[HTML][HTML] High levels of AAV vector integration into CRISPR-induced DNA breaks

KS Hanlon, BP Kleinstiver, SP Garcia… - Nature …, 2019 - nature.com
KS Hanlon, BP Kleinstiver, SP Garcia, MP Zaborowski, A Volak, SE Spirig, A Muller…
Nature communications, 2019nature.com
Adeno-associated virus (AAV) vectors have shown promising results in preclinical models,
but the genomic consequences of transduction with AAV vectors encoding CRISPR-Cas
nucleases is still being examined. In this study, we observe high levels of AAV integration
(up to 47%) into Cas9-induced double-strand breaks (DSBs) in therapeutically relevant
genes in cultured murine neurons, mouse brain, muscle and cochlea. Genome-wide AAV
mapping in mouse brain shows no overall increase of AAV integration except at the …
Abstract
Adeno-associated virus (AAV) vectors have shown promising results in preclinical models, but the genomic consequences of transduction with AAV vectors encoding CRISPR-Cas nucleases is still being examined. In this study, we observe high levels of AAV integration (up to 47%) into Cas9-induced double-strand breaks (DSBs) in therapeutically relevant genes in cultured murine neurons, mouse brain, muscle and cochlea. Genome-wide AAV mapping in mouse brain shows no overall increase of AAV integration except at the CRISPR/Cas9 target site. To allow detailed characterization of integration events we engineer a miniature AAV encoding a 465 bp lambda bacteriophage DNA (AAV-λ465), enabling sequencing of the entire integrated vector genome. The integration profile of AAV-465λ in cultured cells display both full-length and fragmented AAV genomes at Cas9 on-target sites. Our data indicate that AAV integration should be recognized as a common outcome for applications that utilize AAV for genome editing.
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