Chronic rhinosinusitis with nasal polyps is associated with decreased expression of mucosal interleukin 22 receptor

SARS-CoV-2 infection alters mitochondrial and cytoskeletal function in human respiratory epithelial cells mediated by expression of spike protein

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, SCV2), which has resulted in higher morbidity and mortality rate than other respiratory viral infections, such as Influenza A virus (IAV) infection. Investigating the molecular mechanisms of SCV2-host infection vs IAV is vital in exploring antiviral drug targets against SCV2. We assessed differential gene expression in human nasal cells upon SCV2 or IAV infection using RNA sequencing. Compared to IAV, we observed alterations in both metabolic and cytoskeletal pathways suggestive of epithelial remodeling in the SCV2-infected cells, reminiscent of pathways activated as a response to chronic injury. We found that spike protein interaction with the epithelium was sufficient to instigate these epithelial responses using a SCV2 spike pseudovirus. Specifically, we found downregulation of the mitochondrial markers SIRT3 and TOMM22. Moreover, SCV2 spike infection increased extracellular acidification and decreased oxygen consumption rate in the epithelium. In addition, we observed cytoskeletal rearrangements with a reduction in the actin-severing protein cofilin-1 and an increase in polymerized actin, indicating epithelial cytoskeletal rearrangements. This study revealed distinct epithelial responses to SCV2 infection, with early mitochondrial dysfunction in the host cells and evidence of cytoskeletal remodeling that could contribute to the worsened outcome in COVID-19 patients compared to IAV patients. These changes in cell structure and energetics could contribute to cellular resilience early during infection, allowing for prolonged cell survival and potentially paving the way for more chronic symptoms. IMPORTANCE COVID-19 has caused a global pandemic affecting millions of people worldwide, resulting in a higher mortality rate and concerns of more persistent symptoms compared to influenza A. To study this, we compare lung epithelial responses to both viruses. Interestingly, we found that in response to SARS-CoV-2 infection, the cellular energetics changed and there were cell structural rearrangements. These changes in cell structure could lead to prolonged epithelial cell survival, even in the face of not working well, potentially contributing to the development of chronic symptoms. In summary, these findings represent strategies utilized by the cell to survive the infection but result in a fundamental shift in the epithelial phenotype, with potential long-term consequences, which could set the stage for the development of chronic lung disease or long COVID-19.

Enhanced Type 2 Immune Reactions by Increased IL-22/IL-22Ra1 Signaling in Chronic Rhinosinusitis With Nasal Polyps

Purpose

Recent studies have revealed the pathogenic role of interleukin (IL)-22 in atopic dermatitis and asthma. However, little is known about the role of IL-22 in the pathophysiology of chronic rhinosinusitis with nasal polyps. We aimed to investigate the expression of IL-22 and its pathogenic function in type 2 immune reactions of nasal polyps (NP).

Methods

Protein levels of inflammatory mediators were determined by multiplex immunoassay, and principal component analysis (PCA) was performed. Immunofluorescence analysis and mast cell culture were used to determine the cellular sources of IL-22. Normal human bronchial epithelial (NHBE) cells were stimulated using IL-22 in combination with diverse cytokines, and thymic stromal lymphopoietin (TSLP) was measured.

Results

IL-22 expression was not up-regulated in NP compared with control tissues, but IL-22-high NP revealed distinct features characterized by type 2 inflammatory cytokines such as chemokine (C-C motif) ligand (CCL)-11, CCL-24, and IL-5 on the PCA. Additionally, IL-22 positively correlated with type 2 immune mediators and the disease severity in NP. For the localization of the cellular sources of IL-22 in eosinophilic NP, it was expressed in cells mostly composed of eosinophil peroxidase-positive cells and partially of tryptase-positive cells. The human mast cell line, LAD2 cells, released IL-22 mediated by immunoglobulin E. Moreover, IL-22 receptor subunit alpha-1 (IL-22Ra1) expression was significantly increased in NP. IL-22Ra1 was up-regulated with poly(I:C) stimulation in NHBE cells. Furthermore, TSLP production was enhanced when stimulated with a combination of IL-13, poly(I:C), and IL-22. Treatment with anti-IL-22Ra1 also inhibited IL-22-induced enhancement of TSLP production.

Conclusion

IL-22 was associated with type 2 inflammatory reactions in NP. The IL-22/IL-22Ra1 axis was enhanced and might be involved in type 2 inflammatory reactions via TSLP production in NP.

Association of interleukin 22 receptor subunit alpha 1 gene polymorphisms with chronic rhinosinusitis

Introduction

Chronic rhinosinusitis is a multifactorial disease whose pathogenesis, influenced by both genetic and environmental factors, is still unclear. Previous genetic studies have shown that patients with chronic rhinosinusitis have reduced expression of the Interleukin-22 (IL-22) gene.

Objective

Identify and compare the frequency of polymorphisms in the IL22RA1 gene (IL22 alpha-1 subunit receptor) among chronic rhinosinusitis patients – either with or without nasal polyps.

Methods

Peripheral blood samples were collected from 70 chronic rhinosinusitis with polyps patients, 14 chronic rhinosinusitis without polyps patients and 68 subjects without chronic rhinosinusitis, followed by DNA extraction and IL22RA1 gene sequence analysis.

