Bronchial epithelial cells chemokine production

It is well documented that normal human bronchial epithelial cells release a variety of cytokines and chemokines, and proinflammatory cytokines such as IL-la, IL-1 3, and TNF-a stimulate their production in vitro (Fig. 11) [61], We cultured human normal and transformed bronchial epithelial cells, and studied the effect of EM, CAM, and RXM on IL-6 [17], IL-8 [60, 62] and GM-CSF [63] production. Among the antimicrobes tested, only 14-membered-ring macrolides EM, CAM, and RXM showed an inhibitory action on cytokine release by unstimulated and cytokine-stimulated human bronchial epithelial cells (Fig. 12). In contrast, a 16-membered ring macrolide josamycin (JM) failed to show such effects. LDH release assay, a trypan blue dye exclusion test, and a colorimetric MTT assay showed that this effect was not due to cytotoxicity. Percent inhibition of IL-8 protein release in human primary bronchial epithelial cells was 25.0 5.67% at lO M, which is comparable with clinically observed serum concentration. 

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