The IgE Blocking Activity Induced by Dermatophagoides pteronyssinus Subcutaneous Immunotherapy Does Not Correlate with Specific IgA but with IgG4 in both Serum and Saliva.

BACKGROUND: The role of salivary-specific IgG4 and IgA in subcutaneous immunotherapy (SCIT) is not well defined. We aimed to investigate the change of IgG4 and IgA in both serum and saliva and their correlations with IgE-blocking-factor (IgE-BF) during SCIT. METHOD: 307 Dermatophagoides pteronyssinus (DP) allergic rhinitis and/or asthma patients were recruited for this study. 286 patients received DP-SCIT for 1 year. Twenty-one patients received only symptomatic treatment. DP-, Der p 1-, and Der p 2-specific IgE in serum, specific-IgG4 and Der p 2-specific IgA1 and IgA2 in both serum and saliva were measured at timepoints 0, 4, and 12 months during DP-SCIT. Correlation between salivary and serological IgG4, IgA, and their correlation with DP-specific IgE-BF measured in serum was evaluated. RESULTS: During DP-SCIT, the allergen-specific IgG4 in both saliva and serum increased and correlated significantly, the correlation becomes stronger over the treatment time. DP-specific IgE-BF significantly correlated with DP-specific IgG4 in serum (p < 0.0001) at different timepoints and in saliva at 12 months of SCIT (p < 0.01). No change in Der p 2-specific IgA during DP-SCIT was observed, and the IgA in serum did not correlate with IgA in saliva. There was no correlation between DP IgE-BF and Der p 2-specific IgA in serum or saliva. The control group did not exhibit significant changes in any antibody level measured. CONCLUSION: The IgE blocking activity induced by DP-SCIT treatment correlated with specific IgG4 and not IgA. The IgG4 in saliva correlates with serum IgG4 and can be an alternative immunological marker beyond 1 year of SCIT treatment.

An endothelial microRNA-1-regulated network controls eosinophil trafficking in asthma and chronic rhinosinusitis.

BACKGROUND: Airway eosinophilia is a prominent feature of asthma and chronic rhinosinusitis (CRS), and the endothelium plays a key role in eosinophil trafficking. To date, microRNA-1 (miR-1) is the only microRNA known to be regulated in the lung endothelium in asthma models. OBJECTIVE: We sought to determine the role of endothelial miR-1 in allergic airway inflammation. METHODS: We measured microRNA and mRNA expression using quantitative RT-PCR. We used ovalbumin and house dust mite models of asthma. Endothelium-specific overexpression of miR-1 was achieved through lentiviral vector delivery or induction of a transgene. Tissue eosinophilia was quantified by using Congo red and anti-eosinophil peroxidase staining. We measured eosinophil binding with a Sykes-Moore adhesion chamber. Target recruitment to RNA-induced silencing complex was assessed by using anti-Argonaute2 RNA immunoprecipitation. Surface P-selectin levels were measured by using flow cytometry. RESULTS: Serum miR-1 levels had inverse correlations with sputum eosinophilia, airway obstruction, and number of hospitalizations in asthmatic patients and sinonasal tissue eosinophilia in patients with CRS. IL-13 stimulation decreased miR-1 levels in human lung endothelium. Endothelium-specific overexpression of miR-1 reduced airway eosinophilia and asthma phenotypes in murine models and inhibited IL-13-induced eosinophil binding to endothelial cells. miR-1 recruited P-selectin, thymic stromal lymphopoietin, eotaxin-3, and thrombopoietin receptor to the RNA-induced silencing complex; downregulated these genes in the lung endothelium; and reduced surface P-selectin levels in IL-13-stimulated endothelial cells. In our asthma and CRS cohorts, miR-1 levels correlated inversely with its target genes. CONCLUSION: Endothelial miR-1 regulates eosinophil trafficking in the setting of allergic airway inflammation. miR-1 has therapeutic potential in asthmatic patients and patients with CRS.

Impaired barrier function in patients with house dust mite-induced allergic rhinitis is accompanied by decreased occludin and zonula occludens-1 expression.

