IL-13-induced Clara cell secretory protein expression in airway epithelium: role of EGFR signaling pathway.

Previous work showed that the Th2 cytokine interleukin (IL)-13 induces goblet cell metaplasia via an indirect mechanism involving the expression and subsequent activation of epidermal growth factor receptor (EGFR). Because Clara cell secretory protein (CCSP) expression has been reported in cells that express mucins, we examined the effect of IL-13 on CCSP gene and protein expression in pathogen-free rat airways and in pulmonary mucoepidermoid NCI-H292 cells. Intratracheal instillation of IL-13 induced CCSP mRNA in epithelial cells without cilia within 8-16 h, maximal between 24 and 48 h; CCSP immunostaining increased in a time-dependent fashion, maximal at 48 h.