Impact of CRISPR/HDR editing versus lentiviral transduction on long-term engraftment and clonal dynamics of HSPCs in rhesus macaques

Cell Stem Cell. 2024 Apr 4;31(4):455-466.e4. doi: 10.1016/j.stem.2024.02.010. Epub 2024 Mar 19.

Abstract

For precise genome editing via CRISPR/homology-directed repair (HDR), effective and safe editing of long-term engrafting hematopoietic stem cells (LT-HSCs) is required. The impact of HDR on true LT-HSC clonal dynamics in a relevant large animal model has not been studied. To track the output and clonality of HDR-edited cells and to provide a comparison to lentivirally transduced HSCs in vivo, we developed a competitive rhesus macaque (RM) autologous transplantation model, co-infusing HSCs transduced with a barcoded GFP-expressing lentiviral vector (LV) and HDR edited at the CD33 locus. CRISPR/HDR-edited cells showed a two-log decrease by 2 months following transplantation, with little improvement via p53 inhibition, in comparison to minimal loss of LV-transduced cells long term. HDR long-term clonality was oligoclonal in contrast to highly polyclonal LV-transduced HSCs. These results suggest marked clinically relevant differences in the impact of current genetic modification approaches on HSCs.

Keywords: CRISPR-Cas editing; HSC gene therapy; ex vivo; genetic barcoding; hematopoietic stem cells; homology-directed repair; lentiviral gene addition; precise genome editing; rhesus macaque.

MeSH terms

  • Animals
  • CRISPR-Cas Systems / genetics
  • Clustered Regularly Interspaced Short Palindromic Repeats
  • Gene Editing / methods
  • Hematopoietic Stem Cell Transplantation* / methods
  • Hematopoietic Stem Cells
  • Lentivirus / genetics
  • Macaca mulatta / genetics