Plasmid-liposome transfer of the alpha 1 antitrypsin gene to cystic fibrosis bronchial epithelial cells prevents elastase-induced cell detachment and cytokine release.

Human neutrophil elastase (NE) stimulates release of neutrophil chemotactic activity by a bronchial epithelial cell line and from nasal epithelial cells. In this article, we show that NE stimulates the production of neutrophil chemotactic activity by 2CFSMEo-cells, a transformed cystic fibrosis bronchial epithelial cell line. The production of chemotactic activity is dose- and time-dependent and can be blocked by preincubation of NE with alpha 1 antitrypsin (alpha1AT). Incubation of the NE-stimulated culture supernatant with neutralizing concentrations of rabbit anti-human interleukin 8 antibody completely neutralizes the chemotactic activity. Transfection of 2CFSMEo- cells with the eukaryotic expression vector pCMV4alpha1AT, complexed to cationic liposomes in a 1:3 wt/wt ratio, results in at least a 10-fold increase in measured human alpha1AT protein in culture supernatant. Detection of human alpha1AT mRNA by reverse transcriptase polymerase chain reaction in total RNA from transfected, but not untransfected cells, confirms successful gene transfer. Compared with untransfected cells, transfer of the human alpha1AT gene decreases chemotactic activity in culture supernatant and prevents cell detachment after NE exposure. Our data indicate that alpha1AT gene transfer is capable of blocking at least some of the biological effects of free elastase on cultured epithelial cells.