title: Sustained phenotypic correction of hemophilia a mice following oncoretroviral-mediated expression of a bioengineered human factor VIII gene in long-term hematopoietic repopulating cells.
abstract: Hematopoietic stem cells (HSCs) are an attractive target cell population for hemophilia A gene therapy because of their capacity to regenerate the hematolymphoid system permanently following transplantation. Here we transplanted bone marrow (BM) cells transduced with a splicing-optimized MSCV oncoretroviral vector expressing a secretion-improved human factor VIII gene into immunocompromised hemophilic mice that had received a reduced dose conditioning regimen. An enhanced green fluorescent protein (EGFP) reporter gene linked to an encephalomyocarditis virus internal ribosome entry site was incorporated into the vector to allow preselection of transduced cells and facile evaluation of engraftment. Sustained expression of EGFP was demonstrated in the peripheral blood, and therapeutic levels of factor VIII were detected in the plasma of the majority of the recipients for the duration of the observation period (up to 22 weeks). Coordinate expression of factor VIII and EGFP (up to 19 weeks) was transferred to secondary BM transplant recipients, indicating that long-term repopulating HSCs had been successfully gene modified. Notably, the hemophilic phenotype of all treated mice was corrected, thus demonstrating the potential of HSC-directed oncoretroviral-mediated factor VIII gene transfer as a curative therapeutic strategy for hemophilia A.
authors.affiliation: Department of Anatomy and Cell Biology, Flow Cytometry Core Facility, The George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Morvarid
authors.initials: M
authors.lastname: Moayeri
authors.forename: Ali
authors.initials: A
authors.lastname: Ramezani
authors.forename: Richard A
authors.initials: RA
authors.lastname: Morgan
authors.forename: Teresa S
authors.initials: TS
authors.lastname: Hawley
authors.forename: Robert G
authors.initials: RG
authors.lastname: Hawley
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000821:virology; D016026:Bone Marrow Transplantation; D002460:Cell Line; D005169:Factor VIII / Q000032:analysis / Q000235:genetics*; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000821:virology; D006467:Hemophilia A / Q000235:genetics / Q000628:therapy*; D051379:Mice; D008817:Mice, Mutant Strains; D010641:Phenotype; D015202:Protein Engineering; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic / Q000379:methods
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C078147:F8 protein, human; D005169:Factor VIII