Induction of epidermal growth factor receptor family and mucin expression by eosinophil granule proteins in epithelial cells.

Objectives

To determine the effect of the eosinophil cationic granule proteins Major Basic Protein (MBP) and Eosinophil Peroxidase (EPO) on expression of the epidermal growth factor receptors (EGFR) HER1 and HER2 and consequently mucin gene expression in bronchial epithelial cells. Eosinophil accumulation and degranulation at local inflammatory sites is a feature of asthma, allergic rhinitis and nasal polyposis. Eosinophils and their granule proteins have been implicated in cell and tissue remodelling and have been shown to communicate with other cell types at inflammatory sites, including epithelial cells and nerve cells. The HER family of receptors, including HER1 and HER2 are activated by EGF ligands. They are upregulated in rhinosinusitis and nasal polyposis and in several human cancers. Activation of HER receptors leads to the production of mucin. We hypothesize that eosinophil cationic granule proteins including MBP and EPO will change the levels of expression and activation of the HER family and consequently of mucin genes.