BACKGROUND: Tight junction (TJ) defects have recently been associated with asthma and chronic rhinosinusitis. The expression, function, and regulation of nasal epithelial TJs remain unknown in patients with allergic rhinitis (AR). OBJECTIVE: We investigated the expression, function, and regulation of TJs in the nasal epithelium of patients with house dust mite (HDM)-induced AR and in an HDM-induced murine model of allergic airway disease. METHODS: Air-liquid interface cultures of primary nasal epithelial cells of control subjects and patients with HDM-induced AR were used for measuring transepithelial resistance and passage to fluorescein isothiocyanate-dextran 4 kDa (FD4). Ex vivo transtissue resistance and FD4 permeability of nasal mucosal explants were measured. TJ expression was evaluated by using real-time quantitative PCR and immunofluorescence. In addition, the effects of IL-4, IFN-γ, and fluticasone propionate (FP) on nasal epithelial cells were investigated in vitro. An HDM murine model was used to study the effects of allergic inflammation and FP treatment on transmucosal passage of FD4 in vivo. RESULTS: A decreased resistance in vitro and ex vivo was found in patients with HDM-induced AR, with increased FD4 permeability and reduced occludin and zonula occludens-1 expression. AR symptoms correlated inversely with resistance in patients with HDM-induced AR. In vitro IL-4 decreased transepithelial resistance and increased FD4 permeability, whereas IFN-γ had no effect. FP prevented IL-4-induced barrier dysfunction in vitro. In an HDM murine model FP prevented the allergen-induced increased mucosal permeability. CONCLUSION: We found impaired nasal epithelial barrier function in patients with HDM-induced AR, with lower occludin and zonula occludens-1 expression. IL-4 disrupted epithelial integrity in vitro, and FP restored barrier function. Better understanding of nasal barrier regulation might lead to a better understanding and treatment of AR.

Effect of curcumin on nasal symptoms and airflow in patients with perennial allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is a common disorder that can significantly affect patient quality of life. Previous studies have found that curcumin had anti-inflammatory and antioxidant effects and clinical benefits in cancer and asthma. OBJECTIVE: To determine the efficacy of curcumin in the treatment of AR and to explore the molecular mechanisms involved. METHODS: In a randomized, double-blind study, 241 patients with AR received either placebo or oral curcumin for 2 months. The therapeutic effects of curcumin were evaluated by nasal symptoms and nasal airflow resistance. In addition, the production of interferon γ, interleukin (IL) 4, IL-10, and tumor necrosis factor α from mononuclear cells and IL-8, soluble intercellular adhesion molecule, polyethylene glycol 2, and leukotriene C4 from polymorphonuclear neutrophils were compared before and after curcumin treatment. RESULTS: Curcumin alleviated nasal symptoms (sneezing and rhinorrhea) and nasal congestion through reduction of nasal airflow resistance. Curcumin was found to exert diverse immunomodulatory effects, including suppression of IL-4, IL-8, and tumor necrosis factor α and increased production of IL-10 and soluble intercellular adhesion molecule. However, curcumin did not affect the release of prostaglandin E2 and leukotriene C4 from polymorphonuclear neutrophils. CONCLUSION: This pilot study provides the first evidence of the capability of curcumin of improving nasal airflow and modulating immune response in patients with AR.

Nasal mucus proteomic changes reflect altered immune responses and epithelial permeability in patients with allergic rhinitis.

BACKGROUND: Nasal mucus is the first-line defense barrier against (aero-) allergens. However, its proteome and function have not been clearly investigated. OBJECTIVE: The role of nasal mucus in the pathophysiology of allergic rhinitis was investigated by analyzing its proteome in patients with allergic rhinitis (n = 29) and healthy control subjects (n = 29). METHODS: Nasal mucus was collected with a suction device, tryptically digested, and analyzed by using liquid chromatography-tandem mass spectrometry. Proteins were identified by searching the SwissProt database and annotated by collecting gene ontology data from databases and existing literature. Gene enrichment analysis was performed by using Cytoscape/BINGO software tools. Proteins were quantified with spectral counting, and selected proteins were confirmed by means of Western blotting. RESULTS: In total, 267 proteins were identified, with 20 (7.5%) found exclusively in patients with allergic rhinitis and 25 (9.5%) found exclusively in healthy control subjects. Five proteins were found to be significantly upregulated in patients with allergic rhinitis (apolipoprotein A-2 [APOA2], 9.7-fold; α2-macroglobulin [A2M], 4.5-fold; apolipoprotein A-1 [APOA1], 3.2-fold; α1-antitrypsin [SERPINA1], 2.5-fold; and complement C3 [C3], 2.3-fold) and 5 were found to be downregulated (antileukoproteinase [SLPI], 0.6-fold; WAP 4-disulfide core domain protein [WFDC2], 0.5-fold; haptoglobin [HP], 0.7-fold; IgJ chain [IGJ], 0.7-fold; and Ig hc V-III region BRO, 0.8-fold) compared with levels seen in healthy control subjects. CONCLUSION: The allergic rhinitis mucus proteome shows an enhanced immune response in which apolipoproteins might play an important role. Furthermore, an imbalance between cysteine proteases and antiproteases could be seen, which negatively affects epithelial integrity on exposure to pollen protease activity. This reflects the important role of mucus as the first-line defense barrier against allergens.

