Fig. 4

Cellular function reinstitution of genome-edited RBCs. a For cellular function study, in vitro RBC differentiation of cloned erythroid progenitor cells was induced. Nuclei of the resultant cells were initially stained with Hoechst dye and examined under microscope, demonstrating induced in vitro RBC differentiation and maturation. b Cytospin of resultant cells with Wright-Giemsa staining confirmed presence of mature RBCs (no nuclei), RBC with nucleus contraction, and nucleated RBC. c Cell sickling assays of in vitro differentiated RBCs with or without genome editing, and RBCs from the SCD, SCT, and healthy donor blood demonstrated that CRISPR genome editing of patient HSPCs resulted in function reinstitution of the cloned offspring RBCs, which became more resistant to hypoxia. d Time course of sickling cell formation (%). The data are from the average of three clones