Perfluorochemical liquid-enhanced adenoviral vector distribution and expression in lungs of spontaneously breathing rodents

Perfluorochemical (PFC) liquids have been shown to improve gas exchange and lung compliance in models of lung injury. We reasoned they may also be use ful as a vehicle for gene transfer by improving transgene distribution thro ughout the lung as well as increasing total transgene expression. We have d eveloped a model for PFC liquid use in spontaneously breathing rodents that obviates the need for intubation and ventilation. Intratracheal instillati on of the adenoviral vector Adlac-Z resulted in patchy distribution of beta -galactosidase (beta-gal) activity as demonstrated using X-gal histochemist ry. In contrast, in rats instilled with Adlac-Z followed by instillation of PFC liquid, more uniformly distributed and increased beta-gal activity was observed. Activity in distal airway and alveolar epithelium was particular ly increased. Quantitative measure of beta-gal activity in lung homogenates demonstrated a 3- to 6-fold increase in total activity in lungs of rats re ceiving Adlac-Z and PFC liquid compared to animals receiving Adlac-Z alone. These studies show that PFC liquids can enhance both the distribution and the total amount of transgene expressed following adenoviral-mediated vecto r transfer to lungs during spontaneous breathing. Use of PFC liquids may in crease the efficacy of gene transfer strategies for treatment of cystic fib rosis and other lung diseases.