Capsaicin treatment reduces nasal hyperreactivity and transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) overexpression in patients with idiopathic rhinitis.

BACKGROUND: Idiopathic rhinitis (IR) is a prevalent condition for which capsaicin nasal spray is the most effective treatment. However, the mechanisms underlying IR and the therapeutic action of capsaicin remain unknown. OBJECTIVE: We sought to investigate the molecular and cellular bases of IR and the therapeutic action of capsaicin. METHODS: Fourteen patients with IR and 12 healthy control subjects (HCs) were treated with intranasal capsaicin. The therapeutic effect was assessed in patients with IR by using visual analog scale and therapeutic response evaluation scores, and nasal hyperreactivity was evaluated by means of cold dry air provocation. Nasal samples served to measure the levels of neuromediators and expression of chemosensory cation channels, protein gene product 9.5 (PGP 9.5), and the mast cell marker c-kit. The effects of capsaicin were also tested in vitro on human nasal epithelial cells and mast cells. RESULTS: Patients with IR had higher baseline transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) expression in the nasal mucosa and higher concentrations of substance P (SP) in nasal secretions than HCs. Symptomatic relief was observed in 11 of 14 patients with IR after capsaicin treatment. Expression of TRPV1; transient receptor potential cation channel subfamily M, receptor 8 (TRPM8); and PGP 9.5 was only reduced in patients with IR after capsaicin treatment. Capsaicin did not alter c-KIT expression or nasal epithelial morphology in patients with IR and HCs nor did it induce apoptosis or necrosis in cultured human nasal epithelial cells and mast cells. CONCLUSION: IR features an overexpression of TRPV1 in the nasal mucosa and increased SP levels in nasal secretions. Capsaicin exerts its therapeutic action by ablating the TRPV1-SP nociceptive signaling pathway in the nasal mucosa.

Exogenous interleukin-10 alleviates allergic inflammation but inhibits local interleukin-10 expression in a mouse allergic rhinitis model.

BACKGROUND: Interleukin-10 (IL-10) has an important anti-inflammatory and immunoregulatory function, and its expression is negatively correlated with the development and severity of allergic rhinitis (AR). However, the in vivo effects of exogenous IL-10 on AR have not been studied and the mechanisms underlying the effects of IL-10 have not been fully understood. Here, we investigated the effects of intranasal administration of recombinant mouse (rm) IL-10 on the expression of Th responses and local IL-10 in a mouse model of AR induced by ovalbumin. RESULTS: Administration of rmIL-10 during challenge significantly reduced the number of eosinophils and mast cells, as well as Type 2 helper T (Th2) and Th17 cell related cytokine and transcription factor levels in the nasal mucosa and nasal lavage fluid in AR mice. The rmIL-10 treatment significantly inhibited the number of IL-10-positive cells and IL-10 mRNA expression in the nasal mucosa in AR mice. CONCLUSION: Our results show that exogenous IL-10 administrated in challenge phase alleviates nasal allergic inflammation in AR mice, most likely by inhibiting Th2 and Th17 responses. It can also inhibit local IL-10 levels in the nasal mucosa. Our findings indicate that IL-10 may have the potential as an inhibitor of AR.

Differential expression of 11ß-hydroxysteroid dehydrogenase type 1 and 2 in mild and moderate/severe persistent allergic nasal mucosa and regulation of their expression by Th2 cytokines: asthma and rhinitis.

