Group 2 Innate Lymphoid Cells in Airway Diseases

Necroptosis plays a role in TL1A-induced airway inflammation and barrier damage in asthma

BACKGROUND

Airway epithelial cell (AEC) necroptosis contributes to airway allergic inflammation and asthma exacerbation. Targeting the tumor necrosis factor-like ligand 1 A (TL1A)/death receptor 3 (DR3) axis has a therapeutic effect on asthmatic airway inflammation. The role of TL1A in mediating necroptosis of AECs challenged with ovalbumin (OVA) and its contribution to airway inflammation remains unclear.

METHODS

We evaluated the expression of the receptor-interacting serine/threonine-protein kinase 3(RIPK3) and the mixed lineage kinase domain-like protein (MLKL) in human serum and lung, and histologically verified the level of MLKL phosphorylation in lung tissue from asthmatics and OVA-induced mice. Next, using MLKL knockout mice and the RIPK3 inhibitor GSK872, we investigated the effects of TL1A on airway inflammation and airway barrier function through the activation of necroptosis in experimental asthma.

RESULTS

High expression of necroptosis marker proteins was observed in the serum of asthmatics, and necroptosis was activated in the airway epithelium of both asthmatics and OVA-induced mice. Blocking necroptosis through MLKL knockout or RIPK3 inhibition effectively attenuated parabronchial inflammation, mucus hypersecretion, and airway collagen fiber accumulation, while also suppressing type 2 inflammatory factors secretion. In addition, TL1A/ DR3 was shown to act as a death trigger for necroptosis in the absence of caspases by silencing or overexpressing TL1A in HBE cells. Furthermore, the recombinant TL1A protein was found to induce necroptosis in vivo, and knockout of MLKL partially reversed the pathological changes induced by TL1A. The necroptosis induced by TL1A disrupted the airway barrier function by decreasing the expression of tight junction proteins zonula occludens-1 (ZO-1) and occludin, possibly through the activation of the NF-κB signaling pathway.

CONCLUSIONS

TL1A-induced airway epithelial necroptosis plays a significant role in promoting airway inflammation and barrier dysfunction in asthma. Inhibition of the TL1A-induced necroptosis pathway could be a promising therapeutic strategy.

Dietary Fiber-Derived Microbial Butyrate Suppresses ILC2-Dependent Airway Inflammation in COPD

Group 2 innate lymphoid cells (ILC2) strongly modulate COPD pathogenesis. However, the significance of microbiota in ILC2s remains unelucidated. Herein, we investigated the immunomodulatory role of short-chain fatty acids (SCFAs) in regulating ILC2-associated airway inflammation and explores its associated mechanism in COPD. In particular, we assessed the SCFA-mediated regulation of survival, proliferation, and cytokine production in lung sorted ILC2s. To elucidate butyrate action in ILC2-driven inflammatory response in COPD models, we administered butyrate to BALB/c mice via drinking water. We revealed that SCFAs, especially butyrate, derived from dietary fiber fermentation by gut microbiota inhibited pulmonary ILC2 functions and suppressed both IL-13 and IL-5 synthesis by murine ILC2s. Using in vivo and in vitro experimentation, we validated that butyrate significantly ameliorated ILC2-induced inflammation. We further demonstrated that butyrate suppressed ILC2 proliferation and GATA3 expression. Additionally, butyrate potentially utilized histone deacetylase (HDAC) inhibition to enhance NFIL3 promoter acetylation, thereby augmenting its expression, which eventually inhibited cytokine production in ILC2s. Taken together, the aforementioned evidences demonstrated a previously unrecognized role of microbial-derived SCFAs on pulmonary ILC2s in COPD. Moreover, our evidences suggest that metabolomics and gut microbiota modulation may prevent lung inflammation of COPD.

The potential application and molecular mechanisms of natural products in the treatment of allergic rhinitis: A review

BACKGROUNDS

Allergic rhinitis (AR) is a non-infectious chronic inflammation of the nasal mucosa mainly mediated by immunoglobulin E (IgE) in atopic individuals after exposure to allergens. The application of AR guideline-recommended pharmacotherapies can rapidly relieve symptoms of AR but with poor long-term efficacy, and many of these therapies have side effects. Many natural products and their derivatives have shown potential therapeutic effects on AR with fewer side effects.

OBJECTIVES

This review aims to expand understanding of the roles and mechanisms of natural compounds in the treatment of AR and to highlight the importance of utilizing natural products in the treatment of AR.

MATERIAL AND METHOD

We conducted a systematic literature search using PubMed, Web of Science, Google Scholar, and Clinical Trials. The search was performed using keywords including natural products, natural compounds, bioproducts, plant extracts, naturally derived products, natural resources, allergic rhinitis, hay fever, pollinosis, nasal allergy. Comprehensive research and compilation of existing literature were conducted.

RESULTS

This article provided a comprehensive review of the potential therapeutic effects and mechanisms of natural compounds in the treatment of AR. We emphasized that natural products primarily exert their effects by modulating signalling pathways such as NF-κB, MAPKs, STAT3/ROR-γt/Foxp3, and GATA3/T-bet, thereby inhibiting the activation and expansion of allergic inflammation. We also discussed their toxicity and clinical applications in AR therapy.

CONCLUSION

Taken together, natural products exhibit great potential in the treatment of AR. This review is also expected to facilitate the application of natural products as candidates for treating AR. Furthermore, drug discovery based on natural products has a promising prospect in AR treatment.

Innate lymphoid cells are activated in HFRS, and their function can be modulated by hantavirus-induced type I interferons

Hantaviruses cause the acute zoonotic diseases hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Infected patients show strong systemic inflammation and immune cell activation. NK cells are highly activated in HFRS, suggesting that also other innate lymphoid cells (ILCs) might be responding to infection. Here, we characterized peripheral ILC responses, and measured plasma levels of soluble factors and plasma viral load, in 17 Puumala virus (PUUV)-infected HFRS patients. This revealed an increased frequency of ILC2 in patients, in particular the ILC2 lineage-committed c-Kitlo ILC2 subset. Patients' ILCs showed an activated profile with increased proliferation and displayed altered expression of several homing markers. How ILCs are activated during viral infection is largely unknown. When analyzing PUUV-mediated activation of ILCs in vitro we observed that this was dependent on type I interferons, suggesting a role for type I interferons-produced in response to virus infection-in the activation of ILCs. Further, stimulation of naïve ILC2s with IFN-β affected ILC2 cytokine responses in vitro, causing decreased IL-5 and IL-13, and increased IL-10, CXCL10, and GM-CSF secretion. These results show that ILCs are activated in HFRS patients and suggest that the classical antiviral type I IFNs are involved in shaping ILC functions.

The role of innate lymphoid cells in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a connective tissue disorder that affects various body systems. Both the innate and adaptive immunity contribute to the onset and progression of SLE. The main mechanism of SLE is an excessive immune response of immune cells to autoantigens, which leads to systemic inflammation and inflammation-induced organ damage. Notably, a subset of innate immune cells known as innate lymphoid cells (ILCs) has recently emerged. ILCs are pivotal in the early stages of infection; participate in immune responses, inflammation, and tissue repair; and regulate the immune function of the body by resisting pathogens and regulating autoimmune inflammation and metabolic homeostasis. Thus, ILCs dysfunction can lead to autoimmune diseases. This review discusses the maturation of ILCs, the potential mechanisms by which ILCs exacerbate SLE pathogenesis, and their contributions to organ inflammatory deterioration in SLE.

