Neutrophil elastase in respiratory epithelial lining fluid of individuals with cystic fibrosis induces interleukin-8 gene expression in a human bronchial epithelial cell line.

Publication Type	Academic Article
Authors	Nakamura H, Yoshimura K, McElvaney N, Crystal R
Journal	J Clin Invest
Volume	89
Issue	5
Pagination	1478-84
Date Published	05/01/1992
ISSN	0021-9738
Keywords	Bronchi, Cystic Fibrosis, Interleukin-8, Neutrophils, Pancreatic Elastase
Abstract	The respiratory manifestations of cystic fibrosis (CF) are characterized by neutrophil-dominated airway inflammation. Since a variety of inflammatory stimuli are capable of inducing bronchial epithelial cells to express the gene for IL-8, a cytokine that attracts and activates neutrophils, mediators in respiratory epithelial lining fluid (ELF) of CF individuals might induce IL-8 production by epithelial cells, thus recruiting neutrophils to the airways. BET-1A human bronchial epithelial cells at rest or incubated with normal ELF showed little IL-8 gene expression, but after incubation with CF ELF, a marked increase in IL-8 transcript levels was observed. CF ELF contained high levels of neutrophil elastase (NE) and various serine protease inhibitors prevented CF ELF from inducing IL-8 gene expression in BET-1A cells, suggesting that NE was the dominant inducer for IL-8 production in CF ELF. The addition of purified NE caused BET-1A cells to increase IL-8 gene transcription with accumulation of mRNA transcripts and to release IL-8-like neutrophil chemotactic activity. These observations suggest a self-perpetuating inflammatory process on the CF bronchial surface where NE released by neutrophils induced the bronchial epithelium to secrete IL-8, which in turn recruits additional neutrophils to the bronchial surface.
DOI	10.1172/JCI115738
PubMed ID	1569186
PubMed Central ID	PMC443018