Results

Among ten polymorphisms identified in the IL22RA1 gene, three were not found in any of the genetic databases analyzed. Chronic rhinosinusitis patients displayed higher frequency of the c.113_114insA frameshift insertion, possibly pathogenic. Conversely, in the control group, polymorphism c.435A > C had a significant predominance of the mutated allele, perhaps related to a potential protection against the chronic rhinosinusitis phenotype. Polymorphism c.770C > T, characterized as a non-synonymous variant, was exclusively found in Black chronic rhinosinusitis with polyps patients.

Conclusions

Although no direct causal relationship could be established between IL22RA1 gene polymorphisms and the pathophysiology of chronic rhinosinusitis, genetic variations such as c.113_114insA and c.435A > C may be involved in the susceptibility to or protection against the chronic rhinosinusitis phenotype, respectively. Testing this hypothesis will require studies with larger cohorts.

Chronic rhinosinusitis: pathogenesis, therapy options, and more

INTRODUCTION

When rhinosinusitis - the inflammation of the nasal cavity and paranasal sinuses - persists for over 12 weeks, it is termed 'chronic rhinosinusitis' (CRS). Both innate and adaptive immunity contribute to the heterogeneous inflammatory pathogenesis of CRS, which is driven by genetic and environmental factors and the microbiome. CRS is classified by the presence of polyps. Molecular mechanisms in CRS with nasal polyps are similar to those in atopic diseases.

AREAS COVERED

This review focuses on the immune pathogenesis of CRS, differences between the two CRS subtypes, and latest treatments that may aid in the provision of personalized medicine.

EXPERT OPINION

Basic research in the last decade has helped significantly in enhancing our knowledge of the pathophysiologic processes of CRS, due to which there is now a better understanding of the associated natural history, physiopathology, novel treatments, and prevention strategies. Treatment success depends on the clarification of the underlying pathogenesis and disease-contributing factors. The exploration of disease endotypes and introduction of novel agents are important advancements. Prior studies performed without disease-endotyping resulted in the inefficiency of certain drugs and insignificant results. The identification of biomarkers, development of personalized approaches, and utilization of disease algorithms are required for CRS therapy success.

Relative abundance of nasal microbiota in chronic rhinosinusitis by structured histopathology

BACKGROUND

Chronic rhinosinusitis (CRS) is an inflammatory disease process with several different phenotypes. Recent data has shown that CRS phenotypes maintain distinct nasal microbiota that may predict surgical outcomes. Nasal microbiota and structured histopathologic reporting have the potential to further differentiate subtypes and provide additional insight into the pathophysiology of CRS.

METHODS

Sinus swabs collected during functional endoscopic sinus surgery (FESS) were studied by polymerase chain reaction analysis of 16S ribosomal RNA. A structured histopathology report of 13 variables was utilized to analyze sinus tissue removed during FESS. Histopathology variables and relative abundance of nasal microbiota were compared among CRS patients.

RESULTS

A total of 51 CRS patients who underwent FESS were included. Relative abundance of the Firmicutes phylum in nasal microbiota of CRS patients was associated with presence of neutrophilic infiltrate (27.47 ± 44.75 vs 9.21 ± 11.84, p < 0.029), presence of mucosal ulceration (47.67 ± 45.52 vs 13.27 ± 26.48, p < 0.041), presence of squamous metaplasia (5562.70 ± 2715.66 vs 3563.73 ± 2580.84, p < 0.035), and absence of Charcot-Leyden crystals (5423.00 ± 3320.57 vs 679.94 ± 1653.66, p < 0.001). Relative abundance of the Bacteroidetes phylum in nasal microbiota of CRS patients was associated with increased severity of inflammatory degree (p < 0.004) and presence of mucosal ulceration (p < 0.004).

CONCLUSION

Distinct histopathologic features of CRS are associated with relative abundance of nasal microbiota phyla, specifically Firmicutes and Bacteroidetes. These findings contribute to the growing body of literature on microbiota in sinonasal disease and may have important implications for understanding pathophysiologic mechanisms of CRS subtypes and disease management.

Temporal expression of interleukin-22, interleukin-22 receptor 1 and interleukin-22-binding protein during experimental periodontitis in rats

BACKGROUND AND OBJECTIVE

Interleukin-22 (IL-22), mainly produced by CD4+ T-helper subtypes and innate lymphoid cells at barrier surfaces, is found to involve in several diseases, including diabetes, rheumatoid arthritis, peri-implantitis and chronic rhinosinusitis with nasal polyps. The purpose of this study was to investigate histological changes and the levels of interleukin-22, interleukin-22 receptor 1 (IL-22R1) and interleukin-22-binding protein (IL-22BP) in experimental periodontitis.

MATERIAL AND METHODS

Sixty male 8-week-old Sprague Dawley rats were randomly allocated to six groups of 10 rats each. In the periodontitis groups, experimental periodontitis was established and the rats were killed on days 3, 5, 7, 11 and 15 after ligation, while the rats without ligation were killed on day 0, representing the healthy control group (day 0 group). Histopathologic changes were detected by hematoxylin and eosin (H&E) staining, and alveolar bone loss was determined by micro-computed tomography (micro-CT). Tartrate-resistant acid phosphatase (TRAP) staining was used to investigate osteoclast formation. Real-time quantitative PCR (qPCR) and immunohistochemistry were used to investigate the expression and location of IL-22, IL-22R1 and IL-22BP in gingival tissues.

