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.
Raftopoulos
H
H
Department of Genetics and Development, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Ward
M
M
Bank
A
A
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