Inflammatory and Autoimmune Aspects of Multisystem Inflammatory Syndrome in Children (MIS-C): A Prospective Cohort Study

Multisystem Inflammatory Syndrome in Children (MIS-C) is a potentially life-threatening complication of COVID-19. The pathophysiological mechanisms leading to severe disease are poorly understood. This study leveraged clinical samples from a well-characterized cohort of children hospitalized with COVID-19 or MIS-C to compare immune-mediated biomarkers. Our objective was to identify selected immune molecules that could explain, in part, why certain SARS-CoV-2-infected children developed MIS-C. We hypothesized that type-2 helper T cell-mediated inflammation can elicit autoantibodies, which may account for some of the differences observed between the moderate-severe COVID-19 (COVID+) and MIS-C cohort. We enumerated blood leukocytes and measured levels of selected serum cytokines, chemokines, antibodies to COVID-19 antigens, and autoantibodies in children presenting to an academic medical center in Connecticut, United States. The neutrophil/lymphocyte and eosinophil/lymphocyte ratios were significantly higher in those in the MIS-C versus COVID+ cohort. IgM and IgA, but not IgG antibodies to SARS-CoV-2 receptor binding domain were significantly higher in the MIS-C cohort than the COVID+ cohort. The serum levels of certain type-2 cytokines (interleukin (IL)-4, IL-5, IL-6, IL-8, IL-10, IL-13, and IL-33) were significantly higher in children with MIS-C compared to the COVID+ and SARS-CoV-2-negative cohorts. IgG autoantibodies to brain antigens and pentraxin were higher in children with MIS-C compared to SARS-CoV-19-negative controls, and children with MIS-C had higher levels of IgG anti-contactin-associated protein-like 2 (caspr2) compared to the COVID+ and SARS-CoV-19-negative controls. We speculate that autoimmune responses in certain COVID-19 patients may induce pathophysiological changes that lead to MIS-C. The triggers of autoimmunity and factors accounting for type-2 inflammation require further investigation.

Increased SERPINB2 potentiates 15LO1 expression via STAT6 signalling in epithelial cells in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

SERPINB2, a biomarker of Type-2 (T2) inflammatory processes, has been described in the context of asthma. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also correlated with T2 inflammation and elevated 15LO1 induced by IL-4/13 in nasal epithelial cells. The aim of this study was to evaluate the expression and location of SERPINB2 in nasal epithelial cells (NECs) and determine whether SERPINB2 regulates 15LO1 and downstream T2 markers in NECs via STAT6 signalling.

METHODS

SERPINB2 gene expression in bulk and single-cell RNAseq database was analysed by bioinformatics analysis. SERPINB2, 15LO1 and other T2 markers were evaluated from CRSwNP and HCs NECs. The colocalization of SERPINB2 and 15LO1 was evaluated by immunofluorescence. Fresh NECs were cultured at an air-liquid interface with or without IL-13, SERPINB2 Dicer-substrate short interfering RNAs (DsiRNAs) transfection, exogenous SERPINB2, 15-HETE recombinant protein and pSTAT6 inhibitors. 15LO1, 15-HETE and downstream T2 markers were analysed by qRT-PCR, western blot and ELISA.

RESULTS

SERPINB2 expression was increased in eosinophilic nasal polyps compared with that in noneosinophilic nasal polyps and control tissues and positively correlated with 15LO1 and other downstream T2 markers. SERPINB2 was predominantly expressed by epithelial cells in NP tissue and was colocalized with 15LO1. In primary NECs in vitro, SERPINB2 expression was induced by IL-13. Knockdown or overexpression SERPINB2 decreased or enhanced expression of 15LO1 and 15-HETE in NECs, respectively, in a STAT6-dependent manner. SERPINB2 siRNA also inhibited the expression of the 15LO1 downstream genes, such as CCL26, POSTN and NOS2. STAT6 inhibition similarly decreased SERPINB2-induced 15LO1.

CONCLUSIONS

SERPINB2 is increased in NP epithelial cells of eosinophilic CRSwNP (eCRSwNP) and contributes to T2 inflammation via STAT6 signalling. SERPINB2 could be considered a novel therapeutic target for eCRSwNP.

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

Development of Biomarkers and Prognosis Model of Mortality Risk in Patients with COVID-19

Background

As of 30 April 2023, the COVID-19 pandemic has resulted in over 6.9 million deaths worldwide. The virus continues to spread and mutate, leading to continuously evolving pathological and physiological processes. It is imperative to reevaluate predictive factors for identifying the risk of early disease progression.

Methods

A retrospective study was conducted on a cohort of 1379 COVID-19 patients who were discharged from Xin Hua Hospital affiliated with Shanghai Jiao Tong University School of Medicine between 15 December 2022 and 15 February 2023. Patient symptoms, comorbidities, demographics, vital signs, and laboratory test results were systematically documented. The dataset was split into testing and training sets, and 15 different machine learning algorithms were employed to construct prediction models. These models were assessed for accuracy and area under the receiver operating characteristic curve (AUROC), and the best-performing model was selected for further analysis.

Results

AUROC for models generated by 15 machine learning algorithms all exceeded 90%, and the accuracy of 10 of them also surpassed 90%. Light Gradient Boosting model emerged as the optimal choice, with accuracy of 0.928 ± 0.0006 and an AUROC of 0.976 ± 0.0028. Notably, the factors with the greatest impact on in-hospital mortality were growth stimulation expressed gene 2 (ST2,19.3%), interleukin-8 (IL-8,17.2%), interleukin-6 (IL-6,6.4%), age (6.1%), NT-proBNP (5.1%), interleukin-2 receptor (IL-2R, 5%), troponin I (TNI,4.6%), congestive heart failure (3.3%) in Light Gradient Boosting model.

Conclusion

ST-2, IL-8, IL-6, NT-proBNP, IL-2R, TNI, age and congestive heart failure were significant predictors of in-hospital mortality among COVID-19 patients.

Blocking group 2 innate lymphoid cell activation and macrophage M2 polarization: potential therapeutic mechanisms in ovalbumin-induced allergic asthma by calycosin

BACKGROUND

Calycosin, a flavonoid compound extracted from Astragalus membranaceus, has shown anti-asthma benefits in house dust mite-induced asthma. Recent studies have suggested that innate-type cells, including group 2 innate lymphoid cells (ILC2s) and macrophages, serve as incentives for type 2 immunity and targets for drug development in asthma. This work focuses on the effects of calycosin on the dysregulated ILC2s and macrophages in allergic asthma.

METHODS

In vivo, the asthmatic mouse model was established with ovalbumin (OVA) sensitization and challenge, and calycosin was intraperitoneally administered at doses of 20 and 40 mg/kg. In vivo, mouse primary ILC2s were stimulated with interleukin (IL)-33 and mouse RAW264.7 macrophages were stimulated with IL-4 and IL-13 to establish the cell models. Cells were treated with calycosin at doses of 5 and 10 µM.

