Fig. 3

Purified NE or activated neutrophils alters epithelial monolayer integrity. Confluent cultured MLE15 cells were exposed to purified or activated neutrophils for 6 h. a, immunofluorescence staining of untreated cell monolayer with N-terminal E-cad antibody found strong immunoreactive E-cad surrounding cells. b, exposure of cells to purified NE (200 nM) resulted in considerable loss of E-cadherin immunostaining and disruption of cell-cell adhesion. c, activated neutrophils alter epithelial cell layer integrity with the appearance of patchy gaps. The number of neutrophils added to cells was calculated to yield concentration of liberated NE closely equivalent to that of purified NE. d, fluorescence quantification of cultured cells. Note NE-treated cells or cells co-cultured with neutrophils showed significantly less staining than untreated cells. Data are presented as means ± SEM per experimental condition. **** correspond to p < 0.0001 for conditions of cell treatment with NE or PMNs versus control. a.u., arbitrary unit. Scale bar, 120 μm. Experiments were repeated three times with similar observations