Aerosol-Mediated Delivery of Recombinant Adenovirus to the Airways of Nonhuman Primates

Abstract
At present, it is conceivable that gene therapy of the cystic fibrosis airway epithelium is possible using the direct transfer of a functional human cystic fibrosis transmembrane conductance regulator (CFTR) gene to a wide variety of patients' tracheo-bronchial cells. Here we describe a novel approach (aerosolization) to deliver a replication-deficient adenovirus carrying the CFTR gene (Ad.CFTR) to the airways. Results obtained in vitro and in Rhesus monkeys suggest that the delivery of recombinant adenovirus as an aerosol is feasible and is not associated with severe toxicity after single or double administration depending on the Ad.CFTR dose. This study supports the concept of aerosolization as a delivery method for adenovirus-mediated lung gene therapy. With the goal of delivering therapeutic genes to lung epithelia in a noninvasive, safe and practicable fashion, we have evaluated whether aerosolization of recombinant adenovirus could be a means of administration to the airways of Rhesus monkeys. A replication-defective (E1¯, E3¯) adenovirus carrying an expression cassette for the human cystic fibrosis transmembrane conductance regulator (CFTR) gene was chosen as the test system. Our results indicate that this route of administration may represent a way to treat lung diseases by recombinant adenovirus.