title: The human ankyrin 1 promoter insulator sustains gene expression in a β-globin lentiviral vector in hematopoietic stem cells.
abstract: Lentiviral vectors designed for the treatment of the hemoglobinopathies require the inclusion of regulatory and strong enhancer elements to achieve sufficient expression of the β-globin transgene. Despite the inclusion of these elements, the efficacy of these vectors may be limited by transgene silencing due to the genomic environment surrounding the integration site. Barrier insulators can be used to give more consistent expression and resist silencing even with lower vector copies. Here, the barrier activity of an insulator element from the human ankyrin-1 gene was analyzed in a lentiviral vector carrying an antisickling human β-globin gene. Inclusion of a single copy of the Ankyrin insulator did not affect viral titer, and improved the consistency of expression from the vector in murine erythroleukemia cells. The presence of the Ankyrin insulator element did not change transgene expression in human hematopoietic cells in short-term erythroid culture or in vivo in primary murine transplants. However, analysis in secondary recipients showed that the lentiviral vector with the Ankyrin element preserved transgene expression, whereas expression from the vector lacking the Ankyrin insulator decreased in secondary recipients. These studies demonstrate that the Ankyrin insulator may improve long-term β-globin expression in hematopoietic stem cells for gene therapy of hemoglobinopathies.
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Zulema
authors.initials: Z
authors.lastname: Romero
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Campo-Fernandez
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wherley
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Kaufman
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Urbinati
authors.affiliation: Molecular Biology Interdepartmental PhD Program, University of California , Los Angeles, California, USA.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Cooper
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Megan D
authors.initials: MD
authors.lastname: Hoban
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Kismet M
authors.initials: KM
authors.lastname: Baldwin
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Dianne
authors.initials: D
authors.lastname: Lumaquin
authors.affiliation: Department of Internal Medicine and Health Services Research, University of California , Los Angeles, California, USA.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Shantha
authors.initials: S
authors.lastname: Senadheera
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA.
authors.forename: Roger P
authors.initials: RP
authors.lastname: Hollis
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California , Los Angeles, California, USA ; Department of Pediatrics, UCLA Children's Discovery and Innovation Institute David Geffen School of Medicine, University of California , Los Angeles, California, USA.
authors.forename: Donald B
authors.initials: DB
authors.lastname: Kohn