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Pattabhi S, Lotti SN, Berger MP, Singh S, Lux CT, Jacoby K, Lee C, Negre O, Scharenberg AM, Rawlings DJ. In Vivo Outcome of Homology-Directed Repair at the HBB Gene in HSC Using Alternative Donor Template Delivery Methods. Mol Ther Nucleic Acids 2019; 17:277-288. [PMID: 31279229 PMCID: PMC6611979 DOI: 10.1016/j.omtn.2019.05.025] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/22/2022]
Abstract
Gene editing following designer nuclease cleavage in the presence of a DNA donor template can revert mutations in disease-causing genes. For optimal benefit, reversion of the point mutation in HBB leading to sickle cell disease (SCD) would permit precise homology-directed repair (HDR) while concurrently limiting on-target non-homologous end joining (NHEJ)-based HBB disruption. In this study, we directly compared the relative efficiency of co-delivery of a novel CRISPR/Cas9 ribonucleoprotein targeting HBB in association with recombinant adeno-associated virus 6 (rAAV6) versus single-stranded oligodeoxynucleotides (ssODNs) to introduce the sickle mutation (GTC or GTG; encoding E6V) or a silent change (GAA; encoding E6optE) in human CD34+ mobilized peripheral blood stem cells (mPBSCs) derived from healthy donors. In vitro, rAAV6 outperformed ssODN donor template delivery and mediated greater HDR correction, leading to both higher HDR rates and a higher HDR:NHEJ ratio. In contrast, at 12-14 weeks post-transplant into recipient, immunodeficient, NOD, B6, SCID Il2rγ-/- Kit(W41/W41) (NBSGW) mice, a ∼6-fold higher proportion of ssODN-modified cells persisted in vivo compared to recipients of rAAV6-modified mPBSCs. Together, our findings highlight that methodology for donor template delivery markedly impacts long-term persistence of HBB gene-modified mPBSCs, and they suggest that the ssODN platform is likely to be most amenable to direct clinical translation.
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Affiliation(s)
- Sowmya Pattabhi
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | - Samantha N Lotti
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | - Mason P Berger
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | - Swati Singh
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | - Christopher T Lux
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | - Kyle Jacoby
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA
| | | | | | - Andrew M Scharenberg
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA; Casebia Therapeutics, Cambridge, MA, USA; Department of Pediatrics, University of Washington, School of Medicine, Seattle, WA, USA; Department of Immunology, University of Washington, School of Medicine, Seattle, WA, USA
| | - David J Rawlings
- Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA, USA; Department of Pediatrics, University of Washington, School of Medicine, Seattle, WA, USA; Department of Immunology, University of Washington, School of Medicine, Seattle, WA, USA.
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