The IL-1 family of cytokines, which now includes 11 members, is well known to participate in inflammation. Although the most recently recognized IL-1 family cytokines (IL-1F5-11) have been shown to be expressed in airway epithelial cells, the regulation of their expression and function in the epithelium has not been extensively studied. We investigated the regulation of IL-1F5-11 in primary normal human bronchial epithelial cells. Messenger (m)RNAs for IL-1F6 and IL-1F9, but not IL-1F5, IL-1F8 or IL-1F10, were significantly up-regulated by TNF, IL-1b, IL-17 and the Toll-like receptor (TLR)3 ligand doublestranded (ds)RNA. mRNAs for IL-1F7 and IL-1F11 (IL-33) were weakly up-regulated by some of the cytokines tested. Notably, mRNAs for IL-1F6 and IL-1F9 were synergistically enhanced by the combination of TNF/IL-17 or dsRNA/IL-17. IL-1F9 protein was detected in the supernatant following stimulation with dsRNA or a combination of dsRNA and IL-17. IL-1F6 protein was detected in the cell lysate but was not detected in the supernatant. We screened for the receptor for IL-1F9 and found that lung fibroblasts expressed this receptor. We found that IL-1F9 activated mitogen-activated protein kinases and the transcription factor NF-kB in primary normal human lung fibroblasts. IL-1F9 also stimulated the expression of the neutrophil chemokines IL-8 and CXCL3 and the Th17 chemokine CCL20 in lung fibroblasts. These results suggest that epithelial activation by TLR3 (e.g., by respiratory viral infection) and exposure to cytokines from Th17 cells (IL-17) and inflammatory cells (TNF) may amplify neutrophilic inflammation in the airway via induction of IL-1F9 and activation of fibroblasts.

Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with Th2-dominant inflammation including eosinophilia, in contrast to non-polypoid CRS (CRSsNP). Chemokine CCL18/PARC (pulmonary and activation regulated chemokine) is known to recruit naïve T cells, B cells, and immature dendritic cells, as well as activate fibroblasts. CCL18is thought to be involved in Th2-related inflammatory diseases including asthma and atopic dermatitis. Objectives The objective of this study was to investigate the expression of CCL18 in patients with CRS. Methods Using nasal polyp tissue (NP) and uncinate tissue (UT) from controls and patients with CRS, we examined the expression of CCL18 mRNA by real-time PCR and measured CCL18 protein by ELISA, western blot and immunofluorescence. Results Compared to UT tissue in control subjects, CCL18 mRNA was significantly increased in NP (p<0.001) and UT (p<0.05) from patients with CRSwNP but not in UT from patients with CRSsNP. Similarly, CCL18 protein was elevated in NP and UT from CRSwNP and levels were even higher in Samter’s triad patients. Immunohistochemical analysis revealed CCL18 expression in inflammatory cells and CCL18+ cells were significantly increased in NP. Immunofluorescence data showed co-localization of CCL18 in CD68+/CD163+/macrophage mannose receptor+ M2 macrophages and tryptase+ mast cells in NP. Levels of CCL18 correlated with markers of M2 macrophages but not with tryptase, suggesting that M2 macrophages are a major CCL18-producing cells in NP. Conclusion Overproduction of CCL18 might contribute to the pathogenesis of CRSwNP through its known activities, which include recruitment of lymphocytes and dendritic cells, activation of fibroblasts, and initiation of local inflammation.

