The significant expression of TRPV3 in nasal polyps of eosinophilic chronic rhinosinusitis

BACKGROUND

The number of patients with eosinophilic chronic rhinosinusitis (ECRS) has been increasing in recent years in Japan. In ECRS, nasal polyps recur immediately after endoscopic sinus surgery. The molecular biological mechanism underlying the refractoriness of ECRS is unclear.

METHODS

Whole-transcriptome analysis with next-generation sequencing (RNA-seq) was conducted to investigate the molecular biological mechanism of ECRS. Real-time PCR, immunohistochemical staining, and immunofluorescence staining were performed to validate the results of RNA-seq.

RESULTS

RNA-seq analysis revealed that in the nasal polyps of ECRS, the levels of 3 transcripts were elevated significantly and those of 7 transcripts were diminished significantly. Among the genes encoding these transcripts, TRPV3 (transient receptor potential cation channel, subfamily V, member 3) was identified as the only gene that is highly expressed in ECRS nasal polyps but this gene's expression was not previously detected using DNA microarray analysis in peripheral blood eosinophils. TRPV3 is newly identified here as a gene transcribed in ECRS. Our analysis also revealed that TRPV3 was highly expressed in the infiltrating eosinophils and mucosal epithelium of the nasal polyps of ECRS, and further that the more severe the refractoriness was after surgery, the higher the TRPV3 expression was in nasal polyps.

CONCLUSIONS

TRPV3 might play a role in the refractoriness of ECRS. Additional studies are required to evaluate the function of TRPV3 in ECRS.

Nattokinase, profibrinolytic enzyme, effectively shrinks the nasal polyp tissue and decreases viscosity of mucus

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is often comorbid with asthma and resistant to therapeutic interventions. We recently reported that excessive fibrin deposition caused by impairment of fibrinolysis might play pivotal role in forming nasal polyp. Nattokinase (NK), a serine protease produced by Bacillus subtilis, has been reported to be a strong fibrinolytic enzyme. NK could be a promising drug candidate for use in the treatment of both CRSwNP and asthma. The objective of this study was to investigate the effects of NK on nasal polyp tissues from patients with CRSwNP. The nasal discharge from patients with CRSwNP and sputum from subjects with asthma were also used to investigate whether NK influences the viscosity of mucus.

METHODS

To examine the effects on NK on nasal polyp tissues, pieces of nasal polyps were incubated either with saline or NK (10-1000 FU/ml) at 37 °C for 24 h. We assessed the presence of fibrin in nasal polyp tissue incubated with NK by means of immunohistochemistry. To examine the effects of NK on nasal discharge and sputum from patients with CRSwNP and asthma, respectively, were incubated with NK solution at 37 °C for 1 h.

RESULTS

NK effectively shrinks the nasal polyp tissue through fibrin degradation. We also found that the viscosity of the nasal discharge and sputum from patients with CRSwNP and asthma, respectively, was significantly reduced by incubation with NK solution.

CONCLUSIONS

NK may be an effective alternative therapeutic option in patients with CRSwNP and comorbid asthma by causing fibrin degradation.

Neutrophils are a major source of the epithelial barrier disrupting cytokine oncostatin M in patients with mucosal airways disease

BACKGROUND

We have previously shown that oncostatin M (OSM) levels are increased in nasal polyps (NPs) of patients with chronic rhinosinusitis (CRS), as well as in bronchoalveolar lavage fluid, after segmental allergen challenge in allergic asthmatic patients. We also showed in vitro that physiologic levels of OSM impair barrier function in differentiated airway epithelium.

OBJECTIVE

We sought to determine which hematopoietic or resident cell type or types were the source of the OSM expressed in patients with mucosal airways disease.

METHODS

Paraffin-embedded NP sections were stained with fluorescence-labeled specific antibodies against OSM, GM-CSF, and hematopoietic cell-specific markers. Live cells were isolated from NPs and matched blood samples for flow cytometric analysis. Neutrophils were isolated from whole blood and cultured with the known OSM inducers GM-CSF and follistatin-like 1, and OSM levels were measured in the supernatants. Bronchial biopsy sections from control subjects, patients with moderate asthma, and patients with severe asthma were stained for OSM and neutrophil elastase.

