Interaction of thymic stromal lymphopoietin, IL-33, and their receptors in epithelial cells in eosinophilic chronic rhinosinusitis with nasal polyps.

Thymic stromal lymphopoietin (TSLP), IL-25, and IL-33 system contribute to the initiation and development of Th2 responses. This study aimed to explore the involvement of TSLP, IL-25, IL-33, and their receptors in type 2 T-helper (Th) responses in chronic rhinosinusitis with nasal polyps (CRSwNPs) and their cross-regulation in human nasal epithelial cells (HNECs). Immunohistochemistry, quantitative RT-PCR, ELISA, Bio-Plex assay, and flow cytometry were used to detect the expression of TSLP/common γ-like TSLP receptor (TSLPR)/IL-7 receptor α (IL-7Rα), IL-25/IL-17B receptor (IL-17RB), and IL-33/membrane-bound ST2 (ST2L)/soluble ST2 (sST2) in sinonasal mucosa and HNECs. HNECs cultured at an air-liquid interface were used to explore the expression in regulation of these cytokine systems. Compared with controls and noneosinophilic CRSwNP, the expression of TSLP/TSLPR/IL-7Rα and ST2L/sST2 was significantly increased in eosinophilic CRSwNP, predominantly in epithelial cells. In contrast, the expression of IL-33 and IL-25/IL-17RB was enhanced in epithelial cells in both eosinophilic and noneosinophilic CRSwNP compared to controls. The expression of TSLP, TSLPR, and ST2L was positively correlated with symptom and computer tomography scan scores in eosinophilic CRSwNP and with Th2 cytokine expression in sinonasal mucosa. The expression of ST2L was correlated with TSLP and its receptor expression. TSLP could induce ST2L expression that promoted IL-33-induced TSLP expression in HNECs. In addition, TSLP/TSLPR/IL-7Rα and ST2L could be induced by Th2 cytokines, while IL-25/IL-17RB and IL-33 could be upregulated by Th1/Th17 cytokines, in HNECs. The positive feedback loop between TSLP, IL-33 and their receptors, and Th2 cytokines may facilitate Th2-skewed inflammation in eosinophilic CRSwNP.

Liao B ，Cao PP ，Zeng M ，Zhen Z ，Wang H ，Zhang YN ，Hu CY ，Ma J ，Li ZY ，Song J ，Liu JX ，Peng LY ，Liu Y ，Ning Q ，Liu Z ... -  《-》

Thymic stromal lymphopoietin activity is increased in nasal polyps of patients with chronic rhinosinusitis.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with TH2-dominant inflammation. Thymic stromal lymphopoietin (TSLP) is a cytokine that triggers dendritic cell-mediated TH2 inflammatory responses and that enhances IL-1-dependent TH2 cytokine production in mast cells. Although increased TSLP mRNA levels have been found in nasal polyps (NPs), expression of TSLP protein and its function in patients with chronic rhinosinusitis (CRS) have not been fully explored. The objective of this study was to investigate the role of TSLP in patients with CRS. We investigated the presence and stability of TSLP protein in NPs using ELISA and Western blotting and investigated the function of TSLP in nasal tissue extracts with a bioassay based on activation of human mast cells. Although TSLP mRNA levels were significantly increased in NP tissue from patients with CRSwNP compared with uncinate tissue from patients with CRS or control subjects, TSLP protein was significantly decreased in NP tissue, as detected by using the commercial ELISA kit. We found that recombinant TSLP was time-dependently degraded by NP extracts, and this degradation was completely inhibited by a protease inhibitor cocktail, suggesting that TSLP is sensitive to tissue proteases. Interestingly, NP extract-treated TSLP had higher activity in mast cells, although the amount of full-length TSLP was reduced up to 85%. NP extracts significantly enhanced IL-1β-dependent IL-5 production in mast cells compared with uncinate tissue homogenates, and responses were significantly inhibited by anti-TSLP, suggesting that NPs contain biologically relevant levels of TSLP activity. TSLP and its metabolic products might play an important role in the inflammation seen in patients with CRSwNP.

Nagarkar DR ，Poposki JA ，Tan BK ，Comeau MR ，Peters AT ，Hulse KE ，Suh LA ，Norton J ，Harris KE ，Grammer LC ，Chandra RK ，Conley DB ，Kern RC ，Schleimer RP ，Kato A ... -  《-》

The IL-37-Mex3B-Toll-like receptor 3 axis in epithelial cells in patients with eosinophilic chronic rhinosinusitis with nasal polyps.

