Sinonasal Epithelial Cell Expression of Toll-Like Receptor 9 is Decreased in Chronic Rhinosinusitis with Polyps

Abstract

Functional TLR9 protein is expressed by normal and diseased sinonasal epithelial cells. The level of TLR9 expression is decreased in CRSwNP patients, consistent with the previous finding of decreased TLR9 mRNA in whole sinonasal tissue. These findings suggest that impaired innate immune responses to pathogens via TLR9 on sinonasal epithelial cells may represent a critical mechanism in chronic inflammatory sinus disease.