RESULTS

OSM staining was observed in NPs, showed colocalization with neutrophil elastase (n = 10), and did not colocalize with markers for eosinophils, macrophages, T cells, or B cells (n = 3-5). Flow cytometric analysis of NPs (n = 9) showed that 5.1% ± 2% of CD45+ cells were OSM+, and of the OSM+ cells, 56% ± 7% were CD16+Siglec-8-, indicating neutrophil lineage. Only 0.6 ± 0.4% of CD45+ events from matched blood samples (n = 5) were OSM+, suggesting that increased OSM levels in patients with CRS was locally stimulated and produced. A majority of OSM+ neutrophils expressed arginase 1 (72.5% ± 12%), suggesting an N2 phenotype. GM-CSF levels were increased in NPs compared with those in control tissue and were sufficient to induce OSM production (P < .001) in peripheral blood neutrophils in vitro. OSM+ neutrophils were also observed at increased levels in biopsy specimens from patients with severe asthma. Additionally, OSM protein levels were increased in induced sputum from asthmatic patients compared with that from control subjects (P < .05).

CONCLUSIONS

Neutrophils are a major source of OSM-producing cells in patients with CRS and severe asthma.

Proprotein convertases generate a highly functional heterodimeric form of thymic stromal lymphopoietin in humans

RATIONALE

Thymic stromal lymphopoietin (TSLP) is known to be elevated and truncated in nasal polyps (NPs) of patients with chronic rhinosinusitis and might play a significant role in type 2 inflammation in this disease. However, neither the structure nor the role of the truncated products of TSLP has been studied.

OBJECTIVE

We sought to investigate the mechanisms of truncation of TSLP in NPs and the function of the truncated products.

METHODS

We incubated recombinant human TSLP with NP extracts, and determined the protein sequence of the truncated forms of TSLP using Edman protein sequencing and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. We investigated the functional activity of truncated TSLP using a PBMC-based bioassay.

RESULTS

Edman sequencing and mass spectrometry results indicated that NP extracts generated 2 major truncated products, TSLP (residues 29-124) and TSLP (131-159). Interestingly, these 2 products remained linked with disulfide bonds and presented as a dimerized form, TSLP (29-124 + 131-159). We identified that members of the proprotein convertase were rate-limiting enzymes in the truncation of TSLP between residues 130 and 131 and generated a heterodimeric unstable metabolite TSLP (29-130 + 131-159). Carboxypeptidase N immediately digested 6 amino acids from the C terminus of the longer subunit of TSLP to generate a stable dimerized form, TSLP (29-124 + 131-159), in NPs. These truncations were homeostatic but primate-specific events. A metabolite TSLP (29-130 + 131-159) strongly activated myeloid dendritic cells and group 2 innate lymphoid cells compared with mature TSLP.

CONCLUSIONS

Posttranslational modifications control the functional activity of TSLP in humans and overproduction of TSLP may be a key trigger for the amplification of type 2 inflammation in diseases.

Chronic airway inflammation provides a unique environment for B cell activation and antibody production

BACKGROUND

B cells play many roles in health and disease. However, little is known about the mechanisms that drive B cell responses in the airways, especially in humans. Chronic rhinosinusitis (CRS) is an inflammatory disease of the upper airways that affects 10% of Europeans and Americans. A subset of CRS patients develop nasal polyps (NPs), which are characterized by type 2 inflammation, eosinophils and group 2 innate lymphoid cells (ILC2s). We have reported that NP contain elevated levels of B cells and antibodies, making NP an ideal system for studying B cells in the airways.

OBJECTIVE

We sought to determine the mechanisms that drive B cell activation and antibody production during chronic airway inflammation.

