title: Proteasome inhibitors enhance gene delivery by AAV virus vectors expressing large genomes in hemophilia mouse and dog models: a strategy for broad clinical application.
abstract: Delivery of genes that are larger than the wild-type adeno-associated virus (AAV) 4,681 nucleotide genome is inefficient using AAV vectors. We previously demonstrated in vitro that concurrent proteasome inhibitor (PI) treatment improves transduction by AAV vectors encoding oversized transgenes. In this study, an AAV vector with a 5.6 kilobase (kb) factor VIII expression cassette was used to test the effect of an US Food and Drug Administration-approved PI (bortezomib) treatment concurrent with vector delivery in vivo. Intrahepatic vector delivery resulted in factor VIII expression that persisted for >1 year in hemophilia mice. Single-dose bortezomib given with AAV2 or AAV8 factor VIII vector enhanced expression on average ~600 and ~300%, respectively. Moreover, coadministration of AAV8.canineFVIII (1 × 10(13) vg/kg) and bortezomib in hemophilia A dogs (n = 4) resulted in normalization of the whole blood clotting time (WBCT) and 90% reduction in hemorrhages for >32 months compared to untreated hemophilia A dogs (n = 3) or dogs administered vector alone (n = 3). Demonstration of long-term phenotypic correction of hemophilia A dogs with combination adjuvant bortezomib and AAV vector expressing the oversized transgene establishes preclinical studies that support testing in humans and provides a working paradigm to facilitate a significant expansion of therapeutic targets for human gene therapy.
authors.affiliation: Gene Therapy Center, University of North Carolina at Chapel Hill, North Carolina 27599-7352, USA. Paul_Monahan@med.unc.edu
authors.forename: Paul E
authors.initials: PE
authors.lastname: Monahan
authors.forename: Clinton D
authors.initials: CD
authors.lastname: Lothrop
authors.forename: Junjiang
authors.initials: J
authors.lastname: Sun
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Hirsch
authors.forename: Tal
authors.initials: T
authors.lastname: Kafri
authors.forename: Boris
authors.initials: B
authors.lastname: Kantor
authors.forename: Rita
authors.initials: R
authors.lastname: Sarkar
authors.forename: D Michael
authors.initials: DM
authors.lastname: Tillson
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Elia
authors.forename: R Jude
authors.initials: RJ
authors.lastname: Samulski
mesh_terms: D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D001897:Boronic Acids / Q000494:pharmacology*; D000069286:Bortezomib; D002467:Cell Nucleus / Q000378:metabolism; D003131:Combined Modality Therapy; D000229:Dependovirus / Q000235:genetics*; D004195:Disease Models, Animal; D004285:Dogs; D005164:Factor IX / Q000502:physiology; D005169:Factor VIII / Q000502:physiology; D005260:Female; D015316:Genetic Therapy; D005822:Genetic Vectors; D016679:Genome, Viral; D002836:Hemophilia B / Q000235:genetics* / Q000628:therapy; D006801:Humans; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011480:Protease Inhibitors / Q000494:pharmacology*; D011719:Pyrazines / Q000494:pharmacology*; D019076:Transgenes / Q000502:physiology
chemical_list: D001897:Boronic Acids; D011480:Protease Inhibitors; D011719:Pyrazines; D000069286:Bortezomib; D005169:Factor VIII; D005164:Factor IX