Lentivirus vector-mediated gene transfer to the developing bronchiolar airway epithelium in the fetal lamb.
BACKGROUND
Development of effective and durable gene therapy for treatment of the respiratory manifestations of cystic fibrosis remains a formidable challenge. Obstacles include difficulty in achieving efficient gene transfer to mature airway epithelium and the need to stably transduce self-renewing epithelial progenitor cells in order to avoid loss of transgene expression through epithelial turnover. Targeting the developing airway epithelium during fetal life offers the prospect of circumventing these challenges.


METHODS
In the current study we investigated vesicular stomatitis virus glycoprotein (VSVg)-pseudotyped HIV-1-derived lentivirus vector-mediated gene transfer to the airway epithelium of mid-gestation fetal lambs, both in vitro and in vivo. In the in vitro studies epithelial sheet explants and lung organ culture were used to examine transduction of the proximal and more distal airway epithelium, respectively. For the in vivo studies, vector was delivered directly into the proximal airway.


RESULTS
We found that even during the early pseudoglandular and canalicular phases of lung development, occurring through mid-gestation, the proximal bronchial airway epithelium was relatively mature and highly resistant to lentivirus-mediated transduction. In contrast, the more distal bronchiolar airway epithelium was relatively permissive for transduction although the absolute levels achieved remained low.


CONCLUSIONS
This result is promising as the bronchiolar airway epithelium is a major site of pathology in the cystic fibrosis airway, and much higher levels of transduction are likely to be achieved by developing strategies that increase the amount of vector reaching the more distal airway after intratracheal delivery.
Yu
Ze-Yan
ZY
Department of Respiratory Medicine, The Children's Hospital at Westmead, Westmead, Sydney, NSW, Australia.
McKay
Karen
K
van Asperen
Peter
P
Zheng
Maolin
M
Fleming
Jane
J
Ginn
Samantha L
SL
Kizana
Eddy
E
Latham
Margot
M
Feneley
Michael P
MP
Kirkland
Peter D
PD
Rowe
Peter B
PB
Lumbers
Eugenie R
ER
Alexander
Ian E
IE
D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D001980:Bronchi / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D005822:Genetic Vectors / Q000235:genetics*; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D011247:Pregnancy; D020545:Respiratory Mucosa / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism*; D014161:Transduction, Genetic; D014721:Vesicular stomatitis Indiana virus / Q000737:chemistry
D006023:Glycoproteins