Bronchoepithelial expression of CXCR1 and CXCR2 does not facilitate transepithelial migration of neutrophils.

BACKGROUND Neutrophilic airway inflammation is one of the key features of chronic obstructive pulmonary disease (COPD). The chemokine receptors 1 (CXCR1) and 2 (CXCR2) are expressed in the bronchial mucosa during chronic inflammation and might be of importance for transepithelial migration of neutrophils. OBJECTIVES This study addressed the role of bronchoepithelial CXCR1 and CXCR2 expression with respect to transepithelial migration of neutrophils. METHODS Primary bronchial epithelial cells (PBECs) derived from COPD patients and healthy controls as well as transiently CXCR1- and CXCR2-transfected Calu-6 cells were used for transepithelial migration assays of neutrophils under various conditions. Epithelial CXCR1 and CXCR2 expression was verified by means of flow cytometry. RESULTS Transepithelial migration of neutrophils was significantly increased following lipopolysaccharide pretreatment of epithelial cells. Transient transfection of CXCR1 and CXCR2 neither augmented the transepithelial migration of neutrophils, nor did the selective blockade of CXCR1 and CXCR2 have any significant effect on neutrophilic transepithelial migration. In addition, no differences were found in PBECs and neutrophils derived from healthy controls and COPD patients. CONCLUSIONS The data of the present study do not support the hypothesis that bronchoepithelial expression of CXCR1 and/or CXCR2 facilitate transepithelial migration of neutrophils.