In vivo HSC prime editing rescues sickle cell disease in a mouse model

Blood. 2023 Apr 27;141(17):2085-2099. doi: 10.1182/blood.2022018252.


Sickle cell disease (SCD) is a monogenic disease caused by a nucleotide mutation in the β-globin gene. Current gene therapy studies are mainly focused on lentiviral vector-mediated gene addition or CRISPR/Cas9-mediated fetal globin reactivation, leaving the root cause unfixed. We developed a vectorized prime editing system that can directly repair the SCD mutation in hematopoietic stem cells (HSCs) in vivo in a SCD mouse model (CD46/Townes mice). Our approach involved a single intravenous injection of a nonintegrating, prime editor-expressing viral vector into mobilized CD46/Townes mice and low-dose drug selection in vivo. This procedure resulted in the correction of ∼40% of βS alleles in HSCs. On average, 43% of sickle hemoglobin was replaced by adult hemoglobin, thereby greatly mitigating the SCD phenotypes. Transplantation in secondary recipients demonstrated that long-term repopulating HSCs were edited. Highly efficient target site editing was achieved with minimal generation of insertions and deletions and no detectable off-target editing. Because of its simplicity and portability, our in vivo prime editing approach has the potential for application in resource-poor countries where SCD is prevalent.

MeSH terms

  • Anemia, Sickle Cell* / genetics
  • Anemia, Sickle Cell* / therapy
  • Animals
  • CRISPR-Cas Systems
  • Gene Editing* / methods
  • Hematopoietic Stem Cells
  • Hemoglobin, Sickle / genetics
  • Mice


  • Hemoglobin, Sickle