Induction of IL-8 production in human alveolar macrophages and human bronchial epithelial cells in vitro by swine dust

摘要

BACKGROUND—Exposure to swine dustcauses an intense airway inflammation with increased levels ofinterleukin 8 (IL-8) and predominantly neutrophils in the nasal andbronchoalveolar lavage fluids of healthy human subjects. It is notclear which components in the swine house environment are responsiblefor the airway reaction. The aim of the present study was to evaluateand compare the effect in vitro of swine dust components on humanalveolar macrophages and bronchial epithelial cells.
METHODS—Normal human bronchialepithelial cells (NHBE), human pulmonary epithelial carcinoma cell line(A549), and human alveolar macrophages were stimulated with swine dust,lipopolysaccharides (LPS; present in Gram negative bacteria), graindust (swine feed components), and glucans (a structural component offungi) in a dose response manner (1-100 µg/ml).
RESULTS—Swine dust at a concentrationof 100 µg/ml increased IL-8 production 20 fold in NHBE cells, 28 foldin A549 cells, and 15fold in macrophages. LPS (100 µg/ml) stimulatedall three cell types significantly, in macrophages to the same extentas swine dust, but in NHBE and A549 cells swine dust was 5-8 times aspotent. Grain dust (100 µg/ml) had no effect in A549 cells butstimulated NHBE cells and macrophages. Glucans (100 µg/ml) stimulatedA549 cells and macrophages but not NHBE cells. Both glucans and grain dust were weaker stimuli than swine dust and LPS. The LPS content ofswine dust solution was 2.16 (0.2) ng/100 µg and of grain dust was0.53 (0.04) ng/100 µg.
CONCLUSIONS—Swine dust is a strongstimulus for IL-8 production in both bronchial epithelial cells andhuman alveolar macrophages, whereas LPS has different potency in these cells.