Definition

A preparation of autologous, CD34-positive hematopoietic stem cells (HSCs) transduced ex vivo with a lentiviral vector encoding for an engineered form of human gamma-globin (hemoglobin-gamma) gene, gamma-globin G16D, and a short-hairpin (sh) RNA734, with potential to restore gamma-globin expression and function. Autologous CD34-positive stem cells are isolated from the patient’s own bone marrow and the cells are transduced with the lentiviral vector. Upon re-infusion of the CD34-positive cells back into the patient, these cells express gamma-globinG16D, thereby replacing defective beta globin chains with gamma globin chains allowing the body to make fetal hemoglobin (HbF) and thus healthy red blood cells with a greater oxygen-carrying capacity. Gamma-globin comprises is the gamma-chain of HbF; reactivation of HbF in disorders where beta-globin is defective in adult hemoglobin (HbA), such as sickle cell disease and beta thalassemia, may ameliorate these conditions. The G16D form of gamma-globin has increased anti-sickling activity compared to the wild type protein. The shRNA734 is used for positive gene selection.