RESULTS

H&E staining showed increasingly severe destruction of the epithelial layer between day 3 and day 7, and the hyperplasia of pocket epithelium and the formation of periodontal pockets could be detected from day 11 to day 15. Micro-CT indicated an exponential increase in alveolar bone loss from day 3 to day 11 (P < .01). Bone resorption tended to be stationary after this period. TRAP staining showed that the number of multinucleate osteoclasts peaked at day 3 (P < .001, compared with day 0) and decreased at subsequent time points between day 5 and day 15. IL-22BP was expressed strongly under steady-state conditions in epithelial cells. IL-22-positive cells could be clearly observed both in the epithelial layer and around the lamina propria, whereas IL-22R1 was mainly localized in the epithelial layer of the damage period. Real-time qPCR revealed up-regulation of IL-22 and IL-22R1, as well as down-regulation of IL-22BP in gingival tissues during the destructive phase of periodontitis.

CONCLUSION

This study shows the expression and localization of IL-22, IL-22R1 and IL-22BP, as well as the relevant histopathological alterations during the development of experimental periodontitis.

Chronic Rhinosinusitis with Polyps Is Characterized by Increased Mucosal and Blood Th17 Effector Cytokine Producing Cells

Background: Recent studies have implied a role for Th17 cells in CRS with nasal polyps (CRSwNP) patients. However, the capacity of these cells to produce Th17 cytokines is still unknown. Here we sought to quantify IL-17A, IL-17F, IL-21, and IL-22 cytokines produced by Th17 cells in mucosal tissue and peripheral blood of CRSwNP, CRS without nasal polyps (CRSsNP) and control patients.

Methods: Samples were prospectively collected from CRS patients and non-CRS controls. We used flow cytometry to characterize the Th17 cells and their cytokines in sinonasal tissue and peripheral blood.

Results: A total of 36 patients were recruited to the study. CRSwNP patients had significantly more tissue IL-17A (9.53 ± 2.71 vs. 1.11 ± 0.43 vs. 0.77 ± 0.07), IL-17F (4.96 ± 1.48 vs. 0.88 ± 0.31 vs. 0.56 ± 0.04), IL-21 (5.55 ± 2.01 vs. 1.60 ± 0.71 vs. 1.53 ± 0.55) and IL-22 (4.73 ± 1.58 vs. 0.70 ± 0.28 vs. 0.88 ± 0.26) producing Th17 cells compared to CRSsNP and control mucosa per mg of tissue, respectively. Allergic CRSwNP patients had decreased numbers of IL-21 producing Th17 cells compared to non-Allergic CRSwNP. (1.69 ± 0.57 vs. 9.41 ± 3.23) per mg of tissue, respectively (Kruskal-Wallis p < 0.05).

Conclusion: In summary our study identified increased numbers of IL-17A, IL-17F, IL-21 and IL-22 positive Th17 cells in CRSwNP patient polyps and peripheral blood suggesting an altered activation state of those cells both locally and systemically. Atopic CRSwNP had decreased amounts of tissue Th17 cell derived IL-21 implying a potential protective role for IL-21 in CRSwNP allergic inflammation.

Refractory Chronic Rhinosinusitis with Nasal Polyposis

Chronic rhinosinusitis with nasal polyposis (CRSwNP) represents a subset of chronic sinusitis with various causes. Some forms of the disease are driven by allergy, often in association with asthma. Refractory CRSwNP can be associated with cystic fibrosis and other clinical syndromes. More recent literature is presented regarding roles of innate immunity and superantigens. Effective treatment of CRSwNP requires careful endoscopic sinus surgery followed by an individualized treatment plan that often includes oral and topical steroids. Recidivism of polyps is common, and patients require long-term follow-up.

IL-22/IL-22R1 signaling regulates the pathophysiology of chronic rhinosinusitis with nasal polyps via alteration of MUC1 expression

BACKGROUND

IL-22 is an IL-10-family cytokine that regulates chronic inflammation. We investigated the role of IL-22 and its receptor, IL-22R1, in the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

IL-22 and IL-22R1 protein and mRNA expression in NP and in uncinate tissues (UT) from CRS and non-CRS patients was examined using immunohistochemistry and real-time PCR, respectively. Dispersed NP and UT cells were cultured with the Staphylococcus aureus exotoxins, staphylococcal enterotoxin B and alpha-toxin, following which exotoxin-induced IL-22 levels and their association with clinicopathological factors were analyzed. Effects of IL-22 on MUC1 expression and cytokine release in NP cells were also determined.

RESULTS

IL-22 and IL-22R1 in NP were mainly expressed in infiltrating inflammatory cells and in epithelial cells, respectively. IL-22 mRNA levels in NP were significantly higher than those in UTs from non-CRS patients whereas IL-22R1 levels were conversely lower in NPs. NP cells produced substantial amounts of IL-22 in response to exotoxins. Exotoxin-induced IL-22 production by NP cells significantly and negatively correlated with the degree of local eosinophilia and postoperative computed tomography (CT) score, whereas conversely it positively correlated with the forced expiratory volume in 1s (FEV1)/forced vital capacity (FVC) ratio. IL-22 significantly enhanced MUC1 mRNA expression in NP cells. IL-22-induced MUC1 mRNA levels were significantly and positively correlated with IL-22R1 mRNA levels in NPs.

