Induction of interleukin-8 release by lung epithelium with cystic fibrosisepithelial lining fluid is marginally affected by inhibitors of Interleukin-1 beta
Kr. Coulter et al., Induction of interleukin-8 release by lung epithelium with cystic fibrosisepithelial lining fluid is marginally affected by inhibitors of Interleukin-1 beta, PHARMACOTHE, 20(1), 2000, pp. 64-74
Interleukin-1 beta (IL-1 beta) and neutrophil elastase (NE) are present in
the epithelial lining fluid (ELF) of patients with cystic fibrosis (CF). Bo
th factors activate surrounding cells including lung epithelial cells, caus
ing release. of IL-8, a potent chemoattractant for neutrophils. Previous st
udies showed upregulation of IL-8 release by lung epithelial cells as a fun
ction of NE in CF; however, few studies addressed the relationship between
IL-1 beta and activation of lung epithelial cells in CF lungs. Confluent la
yers of AS49 cells, a type II-like human lung epithelial cell line, were in
cubated overnight with IL-1 beta (0-5 ng/ml) or NE (100 nM), and supernatan
ts were analyzed for IL-8 by enzyme-linked immunosorbent assay (ELISA). Bot
h IL-1 beta and NE led to a significant increase in IL-8. 12.8 +/- 2.8 ng/m
l and 0.8 +/- 0.3 ng/ml, respectively. Next, bronchoalveolar lavage (BAL) s
amples were obtained from one healthy adult volunteer and six patients with
CF and measured for IL-8 and IL-1 beta concentrations by ELISA. Both IL-8
(range 169.00 +/- 156.57 to 1742.04 +/- 338.98 pg/ml) and IL-1 beta (range
0-24.26 +/- 0.52 pg/ml) were detected in CF specimens, whereas neither was
detected in the volunteer's specimen. Normal and CF BALs then were incubate
d overnight at a 1:10 dilution with confluent A549 cells. Analysis by ELISA
of cell-free supernatants revealed increased IL-8 production from cells st
imulated with CF BALs only Similar experiments were performed with BAL supe
rnatants that had been incubated with soluble IL-1 type II receptor, solubl
e IL-1 receptor antagonist, or a peptide inhibitor of NE. Addition of IL-1
inhibitors had a marginal effect on the amount of IL-8 release after incuba
tion with CF BAL samples, whereas inhibition of NE had no effect. Our resul
ts indicate that other factors present in ELF in CF account for IL-8 releas
e from lung epithelial cells.