BACKGROUND: Glucocorticoids are used to treat allergic rhinitis, but the mechanisms by which they induce disease remission are unclear. 11ß-hydroxysteroid dehydrogenase (11ß-HSD) is a tissue-specific regulator of glucocorticoid responses, inducing the interconversion of inactive and active glucocorticoids. OBJECTIVE: We analysed the expression and distribution patterns of 11ß-HSD1, 11ß-HSD2, and steroidogenic enzymes in normal and allergic nasal mucosa, and cytokine-driven regulation of their expression. The production levels of cortisol in normal, allergic nasal mucosa and in cultured epithelial cells stimulated with cytokines were also determined. METHODS: The expression levels of 11ß-HSD1, 11ß-HSD2, steroidogenic enzymes (CYP11B1, CYP11A1), and cortisol in normal, mild, and moderate/severe persistent allergic nasal mucosa were assessed by real-time PCR, Western blot, immunohistochemistry, and ELISA. The expression levels of 11ß-HSD1, 11ß-HSD2, CYP11B1, CYP11A1, and cortisol were also determined in cultured nasal epithelial cell treated with IL-4, IL-5, IL-13, IL-17A, and IFN-γ. Conversion ratio of cortisone to cortisol was evaluated using siRNA technique, 11ß-HSD1 inhibitor, and the measurement of 11ß-HSD1 activity. RESULTS: The expression levels of 11ß-HSD1, CYP11B1, and cortisol were up-regulated in mild and moderate/severe persistent allergic nasal mucosa. By contrast, 11ß-HSD2 expression was decreased in allergic nasal mucosa. In cultured epithelial cells treated with IL-4, IL-5, IL-13, and IL-17A, 11ß-HSD1 expression and activity increased in parallel with the expression levels of CYP11B1 and cortisol, but the production of 11ß-HSD2 decreased. CYP11A1 expression level was not changed in allergic nasal mucosa or in response to stimulation with cytokines. SiRNA technique or the measurement of 11ß-HSD1 activity showed that nasal epithelium activates cortisone to cortisol in a 11ß-HSD-dependent manner. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicate that the localized anti-inflammatory effects of glucocorticoids are regulated by inflammatory cytokines, which can modulate the expression of 11ß-HSD1, 11ß-HSD2, and CYP11B1, and by the intracellular concentrations of bioactive glucocorticoids.

Macrophage activation state determines the response to rhinovirus infection in a mouse model of allergic asthma.

BACKGROUND: The mechanisms by which viruses cause asthma exacerbations are not precisely known. Previously, we showed that, in ovalbumin (OVA)-sensitized and -challenged mice with allergic airway inflammation, rhinovirus (RV) infection increases type 2 cytokine production from alternatively-activated (M2) airway macrophages, enhancing eosinophilic inflammation and airways hyperresponsiveness. In this paper, we tested the hypothesis that IL-4 signaling determines the state of macrophage activation and pattern of RV-induced exacerbation in mice with allergic airways disease. METHODS: Eight week-old wild type or IL-4 receptor knockout (IL-4R KO) mice were sensitized and challenged with OVA and inoculated with RV1B or sham HeLa cell lysate. RESULTS: In contrast to OVA-treated wild-type mice with both neutrophilic and eosinophilic airway inflammation, OVA-treated IL-4R KO mice showed increased neutrophilic inflammation with few eosinophils in the airways. Like wild-type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV. There was a shift in lung cytokines from a type 2-predominant response to a type 1 response, including production of IL-12p40 and TNF-α. IL-17A was also increased. RV infection of OVA-treated IL-4R KO mice further increased neutrophilic inflammation. Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40. Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages. CONCLUSIONS: OVA-treated IL-4R KO mice show neutrophilic airway inflammation constituting a model of allergic, type 1 cytokine-driven neutrophilic asthma. In the absence of IL-4/IL-13 signaling, RV infection of OVA-treated mice increased type 1 cytokine and IL-17A production from conventionally-activated macrophages, augmenting neutrophilic rather than eosinophilic inflammation. In mice with allergic airways inflammation, IL-4R signaling determines macrophage activation state and the response to subsequent RV infection.

Altered microRNA expression of nasal mucosa in long-term asthma and allergic rhinitis.

