Lentivirus-mediated platelet gene therapy of murine hemophilia A with pre-existing anti-factor VIII immunity. J Thromb Haemost 2012 Aug;10(8):1570-80
Date
05/29/2012Pubmed ID
22632092Pubmed Central ID
PMC3419807DOI
10.1111/j.1538-7836.2012.04791.xScopus ID
2-s2.0-84864333652 (requires institutional sign-in at Scopus site) 91 CitationsAbstract
BACKGROUND: The development of inhibitory antibodies, referred to as inhibitors, against exogenous factor VIII in a significant subset of patients with hemophilia A remains a persistent challenge to the efficacy of protein replacement therapy. Our previous studies using the transgenic approach provided proof-of-principle that platelet-specific expression could be successful in treating hemophilia A in the presence of inhibitory antibodies.
OBJECTIVE: To investigate a clinically translatable approach for platelet gene therapy of hemophilia A with pre-existing inhibitors.
METHODS: Platelet FVIII expression in preimmunized FVIII(null) mice was introduced by transplantation of lentivirus-transduced bone marrow or enriched hematopoietic stem cells. FVIII expression was determined with a chromogenic assay. The transgene copy number per cell was quantitated with real-time PCR. Inhibitor titer was measured with the Bethesda assay. Phenotypic correction was assessed by the tail clipping assay and an electrolytically induced venous injury model. Integration sites were analyzed with linear amplification-mediated PCR.
RESULTS: Therapeutic levels of platelet FVIII expression were sustained in the long term without evoking an anti-FVIII memory response in the transduced preimmunized recipients. The tail clip survival test and the electrolytic injury model confirmed that hemostasis was improved in the treated animals. Sequential bone marrow transplants showed sustained platelet FVIII expression resulting in phenotypic correction in preimmunized secondary and tertiary recipients.
CONCLUSIONS: Lentivirus-mediated platelet-specific gene transfer improves hemostasis in mice with hemophilia A with pre-existing inhibitors, indicating that this approach may be a promising strategy for gene therapy of hemophilia A even in the high-risk setting of pre-existing inhibitory antibodies.
Author List
Kuether EL, Schroeder JA, Fahs SA, Cooley BC, Chen Y, Montgomery RR, Wilcox DA, Shi QAuthors
Robert R. Montgomery MD Adjunct Professor in the Pediatrics department at Medical College of WisconsinQizhen Shi MD, PhD Professor in the Pediatrics department at Medical College of Wisconsin
David A. Wilcox PhD Professor in the Pediatrics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsAutoantibodies
Blood Platelets
Bone Marrow Transplantation
Disease Models, Animal
Factor VIII
Genetic Therapy
Genetic Vectors
Genotype
Hematopoietic Stem Cell Transplantation
Hemophilia A
Lentivirus
Mice
Mice, 129 Strain
Mice, Inbred C57BL
Mice, Knockout
Mutagenesis, Insertional
Phenotype
Real-Time Polymerase Chain Reaction
Time Factors
Transduction, Genetic
