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Background: Mucin over‐secretion is a significant characteristic of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to investigate the relationship between Th2 cytokines and MUC5AC or MUC5B, and the mechanism of mucin over‐secretion in the type‐2 inflammatory endotype of CRSwNP. Methods: Main Th‐cell cytokines, associated mediators, and mucins were determined in the homogenates of nasal polyp samples from 21 CRSwNP patients and inferior turbinate samples from 8 controls, by ELISA or UniCAP system. Secretion of MUC5AC and MUC5B was measured in the supernatants of IL‐5, IL‐4, or IL‐13 primed nasal polyp fragments. Co‐localization of MUC5AC, MUC5B, and IL‐4 receptor α (IL‐4Rα) in CRSwNP and controls was evaluated by immunohistochemistry. Gene expression of IL‐4Rα in the samples was measured by real‐time reverse transcription‐polymerase chain reaction. Results: Baseline protein levels of the Th2‐cytokines IL‐4, IL‐5, and IL‐13, and mucins MUC5AC and MUC5B were significantly higher in the IL‐5(+) CRSwNP group, compared to control and IL‐5(−) CRSwNP groups. MUC5AC and MUC5B secretions were significantly increased in IL‐4‐ or IL‐13‐primed, but not IL‐5‐primed fragments of nasal polyps. Immuno‐stained serial sections demonstrated that IL‐4Rα was widely expressed in the epithelium and submucosal glands in control and nasal polyp tissues. Gene expression of IL‐4Rα was elevated in nasal polyp tissues, specifically in the IL‐5(+) CRSwNP group. Conclusions: In type‐2 inflammatory nasal polyps, characterized by the tissue expression of IL‐5, MUC5AC and MUC5B are overexpressed. Both IL‐4 and IL‐13 may upregulate mucin expression via IL‐4Rα, which is also overexpressed in IL‐5(+) CRSwNP. The highlight of this study lies in the finding that Th2 inflammatory patterns are strongly related to mucin hypersecretion in endotypes of CRSwNP defined by IL‐5. In the present study, we found that IL‐4, IL‐13, MUC5AC and MUC5B were overexpressed in IL‐5(+) CRSwNP. Th2 associated mediators IgE and ECP were significantly increased in IL‐5(+) CRSwNP as well and intimately corelated to mucin hypersecretion. Both IL‐4 and IL‐13 may upregulate mucin expression via their common receptor, IL‐4Rα, which is also overexpressed in IL‐5(+) CRSwNP. [ABSTRACT FROM AUTHOR]

Background Staphylococcal enterotoxin B ( SEB) is a superantigen known to be a modulator of chronic airway inflammation in mice and humans, yet little is known about the mechanisms that regulate its interaction with the innate immune system. We investigated this mechanism in a murine model of allergic airway inflammation induced by OVA (ovalbumin) in the presence of SEB. Methods Superantigen-induced allergic inflammation was studied in IL-1R knockout ( KO) mice exposed to OVA+ SEB. Multicolor flow cytometry was used to analyze the inflammatory cell profile in airways and lymph nodes. Production of IL-4, IL-5, IL-10, and IL-13 in lymph nodes was assessed by Luminex technology. Results In wild-type mice, endonasal instillation of OVA+ SEB induced a pulmonary inflammation, characterized by an increase in the number of eosinophils, T cells, and dendritic cells and in the production of Th2 cytokines and OVA-specific Ig E. In IL-1 R KO mice exposed to OVA+ SEB, attraction of CD4+ cells and production of Th2 cytokines were reduced. However, knocking out IL-1 R did not affect any of the features of allergic airway inflammation, such as bronchial eosinophilia, OVA-specific IgE production and goblet cell metaplasia. Conclusion We provide new insights into the mechanisms of airways allergy development in the presence of bacterial superantigen. The asthma features induced by OVA+ SEB, such as bronchial eosinophilia, goblet cell proliferation, production of OVA-specific IgE and increase in inflammatory dendritic cells, are IL-1 R independent. Yet, IL-1 R signaling is crucial for CD4 cell accumulation and Th2 cytokine production. [ABSTRACT FROM AUTHOR]

