124. Cas9-Mediated Genome Editing in Hematopoietic Stem/Progenitor Cells

Transplantation of genetically modified autologous hematopoietic stem/progenitor cells (HSPCs) has proven to be an effective clinical treatment for patients with hematologic disease. Genome editing with the CRISPR/Cas9 platform has been shown to precisely alter endogenous gene targets in multiple human cell lines and animal models. Here, we compared Cas9-induced gene modification in primary human HSPCs, including mobilized peripheral blood and steady state bone marrow CD34+ cells. Co-delivery of Streptococcus pyogenes or Staphylococcus aureus Cas9 paired with locus-specific guide RNAs induced targeted gene editing in CD34+ cells and hematopoietic progeny, as determined by T7E1 assay and DNA sequence analysis. Multiple gene targets and delivery strategies were evaluated in these primary human CD34+ cells. Importantly, hematopoietic progeny differentiated from Cas9 gene-edited HSPCs maintained ex vivo hematopoietic colony forming potential. This study provides further evidence of Cas9-mediated genome editing in clinically relevant primary cell populations.