RESULTS

In vivo, we observed significantly reduced numbers of eosinophils, neutrophils, monocyte macrophages and lymphocytes in the bronchoalveolar lavage fluid (BALF) of OVA-exposed mice with 40 mg/kg calycosin. Histopathological assessment showed that calycosin inhibited the airway inflammation and remodeling caused by OVA. Calycosin markedly decreased the up-regulated IL-4, IL-5, IL-13, IL-33, and suppression tumorigenicity 2 (ST2) induced by OVA in BALF and/or lung tissues of asthmatic mice. Calycosin repressed the augment of arginase 1 (ARG1), IL-10, chitinase-like 3 (YM1) and mannose receptor C-type 1 (MRC1) levels in the lung tissues of asthmatic mice. In vivo, calycosin inhibited the IL-33-induced activation as well as the increase of IL-4, IL-5, IL-13 and ST2 in ILC2s. Calycosin also repressed the increase of ARG1, IL-10, YM1 and MRC1 induced by IL-4 and IL-13 in RAW264.7 macrophages. In addition, we found that these changes were more significant in 40 mg/kg calycosin treatment than 20 mg/kg calycosin.

CONCLUSIONS

Collectively, this study showed that calycosin might attenuate OVA-induced airway inflammation and remodeling in asthmatic mice via preventing ILC2 activation and macrophage M2 polarization. Our study might contribute to further study of asthmatic therapy.

ILC2s: Unraveling the innate immune orchestrators in allergic inflammation

The prevalence rate of allergic diseases including asthma, atopic rhinitis (AR) and atopic dermatitis (AD) has been significantly increasing in recent decades due to environmental changes and social developments. With the study of innate lymphoid cells, the crucial role played by type 2 innate lymphoid cells (ILC2s) have been progressively unveiled in allergic diseases. ILC2s, which are a subset of innate lymphocytes initiate allergic responses. They respond swiftly during the onset of allergic reactions and produce type 2 cytokines, working in conjunction with T helper type 2 (Th2) cells to induce and sustain type 2 immune responses. The role of ILC2s represents an intriguing frontier in immunology; however, the intricate immune mechanisms of ILC2s in allergic responses remain relatively poorly understood. To gain a comphrehensive understanding of the research progress of ILC2, we summarize recent advances in ILC2s biology in pathologic allergic inflammation to inspire novel approaches for managing allergic diseases.

Wogonoside Ameliorates Airway Inflammation and Mucus Hypersecretion via NF-κB/STAT6 Signaling in Ovalbumin-Induced Murine Acute Asthma

Asthma is recognized as a chronic respiratory illness characterized by airway inflammation and airway hyperresponsiveness. Wogonoside, a flavonoid glycoside, is reported to significantly alleviate the inflammation response and oxidative stress. Herein, this study aimed to investigate the therapeutic effect and underlying mechanism of wogonoside on airway inflammation and mucus hypersecretion in a murine asthma model and in human bronchial epithelial cells (16HBE). BALB/c mice were sensitized and challenged with ovalbumin (OVA). Pulmonary function and the number of cells in the bronchoalveolar lavage fluid (BALF) were examined. Pathological changes in lung tissue in each group were evaluated via hematoxylin and eosin and periodic acid-Schiff staining, and changes in levels of cytokines in BALF and of immunoglobulin E in serum were determined via an enzyme-linked immunosorbent assay. The expression of relevant genes in lung tissue was analyzed via real-time PCR. Western blotting and immunofluorescence were employed to detect the expression of relevant proteins in lung tissue and 16HBE cells. Treatment with 10 and 20 mg/kg wogonoside significantly attenuated the OVA-induced increase of inflammatory cell infiltration, mucus secretion, and goblet cell percentage and improved pulmonary function. Wogonoside treatment reduced the level of T-helper 2 cytokines including interleukin (IL)-4, IL-5, and IL-13 in BALF and of IgE in serum and decreased the mRNA levels of cytokines (IL-4, IL-5, IL-6, IL-13, and IL-1β and tumor necrosis factor-α), chemokines (CCL-2, CCL-11, and CCL-24), and mucoproteins (MUC5AC, MUC5B, and GOB5) in lung tissues. The expression of MUC5AC and the phosphorylation of STAT6 and NF-κB p65 in lung tissues and 16HBE cells were significantly downregulated after wogonoside treatment. Thus, wogonoside treatment may effectively decrease airway inflammation, airway remodeling, and mucus hypersecretion via blocking NF-κB/STAT6 activation.

Retinoic Acid Treatment Mitigates PM2.5-Induced Type 2 Inflammation: Insights into Modulation of Innate Immune Responses

Some studies have demonstrated the effects of particulate matter (PM) on chronic rhinosinusitis with nasal polyps (CRSwNP) development, as well as the therapeutic role of retinoic acid (RA) in nasal polypogenesis. However, the immunologic effect of PM in innate lymphoid cells (ILCs) and the exact mechanism of the therapeutic effect of RA remain unclear. Therefore, the present study investigated the effects of fine-dust-induced inflammation in CRSwNP and the mechanisms of the therapeutic effect of RA. PM2.5 exposure exacerbated pathological damage in the nasal mucosa of mice with nasal polyps (NP) via upregulation of type 2 inflammation. Additionally, PM2.5 exposure increased the expression of type 2 cytokines and epithelial-cell-derived cytokines (IL-33 and IL-25) significantly, as well as the ILC populations in human-NP-derived epithelial cells (HNECs). Moreover, RA supplementation significantly increased the expression of ILCreg in Lin-CD45+CD127+ cells, which in turn increased the levels of the anti-inflammatory cytokine IL-10. The findings suggest that PM2.5 exposures could aggravate the CRSwNP type 2 inflammation, and RA treatment may ameliorate fine-dust-induced inflammation by modulating the innate immune response.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.

The role of hormones in ILC2-driven allergic airway inflammation

Group 2 innate lymphoid cells (ILC2s) are a type of innate immune cells that produce a large amount of IL-5 and IL-13 and two cytokines that are crucial for various processes such as allergic airway inflammation, tissue repair and tissue homeostasis. It is known that damaged epithelial-derived alarmins, such as IL-33, IL-25 and thymic stromal lymphopoietin (TSLP), are the predominant ILC2 activators that mediate the production of type 2 cytokines. In recent years, abundant studies have found that many factors can regulate ILC2 development and function. Hormones synthesized by the body's endocrine glands or cells play an important role in immune response. Notably, ILC2s express hormone receptors and their proliferation and function can be modulated by multiple hormones during allergic airway inflammation. Here, we summarize the effects of multiple hormones on ILC2-driven allergic airway inflammation and discuss the underlying mechanisms and potential therapeutic significance.

Allergen immunotherapy combined with Notch pathway inhibitors improves HDM-induced allergic airway inflammation and inhibits ILC2 activation

Introduction

Group 2 innate lymphoid cells (ILC2s) play a crucial role in house dust mite (HDM)-induced allergic inflammation, and allergen immunotherapy (AIT) holds promise for treating the disease by reducing the frequency of ILC2s. Despite significant progress in AIT for allergic diseases, there remains a need to improve the control of allergic symptoms.

Methods

We investigated the synergistic effect of the Notch signaling pathway and subcutaneous immunotherapy (SCIT) in treating allergic airway inflammation in mice and their impact on the ratio of ILC2s in lung tissues. This was achieved by establishing the HDM-induced airway allergic disorders (HAAD) model and SCIT model. Additionally, we conducted in vitro investigations into the effect of the Notch signaling pathway on the secretory function of activated ILC2s using fluorescence-activated cell sorting. Furthermore, we explored the coactivation of the Notch signaling pathway with SCIT in vitro by sorting ILC2s from the lung tissues of mice after SCIT modeling.

