Gene correction of HBB mutations in CD34+ hematopoietic stem cells using Cas9 mRNA and ssODN donors.

Autor: Antony, Justin S., Latifi, Ngadhnjim, Haque, A. K. M. Ashiqul, Lamsfus-Calle, Andrés, Daniel-Moreno, Alberto, Graeter, Sebastian, Baskaran, Praveen, Weinmann, Petra, Mezger, Markus, Handgretinger, Rupert, Kormann, Michael S. D.
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Zdroj: Molecular & Cellular Pediatrics; 11/14/2018, Vol. 5 Issue 1, p1-1, 1p
Abstrakt: Background: β-Thalassemia is an inherited hematological disorder caused by mutations in the human hemoglobin beta (HBB) gene that reduce or abrogate β-globin expression. Although lentiviral-mediated expression of β-globin and autologous transplantation is a promising therapeutic approach, the risk of insertional mutagenesis or low transgene expression is apparent. However, targeted gene correction of HBB mutations with programmable nucleases such as CRISPR/Cas9, TALENs, and ZFNs with non-viral repair templates ensures a higher safety profile and endogenous expression control.Methods: We have compared three different gene-editing tools (CRISPR/Cas9, TALENs, and ZFNs) for their targeting efficiency of the HBB gene locus. As a proof of concept, we studied the personalized gene-correction therapy for a common β-thalassemia splicing variant HBBIVS1-110 using Cas9 mRNA and several optimally designed single-stranded oligonucleotide (ssODN) donors in K562 and CD34+ hematopoietic stem cells (HSCs).Results: Our results exhibited that indel frequency of CRISPR/Cas9 was superior to TALENs and ZFNs (P < 0.0001). Our designed sgRNA targeting the site of HBBIVS1-110 mutation showed indels in both K562 cells (up to 77%) and CD34+ hematopoietic stem cells—HSCs (up to 87%). The absolute quantification by next-generation sequencing showed that up to 8% site-specific insertion of the NheI tag was achieved using Cas9 mRNA and a chemically modified ssODN in CD34+ HSCs.Conclusion: Our approach provides guidance on non-viral gene correction in CD34+ HSCs using Cas9 mRNA and chemically modified ssODN. However, further optimization is needed to increase the homology directed repair (HDR) to attain a real clinical benefit for β-thalassemia. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index