METHODS

We analysed B cells from NP or tonsil, or after ILC2 coculture, by flow cytometry. Antibody production from tissue was measured using Luminex assays and the frequency of antibody-secreting cells by ELISpot. Formation of B cell clusters was assessed using immunohistochemistry. Expression of genes associated with B cell activation and class switch recombination was measured by qRT-PCR.

RESULTS

NP contained significantly elevated frequencies of plasmablasts, especially those that expressed the extrafollicular marker Epstein-Barr virus-induced protein 2 (EBI2), but significantly fewer germinal centre (GC) B cells compared with tonsil. Antibody production and the frequency of antibody-secreting cells were significantly elevated in NP, and there was evidence for local class switch recombination in NP. Finally, ILC2s directly induced EBI2 expression on B cells in vitro.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest there is a unique B cell activation environment within NP that is distinct from classic GC-mediated mechanisms. We show for the first time that ILC2s directly induce EBI2 expression on B cells, indicating that ILC2s may play an important role in B cell responses. B cell-targeted therapies may provide new treatment options for CRSwNP.

Heterogeneous inflammatory patterns in chronic rhinosinusitis without nasal polyps in Chicago, Illinois

CRSsNP is a heterogenous disease but type 2 inflammation in CRSsNP was more common than type 1 inflammation among patients in Chicago, Illinois. Distinct therapeutic strategies may be needed depending on the type of inflammation found in CRSsNP.

Immunopathogenesis of Chronic Rhinosinusitis and Nasal Polyposis

Chronic rhinosinusitis (CRS) is a troublesome, chronic inflammatory disease that affects over 10% of the adult population, causing decreased quality of life, lost productivity, and lost time at work and leading to more than a million surgical interventions annually worldwide. The nose, paranasal sinuses, and associated lymphoid tissues play important roles in homeostasis and immunity, and CRS significantly impairs these normal functions. Pathogenic mechanisms of CRS have recently become the focus of intense investigations worldwide, and significant progress has been made. The two main forms of CRS that have been long recognized, with and without nasal polyps, are each now known to be heterogeneous, based on underlying mechanism, geographical location, and race. Loss of the immune barrier, including increased permeability of mucosal epithelium and reduced production of important antimicrobial substances and responses, is a common feature of many forms of CRS. One form of CRS with polyps found worldwide is driven by the cytokines IL-5 and IL-13 coming from Th2 cells, type 2 innate lymphoid cells, and probably mast cells. Type 2 cytokines activate inflammatory cells that are implicated in the pathogenic mechanism, including mast cells, basophils, and eosinophils. New classes of biological drugs that block the production or action of these cytokines are making important inroads toward new treatment paradigms in polypoid CRS.

[The role of a leukotriene receptor antagonist in the restoration of the nasal breathing in the patients presenting with polypous rhinosinusitis]

The present study was designed to investigate the clinical. laboratory, and morphological characteristics of the nasal obstruction process. It included 87 patients presenting with polypous rhinosinusitis. The dynamics of the serum leukotriene C4 (LTC4) level in the patients and the morphological changes in their polypous tissue suggested the existence of the pronounced exudative phase of allergic inflammation and provided a basis for the use of the leukotriene receptor antagonist in the form of the sodium montelucast tablets for the treatment of nasal obstruction.

Age dictates a steroid-resistant cascade of Wnt5a, transglutaminase 2, and leukotrienes in inflamed airways

BACKGROUND

Airway remodeling is a detrimental and refractory process showing age-dependent clinical manifestations that are mechanistically undefined. The leukotriene (LT) and wingless/integrase (Wnt) pathways have been implicated in remodeling, but age-specific expression profiles and common regulators remained elusive.

OBJECTIVE

We sought to study the activation of the LT and Wnt pathways during early- or late-onset allergic airway inflammation and to address regulatory mechanisms and clinical relevance in normal human bronchial epithelial cells (NHBEs) and nasal polyp tissues.