Results

Previously, our group demonstrated that Notch signaling pathway inhibitors can reduce allergic airway inflammation in mice. Notch signaling induces lineage plasticity of mature ILC2s. In this study, we showed that AIT alleviates allergic airway inflammation and suppresses the frequency of ILC2s induced by HDM. Interestingly, AIT combined with a γ-secretase inhibitor (GSI), an inhibitor of the Notch signaling pathway, significantly inhibited the frequency of ILC2s, reduced airway inflammation, and suppressed Th2-type responses in a mouse model. Furthermore, lung ILC2s from HDM-challenged mice with or without AIT were treated with GSI in vitro, and we found that GSI dramatically reduced the secretion of type 2 inflammatory factors in ILC2s.

Discussion

These findings suggest that Notch signaling pathway inhibitors can be used as adjuvant therapy for AIT and may hold potential treatment value in the cooperative control of allergic airway inflammation during early AIT.

Aberrant characteristics of peripheral blood innate lymphoid cells in COPD, independent of smoking history

Background

Distinguishing asthma and COPD can pose challenges in clinical practice. Increased group 1 innate lymphoid cells (ILC1s) have been found in the lungs and peripheral blood of COPD patients, while asthma is associated with elevated levels of ILC2s. However, it is unclear whether the inflammatory characteristics of ILC1s and ILC2s differ between COPD and asthma. This study aims to compare peripheral blood ILC subsets and their expression of inflammatory markers in COPD patients, asthma patients and controls.

Methods

The study utilised multi-colour flow cytometry to analyse peripheral blood ILC populations in clinically stable COPD patients (n=38), asthma patients (n=37), and smoking (n=19) and non-smoking (n=16) controls.

Results

Proportions of peripheral blood inflammatory CD4+ ILC1s were significantly higher in COPD patients than in asthma. Proportions of CD4- ILC1s were increased in COPD patients compared to asthma patients and smoking controls. Frequencies of CD117- ILC2s were significantly reduced in COPD patients compared with asthma patients. In contrast, the fraction of inflammatory CD45RO+ cells within the CD117- ILC2 population was significantly increased. Principal component analyses showed that combined features of the circulating ILC compartment separated COPD patients from asthma patients and both control groups.

Conclusion

Our in-depth characterisation of ILC1 and ILC2 populations in peripheral blood revealed significant differences in their phenotypes between COPD and asthma patients and smoking or non-smoking controls. These findings suggest a role for both ILC subsets in COPD disease pathology, independent of smoking history, and may have implications for patient stratification and therapy development.

Potential of MAIT cells to modulate asthma

Despite recent advances in asthma treatments, the search for novel therapies remains necessary because there are still patients with recurrent asthma exacerbations and poor responses to the existing treatments. Since group 2 innate lymphoid cells (ILC2) play a pivotal role in asthma by triggering and exacerbating type 2 inflammation, controlling ILC2s function is key to combating severe asthma. Mucosal-associated invariant T (MAIT) cells are innate-like T cells abundant in humans and are activated both in a T cell receptor-dependent and -independent manner. MAIT cells are composed of MAIT1 and MAIT17 based on the expression of transcription factors T-bet and RORγt, respectively. MAIT cells play pivotal roles in host defense against pathogens and in tissue repair and are essential for the maintenance of immunity and hemostasis. Our recent studies revealed that MAIT cells inhibit both ILC2 proliferation and functions in a mouse model of airway inflammation. MAIT cells may alleviate airway inflammation in two ways, by promoting airway epithelial cell barrier repair and by repressing ILC2s. Therefore, reagents that promote MAIT cell-mediated suppression of ILC2 proliferation and function, or designer MAIT cells (genetically engineered to suppress ILC2s or promote repair of airway damage), may be effective therapeutic agents for severe asthma.

The SMYD3-dependent H3K4me3 status of IGF2 intensifies local Th2 differentiation in CRSwNP via positive feedback

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous and common upper airway disease divided into various inflammatory endotypes. Recent epidemiological findings showed a T helper 2 (Th2)-skewed dominance in CRSwNP patients. Histone modification alterations can regulate transcriptional and translational expression, resulting in abnormal pathogenic changes and the occurrence of diseases. Trimethylation of histone H3 lysine 4 (H3K4me3) is considered an activator of gene expression through modulation of accessibility for transcription, which is closely related to CRSwNP. H3K4me3 levels in the human nasal epithelium may change under Th2-biased inflammatory conditions, resulting in exaggerated local nasal Th2 responses via the regulation of naïve CD4+ T-cell differentiation. Here, we revealed that the level of SET and MYND domain-containing protein 3 (SMYD3)-mediated H3K4me3 was increased in NPs from Th2 CRSwNP patients compared with those from healthy controls. We demonstrated that SMYD3-mediated H3K4me3 is increased in human nasal epithelial cells under Th2-biased inflammatory conditions via S-adenosyl-L-methionine (SAM) production and further found that the H3K4me3high status of insulin-like growth factor 2 (IGF2) produced in primary human nasal epithelial cells could promote naïve CD4+ T-cell differentiation into Th2 cells. Moreover, we found that SAM production was dependent on the c-Myc/methionine adenosyltransferase 2A (MAT2A) axis in the nasal epithelium. Understanding histone modifications in the nasal epithelium has immense potential utility in the development of novel classes of therapeutics targeting Th2 polarization in Th2 CRSwNP. Video Abstract.

Integration analysis using bioinformatics and experimental validation on the clinical and biological significance of TSLP in cancers

Thymic stromal lymphopoietin (TSLP) has significantly impacted the development and progression of various neoplastic disorders. To comprehensively evaluate the diverse significance of TSLP in malignant tumors, we first integrative analyze the TSLP expression level in paired and unpaired pan-cancer tissue and cell line, compared against the normal tissue. The correlation between TSLP expression, molecular subtypes, immune subtypes, diagnostic value, and prognostic value in pan-cancer was also investigated. We then explored the impact of TSLP expression on multifaced immune cell infiltration and subsequent clinical outcomes in lung adenocarcinoma (LUAD) patients. and conducted cellular experiments to functionally examine the effect of TSLP on cell proliferation, apoptosis, cell cycle, migration, and invasion in LUAD. The anti-neoplastic mechanism of TSLP was further investigated by qRT-PCR and western blotting. Our findings reveal that TSLP expression is abnormally low in various cancers compared to normal tissue and is associated with different molecular and immune subtypes of cancers. Moreover, ROC and survival analysis results suggest that TSLP expression is correlated with the diagnostic, prognostic, clinical features, and immune cells of LUAD patients. Cell experiments showed that overexpression of TSLP elicited a significant reduction in LUAD cell viability, promoted cell apoptosis, impeded cell cycle progression in the G2/M phase, and inhibited cell migration and invasion. In addition, TSLP inhibited LUAD progression through the JAK1/STAT3 signaling pathway. Therefore, targeting TSLP shows potential as a therapeutic strategy for pan-cancer, particularly for LUAD, and as a biomarker for predicting the prognosis of this malignancy.

Soluble TAM Receptor Tyrosine Kinases Correlate with Disease Severity and Predict the Early Responsiveness of Sublingual Immunotherapy in Allergic Rhinitis

Background

Allergic rhinitis (AR) is a common allergic disease, and SLIT has shown effectiveness as a treatment method. This study focuses on the evaluation of serum TAM receptor tyrosine kinases (TYRO3, AXL, and MER) levels as potential indicators of disease severity and predictive markers for sublingual immunotherapy (SLIT) responsiveness in AR patients.

