Short-term correction of factor VIII deficiency in a murine model of hemophilia A after delivery of adenovirus murine factor VIII in utero

Development of in utero gene transfer approaches may provide therapies for genetic disorders with perinatal morbidity, In hemophilia A, prenatal and p ostnatal bleeding may be catastrophic, and modest increments in factor VIII (FVIII) activity are therapeutic. We performed transuterine i.p, gene tran sfer at day 15 of gestation in a murine model of hemophilia A. Normal, carr ier (XHX), and FVIII-deficient (XHY and XHXH) fetuses injected with adenovi ral vectors carrying luciferase or beta-galactosidase reporter genes showed high-level gene expression with 91% fetal survival. The live-born rates of normal and FVIII-deficient animals injected in utero with adenovirus murin e FVIII (3.3 x 10(5) plaque-forming units) was 87%. FVIII activity in plasm a was 50.7 +/- 10.5% of normal levels at day 2 of life, 7.2 +/- 2.2% by day 15 of life, and no longer detectable at day 21 of life in hemophilic anima ls. Injection of higher doses of murine FVIII adenovirus at embryonic day 1 5 produced supranormal levels of FVIII activity in the neonatal period. PCR analysis identified viral genomes primarily in the liver, intestine, and s pleen, although adenoviral DNA was detected in distal tissues when higher d oses of adenovirus were administered. These studies show that transuterine i.p. injection of adenoviral vectors produces therapeutic levels of circula ting FVIII throughout the neonatal period. The future development of effici ent and persisting vectors that produce long-term gene expression may allow for in utero correction of genetic diseases originating in the fetal liver , hematopoietic stem cells, as well as other tissues.