METHODS

Mice were sensitized with house dust mite (HDM) allergens from days 3, 15, or 60 after birth. Remodeling factors in murine bronchoalveolar lavage fluid, lung tissue, or human nasal polyp tissue were analyzed by means of Western blotting, immunoassays, or histology. Regulatory mechanisms were studied in cytokine/HDM-stimulated NHBEs and macrophages.

RESULTS

Bronchoalveolar lavage fluid LT levels were increased in neonatal and adult but reduced in juvenile HDM-sensitized mice. Lungs of neonatally sensitized mice showed increased 5-lipoxygenase levels, whereas adult mice expressed more group 10 secretory phospholipase A₂, Wnt5a, and transglutaminase 2 (Tgm2). Older mice showed colocalization of Wnt5a and LT enzymes in the epithelium, a pattern also observed in human nasal polyps. IL-4 promoted epithelial Wnt5a secretion, which upregulated macrophage Tgm2 expression, and Tgm2 inhibition in turn reduced LT release. Tgm2, group 10 secretory phospholipase A₂, and LT enzymes in NHBEs and nasal polyps were refractory to corticosteroids.

CONCLUSION

Our findings reveal age differences in LT and Wnt pathways during airway inflammation and identify a steroid-resistant cascade of Wnt5a, Tgm2, and LTs, which might represent a therapeutic target for airway inflammation and remodeling.

B-Cells and Antibody-Mediated Pathogenesis in Chronic Rhinosinusitis with Nasal Polyps

The sinonasal mucosa forms a dynamic immune barrier where epithelial cells and the immune system interact with the inhaled environment and nasal microbiome. Recent studies suggest that B-cells, plasma cells and antibody production are highly activated locally within the nasal mucosa of patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Findings additionally suggest that polyp tissue contains elevated levels of cytokines, chemokines and complement that may drive this profound B-cell response. Currently, the data are conflicting on whether the B-cell response found in the CRSwNP nasal mucosa is antigen-specific, a superantigen response or an expansion of natural antibody responses. Indeed, investigations into the specificity of the mucosal antibody responses find increased production of class-switched antibodies that bind to aeroallergens, staphylococcus aureus as well as autoantigens. A continuation of these studies is needed to elucidate whether extrinsic factors, like the inhaled environment, or intrinsic factors, like the mucosal microbiome and host inflammatory response, are key to the pathogenesis of CRSwNP. This chapter will cover the current evidence regarding local B-cell responses in CRSwNP.

Chronic Rhinosinusitis with Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an important clinical entity diagnosed by the presence of both subjective and objective evidence of chronic sinonasal inflammation. Symptoms include anterior or posterior rhinorrhea, nasal congestion, hyposmia, and/or facial pressure or pain that last for a duration of more than 12 weeks. Nasal polyps are inflammatory lesions that project into the nasal airway, are typically bilateral, and originate from the ethmoid sinus. Males are more likely to be affected than females, but no specific genetic or environmental factors have been strongly linked to the development of this disorder to date. CRSwNP is frequently associated with asthma and allergic rhinitis, but the cellular and molecular mechanisms that contribute to the clinical symptoms are not fully understood. Defects in the sinonasal epithelial cell barrier, increased exposure to pathogenic and colonized bacteria, and dysregulation of the host immune system are all thought to play prominent roles in disease pathogenesis. Additional studies are needed to further explore the clinical and pathophysiological features of CRSwNP so that biomarkers can be identified and novel advances can be made to improve the treatment and management of this disease.

Expression Profile of Immune-Associated Genes in Nasal Polyps

Objectives:

We performed this study to investigate the expression profile of immune-associated genes and to probe the role of related genes in the immune pathogenesis of nasal polyps.

Methods:

Microarray analysis was used to find the expression profile of 491 immune-associated genes in nasal polyps. In validation studies, immunohistochemical staining and Western blot analysis were used to detect interleukin (IL)–17 and IL-17 receptor (IL-17R) in nasal polyps and controls.

