IN-VITRO AND IN-VIVO GENE-TRANSFER TO PULMONARY CELLS MEDIATED BY CATIONIC LIPOSOMES

Cationic liposomes have been proposed as alternative to adenovirus in the treatment of cystic fibrosis lung desease. Therefore, we have inve stigated the efficiency of two lipid mixtures in mediating gene transf er in in vitro and in vivo models. The cationic lipid DOTMA ioleyloxy) propyl)-n,n,n-trimethylammoniumchloride) and DOGS (dioctadecylamidogly cylspermine) were used in combination with the neutral lipid DOPE (dio leoylphosphatidylethanolamine). The relative transfection efficiencies of the two cationic liposomes were tested using the bacterial beta-ga lactosidase (lacZ) and the firefly luciferase genes. Gene expression w as detected in both cell lines and primary culture of rhesus monkey ai rway epithelium after transfection with plasmid DNA complexed with DOG S/DOPE or DOTMA/DOFB. Transfection efficiency of both types of lipids was higher in the mouse fibroblast 3T3 cell line as compared to human carcinoma A549 cells and primary epithelial cultures. Administration o f DNA-liposome complexes via intratracheal instillation resulted in ex pression of the lacZ and luciferase marker gene in the mouse airways. In vivo transfection mediated by both types of liposomes were proven t o be far less efficient than adenovirus treatment.