title: Efficient expression of a transgene in platelets using simian immunodeficiency virus-based vector harboring glycoprotein Ibalpha promoter: in vivo model for platelet-targeting gene therapy.
abstract: Platelets release several mediators that modify vascular integrity and hemostasis. In the present study, we developed a technique for efficient transgene expression in platelets in vivo and examined whether this targeted-gene-product delivery system using a platelet release reaction could be exploited for clinical applications. Analysis of luciferase reporter gene constructs driven by platelet-specific promoters (the GPIIb, GPIbalpha, and GPVI) revealed that the GPIbalpha promoter was the most potent in the megakaryoblastic cell line UT-7/TPO and human CD34+-derived megakaryocytes. Transduction of UT-7/TPO; CD34+-derived megakaryocytes; and c-Kit+, ScaI+, and Lineage- (KSL) murine hematopoietic stem cells with a simian immunodeficiency virus (SIV)-based lentiviral vector carrying eGFP resulted in efficient, dose-dependent expression of eGFP, and the GPIbalpha promoter seemed to bestow megakaryocytic-specific expression. Transplantation of KSL cells transduced with SIV vector containing eGFP into mice showed that there was preferable expression of eGFP in platelets driven by the GPIbalpha promoter [7-11% for the cytomeglovirus (CMV) promoter, 16-27% for the GPIbalpha promoter]. Furthermore, transplantation of ex vivo-transduced KSL cells by SIV vector carrying human factorVIII (hFVIII) driven by the GPIbalpha promoter induced the production of detectable transcripts of the hFVIII gene and the hFVIII antigen in bone marrow and spleen for at least 90 days and partially corrected the hemophilia A phenotype. Platelet-targeting gene therapy using SIV vectors appears to be promising for gene therapy approaches toward not only inherited platelet diseases but also other hemorrhagic disorders such as hemophilia A.
authors.affiliation: Research Division of Cell and Molecular Medicine, Center for Molecular Medicine, Jichi Medical School, Minamikawachi, Tochigi 329-0498, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ohmori
authors.forename: Jun
authors.initials: J
authors.lastname: Mimuro
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Takano
authors.forename: Seiji
authors.initials: S
authors.lastname: Madoiwa
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kashiwakura
authors.forename: Akira
authors.initials: A
authors.lastname: Ishiwata
authors.forename: Masanori
authors.initials: M
authors.lastname: Niimura
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Mitomo
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Tabata
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Keiya
authors.initials: K
authors.lastname: Ozawa
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sakata
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D005169:Factor VIII / Q000235:genetics*; D005312:Fetal Blood; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006467:Hemophilia A / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D008533:Megakaryocytes / Q000166:cytology; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D019038:Platelet Glycoprotein GPIb-IX Complex; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D015302:Simian Immunodeficiency Virus / Q000235:genetics*; D019089:Stem Cell Factor / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology
chemical_list: D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D019038:Platelet Glycoprotein GPIb-IX Complex; D011994:Recombinant Proteins; D019089:Stem Cell Factor; C094990:adhesion receptor; D005169:Factor VIII; D013926:Thrombopoietin