Results:

Eighty-seven genes were differentially expressed in the immune-associated gene profile of nasal polyps, and 15 genes showed differential expression in both chips. In nasal polyp tissues, IL-17 was expressed mainly in the cytoplasm of plasma cells and to a lesser degree in the prickle cell layer of the epithelium and the acinus of the serous gland. In turbinates, IL-17 was also expressed in the same location, but the expression of IL-17 in nasal polyps and that in turbinates differed significantly (p > .05). Both IL-17 and IL-17R displayed specific bands in nasal polyps and turbinates, but the bands of IL-17 and IL-17R in nasal polyps were stronger than those in turbinates.

Conclusions:

The differentially expressed genes in immune-associated gene chips will provide clues about, and a theoretical foundation for, the pathogenesis of nasal polyps. Furthermore, IL-17 may play an important role in the occurrence of nasal polyps by overexpression.

Human Nasal Polyp Microenvironment Maintained in Viable and Functional States as Xenografts in SCID Mice

Objectives:

We undertook to maintain human nasal polyp tissue in a viable and functional state in SCID (severe combined immunodeficiency) mice.

Methods:

Small, nondisrupted pieces of human nasal polyp tissues were subcutaneously implanted into SCID mice depleted of natural killer cells. The resulting xenografts were examined histologically, and the sera were evaluated for the presence of human protein.

Results:

The original histologic architecture of the polyp was maintained in the xenografts. The tissues, including pseudostratified columnar epithelial–lined polyps and subepithelial stroma, remained viable, and goblet cells continued to produce mucin for up to 26 weeks after engraftment. Human inflammatory leukocytes, including CD3+ T cells, CD20+ B cells, CD138+ plasma cells, and CD68+ monocytes and/or macrophages, were present. Identification of human immunoglobulin and human interferon-γ in the sera of xenograft-bearing mice indicated that the B cells or plasma cells and T cells within the xenografts remained functional for 2 weeks after engraftment.

Conclusions:

The ability to engraft and maintain nasal polyps provides an in vivo human/mouse chimeric model with which to investigate the role of inflammatory leukocytes and stromal cells in the maintenance and progression of polyposis and to determine how exogenous cytokines may alter the interaction of inflammatory cells, stromal cells, and epithelial cells in the polyp.

Polymorphism between Loci for Human Leukocyte Antigens DR and DQ in Patients with Nasal Polyps

Objectives:

We explored a potential association between nasal polyps (NPs) and polymorphism at loci for human leukocyte antigen (HLA) DR and HLA-DQ.

Methods:

Polymorphism at loci HLA-DR and HLA-DQ were examined in 30 patients with NPs and in 81 healthy subjects by use of the polymerase chain reaction-sequence specific primer method.

Results:

HLA-DR16, HLA-DQ8, and HLA-DQ9 were found to be significantly associated with NPs. HLA-DR16, HLA-DQ8, and HLA-DQ9 specificities were found at higher frequencies in patients with NPs than in control subjects (5% versus 0.62%, RR = 8.9, p = .03; 10% versus 2.47%, RR = 4.81, p = .01; and 20% versus 6.18%, RR = 4.73%, p = .001; respectively). In contrast, HLA-DQ7 was found at lower frequencies in patients with NPs than in controls (10% versus 20.37%, RR = 0.36, p = .04).

Conclusions:

We conclude that HLA-DR16, HLA-DQ8, and HLA-DQ9 represent potential susceptibility determinants and that HLA-DQ7 might confer resistance in nasal polyps.

Lymphocyte Subpopulations and Cytokines in Nasal Polyps: Is there a Local Immune System in the Nasal Polyp?

PURPOSE: The pathogenesis of chronic hyperplastic rhinosinusitis with massive nasal polyposis is still not entirely known. The present study evaluates the lymphocyte subpopulations and their production of cytokines using a technique for detection of intracytoplasmic cytokines by flow cytometry. This information may allow us to determine whether the source of these lymphocytes is from peripheral blood, the common mucosal immune system, or both.

