AJP - Lung Cellular and Molecular Physiology, Vol 268, Issue 5 839-L845, Copyright © 1995 by American Physiological Society
Adenovirus-mediated gene transfer to human fetal lung ex vivo
P. L. Ballard, M. L. Zepeda, M. Schwartz, N. Lopez and J. M. Wilson
Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, USA.
Gene therapy of the fetus or newborn infant is a potentially useful
approach for prevention or treatment of specific lung diseases. To begin to
address issues such as efficiency, duration, and cellular distribution of
transgene expression, we studied transduction of human lung cells by
recombinant, replication-deficient adenovirus containing the lacZ gene
driven by the beta-actin promoter and cytomegalovirus enhancer
(H5.010CBlacZ). Human fetal lungs of 20- to 24-wk gestation received
approximately 10(11) viral particles by instillation into a major bronchus,
and the tissue was cultured as explants in serum-free Waymouth's medium.
beta-galactosidase staining (X-gal) was detected by 24 h in defined regions
of treated tissue and localized to epithelial cells of airways and terminal
saccules. beta-galactosidase activity in homogenate of treated tissue was
maximal 3-5 days after exposure to virus, ranging from 0.2 to 1.5
A420.min-1.mg protein-1 in four experiments (control values were
approximately 0.001). When virus was added directly to lung explants in
culture, beta-galactosidase was expressed in most of the peripheral cells
and rarely in interior cells, the level of activity was dose dependent
between 10(8) and 10(11) viral particles/ml, and transgene expression was
sustained for at least 28 days. Treatment of isolated cultured cells with
virus resulted in equivalent staining of both epithelial cells and
fibroblasts. We conclude that fetal lung cells are efficiently transduced
by recombinant adenovirus, indicating the feasibility of gene therapy in
the infant or fetus. Cultured fetal lung may be useful for testing gene
constructs being considered for therapy.