Methods

A total of 160 AR subjects, including 40 mild AR (MAR) and 120 moderate-severe AR (MSAR) patients, and 40 healthy controls (HC) were recruited. Serum concentrations of TYRO3, AXL, and MER were measured and their relationships with disease severity were examined. In the MSAR group, 102 patients underwent SLIT, and the early efficacy was evaluated. The correlations between the baseline serum concentrations of TYRO3, AXL, and MER and the early responsiveness of SLIT were analyzed.

Results

Serum concentrations of TYRO3, AXL, and MER were significantly reduced in AR patients, particularly in those MSAR subjects. Correlation analysis results indicated that serum TYRO3 and MER levels were negatively correlated with the visual analog scale (VAS) and the total nasal symptom score (TNSS). After one year of follow-up, 80 AR patients completed the treatment and were divided into effective and ineffective groups. Serum baseline levels of TYRO3 and MER were found to be lower in the effective group compared to the ineffective group. Additionally, there was a significant increase in serum TYRO3 and MER levels compared to baseline levels. Receiver operating characteristic (ROC) analysis revealed that circulating TYRO3 and MER had potential values for reflecting AR severity and predicting early SLIT responsiveness.

Conclusion

Serum TYRO3 and MER concentrations were decreased in AR patients and negatively associated with disease severity. Circulating TYRO3 and MER seem to be promising indicators for monitoring the efficacy of SLIT in AR patients.

Epigenomic response to albuterol treatment in asthma-relevant airway epithelial cells

BACKGROUND

Albuterol is the first-line asthma medication used in diverse populations. Although DNA methylation (DNAm) is an epigenetic mechanism involved in asthma and bronchodilator drug response (BDR), no study has assessed whether albuterol could induce changes in the airway epithelial methylome. We aimed to characterize albuterol-induced DNAm changes in airway epithelial cells, and assess potential functional consequences and the influence of genetic variation and asthma-related clinical variables.

RESULTS

We followed a discovery and validation study design to characterize albuterol-induced DNAm changes in paired airway epithelial cultures stimulated in vitro with albuterol. In the discovery phase, an epigenome-wide association study using paired nasal epithelial cultures from Puerto Rican children (n = 97) identified 22 CpGs genome-wide associated with repeated-use albuterol treatment (p < 9 × 10-8). Albuterol predominantly induced a hypomethylation effect on CpGs captured by the EPIC array across the genome (probability of hypomethylation: 76%, p value = 3.3 × 10-5). DNAm changes on the CpGs cg23032799 (CREB3L1), cg00483640 (MYLK4-LINC01600), and cg05673431 (KSR1) were validated in nasal epithelia from 10 independent donors (false discovery rate [FDR] < 0.05). The effect on the CpG cg23032799 (CREB3L1) was cross-tissue validated in bronchial epithelial cells at nominal level (p = 0.030). DNAm changes in these three CpGs were shown to be influenced by three independent genetic variants (FDR < 0.05). In silico analyses showed these polymorphisms regulated gene expression of nearby genes in lungs and/or fibroblasts including KSR1 and LINC01600 (6.30 × 10-14 ≤ p ≤ 6.60 × 10-5). Additionally, hypomethylation at the CpGs cg10290200 (FLNC) and cg05673431 (KSR1) was associated with increased gene expression of the genes where they are located (FDR < 0.05). Furthermore, while the epigenetic effect of albuterol was independent of the asthma status, severity, and use of medication, BDR was nominally associated with the effect on the CpG cg23032799 (CREB3L1) (p = 0.004). Gene-set enrichment analyses revealed that epigenomic modifications of albuterol could participate in asthma-relevant processes (e.g., IL-2, TNF-α, and NF-κB signaling pathways). Finally, nine differentially methylated regions were associated with albuterol treatment, including CREB3L1, MYLK4, and KSR1 (adjusted p value < 0.05).

CONCLUSIONS

This study revealed evidence of epigenetic modifications induced by albuterol in the mucociliary airway epithelium. The epigenomic response induced by albuterol might have potential clinical implications by affecting biological pathways relevant to asthma.

Epigenetic responses to rhinovirus exposure in airway epithelial cells are correlated with key transcriptional pathways in chronic rhinosinusitis

BACKGROUND

Viruses may drive immune mechanisms responsible for chronic rhinosinusitis with nasal polyposis (CRSwNP), but little is known about the underlying molecular mechanisms.

OBJECTIVES

To identify epigenetic and transcriptional responses to a common upper respiratory pathogen, rhinovirus (RV), that are specific to patients with CRSwNP using a primary sinonasal epithelial cell culture model.

METHODS

Airway epithelial cells were collected at surgery from patients with CRSwNP (cases) and from controls without sinus disease, cultured, and then exposed to RV or vehicle for 48 h. Differential gene expression and DNA methylation (DNAm) between cases and controls in response to RV were determined using linear mixed models. Weighted gene co-expression analysis (WGCNA) was used to identify (a) co-regulated gene expression and DNAm signatures, and (b) genes, pathways, and regulatory mechanisms specific to CRSwNP.

RESULTS

We identified 5585 differential transcriptional and 261 DNAm responses (FDR <0.10) to RV between CRSwNP cases and controls. These differential responses formed three co-expression/co-methylation modules that were related to CRSwNP and three that were related to RV (Bonferroni corrected p < .01). Most (95%) of the differentially methylated CpGs (DMCs) were in modules related to CRSwNP, whereas the differentially expressed genes (DEGs) were more equally distributed between the CRSwNP- and RV-related modules. Genes in the CRSwNP-related modules were enriched in known CRS and/or viral response immune pathways.

CONCLUSION

RV activates specific epigenetic programs and correlated transcriptional networks in the sinonasal epithelium of individuals with CRSwNP. These novel observations suggest epigenetic signatures specific to patients with CRSwNP modulate response to viral pathogens at the mucosal environmental interface. Determining how viral response pathways are involved in epithelial inflammation in CRSwNP could lead to therapeutic targets for this burdensome airway disorder.

Xiao-qing-long-tang ameliorates OVA-induced allergic rhinitis by inhibiting ILC2s through the IL-33/ST2 and JAK/STAT pathways

BACKGROUND

Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa that is mediated by immunoglobulin E (IgE). Xiao-qing-long-tang (XQLT) is a traditional Chinese medicine compound that is widely used to treat respiratory diseases such as AR. However, the underlying mechanism of the effect of XQLT on AR remains unclear.

PURPOSE

To elucidate the effect of XQLT on ovalbumin (OVA)-induced AR and the mechanisms of action.

METHODS

The therapeutic efficacy of XQLT was evaluated in a well-established OVA-induced AR mouse model. Nasal symptoms were analyzed, type 2 cytokines and OVA-sIgE levels were measured, nasal mucosa tissues were collected for histological analysis, and the changes of Group 2 innate lymphoid cells (ILC2s) and the IL-33/ST2 and JAK/STAT signaling pathways in the nasal mucosa were observed.