METHODS: Detection of intracytoplasmic cytokines by flow cytometry was performed using a fluoresceinated monoclonal antibody directed against CD4+ and CD8+ lymphocytes and a rhodaminelabeled intracytoplasmic monoclonal antibody directed against four cytokines. In this way, the percentage of lymphocytes synthesizing TH1 and TH2 cytokines were identified in nasal polyp lymphocytes and the corresponding peripheral blood lymphocytes of 13 patients.

RESULTS: Lymphocytes producing interferongamma and IL-2, as well as IL-4 and IL-5, were found in the nasal polyps, suggesting that the nasal polyp possesses both TH1 and TH2 cytokine expression. There are also significant differences between the percentage of lymphocytes producing these cytokines between nasal polyps and peripheral blood, suggesting that nasal polyp lymphocytes derive from at least another source than only peripheral blood lymphocytes. Statistical analysis of four groups of patients demonstrated that no statistically significant difference in the lymphocyte subpopulations in atopic versus non-atopic patients, nor aspirin-intolerant versus aspirin-tolerant patients. In general, CD8 cells always produce more interferon-gamma than IL-2 in both peripheral blood and nasal polyps. In contrast with this data, CD4 cells produce more IL-2 in the peripheral blood than in nasal polyps.

CONCLUSIONS: Data support the concept that nasal polyp lymphocyte subpopulations may be derived from both the local mucosal immune system as well as from random migration of peripheral blood lymphocytes secondary to adhesion molecules and chemokines, which are known to be present in nasal polyps.

Association of HLA-DR3 and HLA-DR4 with Sinonasal Polyposis in Mexican Mestizos

OBJECTIVE: The pathogenesis of sinonasal polyposis (SNP) is not clear; it has been suggested that it is polygenic and multifactorial. The major histocompatibility complex is a useful tool to predict genetic susceptibility to diseases, especially to autoimmune diseases. Since such susceptibility is influenced by ethnicity, it is necessary to have a wide knowledge of the structure of the population to which the patient belongs. The purpose of the study was to determine the association of HLA-DRB1 alleles with sinonasal polyposis in the Mexican Mestizo population.

STUDY DESIGN: We studied the HLA-DR alleles in 34 adult Mexican Mestizo patients with SNP and compared them to those present in 99 healthy controls.

METHODS: Genomic DNA from mononuclear cells was obtained by using the “salting out” technique and high-resolution DNA typing of the HLA-DRB1 alleles was performed after PCR amplification.

RESULTS: We found a statistically significant increased frequency of the HLA-DRB1∗03 allele ( P = 0.03, odds ratio [OR] = 2.9, 95% confidence interval [CI]: 1.0–7.8) and of the HLA-DRB1∗04 allele ( P = 0.009, OR = 2.2, 95% CI: 1.2–4.2) in patients with SNP as compared to controls, and a statistically significant decreased frequency of the HLA-DRB1∗08 allele ( P = 0.01, OR = 0.2, 95% CI: 0.05–0.8).

CONCLUSION: The HLA-DR locus seems to be associated with the genetic susceptibility to develop SNP in Mexicans.

EBM rating: B-2b

Nasal polyposis: Prevalence of positive food and inhalant skin tests

OBJECTIVES: To investigate the etiology of nasal polyps and its relationship to allergy. The prevalence of positive food and inhalant skin tests in patients with nasal polyps and nonatopic controls was compared.

STUDY DESIGN AND SETTING: Prospective controlled study in tertiary referral rhinology clinic.

RESULTS: Seventy percent (70%) of the patients with nasal polyps had positive skin tests to an average of four foodstuffs, compared to 34 percent of controls ( P = 0.006). Only 35 percent of the nasal polyp patients also had positive inhalant skin tests. Overall, the prevalence of positive inhalant skin tests was similar in the nasal polyp patients and controls.

CONCLUSIONS: These findings suggest that the positive skin tests to foods are not merely a reflection of the general atopic status of patients with nasal polyps. It may be that non-IgE-mediated hypersensitivities, such as to ingested foods, play a role on the basis of a significant number of patients with positive intradermal skin tests to foods.

