Long-term persistence of human bone marrow stromal cells transduced with factor VIII-retroviral vectors and transient production of therapeutic levels of human factor VIII in nonmyeloablated immunodeficient mice.
The potential of using bone marrow (BM)-derived human stromal cells for ex vivo gene therapy of hemophilia A was evaluated. BM stromal cells were transduced with an intron-based Moloney murine leukemia virus (Mo-MuLV) retroviral vector that contained the B domain-deleted human factor VIII (FVIIIdeltaB) cDNA. This FVIII-retroviral vector was pseudotyped with the gibbon ape leukemia virus envelope (GALV-env) to attain higher transduction efficiencies. Using optimized transduction methods, high in vitro FVIII expression levels of 700 to 2500 mU of FVIII/10(6) cells per 24 hr were achieved without selective enrichment of the transduced BM stromal cells. After xenografting of 1.5-3 x 106 engineered BM stromal cells into the spleen of nonobese diabetic severe combined immunodeficient (NOD-SCID) mice, human plasma FVIII levels rose to 13 +/- 4 ng/ml but declined to basal levels by 3 weeks postinjection because of promoter inactivation. About 10% of these stromal cells engrafted in the spleen and persisted for at least 4 months after transplantation in the absence of myeloablative conditioning. No human BM stromal cells could be detected in other organs. These findings indicate that retroviral vector-mediated gene therapy using engineered BM stromal cells may lead to therapeutic levels of FVIII in vivo and that long-term engraftment of human BM stromal cells was achieved in the absence of myeloablative conditioning and without neo-organs. Hence, BM stromal cells may be useful for gene therapy of hemophilia A, provided prolonged expression can be achieved by using alternative promoters.
Chuah
M K
MK
Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, University of Leuven, Belgium.
Van Damme
A
A
Zwinnen
H
H
Goovaerts
I
I
Vanslembrouck
V
V
Collen
D
D
VandenDriessche
T
T
D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology* / Q000821:virology; D016026:Bone Marrow Transplantation; D005169:Factor VIII / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D017154:Stromal Cells / Q000502:physiology* / Q000821:virology
D011994:Recombinant Proteins; D005169:Factor VIII