RESULTS

XQLT significantly alleviated the nasal symptoms and histological damage to the nasal mucosa in AR mice, and reduced the levels of type 2 cytokines and OVA-sIgE. In addition, after XQLT treatment, the numbers of ILC2s in the nasal mucosa of AR mice were reduced, and the mRNA levels of the transcription factors GATA3 and ROR-α were decreased. Moreover, IL-33/ST2 signaling pathway was inhibited. The costimulatory cytokine associated JAK/STAT signaling pathway was also inhibited in ILC2s.

CONCLUSION

Our study demonstrated that XQLT regulated ILC2s through the IL-33/ST2 and JAK/STAT pathways to ameliorate type 2 inflammation in OVA-induced AR. These findings suggest that XQLT might be used to treat AR.

Unraveling the Role of Epithelial Cells in the Development of Chronic Rhinosinusitis

The pathophysiology of CRS is multifactorial and complex yet needs to be completed. Recent evidence emphasizes the crucial part played by epithelial cells in the development of CRS. The epithelial cells act as physical barriers and play crucial roles in host defense, including initiating and shaping innate and adaptive immune responses. This review aims to present a comprehensive understanding of the significance of nasal epithelial cells in CRS. New research suggests that epithelial dysfunction plays a role in developing CRS through multiple mechanisms. This refers to issues with a weakened barrier function, disrupted mucociliary clearance, and irregular immune responses. When the epithelial barrier is compromised, it can lead to the passage of pathogens and allergens, triggering inflammation in the body. Furthermore, impaired mucociliary clearance can accumulate pathogens and secretions of inflammatory mediators, promoting chronic inflammation. Epithelial cells can release cytokines and chemokines, which attract and activate immune cells. This can result in an imbalanced immune response that continues to cause inflammation. The interaction between nasal epithelial cells and various immune cells leads to the production of cytokines and chemokines, which can either increase or decrease inflammation. By comprehending the role of epithelial cells in CRS, we can enhance our understanding of the disease's pathogenesis and explore new therapeutics.

Pathogenesis of chronic rhinosinusitis with nasal polyp and a prominent T2 endotype

Chronic rhinosinusitis is a heterogenous and multifactorial disease, characterized by persistent inflammation of the nose and paranasal sinuses, which causes nasal obstruction, nasal discharge, facial pain, and smell disturbance. Chronic rhinosinusitis is divided into two phenotypes: chronic rhinosinusitis with nasal polyp and chronic rhinosinusitis without nasal polyp. Nasal polyps can be associated with many inflammatory cells including eosinophil cells, neutrophil cells, plasma cells, and lymphocytes. T2 endotype is characterized by the type-2 immune response and nasal polyps are associated with eosinophilic dominant infiltration. In contrast, in the T1 and T3 endotypes, chronic rhinosinusitis can be associated with neutrophilic dominant infiltration. In addition, there are mixed types of inflammation with different proportions of eosinophils-neutrophils in chronic rhinosinusitis. In the T2 endotype, there is an increase in the production of Th2 cytokines, including interleukin-4, interleukin-5, and interleukin-13, high levels of immunoglobulin-E in polyp tissue, and eosinophilia. Stimulation of Th2 cells, type-2 innate lymphoid cells, epithelial cell damage, Staphylococcus aureus enterotoxins, and autoimmune antibodies have important roles in the enhancement of Th2 cytokines and pathogenesis of chronic rhinosinusitis with nasal polyp. Monoclonal antibodies target type-2 inflammation, decrease nasal polyp size, and improve the clinical symptoms of CRSwNP patients. The present review will focus on factors involved in the pathogenesis of chronic rhinosinusitis and its treatment.

The causal relationship between multiple autoimmune diseases and nasal polyps

Background

Although previous sporadic studies have reported the associations between a few autoimmune diseases and nasal polyps, these studies have limitations such as conflicting results, small sample sizes, and low levels of evidence.

Methods

Several autoimmune diseases were selected as exposures while the nasal polyps were selected as outcomes. Bidirectional univariable Mendelian randomization and multivariable Mendelian randomization analyses were performed after rigorous screening of instrumental variables. Then mediation analyses were conducted to further investigate the underlying mechanisms.

Results

For the first time, we investigated the causal relationships between nine autoimmune diseases and nasal polyps in different genders and found: (1) there was a causal association between adult-onset Still's disease and nasal polyps; (2) sarcoidosis, ulcerative colitis, type 1 diabetes, and Crohn's disease had no significant associations with nasal polyps; (3) celiac disease showed a suggestive positive association with female nasal polyps, whereas juvenile arthritis and multiple sclerosis showed suggestive positive associations with male nasal polyps. By contrast, arthropathic psoriasis showed a suggestive negative association with nasal polyps. In addition to these nine diseases, previous controversial issues were further investigated: (1) there was a causal relationship between rheumatoid arthritis and nasal polyps, which was partially mediated by "BAFF-R for IgD+ B cells"; (2) ankylosing spondylitis showed suggestive positive associations with the female but not the male nasal polyps. Besides, we validated that there was no causal effect of autoimmune hyperthyroidism on nasal polyps.

Conclusion

Specific conclusions regarding the causal effects of multiple autoimmune diseases on nasal polyps are the same as above. By comparing results between different genders, we have initially observed the sex bimodality in the causal effects between autoimmune diseases and nasal polyps, with those on male nasal polyps being stronger than those on female nasal polyps. Our study lays a solid foundation for further research in the future, not only helping identify individuals susceptible to nasal polyps early but also improving our understanding of the immunopathogenesis of these heterogeneous diseases.

The efficacy and safety of tezepelumab in the treatment of uncontrolled asthma: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Tezepelumab is a human thymic stromal lymphopoietin (TSLP) antibody with effects in asthma. Therefore, our study aimed to evaluate the overall efficacy and safety of tezepelumab for the treatment of uncontrolled asthma.

METHODS

The databases Cochrane Library, PubMed, Embase, Web of Science, and Clinical Trials were searched from inception to April 1, 2022. Only randomized controlled trial (RCTs) that evaluated tezepelumab and a comparator for treating uncontrolled asthma were included. Additionally, articles were limited to English. The primary outcome was clinical efficacy, and the secondary outcome was adverse events. The risk of bias and quality were assessed by the Cochrane Collaboration bias assessment tool. The meta-analysis was performed using Review Manager Version 5.3.

RESULTS

Four RCTs with a total of 1600 patients were included in the study. Pooled analysis indicated that tezepelumab had significantly decreased annualized asthma exacerbations (odds ratio [OR] = 0.67, 95% confidence interval [CI] = [0.57, -0.80], P < .00001) and the asthma control questionnaire score of 6 (ACQ-6) among the patients (standard mean difference [SMD] = -0.29, 95% CI = [-0.39, -0.20], P < .00001) compared to placebo. Furthermore, tezepelumab treatment significantly improved forced expiratory volume in 1 second (FEV1, SMD = 0.28, 95% CI = [0.11, 0.45], P = .001). Regarding safety, the pooled analysis indicated that patients treated with tezepelumab showed no significant difference in adverse events that led to discontinuation of the treatment, but they experienced some other (non-serious) adverse events compared to the placebo group. However, there was a significant decrease in the incidence of serious adverse events and any adverse events in the tezepelumab group. Tezepelumab use was associated with adverse events, including nasopharyngitis, headache, and bronchitis, despite effectively treating asthma.

CONCLUSION

Tezepelumab effectively improved FEV1, reduced the disease symptom score, and decreased the risk of exacerbations in uncontrolled asthma patients. Tezepelumab was associated with some adverse events compared to placebo. This suggests that careful management of adverse events is required if tezepelumab is used to treat asthma patients.