SIGNIFICANCE: Evaluation of the allergic status of patients with polyposis is important. Dietary manipulation may be indicated, though its role needs further investigation.

Altered Th17/Treg Ratio in Nasal Polyps With Distinct Cytokine Profile: Association With Patterns of Inflammation and Mucosal Remodeling

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease that can be classified as eosinophilic or noneosinophilic. Nasal polyps can exhibit different types of mucosal inflammation and responses to treatment. Imbalanced ratios of T-helper 17(Th17) and regulatory T (Treg) cells may contribute to the pathogenesis of nasal polyps.This study assessed the frequency of Th17 and Treg cells and related cytokines in patients with nasal polyps and tested for associations with mucosal remodeling.Surgical samples from 12 controls and 33 CRSwNP patients were analyzed histopathologically. The frequency of Th17 and Treg cells in peripheral blood mononuclear cells (PBMCs) and tissues were determined using flow cytometry. Th17 and Treg cells-related cytokines in plasma were measured by Cytometric Bead Array (CBA) multiplex assays and enzyme-linked immunosorbent assays (ELISAs).Eosinophilic CRSwNP (ECRSwNP) patients exhibited robust eosinophilia, whereas non-ECRSwNP patients were characterized by neutrophilia. Compared with non-ECRSwNP, an increased Th17/Treg ratio in ECRSwNP was associated with a less increased frequency of Th17 cells and a more striking reduction of Treg cells. An altered Th17/Treg cell ratio was positively correlated with eosinophilic and neutrophilic infiltration, submucosal basement membrane thickness, and the degree of subepithelial collagen deposition. Compared with non-ECRSwNP, ECRSwNP had higher levels of IL-17A and IL-4, and lower levels of IL-10 and TGF-β1, whereas non-ECRSwNP showed higher levels of IFN-γ and IL-6.Th17/Treg cell imbalance in nasal polyps (both in tissues and PBMCs) with distinct cytokine profile may contribute to different inflammatory patterns (eosinophilic versus neutrophilic inflammation) and corresponding features of mucosal remodeling. Effective strategies can be designed to target a Th17/Treg imbalance to restore immune homeostasis in nasal polyps.

Age-Related Decline of Neutrophilic Inflammation Is Associated with Better Postoperative Prognosis in Non-eosinophilic Nasal Polyps

Background

Innate and adaptive immune responses change with increasing age and affect the course of diseases. Previous study investigated immunologic alteration in Western nasal polyps (NP) which is mostly eosinophilic. However, there are no reports regarding age-related immune changes of non-eosinophilic NP (NE-NP) which is a predominant subtype in Asian population.

Methods

A total of 153 subjects, including 20 with control, 63 with chronic rhinosinusitis (CRS) without NP (CRSsNP), and 70 with CRS with NP were enrolled. Age-related changes in computed tomography (CT), cytokines and clinical information were investigated. Tissue samples were analyzed for protein levels of IL-5, IL-17A, IL-23, interferon (IFN)-γ, CCL-11, and CXCL-8, using Luminex immunoassay and for mRNA expression levels of interleukin (IL)-5, IL-17A, IL-23p19, IFN-γ, CCL-11, CXCL-1, CXCL-2, CXCL-8, and CXCR2 by quantitative RT-PCR. Immunohistochemistry (IHC) was performed for the number of inflammatory cells.

Results

We observed that Lund-Mackay CT scores decreased with age in NE-NP. The number of human neutrophil elastase-positive cells and myeloperoxidase gene expression decreased in older patients with NE-NP, but not in control subjects, CRSsNP, and E-NP. Neutrophil-associated cytokines including IL-17A and IL-23, were negatively correlated with age in NE-NP at the protein and mRNA levels. Additionally, the expression of CXCR2, a receptor for CXCL-1 and CXCL-2, was decreased with age in NE-NP. However, there were no age-related changes in blood neutrophil count, and neutrophil-recruiting chemokines such as CXCL-1, CXCL-2, and CXCL-8. Elderly NE-NP patients showed better endoscopic scores at 12 months after surgery compared with the non-elderly.

