In Utero AAV-Mediated Gene Transfer to Rabbit Pulmonary Epithelium

Abstract

In utero intra-amniotic administration of adeno-associated virus (AAV) for treatment of cystic fibrosis (CF) has the potential to be an efficient way to target the rapidly dividing undifferentiated cells of the fetal pulmonary epithelium, while simultaneously treating other tissues involved in CF (such as the intestines), but has never before been studied. Intra-amniotic administration of 1x10(12) particles of AAV-luciferase vector to 110 fetal rabbits at 24-25 days gestation resulted in transgene expression in amniotic membranes, trachea, and pulmonary epithelium. The highest level of transgene expression was found in amniotic membranes. Transgene expression peaked in the lungs 10 days after vector delivery, decreased at day 17, and was no longer detectable after 24 days. The number of pulmonary cells transduced was approximately 1 in 500 and immunohistochemical analysis showed expression in varying cell types, including alveolar cells. Transgene expression was not detected in fetal rabbit intestines, skin or liver, nor in maternal ovaries or liver. Intra-amniotic administration of AAV does not result in the tissue inflammation and fetal loss previously documented with in utero adenoviral administration, and results in high levels of transgene expression in amniotic membranes with lower levels in fetal pulmonary epithelium.

The developmental stage determines the distribution and duration of gene expression after early intra-amniotic gene transfer using lentiviral vectors

“…5,12,19,24 However, in general, gene transfer after intra-amniotic vector injection has been inefficient and transient because of the relatively late developmental stage at which these experiments have been performed. 5,26,27 In contrast to previous studies, we have recently reported that early IAGT results in efficient transduction of skin stem cell populations 28 and the ectoderm-derived stem cell populations of the eye, 29 including stem cells in the neuroectoderm-derived retina. However, in the course of these studies we observed a broad range of transduction events involving multiple tissues of all three germ layers.…”

Jaagsiekte sheep retrovirus pseudotyped lentiviral vector-mediated gene transfer to fetal ovine lung

“…AAV vectors have achieved long-term transgene expression in non-human primates (up to 24 months) 20 but only short-term expression, up to 24 days, in rabbits 21 following in utero delivery. In adult mice, AAV efficiently transduced respiratory epithelium for up to 9 months, although a steady decline in transgene expression was reported.…”

Fetal Liver-Derived Mesenchymal Stem Cell Engraftment After Allogeneic In Utero Transplantation into Rabbits

“…According to several reports [17][18][19] and from our own experience [20,21], the pregnant rabbit is a useful and reliable middle-sized animal model to evaluate proof-of-principle strategies based on gene transfer or cell transplantation into the fetus, which allow accurate organ-directed manipulation and delivery. Using fetal instead of adult donor cells for in utero transplantation approaches may also offer some benefit.…”