Targeting Epithelium Dysfunction and Impaired Nasal Biofilms to Treat Immunological, Functional, and Structural Abnormalities of Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) with (CRSwNP) or without (CRSsNP) nasal polyps is a prevalent and heterogeneous disorder existing as a spectrum of clinical conditions with complex underlying pathomechanisms. CRS comprises a broad syndrome characterized by multiple immunological features involving complex interactions between the genes, the microbiome, host- and microbiota-derived exosomes, the epithelial barrier, and environmental and micromilieu exposures. The main pathophysiological feature is an epithelial barrier disruption, accompanied by microbiome alterations and unpredictable and multifactorial immunologic overreactions. Extrinsic pathogens and irritants interact with multiple epithelial receptors, which show distinct expression patterns, activate numerous signaling pathways, and lead to diverse antipathogen responses. CRSsNP is mainly characterized by fibrosis and mild inflammation and is often associated with Th1 or Th17 immunological profiles. CRSwNP appears to be associated with moderate or severe type 2 (T2) or Th2 eosinophilic inflammation. The diagnosis is based on clinical, endoscopic, and imaging findings. Possible CRS biomarkers from the peripheral blood, nasal secretions, tissue biopsies, and nasally exhaled air are studied to subgroup different CRS endotypes. The primary goal of CRS management is to maintain clinical control by nasal douching with isotonic or hypertonic saline solutions, administration of nasal and systemic steroids, antibiotics, biologic agents, or, in persistent and more severe cases, appropriate surgical procedures.

Current and emerging biological therapies for Chronic rhinosinusitis with nasal polyps with type 2 inflammation

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP), especially CRSwNP with type 2 inflammation, remains the most difficult-to-treat subtype with high prevalence worldwide. The emergence of biologics has the potential to fulfill the unmet medical needs of patients with CRSwNP driven by type 2 inflammation.

AREAS COVERED

A current review of the literature was performed to overview current and emerging biological therapies in the treatment of CRSwNP.

EXPERT OPINION

In an era of precision medicine, biologics have been given expectations to provide customized therapies to patients with CRSwNP, particularly those with refractory CRSwNP. Large clinical trials and real-world experiences are both essential for the application of biologics. Moreover, to make biological therapy more tailored to patients, an in-depth understanding of the different mechanisms of biologics, further elucidating the relationship between biologics and conventional medical and surgical treatments, and identifying predictive biomarkers warrant thorough investigations.

New insights into the pathophysiology and therapeutic targets of asthma and comorbid chronic rhinosinusitis with or without nasal polyposis

Asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) or without (CRSsNP) are chronic respiratory diseases. These two disorders often co-exist based on common anatomical, immunological, histopathological, and pathophysiological basis. Usually, asthma with comorbid CRSwNP is driven by type 2 (T2) inflammation which predisposes to more severe, often intractable, disease. In the past two decades, innovative technologies and detection techniques in combination with newly introduced targeted therapies helped shape our understanding of the immunological pathways underlying inflammatory airway diseases and to further identify several distinct clinical and inflammatory subsets to enhance the development of more effective personalized treatments. Presently, a number of targeted biologics has shown clinical efficacy in patients with refractory T2 airway inflammation, including anti-IgE (omalizumab), anti-IL-5 (mepolizumab, reslizumab)/anti-IL5R (benralizumab), anti-IL-4R-α (anti-IL-4/IL-13, dupilumab), and anti-TSLP (tezepelumab). In non-type-2 endotypes, no targeted biologics have consistently shown clinical efficacy so far. Presently, multiple therapeutical targets are being explored including cytokines, membrane molecules and intracellular signalling pathways to further expand current treatment options for severe asthma with and without comorbid CRSwNP. In this review, we discuss existing biologics, those under development and share some views on new horizons.

Increased expression of CSF1 in patients with eosinophilic asthma

BACKGROUND

The link between colony-stimulating factor 1 (CSF1) and asthma was reported recently. However, the role and mechanism of CSF1 in asthma remain poorly understood. In this study, we aimed to explore the expression and its potential mechanism of CSF1 in asthma.

METHODS

CSF1 expression in the airway samples from asthmatics and healthy controls were examined, then the correlations between CSF1 and eosinophilic indicators were analyzed. Subsequently, bronchial epithelial cells (BEAS-2B) with CSF1 overexpression and knockdown were constructed to investigate the potential molecular mechanism of CSF1. Finally, the effect of CSF1R inhibitor on STAT1 was investigated.

RESULTS

The expression of CSF1 was significantly increased in patients with asthma compared to healthy controls, especially in patients with severe and eosinophilic asthma. Upregulated CSF1 positively correlated with airway-increased eosinophil inflammation. In vitro, cytokines interleukin 13 (IL-13) and IL-33 can stimulate the upregulation of CSF1 expression. CSF1 overexpression enhanced p-CSF1R/CSF1R and p-STAT1/STAT1 expression, while knockdown CSF1 using anti-CSF1 siRNAs decreased p-CSF1R/CSF1R and p-STAT1/STAT1 expression. Furthermore, the inhibitor of CSF1R significantly decreased p-STAT1/STAT1 expression.

CONCLUSIONS

Sputum CSF1 may be involved in asthmatic airway eosinophil inflammation by interacting with CSF1R and further activating the STAT1 signaling. Interfering this potential pathway could serve as an anti-inflammatory therapy for asthma.

The Role and Clinical Relevance of Osteopontin in Allergic Airway Diseases

The airway epithelium is exposed to numerous external irritants including infectious agents, environmental allergens, and atmospheric pollutants, releasing epithelial cytokines including thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 and initiating downstream type 2 (IL-4, IL-13, and IL-5) and IgE-driven pathways. These pathways trigger the initiation and progression of allergic airway diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. However, the use of biological agents that target downstream cytokines, such as IL-5, IL-4, and IL-13 receptors and IgE, might not be sufficient to manage some patients successfully. Instead of blocking downstream cytokines, targeting upstream epithelial cytokines has been proposed to address the complex immunologic networks associated with allergic airway diseases. Osteopontin (OPN), an extracellular matrix glyco-phosphoprotein, is a key mediator involved in Th1-related diseases, including systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Emerging evidence, including ours, indicates that epithelial-cell-derived OPN also plays an essential role in Th2-skewed airway diseases, including CRSwNP, AR, and allergic asthma involving the Th17 response. Therefore, we reviewed the current knowledge of epithelial-cell-derived OPN in the pathogenesis of three type-2-biased airway diseases and provided a direction for its future investigation and clinical relevance.

B Lineage Cells and IgE in Allergic Rhinitis and CRSwNP and the Role of Omalizumab Treatment

BACKGROUND

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) are two prevalent nasal diseases where both type 2 inflammation and immunoglobulin E (IgE) may play important roles. Although they can exist independently or comorbidly, subtle but important differences exist in immunopathogenesis.

OBJECTIVE

To summarize current knowledge of pathophysiological roles of B lineage cells and IgE in AR and CRS with nasal polyps (CRSwNP).

METHODS

Searched PubMed database, reviewed AR and CRSwNP-related literature, and discussed disease diagnosis, comorbidity, epidemiology, pathophysiology, and treatment. Similarities and differences in B-cell biology and IgE are compared in the 2 conditions.