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by biased Th2 inflammation and CRS without nasal polyps (CRSsNP) by a Th1 immune response. Colonization by Staphylococcus aureus is increased in CRSwNP. We aimed to determine macrophage phenotypes in nasal mucosa of CRSwNP and CRSsNP and to examine phagocytosis of S. aureus in these pathologies. Methods: Macrophage phenotyping was performed by immunohistochemical staining on nasal mucosa sections from 28 patients; in addition flow cytometry analysis was performed. Tissue homogenate protein levels of IFN-γ, IL-5, IL-6, IL-1β, TGF-β, eosinophil cationic protein (ECP) and total IgE were analyzed and correlated with macrophage subtypes. Phagocytosis of S. aureus was analyzed by flow cytometry. Survival of S. aureus in Thp1 cells in the presence of polarizing cytokines was studied in vitro. Results: By immunohistochemical analysis more M2 macrophages were present in CRSwNP than in CRSsNP. This also was positively correlated with increased levels of IL-5, ECP and locally produced IgE and decreased levels of IL-6, IL-1β and IFN-γ. FACS analysis of dissociated nasal tissue confirmed the presence of increased numbers of M2 macrophages (CD206+HLADR+CD14+CD11c+CD20-) in CRSwNP as compared to controls, while the number of M1 macrophages (CD206-HLADR+CD14+CD11cintCD16-CD20-) was not different. Phagocytosis of S. aureus by human tissue derived macrophages was reduced in CRSwNP as compared to macrophages from the control inferior turbinates. Conclusions: Decreased phagocytosis of S. aureus and an M2 activation phenotype in CRSwNP could potentially contribute to persistence of chronic inflammation in CRSwNP. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus may modify airway disease by inducing local formation of polyclonal IgE antibodies (abs), the role of which is unknown. Methods: Nasal mucosal tissue and serum was obtained from 12 allergic rhinitis (AR) and 14 nasal polyp (NP) subjects. Skin prick tests were performed, and total and specific IgE abs to inhalant allergens and enterotoxin B were determined in serum and tissue. Tissue fragments were stimulated with anti-IgE, enterotoxin B, or grass and house dust mite allergens in different concentrations for 30 min. RBL SX38 cells were sensitized with NP homogenates containing IgE and stimulated with grass pollen extracts. Results: In AR patients, degranulation of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens corresponded in almost all cases. Total IgE concentrations in serum and mucosal tissue homogenates highly correlated. In contrast, in NP patients, reactivity of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens or Staphylococcus aureus enterotoxin B corresponded for tissue, but not for serum. Total IgE was significantly higher in tissue compared to serum and failed to show correlation. Tissue IgE to grass pollen was functional to degranulate RBL cells. Conclusion: We here demonstrate that mucosal IgE abs in NP tissue are functional and able to activate mast cells; specific IgE abs in NP tissue can be found independently of their presence in serum. We postulate that superantigen-induced polyclonal IgE in airway disease contributes to chronic inflammation by continuously activating mast cells. [ABSTRACT FROM AUTHOR]

To cite this article: Pérez- Novo CA, Holtappels G, Vinall SL, Xue L, Zhang N, Bachert C, Pettipher R. CRTH2 mediates the activation of human Th2 cells in response to PGD2 released from IgE/anti-IgE treated nasal polyp tissue. Allergy 2010; 65: 304–310. Background: Mast cells release mediators upon stimulation that contribute to the pathogenesis of chronic airway disease, including the recruitment and activation of Th2 lymphocytes. The objective was to determine the involvement of prostaglandin D2 (PGD2) and its receptors in the chemotaxis of Th2 cells, using nasal polyp tissue. Methods: Tissue explants from ten patients with nasal polyposis were incubated with RPMI alone or RPMI containing IgE/anti-IgE for 30 min. Some samples were treated with diclofenac to inhibit the production of PGD2. Supernatants were assayed for PGD2 content and for their ability to promote human Th2 cell chemotaxis in the presence and absence of a CRTH2 antagonist. Transcript levels of D protanoid receptor type 1 (DP1), chemoattractant receptor-homologous receptor expressed on Th2 cells (CRTH2) and PGD2 synthase were analysed by real time PCR. Results: Increased release of PGD2 by nasal polyp tissue treated with IgE/anti-IgE was significantly inhibited by preincubation of the tissue with diclofenac. Transcript levels of PGD2 synthase, DP1 and CRTH2 receptors increased after stimulation with IgE/anti-IgE. Supernatants from IgE/anti-IgE-stimulated nasal polyp tissue caused significantly increased chemotaxis of Th2 cells. The levels of PGD2 produced and the degree of Th2 cell chemotaxis were highly correlated. Diclofenac inhibited the production of Th2 cell chemotactic activity, and the chemotactic effect of the supernatant on Th2 cells was inhibited by the CRTH2 antagonist ramatroban. Conclusion: These data suggest that in immunologically activated nasal polyp tissue, PGD2 produced by mast cells promotes the migration of Th2 cells through a CRTH2 dependent mechanism. [ABSTRACT FROM AUTHOR]