The role of IL-37, an immunosuppressive cytokine, in patients with inflammatory diseases is unclear. We sought to explore the expression and pathogenic function of IL-37 in patients with chronic rhinosinusitis (CRS). Expression levels of IL-37, IL-18 receptor α, IL-1 receptor 8, Mex3 RNA binding family member B (Mex3B), and thymic stromal lymphopoietin (TSLP) in nasal samples were studied by using quantitative RT-PCR, immunohistochemistry, Western blotting, and ELISA. Human nasal epithelial cells (HNECs) and the BEAS-2B cell line were stimulated with various cytokines and Toll-like receptor (TLR) agonists. In some experiments BEAS-2B cells were transfected with Mex3B small interfering RNA or overexpressing lentiviruses. Genes regulated by IL-37b in HNECs were studied by using RNA sequencing analysis. IL-37b function was confirmed in mice in vivo. Compared with control subjects, although mRNA and protein expression of IL-37 were upregulated in diseased tissues, especially in nasal epithelial cells, in patients with CRS without nasal polyps or in patients with chronic rhinosinusitis with nasal polyps (CRSwNP), IL-37 levels in nasal secretions were reduced in patients with eosinophilic CRSwNP. Type 2 cytokines inhibited IL-37 secretion from HNECs. HNECs expressed IL-37 receptors, IL-18 receptor α, and IL-1 receptor 8. IL-37b downregulated the expression of Mex3B, a TLR3 coreceptor, in HNECs. IL-37b suppressed polyinosinic-polycytidylic acid-induced TSLP production in HNECs in vitro and in murine nasal epithelial cells in vivo. Knocking down or overexpressing Mex3B in BEAS-2B cells abolished the inhibitory effect of IL-37b. Secreted IL-37 levels negatively correlated with Mex3B and TSLP levels and eosinophil numbers in patients with eosinophilic CRSwNP. The suppressed IL-37 secretion caused by a type 2 milieu can enhance Mex3B-mediated TLR3 activation and subsequent TSLP production in nasal epithelial cells and therefore promotes eosinophilic inflammation in patients with CRSwNP.

Liu JX ，Liao B ，Yu QH ，Wang H ，Liu YB ，Guo CL ，Wang ZC ，Li ZY ，Wang ZZ ，Ruan JW ，Pan L ，Yao Y ，Chen CL ，Wang H ，Liang Y ，Zhen G ，Liu Z ... -  《-》

TSLP regulates eotaxin-1 production by nasal epithelial cells from patients with eosinophilic CRSwNP.

Wang WW ，Lu DM ，Zheng M ，Zhang JG ，Zhang B ... -  《RHINOLOGY》

Clinical severity and epithelial endotypes in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a heterogeneous disease defined by epithelial inflammation. The link between measures of traditional disease severity and markers of epithelial inflammation is poorly understood as prior research has focused on presence of polyps or degree of eosinophilia. The expression of 3 epithelial derived cytokines implicated in initiation of T-helper 2 (Th2) inflammation and an eosinophil chemoattractant were compared with clinical measures used in CRS. Sinus mucosal samples from CRS patients undergoing sinus surgery were analyzed for interleukin-25 (IL-25), IL-33, thymic stromal lymphopoietin (TSLP), and eotaxin-3 messenger RNA (mRNA) expression by quantitative polymerase chain reaction (PCR). Tumor patients undergoing surgery transnasally with normal sinus mucosa were controls. Gene expression was compared with symptom, radiology, and endoscopy scores, serological markers, presence of reactive airways disease (RAD), and atopy. Thirty-seven patients (38% female, mean age 48 ± 15 years), 12 CRS with nasal polyps (CRSwNP), 18 CRS without nasal polyps (CRSsNP), and 7 controls were recruited. CRSwNP phenotype predicted elevated IL-25, IL-33, and eotaxin-3 levels. Increased eotaxin-3 correlated with poorer computed tomography (CT) (p = 0.004) and endoscopic scores (p = 0.049). Increased IL-25 correlated with poorer CT scores (p = 0.012) and raised serum eosinophils (p = 0.006). No associations with RAD, atopy, and symptom measures were found. No associations for IL-33 and TSLP were found. Inflammatory mediators of the epithelium in CRS has some correlation with traditional measures of disease burden. Certain epithelial profiles may predict highly dysfunctional epithelial barriers and prospective evaluation of the clinical outcomes from interventions is required. Future endotyping of the epithelium in CRS may be able to provide prognostic information.

Lam M ，Hull L ，McLachlan R ，Snidvongs K ，Chin D ，Pratt E ，Kalish L ，Sacks R ，Earls P ，Sewell W ，Harvey RJ ... -  《-》