Aerosol delivery of an enhanced helper-dependent adenovirus formulation to rabbit lung using an intratracheal catheter

Background Poor transduction of the ciliated airway epithelium and inefficient airway delivery of viral vectors are common difficulties encountered in lung gene therapy trials with large animals and humans. Methods We delivered a helper-dependent adenovirus vector, incorporating a human epithelial cell-specific expression cassette, to rabbit lung. An intratracheal device was used to aerosolize a moderate dose of virus (5 x 1011 particles), mixed with the enhancing agent LPC (L-alpha-lysophosphatidylcholine), directly into the airways. Lung mechanics, body weight and temperature, transgene expression and histopathology were studied at day 5. Results Transgene expression was seen in the epithelium of large and small airways, from trachea to terminal bronchioles, with a strong tendency toward the right lung. All cell types of the surface epithelium were transduced. Extensive transduction of the epithelium (66% of cells in trachea) was obtained using virus formulated in isotonic 0.1% LPC, while virus formulated in 0.01% LPC transduced fewer cells (24% in trachea). A transient decrease in dynamic lung compliance was observed immediately following aerosol delivery. Fever and mild-to-moderate patchy pneumonia without edema were also observed. Conclusion These data demonstrate a strategy for efficient and effective transduction of airway epithelium in a large animal. Copyright (C) 2005 John Wiley & Sons, Ltd.