High-level transfer and long-term expression of the human beta-globin gene in a mouse transplant model.
Insertion of a normally functioning human beta-globin gene into the hematopoietic stem cells (HSC) of patients with beta-thalassemia may be an effective approach to the therapy of this disorder. Safe, efficient gene transfer and long-term, high-level expression of the transferred human beta-globin gene in animal models are prerequisites for HSC somatic gene therapy. We have recently shown for the first time that, using a modified beta-globin retroviral vector in a mouse transplant model, long-term, high-level expression of a transferred human beta-globin gene is possible. The human beta-globin gene continues to be detected up to eight months post-transplantation of beta-globin-transduced hematopoietic cells into lethally irradiated mice. The transferred human beta-globin gene is detected in three of five mice surviving long-term (> 4 months) transplanted with bone marrow cells transduced with high-titer virus. The unrearranged 5.1 kb human beta-globin gene-containing provirus is seen by Southern blotting in two of these mice. More importantly, long-term expression of the transferred gene is seen in two mice at levels of 5% and 20% that of endogenous murine beta-globin. We document stem cell transduction by showing continued high-level expression of the human beta-globin gene in secondarily transplanted recipient mice. These results provide evidence of HSC transduction with a human beta-globin gene in animals and demonstrate that retroviral-mediated unrearranged human beta-globin gene transfer leads to a high level of human beta-globin gene expression in the long term for the first time. A gene therapy strategy may be a feasible therapeutic approach to the beta-thalassemias if consistent human beta-globin gene transfer and expression into HSC can be achieved.
Department of Genetics and Development, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
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Raftopoulos
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Ward
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Bank
D000818:Animals; D016026:Bone Marrow Transplantation / Q000502:physiology; D005333:Fetus; D018014:Gene Transfer Techniques; D005914:Globins / Q000096:biosynthesis* / Q000235:genetics; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction; D012190:Retroviridae
D005914:Globins