Conclusion

Age-related decline in neutrophil inflammation may favorably affect postoperative results in elderly patients with NE-NP.

[The role of Th9, Th17 and Treg cells on pathogenesis of nasal polyps]

OBJECTIVE

To investigate the expression levels of Th9, Th17 and Treg cells in peripheral blood of patients with chronic rhinosinusitis with nasal polyps (CRSwNP), and explore the role of Th9, Th17 and Treg cells in the progression of CRSwNP.

METHOD

Forty-six cases with CRSwNP served as an experimental group, while 22 cases with simple nasal bleeding or nasal septum deviation served as a control group. The peripheral blood of patients in both groups was collected and analyzed. (1) Using flow cytometry (FCM) to detect the expression rates of Th9, Th17 and Treg cells in peripheral blood. (2) Using qRT-PCR to detect the expression of relevant transcription factor of Th9, Th17 and Treg cells (IL-9mRNA, PU. 1, IRF-4, RoRc, and Foxp3). (3) Using SPSS16.0 to analyse the differentiations and the revelance among these three cells.

RESULT

(1) The expression rates of Th9 and Th17 cells in patients with CRSwNP (1.29% ± 0.18%, 4.03% ± 0.69%) was higher than the control group (0.45% ± 0.14%, 1.35% ± 0.26%). But the expression rates of Treg cells in the experimental group (2.98% ± 0.13%) was significantly lower than the control group (5.44% ± 0.57%). The differences were statistically significant (P < 0.05). (2) The expression of revelant transcription factor (IL-9mRNA, PU.1, IRF-4, RoRc) in NP group was also higher than the control group. The expression of Foxp3 in the control group was higher than NP, the differences both were statistically significant (P < 0.05). (3) The difference between Th9 and Th17 in patients with NP was not significant (P > 0.05), and the negative correlation was found between Th17 and Treg (r = -0.549, P < 0.05).

CONCLUSION

The high expression level of Th9 and Th17 cells might promote the development of NP, whereas the low expression level of Treg cells might further aggravate the occurrence of NP. The main function of the imbalance of Th17/Treg cells may be immune regulation in the pathogenesis of nasal polys.

[Expression and role of IL-33 and its receptor ST2 in eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps]

OBJECTIVE

To investigate the expression and role of Interleukin-33 (IL-33) and ST2 in the nasal polyps of human Eosinophilic and non-Eosinophilic chronic rhinosinusitis with nasal polyps (ECRS and non-ECRS).

METHOD

IL-33 and ST2 protein expression in nasal polyps of ECRS and non-ECRS as well as in seemingly normal mucosa of the inferior turbinate tissue was investigated by immunohistochemical staining and messenger RNA (mRNA) expression of IL-33 and ST2 was assessed by realtime polymerase chain reaction (PCR) in 27 subjects with ECRS, 33 subjects with non-ECRS, and 11 control subjects.

RESULT

(1) The ST2 was found both in nasal polyps of ECRS and non-ECRS,especially in ECRS, yet hardly found in the normal mucosa of the inferior turbinate tissue; (2) The expression of ST2 mRNA in nasal polyps of ECRS was higher than that in non-ECRS and normal inferior turbinate tissue, and the difference was both prominent in statistics (P<0.01); (3) The expression patterns of IL-33 at both mRNA and protein levels were not significantly different among the three groups (P>0.05).

CONCLUSION

The IL-33 and its receptor ST2 were both expressed in human nasal polyps including ECRS and non-ECRS, meanwhile the expression patterns of ST2 at both mRNA and protein levels were significantly higher in nasal polyps of ECRS. The current study suggests that IL-33 and its receptor ST2 may play important roles in the pathogenesis of chronic rhinosinusitis with nasal polyps, especially in ECRS through the increased expression of ST2 in Eosinophils as a hypothesis.