title: Characterization of Adeno-Associated Viral Vector-Mediated Human Factor VIII Gene Therapy in Hemophilia A Mice.
abstract: Adeno-associated viral (AAV) vectors are promising vehicles for hemophilia gene therapy, with favorable clinical trial data seen in the treatment of hemophilia B. In an effort to optimize the expression of human coagulation factor VIII (hFVIII) for the treatment of hemophilia A, an extensive study was performed with numerous combinations of liver-specific promoter and enhancer elements with a codon-optimized hFVIII transgene. After generating 42 variants of three reduced-size promoters and three small enhancers, transgene cassettes were packaged within a single AAV capsid, AAVrh10, to eliminate performance differences due to the capsid type. Each hFVIII vector was administered to FVIII knockout (KO) mice at a dose of 1010genome copies (GC) per mouse. Criteria for distinguishing the performance of the different enhancer/promoter combinations were established prior to the initiation of the studies. These criteria included prominently the level of hFVIII activity (0.12-2.12 IU/mL) and the pattern of development of anti-hFVIII antibodies. In order to evaluate the impact of capsid on hFVIII expression and antibody formation, one of the enhancer and promoter combinations that exhibited high hFVIII immunogenicity was evaluated using AAV8, AAV9, AAVrh10, AAVhu37, and AAVrh64R1 capsids. The capsids subdivided into two groups: those that generated anti-hFVIII antibodies in ≤20% of mice (AAV8 and AAV9), and those that generated anti-hFVIII antibodies in >20% of mice (AAVrh10, AAVhu37, and AAVrh64R1). The results of this study, which entailed extensive vector optimization and in vivo testing, demonstrate the significant impact that transcriptional control elements and capsid can have on vector performance.
authors.affiliation: 1 Gene Therapy Program, Department of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Jenny A
authors.initials: JA
authors.lastname: Greig
authors.affiliation: 1 Gene Therapy Program, Department of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: 1 Gene Therapy Program, Department of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Reicherter
authors.affiliation: 1 Gene Therapy Program, Department of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Shu-Jen
authors.initials: SJ
authors.lastname: Chen
authors.affiliation: 2 School of Nursing, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hanlon
authors.affiliation: 3 Dimension Therapeutics , Cambridge, Massachusetts.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Tipper
authors.affiliation: 3 Dimension Therapeutics , Cambridge, Massachusetts.
authors.forename: K Reed
authors.initials: KR
authors.lastname: Clark
authors.affiliation: 3 Dimension Therapeutics , Cambridge, Massachusetts.
authors.forename: Samuel
authors.initials: S
authors.lastname: Wadsworth
authors.affiliation: 4 Department of Pathology and Laboratory Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.affiliation: 1 Gene Therapy Program, Department of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.
authors.forename: James M
authors.initials: JM
authors.lastname: Wilson
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology; D000229:Dependovirus / Q000235:genetics; D004195:Disease Models, Animal; D005169:Factor VIII / Q000235:genetics* / Q000627:therapeutic use; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000627:therapeutic use*; D006467:Hemophilia A / Q000235:genetics / Q000628:therapy*; D006801:Humans; D007108:Immune Tolerance / Q000235:genetics; D008099:Liver / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D011401:Promoter Regions, Genetic; D019076:Transgenes / Q000276:immunology
chemical_list: D036022:Capsid Proteins; D005169:Factor VIII
keywords: AAV; gene therapy; hemophilia A; human coagulation factor VIII