CONCLUSIONS

These data suggest that imbalance of IL-22/IL-22R1 signaling regulates the pathogenesis of CRSwNP, including local eosinophilia, via alteration of MUC1 expression.

A comprehensive review of the nasal microbiome in chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) has been known as a disease with strong infectious and inflammatory components for decades. The recent advancement in methods identifying microbes has helped implicate the airway microbiome in inflammatory respiratory diseases such as asthma and COPD. Such studies support a role of resident microbes in both health and disease of host tissue, especially in the case of inflammatory mucosal diseases. Identifying interactive events between microbes and elements of the immune system can help us to uncover the pathogenic mechanisms underlying CRS. Here we provide a review of the findings on the complex upper respiratory microbiome in CRS in comparison with healthy controls. Furthermore, we have reviewed the defects and alterations of the host immune system that interact with microbes and could be associated with dysbiosis in CRS.

Pathophysiology of chronic rhinosinusitis, pharmaceutical therapy options

Research in immunology has brought great progress in knowledge of inflammatory processes in the last 2 decades, which also has an impact on the upper airways. Our understanding of the pathophysiology of chronic rhinosinusitis developed from a rather mechanistic point of view with a focus on narrow clefts and mucociliary clearance to the appreciation of a complex network of immunological pathways forming the basis of disease. We today differentiate various forms of inflammation, we start to understand complex immune-regulatory networks and the reasons for their failure, and have already developed innovative approaches for therapy for the most severely ill subjects. Due to this new knowledge in inflammation and remodeling processes within mucosal tissue, specifically on the key driving factors, new diagnostic tools and therapeutic approaches for chronic rhinosinusitis have developed; the differentiation of endotypes based on pathophysiological principles will be crucial for the use of innovative therapies, mostly humanized monoclonal antibodies. Several hundred of those antibodies are currently developed for various indications and will impact our specialty as well as pneumology to a great extent.

Clinical and biological markers of difficult-to-treat severe chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the upper airways of which two major phenotypes exist, CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). Some patients with CRS have suboptimal response to current guideline treatments. These patients remain severe and uncontrolled by treatment and have a poor quality of life. It is highly important to identify both clinical and biological markers, so-called biomarkers, in this subset of patients. The presence of nasal polyps and comorbidity with asthma and with aspirin-exacerbated respiratory disease (AERD) are the most common clinical traits that have been associated to difficult-to-treat severe CRS. In addition to clinical traits, numerous biological markers, with known etiopathogenic roles in CRS, have been associated to difficult-to-treat or recalcitrant CRS. This review summarizes the existing knowledge of the clinical and biological markers associated to difficult-to-treat or uncontrolled severe CRS.

The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses

Chronic rhinosinusitis (CRS) is a broad clinical syndrome that is characterized by prolonged mucosal inflammation of the nose and paranasal sinuses, and is typically divided into two subtypes based on the presence or absence of nasal polyps. The etiology and pathogenesis of both forms remain areas of active research. Over the last 15 years, a number of hypotheses have been proposed to explain all or part of the clinical CRS spectrum. These hypotheses reflect the concept that CRS results from a dysfunctional interplay between individual host characteristics and factors exogenous to the host. Six broad theories on CRS etiology and pathogenesis are discussed as follows: (1) the "fungal hypothesis," (2) the "superantigen hypothesis," (3) the "biofilm hypothesis," and (4) the "microbiome hypothesis," all of which emphasize key environmental factors, and (5) the "eicosanoid hypothesis" and (6) the "immune barrier hypothesis," which describe specific host factors. These theories are reviewed, and the evidence supporting them is critically appraised.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

Differential expression of innate immunity genes in chronic rhinosinusitis

BACKGROUND

Prior research has identified several components of the innate immune system that may play a significant role in chronic rhinosinusitis (CRS), but the role of innate immunity in patients with CRS is poorly understood. The objective of this study was to determine differential expression of innate immunity genes in the mucosa of patients with CRS with nasal polyposis (CRSwNP) and CRS without nasal polyposis (CRSsNP) when compared with controls.

METHODS

Control patients (n = 9) and patients with CRS (n = 36) who failed medical management were prospectively enrolled. Ethmoid mucosa samples were harvested during surgery and quantitative real-time polymerase chain reaction was used to determine levels of mRNA expression of Toll-like receptor (TLR) 2 and TLR9 and interleukin-22 receptor (IL-22R). The average change in crossover threshold and fold change were calculated and differences between controls, CRSwNP, and CRSsNP were compared. Statistical analysis was performed using the Kruskall-Wallis and adjusted Mann-Whitney U tests.

RESULTS

Patients with CRSwNP (n = 16) and CRSsNP (n = 20) showed lower mean expression of TLR2 (p < 0.05) compared with controls. Patients with CRSsNP showed significantly higher mean expression of IL-22R (p < 0.05) than controls.

CONCLUSION

The sinonasal innate immune system may have a significant role in the development of CRS. We found differential expression of innate immune mediators between patients with and without nasal polyposis. These results provide further evidence of disruption of innate immunity at the mucosal level in CRS and highlight differences between polyp- and non-polyp-forming CRS phenotypes at the molecular level. In addition to our knowledge, this is the first report of altered IL-22R expression in CRSsNP patients. This study was a part of the clinical trial NCT01332136 registered in www.clinicaltrials.gov.

