Pulmonary inflammation associated with repeated, prenatal exposure to an E1, E3-deleted adenoviral vector in sheep

Abstract

Fetal gene therapy may prove useful in treating diseases electively killed and 13 died in utero. The incidence of morthat manifest in the perinatal or early postnatal period.tality was higher than the р10% we have experienced with Adenoviruses effectively transfer gene expression to a varother fetal sheep studies and was not likely related to comiety of tissues but also stimulate inflammatory and immune plications arising from surgical or anesthetic procedures. responses. The purpose of this study was to test the Inflammatory and fibrotic responses were observed in the hypothesis that exposure of fetal sheep to a first generation lungs and may represent untoward long-term conseadenovirus vector encoding bacterial ␤-galactosidase, quences of in utero adenoviral gene therapy. Tolerance to Av1nBg, before the development of the immune system, is Av1nBg was not established, and repeated exposure to safe, minimizes inflammatory and immune responses and Av1nBg before birth was associated with significant patholinduces tolerance. A total of 22 fetal sheep was studied; of ogy and mortality. these, two were born with respiratory distress, seven were

Widespread and efficient marker gene expression in the airway epithelia of fetal sheep after minimally invasive tracheal application of recombinant adenovirus in utero

“…3,4,8,10 Assuming that this is due to the lack of adenovirus receptors on the apical side of the airway epithelia, we applied two strategies to enhance virus transduction. Initially, we applied the virus with DEAE dextran.…”

“…In sheep as in humans, this is not a suitable approach because of the considerable dilution factor by the large amniotic fluid volume and loss of vector by infection of the skin and fetal membranes. 4 To overcome these problems, other investigators have used complicated open uterus surgery, 5,7,10 or at least laparotomy and fetoscopy, 11 both of which are highly invasive techniques, but the results of gene transfer to the airways were still very poor. Because the upper respiratory tract is easily visualized by ultrasound in the sheep 12 and human fetus, 13 we chose in this study to use percutaneous ultrasoundguided injection to access the fetal trachea directly in utero.…”

“…1 Several groups have therefore attempted to achieve transfer of marker genes to the fetal airways in rodents, sheep and primates. [2][3][4][5][6][7][8][9][10][11] However, it has proven remarkably difficult to achieve consistent gene transfer to the airway epithelia in utero, which could be considered as sufficient to validate this procedure as a model for future in utero gene therapy of CF. Our investigations in mice have shown that it is possible to achieve high level of widespread gene delivery to the fetal airways after intra-amniotic adenovirus application from day 15 of gestation onwards.…”

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

“…These include intratracheal, 1-3 intravascular, 4,5 intraventricular, 6,7 intracardiac, 8 intraperitoneal, 5,[9][10][11][12] intraplacental, 13 intramuscular [14][15][16][17][18] and intra-amniotic injection. 1,5,[19][20][21][22] Intra-amniotic gene transfer (IAGT) has been used to target organs exposed to amniotic fluid, that is, the skin, amniotic membranes and the respiratory and digestive systems. 12,14,19,23,24 The skin and the amniotic membranes are directly exposed to the amniotic cavity, whereas the respiratory and digestive systems contact amniotic fluid through fetal breathing 23,25 and swallowing.…”

Synergistic effect of ultrasound and PEI on DNA transfection in vitro

“…However, progress in gene therapy has been delayed by limited ability to deliver appropriate amounts of DNA to required sites of action and thereby achieve therapeutic gene expression levels [2]. Viral and non-viral vectors have been used for DNA delivery with varying levels of success, but always accompanied by disadvantages, such as insufficient expression levels or safety concerns [3,4].…”