Resistance of Human Tracheal Epithelial Cells to Killing by Neutrophils, Neutrophil Elastase, and Pseudomonas Elastase

Publisher Website
Google Scholar
Abstract
The airway disease of cystic fibrosis (CF) is characterized by massive polymorphonuclear leukocyte (PMN) infiltration and the presence of variable but substantial quantities of uninhibited elastases derived from both PMNs and the common infecting organism Pseudomonas aeruginosa. In order to determine whether these agents inflict fatal injury on the airway epithelium, we exposed primary cultures of human tracheal epithelial (HTE) cells to activated PMNs, PMN elastase (PMNE), and elastase from P. aeruginosa (PSE) and monitored cytotoxicity by 51Cr release assay. Activated PMNs did not kill HTE cells, and fewer than 2% of the added PMNs adhered to the HTE cell layer. Pretreatment of HTE cells with lipopolysaccharide, incubation of PMNs with cytochalasin B, or increasing the incubation period to 8 h did not increase PMN adherence or target cell killing. However, poor PMN adherence was not by itself responsible for lack of cytotoxicity, since PMNs were not cytotoxic for 9HTEo− cells, a HTE cell line to which P...