the WGS detection limit since only one single putative insertion was detected out of 118 reads, based on >100 computationally predicted off-target sites. AAV integrations were identified by WGS and shearing extension primer tag selection ligation-mediated PCR (S-EPTS/LM-PCR) and occurred preferentially in CRISPR-Cas9-induced double-strand DNA breaks in the F9 locus. In contrast, AAV integrations outside F9 were not in proximity to any of ∼5,000 putative computationally predicted off-target sites (median distance of 70 kb). Moreover, without relying on such off-target prediction algorithms, analysis of DNA sequences close to AAV integrations outside the F9 locus revealed no homology to the F9-specific gRNA. This study supports the use of S-EPTS/LM-PCR for direct comprehensive, sensitive, and unbiased off-target analysis.

References
1.
Miller D, Petek L, Russell D . Human gene targeting by adeno-associated virus vectors is enhanced by DNA double-strand breaks. Mol Cell Biol. 2003; 23(10):3550-7. PMC: 164770. DOI: 10.1128/MCB.23.10.3550-3557.2003. View

2.
Mali P, Yang L, Esvelt K, Aach J, Guell M, DiCarlo J . RNA-guided human genome engineering via Cas9. Science. 2013; 339(6121):823-6. PMC: 3712628. DOI: 10.1126/science.1232033. View

3.
Li N, Gou S, Wang J, Zhang Q, Huang X, Xie J . CRISPR/Cas9-Mediated Gene Correction in Newborn Rabbits with Hereditary Tyrosinemia Type I. Mol Ther. 2020; 29(3):1001-1015. PMC: 7934638. DOI: 10.1016/j.ymthe.2020.11.023. View

4.
Pickar-Oliver A, Gersbach C . The next generation of CRISPR-Cas technologies and applications. Nat Rev Mol Cell Biol. 2019; 20(8):490-507. PMC: 7079207. DOI: 10.1038/s41580-019-0131-5. View

5.
Pattanayak V, Lin S, Guilinger J, Ma E, Doudna J, Liu D . High-throughput profiling of off-target DNA cleavage reveals RNA-programmed Cas9 nuclease specificity. Nat Biotechnol. 2013; 31(9):839-43. PMC: 3782611. DOI: 10.1038/nbt.2673. View