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Bestas B, Wimberger S, Degtev D, Madsen A, Rottner AK, Karlsson F, Naumenko S, Callahan M, Touza JL, Francescatto M, Möller CI, Badertscher L, Li S, Cerboni S, Selfjord N, Ericson E, Gordon E, Firth M, Chylinski K, Taheri-Ghahfarokhi A, Bohlooly-Y M, Snowden M, Pangalos M, Nuttall B, Akcakaya P, Sienski G, Maresca M. A Type II-B Cas9 nuclease with minimized off-targets and reduced chromosomal translocations in vivo. Nat Commun 2023; 14:5474. [PMID: 37673883 PMCID: PMC10482872 DOI: 10.1038/s41467-023-41240-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 08/25/2023] [Indexed: 09/08/2023] Open
Abstract
Streptococcus pyogenes Cas9 (SpCas9) and derived enzymes are widely used as genome editors, but their promiscuous nuclease activity often induces undesired mutations and chromosomal rearrangements. Several strategies for mapping off-target effects have emerged, but they suffer from limited sensitivity. To increase the detection sensitivity, we develop an off-target assessment workflow that uses Duplex Sequencing. The strategy increases sensitivity by one order of magnitude, identifying previously unknown SpCas9's off-target mutations in the humanized PCSK9 mouse model. To reduce off-target risks, we perform a bioinformatic search and identify a high-fidelity Cas9 variant of the II-B subfamily from Parasutterella secunda (PsCas9). PsCas9 shows improved specificity as compared to SpCas9 across multiple tested sites, both in vitro and in vivo, including the PCSK9 site. In the future, while PsCas9 will offer an alternative to SpCas9 for research and clinical use, the Duplex Sequencing workflow will enable a more sensitive assessment of Cas9 editing outcomes.
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Affiliation(s)
- Burcu Bestas
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Sandra Wimberger
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
- Department of Chemistry & Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Dmitrii Degtev
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Alexandra Madsen
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Antje K Rottner
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Fredrik Karlsson
- Data Sciences and Quantitative Biology, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Cambridge, UK
| | - Sergey Naumenko
- Department of Biostatistics, Harvard Chan School of Public Health, Boston, MA, USA
| | - Megan Callahan
- Translational Genomics, Translational Medicine, R&D Oncology, AstraZeneca, Waltham, MA, USA
| | - Julia Liz Touza
- Translational Genomics, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Margherita Francescatto
- Data Sciences and Quantitative Biology, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Cambridge, UK
| | - Carl Ivar Möller
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Lukas Badertscher
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Songyuan Li
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Silvia Cerboni
- Translational Science and Experimental Medicine, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Niklas Selfjord
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Elke Ericson
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Euan Gordon
- Discovery Biology, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Mike Firth
- Data Sciences and Quantitative Biology, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Cambridge, UK
| | | | - Amir Taheri-Ghahfarokhi
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Mohammad Bohlooly-Y
- Translational Genomics, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Mike Snowden
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | | | - Barrett Nuttall
- Translational Genomics, Translational Medicine, R&D Oncology, AstraZeneca, Waltham, MA, USA
| | - Pinar Akcakaya
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Grzegorz Sienski
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden.
| | - Marcello Maresca
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden.
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Peterka M, Akrap N, Li S, Wimberger S, Hsieh PP, Degtev D, Bestas B, Barr J, van de Plassche S, Mendoza-Garcia P, Šviković S, Sienski G, Firth M, Maresca M. Harnessing DSB repair to promote efficient homology-dependent and -independent prime editing. Nat Commun 2022; 13:1240. [PMID: 35332138 PMCID: PMC8948305 DOI: 10.1038/s41467-022-28771-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 02/07/2022] [Indexed: 12/26/2022] Open
Abstract
Prime editing recently emerged as a next-generation approach for precise genome editing. Here we exploit DNA double-strand break (DSB) repair to develop two strategies that install precise genomic insertions using an SpCas9 nuclease-based prime editor (PEn). We first demonstrate that PEn coupled to a regular prime editing guide RNA (pegRNA) efficiently promotes short genomic insertions through a homology-dependent DSB repair mechanism. While PEn editing leads to increased levels of by-products, it can rescue pegRNAs that perform poorly with a nickase-based prime editor. We also present a small molecule approach that yields increased product purity of PEn editing. Next, we develop a homology-independent PEn editing strategy, which installs genomic insertions at DSBs through the non-homologous end joining pathway (NHEJ). Lastly, we show that PEn-mediated insertions at DSBs prevent Cas9-induced large chromosomal deletions and provide evidence that continuous Cas9-mediated cutting is one of the mechanisms by which Cas9-induced large deletions arise. Altogether, this work expands the current prime editing toolbox by leveraging distinct DNA repair mechanisms including NHEJ, which represents the primary pathway of DSB repair in mammalian cells. Prime editing is a next-generation approach for precision genome engineering. Here the authors design a nuclease-based prime editor that leverages DNA repair pathways for targeted genomic insertions.
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Affiliation(s)
- Martin Peterka
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden.
| | - Nina Akrap
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Songyuan Li
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Sandra Wimberger
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden.,Department of Chemistry & Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Pei-Pei Hsieh
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Dmitrii Degtev
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Burcu Bestas
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Jack Barr
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Stijn van de Plassche
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Patricia Mendoza-Garcia
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Saša Šviković
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Grzegorz Sienski
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Mike Firth
- Data Sciences and Quantitative Biology, Discovery Sciences, AstraZeneca, Cambridge, UK
| | - Marcello Maresca
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden.
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