AEROSOL DELIVERY OF LIPID-DNA COMPLEXES TO LUNGS OF RHESUS-MONKEYS

Purpose. The potential use of aerosol delivery for non-viral gene ther apy was tested by nebulization of lipid:DNA complexes to the lungs of rhesus monkeys. Methods. Four female rhesus monkeys were dosed with li pid:DNA formulations via aerosol inhalation, where the DNA coded for t he human Cystic Fibrosis Transmembrane Conductance Regulator (hCFTR) p rotein. Delivery of DNA was determined in lung samples by polymerase c hain reaction (PCR) by qualitative and quantitative methods. Transgene specific messenger RNA was measured by reverse transcriptase PCR (RT- PCR) and protein expression and localization were evaluated by immunoh istochemistry (IHC). Results, Approximately four mg of DNA, complexed with cationic lipid 1,2-dimyristoyl-sn-glycero-3-ethylphosphylcholine (EDMPC) and cholesterol were delivered to the lungs of animals by air jet nebulizer. Three days after dosing, tissue samples from the lung w ere collected and shown to have vector specific DNA, RNA and the prese nce of CTFR protein. Specifically, the hCFTR protein was distributed w idely, although non-uniformly, throughout airway epithelium being loca ted on the apical surface of epithelial cells. Importantly, no adverse clinical effects were observed and the lungs showed no histological a bnormalities or signs of acute inflammation. Conclusions. This study s hows that lipid:DNA formulations based on EDMPC and cholesterol can be administered to primates by nebulization resulting in measurable expr ession of the hCFTR protein. The absence of inflammation is also encou raging and such systems may have utility for delivery of genes to the lungs for the treatment of a variety of pulmonary diseases including c ystic fibrosis.