Adenovirus-mediated gene transfer in the midgestation fetal mouse

Background. The development of strategies for gene transfer in utero will make possible the amelioration, and eventually the cure, of genetic diseases associated with pre- and postnatal morbidity and mortality. We have developed a murine model for in utero, intrahepatic, adenovirus-mediated gene transfer in Day 15 fetuses and compared the level and distribution of luciferase reporter gene expression in newborns with those observed in adult animals injected intravenously. Material and methods. CD-1 fetuses underwent intrahepatic injection on Day 15 of gestation with 1 x 10(7) particle-forming units (PFU) of an E1- and E3-deleted recombinant adenovirus containing the luciferase reporter gene or with normal saline. At birth, pups were euthanized, and the brain, heart, intestine, liver, lungs, and spleen harvested and analyzed for luciferase activity. Results. Two adenovirus-injected litters proceeded to term and one female aborted. Tissues from 10 newborn mice in the experimental group and 5 newborns in the control group were analyzed; tissues from the remaining newborns were reserved for other studies. High-level luciferase expression was detected in all adenovirus-injected newborn livers. Lower levels of luciferase activity were detected in distant organs. Hepatic toxicity as determined by serum transaminase elevations was observed in adult, but not in newborn mice previously injected with the adeno-luciferase virus. Conclusions. In utero intrahepatic gene delivery with adenoviral vectors in the developing murine fetus is feasible and produces high-level gene expression. These studies suggest that viral and nonviral gene delivery vectors may be useful in the development of future approaches to prenatal treatment of genetic disorders. (C) 1999 Academic Press.