BACKGROUND: Asthma and allergic rhinitis (AR) commonly coexist and can be taken as manifestations of one syndrome. Evidence exists that microRNAs (miRNAs) are important in controlling inflammatory processes and they are considered promising biomarkers. However, little is known about the differences in miRNA expression in patients with chronic allergic airway disease. This study evaluated the inflammatory and miRNA profiles of the nasal mucosa of patients with long-term asthma with and without AR. METHODS: We analyzed inflammatory cells, cytokines, and miRNAs in nasal biopsies and measured exhaled and nasal nitric oxide levels during the nonpollen season in 117 middle-aged men who had suffered mainly from allergic asthma for approximately 20 years and also in 33 healthy controls. RESULTS: The differences in the number of nasal eosinophils and cytokine expression levels were modest in nasal biopsies taken from asthmatics. Downregulation of miR-18a, miR-126, let-7e, miR-155, and miR-224 and upregulation of miR-498, miR-187, miR-874, miR-143, and miR-886-3p were observed in asthmatic patients in comparison to controls. The differences in miRNA expression were mainly similar in asthmatics with and without AR. With regard to asthma severity, a trend of increased miRNA expression in persistent asthma was seen, whereas the downregulation of certain miRNAs was most distinct in nonpersistent-asthma patients. CONCLUSIONS: Differences in miRNA expression in the nasal mucosa of subjects with long-term asthma and AR can be seen also when no markers of Th2-type inflammation are detected. Asthma severity had only a minor impact on miRNA expression.

Work-related airway symptoms, nasal reactivity and health-related quality of life in female hairdressers: a follow-up study during exposure.

OBJECTIVES: Hairdressers often complain of work-related rhinitis (WR). They are infrequently sensitized to persulphates. The cause and mechanism of the symptoms and the effects on their health-related quality of life (HRQoL) remains unclear. The objectives were to follow female hairdressers with WR mainly from bleaching powder regarding nasal reactivity to persulphate and to evaluate symptoms, HRQoL and inflammatory markers in nasal lavage during a working period after vacation and compared with hairdressers without symptoms and pollen allergic women. METHODS: Skin prick tests to persulphate were performed in the hairdressers. Participants kept a diary of symptoms and of work tasks (hairdressers only). They completed HRQoL questionnaires. Eosinophil cationic protein (ECP) in nasal lavage fluid was examined. The symptomatic hairdressers performed nasal challenges with persulphate before and after the exposure. RESULTS: Skin prick tests were negative. Although the nasal reactivity to persulphate did not change a steady increase in nasal symptoms, especially blockage, and in ECP was noticed in the symptomatic hairdressers. The HRQoL deteriorated in the symptomatic hairdressers indicating an effect on their working situation and daily life. The atopics had more, but varying symptoms (itching, sneezing and secretion). CONCLUSIONS: The difference in the clinical picture between the symptomatic hairdressers and the pollen allergic women, the increase in symptoms and ECP in the nasal lavage support the view that a sensitization to hairdresser chemicals by a mechanism not yet understood is operating. The deterioration of the HRQoL in the symptomatic hairdressers indicates a considerable effect on their life.

Mono-allergic and poly-allergic rhinitis patients have comparable numbers of mucosal Foxp3+CD4+ T lymphocytes.

BACKGROUND: We previously found that allergic rhinitis patients with an isolated pollen sensitization responded more strongly to a nasal provocation with grass pollen (GP) than patients who had an additional house dust mite (HDM) sensitization. To elucidate this phenomenon, we investigated the dynamics of Foxp3+CD4+ T lymphocytes in allergic rhinitis patients with distinct allergen sensitizations. METHODS: Three groups of allergic rhinitis patients with skin prick test confirmed allergic sensitizations were investigated and compared to 14 healthy controls: 14 subjects with an isolated grass pollen sensitization (Mono-GP); 9 subjects with isolated housedust mite sensitization (Mono-HDM); 29 subjects with grass pollen and house dust mite sensitization (poly-sensitized). Subjects in the Mono-GP group were challenged with grass pollen extract, subjects in the Mono-HDM group were challenged with house dust mite extract, subjects in the poly-sensitized group and the healthy controls were randomly challenged with either grass pollen or house dust mite. Nasal biopsies were taken before and after nasal provocation. We compared the distribution of FoxP3+CD4+ cells in nasal biopsies before and after nasal provocation using immunohistochemistry. RESULTS: There was no difference in the number of FoxP3+CD4+ cells between healthy and the three allergic groups at baseline.Nasal provocation did result in an increase in eosinophils in the three allergic groups, but did not result in a change in the number of FoxP3+CD4+ cells in any of the groups or induced differences between any of the groups. CONCLUSION: Clinical differences in the response between mono-GP and multiple-sensitized allergic individuals are not related to differences in the number of regulatory T cells in the nasal mucosa.

Japanese traditional medicine, Senn-kinn-naidaku-sann up-regulates Toll-like receptor 4 and reduces murine allergic rhinitis.

