@article{3152040, title = "The New Self-Inactivating Lentiviral Vector for Thalassemia Gene Therapy Combining Two HPFH Activating Elements Corrects Human Thalassemic Hematopoietic Stem Cells", author = "Papanikolaou, Eleni and Georgomanoli, Maria and Stamateris, Evangelos and and Panetsos, Fottes and Karagiorga, Markisia and Tsaftaridis, and Panagiotis and Graphakos, Stelios and Anagnou, Nicholas P.", journal = "Human Gene Therapy", year = "2012", volume = "23", number = "1", pages = "15-31", publisher = "MARY ANN LIEBERT INC PUBL", issn = "1043-0342, 1557-7422", doi = "10.1089/hum.2011.048", abstract = "To address how low titer, variable expression, and gene silencing affect gene therapy vectors for hemoglobinopathies, in a previous study we successfully used the HPFH (hereditary persistence of fetal hemoglobin)-2 enhancer in a series of oncoretroviral vectors. On the basis of these data, we generated a novel insulated self-inactivating (SIN) lentiviral vector, termed GGHI, carrying the (A)gamma-globin gene with the -117 HPFH point mutation and the HPFH-2 enhancer and exhibiting a pancellular pattern of (A)gamma-globin gene expression in MEL-585 clones. To assess the eventual clinical feasibility of this vector, GGHI was tested on CD34(+) hematopoietic stem cells from nonmobilized peripheral blood or bone marrow from 20 patients with beta-thalassemia. Our results show that GGHI increased the production of gamma-globin by 32.9% as measured by high-performance liquid chromatography ( p=0.001), with a mean vector copy number per cell of 1.1 and a mean transduction efficiency of 40.3%. Transduced populations also exhibited a lower rate of apoptosis and resulted in improvement of erythropoiesis with a higher percentage of orthochromatic erythroblasts. This is the first report of a locus control region (LCR)-free SIN insulated lentiviral vector that can be used to efficiently produce the anticipated therapeutic levels of gamma-globin protein in the erythroid progeny of primary human thalassemic hematopoietic stem cells in vitro." }