Histopathological evaluation of chronic rhinosinusitis: a critical review

BACKGROUND

Chronic rhinosinusitis (CRS) consists of a constellation of symptoms, including facial pressure/pain, hyposmia, rhinorrhea, and nasal congestion. On histopathological evaluation, the disease can be divided into pathophysiologically distinct subgroups. This study systematically reviews the literature regarding the unique histopathological findings of the various subtypes of CRS to determine the potential diagnostic value of performing tissue analysis of CRS specimens beyond routine hematoxylin and eosin (H&E) staining.

METHODS

A PubMed search was untaken to identify articles that evaluated the histopathological features of CRS. Six hundred fifty-four relevant articles were identified and after application of specific exclusion criteria, 71 articles were further reviewed in detail.

RESULTS

All articles included analysis of tissue samples from in-office biopsies or intraoperative specimens of patients who underwent sinus surgery. CRS was often further divided into subgroups and compared with each other and with a control group. The subgroups included CRS with and without nasal polyps, asthmatic and nonasthmatic patients, and with and without eosinophilia. Distinct inflammatory mediators were found for the different subgroups. Twenty-eight articles evaluated these inflammatory markers for their potential value as prognostic indicators.

CONCLUSION

CRS is a heterogeneous disease based on its histopathological findings. Information that is obtainable from light microscopy, but typically goes unreported, can serve as valuable prognostic indictors. However, routine H&E staining is suboptimal in distinguishing among the various subgroups of CRS. Assessment of specific inflammatory mediators in sinus mucosa specimens may help provide prognostic information and guide more tailored treatment for the individual patient.

Clinical features of cytotoxic CD8+ T-lymphocyte deficiency in chronic rhinosinusitis patients: a demographic and functional study

BACKGROUND

Identification of Staphylococcus aureus intracellularly in chronic rhinosinusitis (CRS) suggests an underlying cellular immunodeficiency. Supporting this, we have previously reported low CD8+ (cytotoxic) T-lymphocyte levels in a subpopulation of CRS patients and identified polymorphisms in the CD8A gene associated with CRS. In order to better understand the role of low CD8+ in CRS, we wished to determine the phenotype for CRS/Low CD8+ in comparison to that of conventional CRS.

METHODS

Sixty-seven low CD8+ CRS patients identified during investigation of CRS were compared for demographics, disease evolution, and bacteriology on endoscopic culture were compared with an existing population of 480 patients with CRS with nasal polyposis previously recruited for genetic association studies.

RESULTS

Mean level of CD8+ in the CRS/Low CD8+ population was 0.15 × 10(9)/L (range, 0.20-1.5 × 10(9)/L). There was no difference between both groups in terms of history of allergy, asthma, eczema, acetylsalicylic acid (ASA) intolerance or smoking. The bacteriology was similar between both groups (S. aureus: CRS/Low CD8+: 35%; CRS 32%, p = 0.643). Evolution of disease was somewhat milder in CRS/Low CD8+, with fewer patients requiring surgery, and first surgery performed at a more advanced age. However, antibiotic use was higher in CRS/Low CD8+. Subgroup analysis restricted to CRS with nasal polyposis (CRSwNP)/Low CD8 or CRS without nasal polyposis (CRSsNP)/Low CD8 phenotypes did not substantially alter these results.

CONCLUSION

Low CD8+ levels are often identified in CRS patients; however, these patients have disease remarkably similar to those with conventional CRS. This suggests that immune deficiency, whether systemic or locally mediated, is well tolerated and may be present in other forms in CRS. CRS patients with low CD8+ levels may possibly require antibacterial therapies as part of ongoing management.

Host-microbial interactions in patients with chronic rhinosinusitis

There has been considerable investigation of host-microbial interactions in patients with chronic rhinosinusitis (CRS) in hopes of elucidating mechanisms of disease and better treatment. Most attention has been paid to bacterial infection and potential underlying defects in innate immunity. Bacterial biofilm is present in most patients with CRS undergoing surgical intervention, and its presence is associated with more severe disease and worse surgical outcomes. A role for viral or fungal infection in patients with CRS is less clear. There is no evidence for a primary defect in mucociliary clearance in most patients with CRS. Decreased levels of certain antimicrobial proteins, most notably lactoferrin, have been found in sinus secretions, whereas levels of other antimicrobial proteins have been found to be normal. No primary defects in Toll-like receptors have been found in patients with CRS, although a 50% reduced expression of Toll-like receptor 9 was reported in patients with recalcitrant nasal polyps. A polymorphism in a bitter taste receptor was recently associated with refractory CRS and persistent Pseudomonas aeruginosa infection. A downregulation of innate immunity by maladaptive T_H2 tissue inflammation has also been described in patients with recalcitrant nasal polyps, suggesting a link to persistent infection. To date, an effective means of restoring host-microbial balance and mitigating disease in patients with CRS remains elusive.

Rhinosinusitis and asthma-microbiome and new perspectives

PURPOSE OF REVIEW

Microbiome is one of the new perspectives in human health research, including airway diseases. There are several publications about the relationship of the microbiome and allergic diseases. Although pathogenesis of chronic rhinosinusitis (CRS) as well as its relationship with asthma has been widely investigated, the relationship of the microbiome and CRS is not yet well known.

