Elevated Expression of mRNA for CCL2, CCL19, CCR7 and CXCR3 in Chronic Rhinosinusitis with Nasal Polyposis

Abstract

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a condition characterized by chronic inflammation in the nasal mucosa. We postulate that chemokines and chemokine receptors play an important role in this inflammatory process and contribute to polyp formation characteristic of CRSwNP. Nasal polyp tissue was obtained from individuals with CRSwNP and uncinate tissue (UT) was obtained from CRS patients and normal control subjects. Two different assays, Affymetrix Microarray (AF - based on hybridization) and Taqman Gene Expression Assay (TQ - based on real-time PCR), were used to characterize the expression of various chemokines and chemokine receptors. The level of mRNA expression for several genes was significantly elevated in polyp tissue from individuals with CRSwNP compared to UT from normal subjects in both assays. These include the chemokines CCL2 (5 fold in AF [p<0.01], 3.9 fold in TQ [p<0.05]) and CCL19 (4.2 fold in AF [p<0.05], 3.8 fold in TQ [p<0.05]), and the chemokine receptors CCR7 (3.4 fold in AF [p<0.05], 22.8 fold in TQ [p<0.01]) and CXCR3 (2.2 fold in AF [p<0.05], 5 fold in TQ [p<0.05]). These findings demonstrate confirmed elevation in nasal polyp tissue of mRNA for the chemokines CCL2 (MCP-1) and CCL19, and the chemokine receptors CXCR3 (traditionally associated with recruitment of Th1 cells) and CCR7 (receptor for CCL19). This may contribute to the chronic inflammatory state of the nasal mucosa characteristic of CRSwNP. Further studies will be required to confirm these findings at the protein level and establish their relevance to the pathogenesis of CRSwNP.