Figure 1.

MSCs favored the expansion of GE-HSPCs

(A) Schematic representation of the co-culture protocol used to support the expansion of GE-HSPCs. HSPCs were pre-stimulated for 3 days in HSPC GE medium (hSCF, hFLT3, hTPO, hIL-6, SR1, UM171) and recovered in HSPC medium conditioned from MSCs in the presence of MSCs for 72 h. GE-HSPCs recovered in HSPC medium on plastic according to our standard method were used as controls. (B) GE-HSPC total cell count after 72 h expansion. Gray bars: GE-HSPCs expanded on MSC feeder; black bars: GE-HSPCs expanded in plastic dishes. (C) Absolute number of GE-HSPCs with a primitive phenotype was determined after 72 h expansion. Each error bar shows means ± SEM (n = 4). (D) CFU assay at 7 days after plating GE-HSPCs into methylcelluose medium. (E) Percentage of GFP⁺ HSPCs 72 h after gene editing in the presence of MSCs (GE CD34⁺ + MSCs) and according to standard protocol (GE CD34⁺) (n = 4). (F) Absolute number of phenotypically primitive GFP⁺ GE-HSPCs after 72 h expansion. For all experiments, each error bar shows means ± SEM (n = 4). p values were determined by Mann-Whitney test (∗p ≤ 0.05).