Bilateral nasal polyposis (NP) is characterized by high concentrations of IgE in NP tissue, which show no relation to the atopic status. We aimed to study the relationship between systemic and local IgE formation, nasal carriage ofStaphylococcus aureusand nasal polyposis.In serum and nasal tissue homogenates from 24 NP patients and 12 controls, we determined concentrations of total IgE and IgE antibodies to inhalant allergens andS. aureusenterotoxins (SAEs; A,B,C,D,E,TSST) by ImmunoCAP. Tissue cryosections were stained for CD3, CD20, CD38, CD23, FcεRI, IgE and SEA/SEB.We demonstrated a higher incidence ofS. aureuscolonization (17/24) and IgE antibodies to SAEs in NP tissue (12/24) compared with controls (3/12 and 0/12, respectively). Total IgE and IgE antibodies in serum and NP tissue were dissociated because of local polyclonal IgE formation in NP tissue. Staining of NP tissue revealed follicular structures characterized by B and T cells, and lymphoid accumulations with diffuse plasma cell infiltration.We demonstrated the organization of secondary lymphoid tissue in polyp tissue and a polyclonal hyper-immunoglobulinemia E associated with the presence of IgE antibodies to SAEs, colonization withS. aureus, and tissue eosinophilia in a relevant subgroup of polyp patients. [ABSTRACT FROM AUTHOR]

Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a type 2-mediated inflammatory disease associated with significant clinical, social, and economic burdens and high unmet therapeutic need. Dupilumab, a fully human monoclonal antibody targeting the interleukin-4 receptor α (IL-4Rα) subunit, demonstrated efficacy and acceptable safety in CRSwNP and other type 2 diseases (eg, atopic dermatitis and asthma). We now report the local effects of dupilumab on type 2 inflammatory biomarkers in nasal secretions and nasal polyp tissues of patients with CRSwNP in a randomized, placebo-controlled, phase 2 trial (NCT01920893)., Methods: Cytokines, chemokines, and total immunoglobulin E (IgE) levels were measured using immunoassay techniques in nasal secretions and nasal polyp tissue homogenates of CRSwNP patients receiving dupilumab 300 mg or placebo weekly for 16 weeks., Results: With dupilumab, type 2 biomarker concentrations decreased in nasal secretions (least squares mean area under the curve from 0 to 16 weeks for the change from baseline) vs placebo for eotaxin-3 (-30.06 vs -0.86 pg/mL; P = 0.0008) and total IgE (-7.90 vs -1.86 IU/mL; P = 0.022). Dupilumab treatment also decreased type 2 biomarker levels in nasal polyp tissues at Week 16 vs baseline for eosinophilic cationic protein (P = 0.008), eotaxin-2 (P = 0.008), eotaxin-3 (P = 0.031), pulmonary and activation-regulated chemokine (P = 0.016), IgE (P = 0.023), and IL-13 (P = 0.031)., Conclusions: Dupilumab treatment reduced multiple biomarkers of type 2 inflammation in nasal secretions and polyp tissues of patients with CRSwNP, demonstrating that antagonism of IL-4Rα signaling suppresses IL-4-/IL-13-dependent processes, such as mucosal IgE formation, as well as the expression of chemokines attracting inflammatory cells to the nasal mucosa., (© 2018 The Authors. Allergy Published by John Wiley & Sons Ltd.)