RECENT FINDINGS

The relationship between the hygiene hypothesis and microorganisms inside the human body and in the environment around it has been clearly shown. Furthermore, several researchers have reported that the microorganisms in the gut play a major role in regulating the immune cells that are of relevance to asthma and allergic diseases, such as Th1, Th2, Th17, Treg and dendritic cells as well as Toll-like receptors. Reduced contact of people with natural environmental features and biodiversity may adversely affect the human commensal microbiota and its immunomodulatory capacity.Some studies have shown a close relationship between CRS and Staphylococcus aureus, anaerobes and so on in the nasal cavity or paranasal sinuses, although the relationship between CRS and microorganisms in the gut has not been demonstrated.

SUMMARY

In this review, we summarized about the microbiome, mainly in asthma and allergic diseases. The relationship between asthma and CRS has been clearly shown, and in particular, CRS with nasal polyps (CRSwNP) has been considered to be Th2-dominant. Studies examining environmental microbial exposure in populations at risk for CRS are necessary to improve our understanding of the role this factor plays in disease development.

A polymorphism of interleukin-22 receptor alpha-1 is associated with the development of childhood IgA nephropathy

Recent studies suggest that dysregulated innate immunity plays an important role in the pathogenesis of immunoglobulin A nephropathy (IgAN). The interleukin-20 subfamily and its receptor, interleukin-22 receptor alpha-1 (IL-22R1), were recently identified as immunomodulators in human diseases, acting as mediators of mucosal host defense. However, the potential role of IL-22R1 in the pathogenesis of IgAN has not been explored. In the current study, 194 patients with IgAN and 287 normal controls were genotyped for coding polymorphisms of the IL-22R1 gene and the association between the polymorphisms and IgAN was investigated. Local expression of IL-22R1 was examined in patients with IgAN and healthy controls using immunohistochemistry. Our case-control analysis showed that genotypes of rs3795299 were associated with childhood IgAN. Individuals with the CC genotype of rs3795299 had about 3-fold reduced risk of IgAN compared with those with the GG genotype in the codominant model (P=0.0028) and those with the genotypes containing the G allele (GG or GC) in the recessive model (P=0.002). After Bonferroni correction, the association between the rs3795299 CC genotype and reduced risk of developing IgAN remained significant. Furthermore, the renal expression of IL-22R1 was significantly higher in healthy controls compared with subjects with IgAN. Our data suggest that the CC genotype of rs3795299 polymorphism in the IL-22R1 gene is associated with the reduced risk of IgAN, and this genetic association was supported by the higher renal expression of IL-22R1 in healthy controls compared with patients with IgAN.

Role of innate immunity in the pathogenesis of chronic rhinosinusitis: progress and new avenues

Chronic rhinosinusitis is a heterogeneous and multifactorial disease with unknown etiology. Aberrant responses to microorganisms have been suggested to play a role in the pathophysiology of the disease. Research has focused on the presence, detection, response to, and eradication of these potential threats. Main topics seem to center on the contribution of structural cells such as epithelium and fibroblasts, on the consequences of activation of pattern-recognition receptors, and on the role of antimicrobial agents. This research should be viewed not only in the light of a comparison between healthy and diseased individuals, but also in a comparison between patients who do or do not respond to treatment. New players that could play a role in the pathophysiology seem to surface at regular intervals, adding to our understanding (and the complexity) of the disease and opening new avenues that may help fight this incapacitating disease.

P-glycoprotein functions as an immunomodulator in healthy human primary nasal epithelial cells

BACKGROUND

P-glycoprotein (P-gp) is an adenosine triphosphate (ATP)-dependent efflux pump that confers chemotherapeutic resistance in cancer cells. Recent studies suggest that P-gp may also function as an immunomodulator through regulation of cytokine transport. Sinonasal epithelial cells have been recognized as drivers of local innate and adaptive immunity and are known to overexpress P-gp in the setting of inflammation. The objective of this study is to therefore determine whether P-gp participates in the regulation of cytokine secretion in sinonasal epithelial cells.

METHODS

Primary nasal epithelial cell cultures (PNECCs) were cultivated from 5 healthy patients. Membranous P-gp was quantified through quantitative fluorescent immunohistochemistry (Q-FIHC) and confirmed by enzyme-linked immunosorbent assay (ELISA). Sensitivity to inhibition was determined using a rhodamine 123 accumulation assay. Baseline and lipopolysaccharide (LPS)-stimulated cytokine secretion of interleukin 6 (IL-6), IL-8, granulocyte macrophage colony stimulating factor (GM-CSF), and thymic stromal lymphopoietin (TSLP) were quantified by ELISA and compared to LPS stimulated secretion in the setting of P-gp-specific inhibition. Differences in P-gp expression and cytokine secretion were compared using 2-tailed Student t tests with post hoc testing using the Bonferroni procedure.

RESULTS

Membranous P-gp is detectable in PNECCs and upregulated following LPS exposure. P-gp is sensitive to inhibition by both PSC 833 and verapamil in a dose-dependent fashion. LPS stimulated secretion of normalized IL-6 (mean, 95% confidence interval [CI]) (79.67, 42.26-117.07), GM-CSF (39.92, 7.90-71.94), and TSLP (6.65, 5.35-7.96) was significantly reduced following P-gp inhibition (37.60, 11.54-63.65, p = 0.023; 7.64, 2.25-13.03, p = 0.044; and 5.13, 4.44-5.82, p = 0.038; respectively).

