Human fetal trachea-SCID mouse xenografts: efficacy of vesicular stomatitis virus-G pseudotyped lentiviral-mediated gene transfer.
OBJECTIVE
Postnatal gene transfer in respiratory epithelium has been inefficient, particularly in submucosal gland cells, the target cells for cystic fibrosis transmembrane regulator (CFTR) gene transfer in cystic fibrosis. The authors hypothesized that fetal tracheobronchial epithelium may be more receptive to gene transfer in that precursor cells of the respiratory epithelium may be more accessible.


METHODS
Vesicular stomatitis virus-G (VSV-G) pseudotyped lentiviral vector was first tested in human fetal tracheal organ culture then validated in a human fetal tracheal xenograft model in severe combined immunodeficiency (SCID) mice. Between 7 x 10(7) and 1.6 x 10(8) transducing units of lentiviral vector encoding the transgene LacZ under the control of the human CMV promoter were administered onto the lumenal surface of the xenografts (n = 6). Biopsy specimens were taken from the xenografts at one month (n = 1), 2 months (n = 2), 3 months (n = 1), 6 months (n = 4), and 9 months (n = 1) after vector administration. Analysis of transgene expression was performed on X-gal stained sections.


RESULTS
Transgene expression was observed in 20.2% to 99% of the surface epithelial cells (mean, 70.8 +/- 32.3% SD) and in 28.4% to 99% of the submucosal gland cells (mean, 68.5 +/- 26.2% SD) out to 9 months after vector administration in the tracheal xenografts, equivalent to 63 weeks postconceptual age. No staining was seen in the controls.


CONCLUSIONS
Excellent gene transfer in human fetal tracheal xenografts after VSV-G pseudotyped lentiviral vector administration, which may result from more accessible target precursor cells during development, suggests the feasibility of fetal gene therapy for the treatment of congenital airway disease such as cystic fibrosis.
Lim
Foong-Yen
FY
Children's Institute for Surgical Science at The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Kobinger
Gary P
GP
Weiner
Daniel J
DJ
Radu
Antoneta
A
Wilson
James M
JM
Crombleholme
Timothy M
TM
D000818:Animals; D002460:Cell Line; D016332:Fetal Tissue Transplantation / Q000379:methods; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D016513:Mice, SCID; D009924:Organ Culture Techniques; D014132:Trachea / Q000196:embryology / Q000637:transplantation*; D014161:Transduction, Genetic; D019076:Transgenes / Q000235:genetics; D014183:Transplantation, Heterologous; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics
D001616:beta-Galactosidase