OBJECTIVE: To determine the mechanisms by which a traditional herbal medicine, Senkinnaidakusan (SKNS), controls Th2 responses, we examined the production of IL-12 by murine macrophages treated with SKNS. RESULTS: Treatment with SKNS significantly increased TLR4 mRNA in macrophages. Furthermore, pre-treatment with SKNS enhanced the production of IL-12 by macrophages stimulated with LPS. When SKNS was orally administered to C3H/HeN mice at the induction phase after OVA sensitization, the serum levels of OVA-specific immunoglobulin (Ig)E and IgG1 decreased, Interleukin (IL)-4 production by spleen T cells in response to OVA was significantly suppressed, while interferon (IFN)-gamma production was increased. After nasal challenge of OVA, eosinophilic infiltration in the nasal mucosa and the number of sneezes were significantly inhibited in SKNS-treated mice compared with control mice. Besides, expression of IL-5 in the nasal mucosa was also inhibited. Using another strain of mice, C3H/HeJ (TLR4 negative), there was no difference in OVA-specific Igs or splenic cytokine production between the SKNS treatment and non-treatment groups. The eosinophilic infiltration in the nasal mucosa, the number of sneezes and IL-5 expression in the nasal mucosa were also not effected even after SKNS treatment. CONCLUSION: These results suggest that oral administration of SKNS inhibits Th2 responses by enhancement of IL-12 release from macrophages via up-regulation of TLR4 expression.

Distinct TLR-mediated pathways regulate house dust mite-induced allergic disease in the upper and lower airways.

BACKGROUND: Allergic rhinitis (AR) and asthma are 2 entities of allergic airway diseases that frequently occur together, which is referred to as united airways. In contrast to this general concept, we hypothesized that innate immunity of the upper and lower airways is respectively distinctive, because the immunologic conditions of the nasal and lung mucosa as well as the functions of the immune cells within their epithelia are different. OBJECTIVE: We wanted to identify distinctive mechanisms of innate immunity in the nose and lung mucosa, which are responsible for house dust mite (HDM)-induced AR and allergic asthma (AA), respectively. METHODS: We constructed a mouse model of AR or AA induced by sensitization and consequent provocation with HDM extracts. RESULTS: HDM-derived ß-glucans, rather than LPS, were proven to be essential to activating innate immunity in the nasal mucosa and triggering AR, which depended on Toll-like receptor 2 (TLR2), but not on TLR4; however, the LPS/TLR4 signaling axis, rather than ß-glucans/TLR2, was critical to HDM-induced AA. These differences were attributed to the specific role of ß-glucans and LPS in inducing the surface expression of TLR2 and TLR4 and their translocation to lipid rafts in nasal and bronchial epithelial cells, respectively. We also showed that dual oxidase 2-generated reactive oxygen species mediate both ß-glucan-induced TLR2 activation and LPS-induced TLR4 activation. CONCLUSIONS: We describe a novel finding of distinctive innate immunity of the nose and lungs, respectively, which trigger AR and AA, by showing the critical role of HDM-induced TLR activation via dual oxidase 2-mediated reactive oxygen species.

Characterisation of CD154+ T cells following ex vivo allergen stimulation illustrates distinct T cell responses to seasonal and perennial allergens in allergic and non-allergic individuals.

BACKGROUND: Allergic sensitisation has been ascribed to a dysregulated relationship between allergen-specific Th1, Th2 and regulatory T cells. We sought to utilise our short-term CD154 detection method to further analyse the relationship between these T cell subsets and investigate differences between seasonal and perennial allergens. Using peripheral blood samples from grass-allergic, cat-allergic and healthy non-atopic subjects, we compared the frequencies and phenotype of CD154-positive T helper cells following stimulation with seasonal (grass) and perennial (cat dander) allergens. RESULTS: We identified a higher frequency of CD154+ T cells in grass-allergic individuals compared to healthy controls; this difference was not evident following stimulation with cat allergen. Activated Th1, Th2 and Tr1-like cells, that co-express IFNγ, IL4 and IL10, respectively, were identified in varying proportions in grass-allergic, cat-allergic and non-allergic individuals. We confirmed a close correlation between Th1, Th2 and Tr1-like cell frequency in non-allergic volunteers, such that the three parameters increased together to maintain a low Th2: Th1 ratio. This relationship was dysregulated in grass-allergic individuals with no correlation between the T cell subsets and a higher Th2: Th1 ratio. We confirmed previous reports of a late-differentiated T cell phenotype in response to seasonal allergens compared to early-differentiated T cell responses to perennial allergens. CONCLUSIONS: The findings confirm our existing work illustrating an important balance between Th1, Th2 and Tr1-like responses to allergens in health, where Th2 responses are frequently observed, but balanced by Th1 and regulatory responses. We confirm previous tetramer-based reports of phenotypic differences in T cells responding to seasonal and perennial allergens.

