title: Computationally designed liver-specific transcriptional modules and hyperactive factor IX improve hepatic gene therapy.
abstract: The development of the next-generation gene therapy vectors for hemophilia requires using lower and thus potentially safer vector doses and augmenting their therapeutic efficacy. We have identified hepatocyte-specific transcriptional cis-regulatory modules (CRMs) by using a computational strategy that increased factor IX (FIX) levels 11- to 15-fold. Vector efficacy could be enhanced by combining these hepatocyte-specific CRMs with a synthetic codon-optimized hyperfunctional FIX-R338L Padua transgene. This Padua mutation boosted FIX activity up to sevenfold, with no apparent increase in thrombotic risk. We then validated this combination approach using self-complementary adenoassociated virus serotype 9 (scAAV9) vectors in hemophilia B mice. This resulted in sustained supraphysiologic FIX activity (400%), correction of the bleeding diathesis at clinically relevant, low vector doses (5 × 10(10) vector genomes [vg]/kg) that are considered safe in patients undergoing gene therapy. Moreover, immune tolerance could be induced that precluded induction of inhibitory antibodies to FIX upon immunization with recombinant FIX protein.
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Nisha
authors.initials: N
authors.lastname: Nair
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium; Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium;
authors.forename: Melvin Y
authors.initials: MY
authors.lastname: Rincon
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Hanneke
authors.initials: H
authors.lastname: Evens
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Shilpita
authors.initials: S
authors.lastname: Sarcar
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Sumitava
authors.initials: S
authors.lastname: Dastidar
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Emira
authors.initials: E
authors.lastname: Samara-Kuko
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium;
authors.forename: Omid
authors.initials: O
authors.lastname: Ghandeharian
authors.affiliation: Department of Pediatrics, Division of Metabolism, University of Zurich, Zurich, Switzerland; and.
authors.forename: Hiu
authors.initials: H
authors.lastname: Man Viecelli
authors.affiliation: Department of Pediatrics, Division of Metabolism, University of Zurich, Zurich, Switzerland; and.
authors.forename: Beat
authors.initials: B
authors.lastname: Thöny
authors.affiliation: Inflammation Research Center, Vlaams Instituut voor Biotechnologie, and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: De Bleser
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium; Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium;
authors.forename: Thierry
authors.initials: T
authors.lastname: VandenDriessche
authors.affiliation: Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium; Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium;
authors.forename: Marinee K
authors.initials: MK
authors.lastname: Chuah
mesh_terms: D000818:Animals; D001483:Base Sequence; D019295:Computational Biology; D000229:Dependovirus / Q000235:genetics; D005164:Factor IX / Q000235:genetics*; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics / Q000627:therapeutic use*; D002836:Hemophilia B / Q000235:genetics / Q000628:therapy*; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D050436:Regulatory Elements, Transcriptional; D019076:Transgenes
chemical_list: D005164:Factor IX