CONCLUSION

P-gp is functionally active in PNECCs. P-gp participates in modulation of epithelial secretion of LPS stimulated IL-6, GM-CSF, and TSLP.

Th22 and related cytokines in inflammatory and autoimmune diseases

INTRODUCTION

Th22 and related cytokines regulate various processes and have been linked to diverse effects. The levels of Th22 and cytokine IL-22 are increased in several disorders and positively related to some autoimmune diseases. Preclinical studies have suggested that the inhibition or stimulation of IL-22 is an attractive approach to reverse the immune disorders. Simultaneously, considering many patients with refractory autoimmune diseases respond poorly to the therapies which are highly toxic, more effective therapies are to be examined.

AREAS COVERED

The role of Th22 cells and related cytokines and therapeutic strategies targeting them in many illnesses, especially inflammatory and autoimmune diseases.

EXPERT OPINION

Th22 cells and related cytokine IL-22 regulate multiple biological functions and play an important role in a number of inflammatory and autoimmune diseases. They have unique and attractive advantages for targeting. Targeting IL-22 has already been trialed in many mice experiments, showing better efficacy and fewer side effects compared with classical drugs. Targeting IL-22 or Th22 might provide pathogenetic treatment. However, Th22 subset is a recently identified Th subset and its associated research is extremely limited. Therefore, there are still many unanswered questions and further researches are warranted.

Interleukin 22 signaling promotes cell growth in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a specific type of aggressive B-cell non-Hodgkin lymphoma. We recently found that IL-22RA1, one of the two subunits of the interleukin 22 (IL-22) receptor, is expressed in MCL cell lines but not benign lymphocytes. In view of normal functions of IL-22 signaling, we hypothesized that the aberrant expression of IL-22RA1 may contribute to the deregulation of various cell signaling pathways, thereby promoting cell growth in MCL. In this study, we first demonstrated the expression of IL-22RA1 in all three MCL cell lines and eight frozen tumors examined using reverse transcription-polymerase chain reaction and Western blot analysis. In support of the concept that IL-22 signaling is biologically important in MCL, we found that MCL cells treated with recombinant IL-22 had a significant increase in cell growth that was associated with STAT3 activation. To investigate the mechanism underlying the aberrant expression of IL-22RA1, we analyzed the gene promoter of IL-22RA1, and we found multiple binding sites for NF-κB, a transcriptional factor strongly implicated in the pathogenesis of MCL. Pharmacologic inhibition of NF-κB resulted in a substantial reduction in the level of IL-22RA1 protein expression in MCL cells. To conclude, IL-22RA is aberrantly expressed in MCL, and we have provided evidence that IL-22 signaling contributes to the pathogenesis of MCL.

Interleukin-22: a cytokine produced by T, NK and NKT cell subsets, with importance in the innate immune defense and tissue protection

Interleukin (IL)-22 is a member of the IL-10 cytokine family that is produced by special immune cell populations, including Th22, Th1, and Th17 cells, classical and non-classical (NK-22) NK cells, NKT cells, and lymphoid tissue inducer cells. This cytokine does not influence cells of the hematopoietic lineage. Instead, its target cells are certain tissue cells from the skin, liver and kidney, and from organs of the respiratory and gastrointestinal systems. The main biological role of IL-22 includes the increase of innate immunity, protection from damage, and enhancement of regeneration. IL-22 can play either a protective or a pathogenic role in chronic inflammatory diseases depending on the nature of the affected tissue and the local cytokine milieu. This review highlights the primary effects of IL-22 on its target cells, its role in the defense against infections, in tumorigenesis, in inflammatory diseases and allergy as well as the potential of the therapeutic modulation of IL-22 action.

Perspectives on the etiology of chronic rhinosinusitis

PURPOSE OF REVIEW

This article reviews recent insights surrounding the etiology and pathogenesis of chronic rhinosinusitis. In particular, we highlight the increasing recognition of host-mediated mechanisms in driving mucosal inflammation.

RECENT FINDINGS

Published differences between epithelium from patients with chronic rhinosinusitis and normal controls can be classified into several broad categories. Alterations are reported in the various components of the epithelial innate immune system including epithelial-expressed pattern-recognition receptors (PRRs) and the levels of antimicrobial innate immune effector molecules. Other studies demonstrate differences in the proteins involved in maintaining epithelial barrier integrity. Finally, recent studies show in chronic rhinosinusitis that epithelial-derived cytokines, chemokines and inducible surface proteins are involved in recruiting and activating cells of the adaptive immune system.

CONCLUSION

The sinonasal epithelium provides a mechanical and innate immune barrier to a diverse array of environmental agents. This barrier also plays a key role in regulating the acquired mucosal immune response in the nose. Recent studies suggest that defects in this barrier may foster development of chronic sinonasal inflammation in response to environmental agents, and pathogenic or commensal organisms. The ability to dissect and analyze defects in the inflammatory response in rhinosinusitis may help identify novel targets for drug development.

