Ex vivo prime editing of patient haematopoietic stem cells rescues sickle-cell disease phenotypes after engraftment in mice

Nat Biomed Eng. 2023 May;7(5):616-628. doi: 10.1038/s41551-023-01026-0. Epub 2023 Apr 17.


Sickle-cell disease (SCD) is caused by an A·T-to-T·A transversion mutation in the β-globin gene (HBB). Here we show that prime editing can correct the SCD allele (HBBS) to wild type (HBBA) at frequencies of 15%-41% in haematopoietic stem and progenitor cells (HSPCs) from patients with SCD. Seventeen weeks after transplantation into immunodeficient mice, prime-edited SCD HSPCs maintained HBBA levels and displayed engraftment frequencies, haematopoietic differentiation and lineage maturation similar to those of unedited HSPCs from healthy donors. An average of 42% of human erythroblasts and reticulocytes isolated 17 weeks after transplantation of prime-edited HSPCs from four SCD patient donors expressed HBBA, exceeding the levels predicted for therapeutic benefit. HSPC-derived erythrocytes carried less sickle haemoglobin, contained HBBA-derived adult haemoglobin at 28%-43% of normal levels and resisted hypoxia-induced sickling. Minimal off-target editing was detected at over 100 sites nominated experimentally via unbiased genome-wide analysis. Our findings support the feasibility of a one-time prime editing SCD treatment that corrects HBBS to HBBA, does not require any viral or non-viral DNA template and minimizes undesired consequences of DNA double-strand breaks.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anemia, Sickle Cell* / genetics
  • Anemia, Sickle Cell* / therapy
  • Animals
  • CRISPR-Cas Systems
  • DNA
  • Gene Editing*
  • Hematopoietic Stem Cells
  • Humans
  • Mice
  • Phenotype
  • beta-Globins / genetics


  • beta-Globins
  • DNA