Eosinophil recruitment to nasal nerves after allergen challenge in allergic rhinitis.

In allergen challenged animal models, eosinophils localize to airway nerves leading to vagally-mediated hyperreactivity. We hypothesized that in allergic rhinitis eosinophils recruited to nasal nerves resulted in neural hyperreactivity. Patients with persistent allergic rhinitis (n=12), seasonal allergic rhinitis (n=7) and controls (n=10) were studied. Inferior nasal turbinate biopsies were obtained before, 8 and 48h after allergen challenge. Eight hours after allergen challenge eosinophils localized to nerves in both rhinitis groups; this was sustained through 48h. Bradykinin challenge, with secretion collection on the contralateral side, was performed to demonstrate nasal nerve reflexes. Twenty fourhours after allergen challenge, bradykinin induced a significant increase in secretions, indicating nasal hyperreactivity. Histological studies showed that nasal nerves expressed both vascular cell adhesion molecule-1 (VCAM-1) and chemokine (C-C motif) ligand 26 (CCL-26). Hence, after allergen challenge eosinophils are recruited and retained at nerves and so may be a mechanism for neural hyperreactivity.

Nasal levels of soluble IL-33R ST2 and IL-16 in allergic rhinitis: inverse correlation trends with disease severity.

BACKGROUND: Serum levels of IL-16, IL-33 and the decoy receptor of IL-33, soluble ST2, are elevated in allergic rhinitis. Recent studies show that IL-16, soluble ST2 or anti-IL-33 reduce type 2 cytokines (such as IL-5) and eosinophilia in murine models of allergic asthma or allergic rhinitis respectively. OBJECTIVE: In this study, we studied the release of IL-5, IL-16, IL-33 and soluble ST2 in allergic rhinitis patients after nasal allergen challenge and natural pollen exposure. METHODS: The nasal lavages of 15 allergic and 14 non-allergic volunteers were collected during the pollen allergy season. In addition, six allergic volunteers underwent unilateral nasal allergen and control challenge out of season and nasal secretions and sera were collected. IL-5, IL-16, IL-33 and soluble ST2 in nasal secretions and sera were measured by electrochemiluminescent assay or ELISA, respectively. RESULTS: Nasal IL-5, IL-16 and soluble ST2 levels were significantly increased in seasonally pollen exposed allergic volunteers compared to control subjects (P < 0.001, P = 0.018 and P = 0.002 respectively), whereas IL-33 remained undetectable. Nasal IL-16 showed a weak inverse correlation trend with nasal symptoms (r = -0.48, P = 0.07). Nasal soluble ST2 concentrations were inversely correlated with nasal symptoms (r = -0.61, P = 0.02) and positively correlated with IL-16 (r = 0.56, P = 0.03). Significant increases of nasal IL-5, IL-16 and ST2 but not IL-33 were observed after nasal allergen challenge. At 24 h after allergen challenge, local ST2 and IL-5 concentrations showed an inverse correlation trend (r = -0.83, P = 0.04). Serum levels of IL-5, IL-16 and soluble ST2 rose in at least five of six volunteers tested at 5 or 24 h post-challenge. CONCLUSIONS AND CLINICAL RELEVANCE: The observed upregulation of soluble ST2 and IL-16 after nasal allergen challenge and during peak pollination season suggests potential regulatory roles of these cytokines in the inflammatory reaction in allergic rhinitis.

Immunomodulatory effects of IL-23 and IL-17 in a mouse model of allergic rhinitis.