Background Chronic rhinosinusitis (CRS) is a heterogeneous chronic disease characterized by local inflammation of the sinonasal tissues. The pathogenesis of CRS remains controversial but it has been associated with the accumulation of various immune and inflammatory cells in sinus tissue. Objectives The objective of this study was to investigate the expression of chemokine CCL23, known to bind to CCR1 and recruit monocytes, macrophages, and dendritic cells, in patients with CRS. Methods We collected nasal tissue from patients with CRS and control subjects. We assayed mRNA for CCL23 by using real-time PCR and measured CCL23 protein by ELISA, immunohistochemistry and immunofluorescence. Results CCL23 mRNA was significantly elevated in nasal polyps from patients with polypoid CRS (CRSwNP) (p<0.05) compared to inferior turbinate and uncinate tissue from patients with CRS or control subjects. CCL23 protein was also elevated in nasal polyps, although these levels were not statistically significant. Immunohistochemical analysis revealed CCL23 expression in mucosal epithelial cells and inflammatory cells, but accumulation of CCL23 positive inflammatory cells occurred only in nasal polyps. Immunofluorescence data showed CCL23 co-localization with ECP positive eosinophils. The concentration of CCL23 in nasal polyps positively correlated with the concentration of ECP, suggesting that eosinophils are major CCL23 producing cells in nasal polyps. Finally, we found that CCL23 protein was significantly elevated in nasal polyps from patients with CRSwNP with aspirin sensitivity. Conclusion Overproduction of CCL23 in nasal polyps may contribute to the pathogenesis of eosinophilic CRSwNP via the recruitment of CCR1 positive inflammatory cells including monocytes and macrophages, and the amplification of local inflammation.

Background Local production of IgA and IgE in the airways has been proposed to be an important event in both immune protection from pathogens and the pathogenesis of airway allergic diseases. Objective The objective of this study was to investigate the production of B cell-activating factor of the TNF family (BAFF), an important regulator of B cell survival and immunoglobulin class switch recombination, in bronchoalveolar lavage (BAL) fluid after segmental allergen challenge (SAC) of allergic subjects. Methods SAC with saline or allergen was performed in 16 adult allergic subjects. BAL was performed at both saline-and allergen-challenged sites 20–24 hr after challenge. Concentrations of B cell-active cytokines including BAFF, IL-6 and IL-13 were measured using specific ELISA and cytometric bead array assays. Results BAFF protein was significantly elevated in BAL fluid after allergen challenge (53.8 pg/ml (0–407.4 pg/ml), p=0.001) compared with those at saline sites (0 pg/ml (0–34.7 pg/ml)). In the BAL fluid after allergen challenge, BAFF levels were significantly correlated with absolute numbers of total cells (r=0.779, p<0.001), lymphocytes (r=0.842, p<0.001), neutrophils (r=0.809, p<0.001) and eosinophils (r=0.621, p=0.010) but did not correlate with macrophages. Normalization to albumin indicated that BAFF production occurred locally in the airways. BAFF levels were also significantly correlated with other B cell-activating cytokines, IL-6 (r=0.875, p<0.001) and IL-13 (r=0.812, p<0.001). Conclusion The antigen-induced production of BAFF in the airway may contribute to local class switch recombination and immunoglobulin synthesis by B cells.

Mast cells produce a large amount of several chemokines after cross-linking of FcεRI and participate in the pathogenesis of allergic diseases. The objective of this study was to comprehensively investigate FcεRI-mediated chemokine induction in human mast cells and the effect of a corticosteroid (dexamethasone) and a calcineurin inhibitor (FK506). Human peripheral blood-derived mast cells were stimulated with anti-IgE Ab in the presence of dexamethasone or FK506. Gene expression profiles were evaluated using GeneChip and confirmed by real-time PCR, and chemokine concentrations were measured by cytometric bead arrays and ELISA. Expression of eight chemokines was significantly induced in mast cells by anti-IgE stimulation. Induction of CCL2, CCL7, CXCL3, and CXCL8 by anti-IgE was significantly inhibited by dexamethasone but was enhanced by FK506. In contrast, induction of CCL1, CCL3, CCL4, and CCL18 was significantly inhibited by FK506 but, with the exception of CCL1, was enhanced by dexamethasone. Combination of dexamethasone and FK506 suppressed production of all chemokines by anti-IgE stimulation. Studies using protease inhibitors indicate that mast cell proteases may degrade several of the chemokines. These results suggest that corticosteroids and calcineurin inhibitors inhibit expression of distinct subsets of chemokines, and a combination of these drugs almost completely suppresses the induction of all chemokine genes in human mast cells in response to FcεRI-dependent stimulation. This implies that a combination of a corticosteroid and a calcineurin inhibitor may be more effective than each single agent for the treatment of allergic diseases in which mast cell-derived chemokines play a major role.