Therapeutic production of HbF in erythroblasts derived from CD34⁺ bone marrow cells of β-thalassemia major patients transduced with the V5m3-400 γ-globin, BCL11A shRNA, or GG1-VP64 lentiviral vectors. (A) Cell accumulation at the indicated time points during the 2-phase culture is shown. Data represent the mean ± SEM of the cumulative fold expansion of both normal and β-thalassemic viable cells either mock-transduced or transduced with the indicated lentiviral vectors. (B) Fold increase in cell number for the indicated groups as measured from the prior time point. (C) Cellulose acetate Hb electrophoresis of lysates from erythroblasts derived from CD34⁺ BM cells of 3 independent β-thalassemic donors that were transduced either under mock conditions or with the indicated vectors. The percentage of HbF as determined by HPLC analysis is indicated below each sample lane. Control samples include the following: PB indicates erythroblasts derived from cytokine-mobilized peripheral blood CD34⁺ cells of normal donors; and CB, erythroblasts derived from CD34⁺ cord blood cells. Vertical lines have been inserted to represent repositioned lanes on the gel images. (D) Representative Hb HPLC traces from erythroblasts derived from β-thalassemic either mock-transduced or transduced with the indicated vectors. (E) The percentage of total Hb content, relative to that of erythroblasts derived from normal PB CD34⁺ cells, of β-thalassemic erythroblasts derived from the indicated transduced cell populations (± SEM). *P < .05 compared with mock control (paired t test).