Cyclosporin H Improves the Transduction of CD34+ Cells with an Anti-Sickling Globin Vector, a Possible Therapeutic Approach for Sickle Cell Disease

Sickle cell disease (SCD) is a debilitating monogenic disease originating from mutations in the hemoglobin beta chain gene producing an abnormal hemoglobin HbS. The polymerization of HbS is responsible for the sickling of erythrocytes leading to anemia and vaso-occlusive events. Gene therapy is a promising treatment of SCD, and two different gene therapy drugs, using gene editing or gene transfer, have already reached the marketing stage. There is still a need to improve the efficacy of gene therapy in SCD, particularly when using anti-sickling beta-globin gene transfer strategies, which must outcompete the pathological HbS. One possibility is to increase transduction by inhibiting lentiviral restriction factors such as interferon-induced transmembrane proteins (IFITMs). This can be achieved by the addition of cyclosporin H (CsH) during the transduction process. This strategy was applied here in CD34