Technical advances in rhinologic basic science research

Chronic rhinosinusitis (CRS) is the single most common self-reported chronic health condition in the United States and is estimated to affect 16% of the adult population annually. Despite the prevalence of this disease, there still exists an incomplete understanding of CRS pathophysiology. In this review, the authors highlight technological advances in rhinology: real-time polymerase chain reaction, epithelial cell culture, flow cytometry, genomics/single-nucleotide polymorphism detection, microarrays, and genetic/nongenetic animal models of sinusitis. The purpose of this review is to describe these methodologies and their contributions toward achieving a better understanding of CRS.

The role of innate immunity in the pathogenesis of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory condition with a multifactorial basis. Infectious triggers of CRS have been proposed, but demonstration remains elusive. Evolving research suggests that abnormal host mucosal immune responses, rather than specific pathogens themselves, may underlie the chronic inflammatory state. Despite constant contact with airborne particulates and microorganisms, the sinonasal epithelium maintains mucosal homeostasis through innate and adaptive immune mechanisms that eliminate potential threats. Innate immunity encompasses a broad collection of constitutive and inducible processes that can be nonspecific or pathogen directed. Some innate immune pathways are closely intertwined with tissue growth and repair. The persistent inflammation observed in CRS may result from a pathologic imbalance in innate immune interactions between the host and the environment. Impairment of critical innate immune protection renders the sinonasal mucosal surface susceptible to colonization and potential injury, stimulating the prominent adaptive immune response that characterizes CRS.

Polymorphisms in the interleukin-22 receptor alpha-1 gene are associated with severe chronic rhinosinusitis

Rationale: Stimulation of interleukin-22 receptor alpha-1 (IL22RA1) was reported to increase the innate immune responses in inflammatory diseases. Moreover, a reduced level of IL22RA1 was found in patients with recalcitrant CRS with nasal polyps.

Objective: To explore association between single nucleotide polymorphisms (SNPs) in IL22RA1 and severe CRS.

Methods: We extracted DNA from 206 cases with severe CRS and 196 postal code–matched controls. Twenty-three SNPs in the IL22RA1 gene were selected from the pooling-based genome-wide association study and from the CEU HapMap dataset and genotyped. PLINK software was used to determine association.

Results: After Bonferroni correction, three SNPs (rs4292900 Pnom = 0.0006, OR = 1.757; rs4648936 Pnom = 0.0011, OR = 1.716; rs16829225 Pnom = 0.0014, OR = 1.977) show significant differences in allelic frequencies between cases and controls.

Conclusion: Polymorphisms in IL22RA1 are associated with severe CRS. Replication and functional studies are involved to better understand the mechanism by which these polymorphisms contribute to the pathogenesis of CRS.

Perspectives on the etiology of chronic rhinosinusitis: an immune barrier hypothesis

BACKGROUND

Chronic rhinosinusitis (CRS) has been defined as persistent symptomatic inflammation of the nasal and sinus mucosa resulting from the interaction of multiple host and environmental factors. Recent studies have implicated Alternaria fungi or toxigenic Staphylococcus aureus as critical agents in CRS pathogenesis. The emphasis on environmental agents in CRS etiology has focused interest toward elimination of those agents as the prime mechanism of therapy. This viewpoint is in marked contrast to the current perspective on some other chronic inflammatory epithelial disorders that afflict the skin, lungs, and gut, wherein host factors are believed to predispose to disease expression in the presence of ubiquitous environmental agents.

METHODS

The current review evaluates CRS etiology from this perspective and considers that CRS develops, in part, as an outcome of a dysfunctional host response. Specifically, evidence from our laboratory and others will be reviewed indicating that CRS is associated with a failure of the mechanical and immunologic barriers across the nasal mucosa. The hypothesis would further propose that genetic and epigenetic variation predisposes susceptible individuals to barrier failure in the presence of environmental stress leading to CRS.

RESULTS

From this unifying perspective, bacteria and fungi are seen as disease modifiers rather than primary etiologic agents.

CONCLUSION

The goal is to place concepts of CRS pathophysiology in a framework consistent with a current understanding of chronic inflammation in general and epithelial disease in particular.

Advances in upper airway diseases and allergen immunotherapy in 2007

The purpose of this review is to highlight important articles on upper airway diseases and immunotherapy that appeared in 2007. Advances in rhinitis include the realization that allergic rhinitis might be caused by local nasal IgE sensitization to aeroallergens in the absence of systemic evidence of IgE sensitization. After inhalation, allergens might reach systemic circulation. Epidemiologic studies continue to show that allergic rhinitis impairs school performance and is a risk factor for future asthma. New pathways are being identified in chronic sinusitis, as well as in different types of allergic ocular diseases. New treatments for patients with allergic rhinitis include use of beta-1,3-glucan, a mushroom product that can reduce allergic symptoms by inducing T(H)1 response, and olopatadine nasal spray. Studies on immunotherapy in 2007 suggest that sublingual immunotherapy induces similar immunologic alterations as those induced by subcutaneous immunotherapy, although to a lesser degree. Among allergists in the United States, there is a sizable variation in clinical practice, particularly related to concomitant administration of immunotherapy and beta-blockers, to administration of angiotensin-converting enzyme inhibitors, and to patients with HIV or autoimmune diseases. The combination of omalizumab with allergen subcutaneous immunotherapy can enhance clinical efficacy. Recombinant technology can modify allergen structure to prevent binding to IgE (allergenicity) while enhancing immunogenicity (stimulation of T cells), which might improve the safety and efficacy of immunotherapy.