BACKGROUND: Interleukin-23 (IL-23) and IL-17 may be involved in the pathogenesis of allergic rhinitis (AR). However, a differentiation of the role of IL-23 and IL-17 has not been performed yet. OBJECTIVE: The aim of this study was therefore to investigate the immunomodulatory effects of IL-23 and IL-17, using a mouse model of AR. METHODS: Anti-IL-23p19 and anti-IL-17 Abs were administrated intranasally during rechallenge in ovalbumin (OVA)-induced AR in BALB/c mice. Immunomodulatory effects were evaluated by measuring nasal rubbing and sneezing occurrences, serum OVA-specific antibodies, Th2 responses (i.e. expression of IL-4, IL-5, IL-13 and IFN-γ genes in nasal mucosa, IL-4(+) CD4(+) T cells percentages in superficial cervical lymph nodes (LNs) and IL-4 production in LNs stimulated with OVA in vitro), and neutrophil, eosinophil and mast cell recruitment into the nasal mucosa. RESULTS: The effect of IL-17 antagonism was limited to attenuating the Th2 responses and neutrophil and eosinophil infiltration. In contrast, treatment with anti-IL-23p19 Abs markedly reduced nasal rubbing and sneezing events, Th2 responses, serum OVA-specific IgE and IgG1 levels, as well as mucosal neutrophil, eosinophil and mast cell infiltration. CONCLUSION AND CLINICAL RELEVANCE: IL-17 and IL-23 may play a pathogenic role in an established AR mouse model; with a more pronounced contribution of IL-23 than IL-17.

Aberrant dendritic cell function conditions Th2-cell polarization in allergic rhinitis.

BACKGROUND: Myeloid (m) and plasmacytoid (p) dendritic cells (DCs) regulate immune responses to allergens, whereas it remains unclear whether abnormal DC function characterizes patients with airway allergy and whether putative dysfunction exists only in target organs. To evaluate DC function from patients with allergic rhinitis (AR), we assessed nasal, cutaneous as well as blood DCs after in vivo and in vitro allergen challenge, respectively. METHODS: DCs were immunostained in nasal and skin tissues, and cytokine expression was assessed by dual immunofluorescence. Cytokine production and regulation of cocultured peripheral CD4+ T cells were assayed by ELISA. RESULTS: In AR patients, local allergen challenge resulted in increases in pDC and mDC numbers at 8 h in the nasal mucosa and at 8-48 h in the skin. Defects in IL-10 and IFN-α were observed in both organs from AR. Blood mDCs from AR exhibited reduced IL-10 and IL-12 expression. The capacity of activated pDCs from AR to produce IFN-α and to trigger IL-10 by allogeneic CD4(+) T cells was diminished, whereas mDCs from these patients supported Th2- and Th17-cell differentiation. CONCLUSION: In allergic rhinitis, DCs are altered not only locally but also in the systemic circulation. mDCs and pDCs increased in airway and skin tissues exposed to the allergen and displayed reduced production of IL-10 and 'type 1 signals' (IL-12, IFN-α) both locally and in blood. Functional studies showed that this results in preferential Th2/Th17-cell polarization and impaired generation by blood DCs of IL-10+ T cells, linking systemic DC dysfunction and biased T-cell responses.

Downregulation of polymeric immunoglobulin receptor and secretory IgA antibodies in eosinophilic upper airway diseases.

BACKGROUND: Immunoglobulin (Ig) A represents a first-line defence mechanism in the airways, but little is known regarding its implication in upper airway disorders. This study aimed to address the hypothesis that polymeric Ig receptor (pIgR)-mediated secretory IgA immunity could be impaired in chronic upper airway diseases. METHODS: Nasal and ethmoidal biopsies, as well as nasal secretions, were collected from patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) or without nasal polyps (CRSsNP), allergic rhinitis (AR) and controls, and assayed for IgA1/IgA2 synthesis, pIgR expression, production of secretory component (SC), IgA and relevant IgA antibodies, and correlated with local eosinophils and inflammatory features (IL-12, IL-13 and ECP). RESULTS: pIgR expression was decreased in the ethmoidal mucosa in patients with CRSwNP (P = 0.003) and in AR (P = 0.006). This pIgR defect was associated with reduced levels of SC (P = 0.007) and IgA antibodies to Staphylococcus aureus enterotoxin B (SAEB) (P = 0.003) in nasal secretions from patients with CRSwNP, and with increased IgA deposition in subepithelial areas. pIgR downregulation was selectively observed in patients with tissue eosinophilia, whilst no clear relation to smoking history was observed. CONCLUSION: Epithelial pIgR expression is decreased in patients with CRSwNP and AR and results in decreased SC and IgA antibodies to certain bacterial antigens (SAEB) in nasal secretions of patients with CRSwNP in parallel to subepithelial accumulation of IgA. This defect in mucosal immunity is associated with eosinophilic, Th2-related inflammation.