Interleukin-33 promotes the inflammatory reaction in chronic rhinosinusitis with nasal polyps by NF-κB signaling pathway

Interleukin (IL)-33 promotes T helper (Th2) immune response and may be involved in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). Using murine and human specimens, we evaluated the role of IL-33 in CRSwNP.

To establish CRSwNP, Balb/c mice were sensitized with house dust mite, followed up by intranasal exposure to Staphylococcus aureus to stimulate the inflammatory response of nasal mucosa. The hematoxylin-eosin staining and total serum IgE were used to the successful construction of CRSwNP model. For mechanistic studies, we blocked mice with IL-33 and the Th2 cells counts in tissue were detected. Th2 cytokine expression of IL-4, IL-5, IL-13, IL-22, CCL-11, and CCL-24 in control group, CRSwNP group and IL-33 blockade group at 12 weeks after CRSwNP model establishment, were analyzed by qRT-PCR. Meanwhile, the relative mRNA and protein expression levels of NF-κB, MyD88 and TLR7 were detected after IL-33 blockade. To document the inflammatory response in patients with CRSwNP, The relative mRNA expression of IL-4, IL-5, IL-13, IL-22, CCL-11, and CCL-24 in control individuals and patients with CRSwNP (chronic rhinosinusitis with nasal polyps) were analyzed by qRT-PCR.

The CRSwNP model was successfully constructed. After IL-33 blocked, the relative expression of IL-33 and Th2 cells counts were reduced significantly. CRSwNP mice showed overproduction of IL-4, IL-5, IL-13, IL-22, CCL-11, and CCL-24 and IL-33 blockade inhibited the expression of IL-4, IL-5, IL-13, IL-22, CCL-11, and CCL-24. Furthermore, IL-33 blockade decreased the mRNA levels of NF-κB, MyD88 and TLR7, and also restrained the protein expression of them. On the other hand, patients' specimens with CRSwNP showed high levels of Th2 cytokines including IL-33, IL-4, IL-5, IL-13, IL-22, CCL-11, and CCL-24.

CRSwNP is associated with overexpression of IL-33, with subsequent activation of Th2 immune response by NF-κB signaling pathway.