RESULTS

Both AR and CRSwNP have evidence for pathological type 2 inflammation, B-cell activation and differentiation, and IgE production. However, distinctions exist in the clinical and serological profiles at diagnosis, as well as treatments utilized. B-cell activation in AR may more frequently be regulated in the germinal center of lymphoid follicles, whereas CRSwNP may occur via extrafollicular pathways although controversies remain in these initial activating events. Oligoclonal and antigen-specific IgE maybe predominate in AR, but polyclonal and antigen-nonspecific IgE may predominate in CRSwNP. Omalizumab has been shown efficacious in treating both AR and CRSwNP in multiple clinical trials but is the only Food and Drug Administration-approved anti-IgE biologic to treat CRSwNP or allergic asthma. Staphylococcus aureus frequently colonizes the nasal airway and has the ability to activate type two responses including B-cell responses although the extent to which it modulates AR and CRSwNP disease severity is being investigated.

CONCLUSION

This review highlights current knowledge of the roles of B cells and IgE in the pathogenesis of AR and CRSwNP and a small comparison between the 2 diseases. More systemic studies should be done to elevate the understanding of these diseases and their treatment.

Adaptive immune dysfunction in patients with COVID-19 and impaired kidney function during the omicron surge

BACKGROUND

Little is known about the characteristics of lymphocyte subsets and the association with patient outcomes in COVID-19 with and without impaired kidney function.

METHODS

Lymphocyte subsets were compared in COVID-19 patients with or without kidney dysfunction. The primary outcome was a composite of all-cause mortality or intensive care unit admission. Secondary outcomes included duration of viral shedding, length of hospital stay, and acute kidney injury.

RESULTS

Lymphocyte subset cell counts demonstrated the lowest in patients with severe/critical COVID-19 and kidney dysfunction. Among all lymphocyte subset parameters, Th cell count was the most significant indicator for outcomes. ROC of the combined model of Th cell count and eGFR presented better predictive value than that of the other parameters. Th cell count <394.5 cells/μl and eGFR <87.5 ml/min/1·73m² were independently associated with poor outcomes. The propensity score matching analysis revealed consistent results.

CONCLUSIONS

Reduced Th cell count and eGFR may be applied as promising predictive indicators for identifying COVID-19 patients with high risk and poor outcomes.

Special Issue on ‘Asthma and Allergic Inflammation’

Asthma is a chronic inflammatory airway disease, driven by either allergic or non-allergic stimuli, which usually manifests as wheezing, reversible airflow limitation, and bronchial hyperresponsiveness [...]

Antiallergic Effects of Callerya atropurpurea Extract In Vitro and in an In Vivo Atopic Dermatitis Model

(1) Background: Callerya atropurpurea is found in Laos, Thailand, and Vietnam. Although the anti-inflammatory action of C. atropurpurea has been investigated, the functions of this plant in allergic responses are not understood. Here, we explored the antiallergic mechanism of C. atropurpurea ethanol extract (Ca-EE) using in vitro assays and an in vivo atopic model. (2) Methods: The constituents of Ca-EE were analyzed using GC/MS. Inhibition of lipoxygenase and β-hexosaminidase activity was examined, and the expression of inflammatory genes was measured by quantitative real-time PCR. The regulatory roles of Ca-EE in IgE/FcεRI signaling were examined by Western blotting. The DNCB-induced atopic dermatitis mouse model was performed with histological analysis. (3) Results: Ca-EE comprised cis-raphasatin, lupeol, some sugars, and fatty acids. In RBL-2H3 cells, treatment with Ca-EE significantly reduced the activities of lipoxygenase and β-hexosaminidase, as well as cytokine gene expression. IgE-mediated signaling was downregulated by blocking Lyn kinases. Moreover, Ca-EE effectively inhibited allergic symptoms in the DNCB-induced atopic dermatitis model without toxicity. (4) Conclusions: Ca-EE displayed antiallergic activities through regulating IgE/Lyn signaling in RBL-2H3 cells and a contact dermatitis model. These results indicate that Ca-EE could be effective for allergic disease treatment.

Development of sensitization to peanut and storage proteins and relation to markers of airway and systemic inflammation: A 24-year follow-up

BACKGROUND

Long-time data of peanut allergy over time is sparse. We aimed to study the longitudinal development of sensitization to peanut extract and storage protein allergen molecules and associations with asthma status, airway and systemic inflammation markers.

METHODS

The Swedish birth cohort BAMSE followed 4089 participants with questionnaires, clinical investigations and blood sampling between 0 and 24 years. Information on (i) background factors at 2 months, (ii) peanut allergy symptoms and IgE data (ImmunoCAP) at 4, 8, 16, and 24 years, and (iii) IgE to storage proteins, lung function data including exhaled nitric oxide (FENO) as well as systemic inflammatory markers at 24 years of age were collected.

RESULTS

The prevalence of peanut extract sensitization, defined as IgE ≥ 0.35 kU_A /L, was 5.4%, 8.0%, 7.5%, and 6.2% at 4, 8, 16, and 24 years of age, respectively. Between 8 and 24 years of age, (33/1565) participants developed IgE-ab to peanut extract (median 1,4, range 0.7-2.6 kU_A /L), and among those 85% were also sensitized to birch. Only six individuals developed sensitization to Ara h 2 (≥0.1 kU_A /L) between 8 and 24 years of age, of whom three had an IgE-ab level between 0.1-0.12 kU_A /L. Storage protein sensitization was associated with elevated FENO, blood eosinophils and type 2 inflammation-related systemic proteins.

CONCLUSION

Sensitization to peanut extract after 4 years of age is mainly induced by birch cross-sensitization and IgE to Ara h 2 rarely emerges after eight years of age. Storage protein sensitization is associated with respiratory and systemic inflammation.

Atorvastatin attenuates allergic inflammation by blocking prostaglandin biosynthesis in rats with allergic rhinitis

BACKGROUND

Prostaglandins (PGs) are bioactive lipid mediators derived from the nuclear and plasma membranes via the cyclooxygenase (COX) pathway of arachidonic acid (AA) metabolism. PGs bridge the interactions between various immunomodulatory cells in allergic rhinitis (AR) and are considered key players in regulating pro-inflammatory and anti-inflammatory responses. AA conversion to PGs involves rate-limiting enzymes that may be blocked by statins. The mechanisms by which statins regulate these enzymes in AR remain unclear. We investigated the effects of oral atorvastatin on PGs production in AR.

METHODS

An ovalbumin-induced AR rat model was constructed and the changes in nasal symptom score and nasal mucosa histopathological characteristics of AR rats under different atorvastatin doses were assessed. qRT-PCR, western blotting, and immunofluorescence were used to detect the mRNA and protein expression levels of rate-limiting enzymes and downstream molecules of AA metabolism in the nasal mucosa and liver.

RESULTS

Oral atorvastatin significantly alleviated symptoms and eosinophil infiltration in the nasal mucosa, inhibited goblet cell hyperplasia and mast cell recruitment, and decreased mucus secretion in AR rats. Increasing atorvastatin dose increased the anti-inflammatory effects. High-dose atorvastatin inhibited upregulation of the inflammatory mediator PGD₂ in the nasal mucosa of AR rats. Compared to the control group, the mRNA and protein expression of the rate-limiting enzymes COX-2, PGDS, and PGES in AA metabolism in the AR group were upregulated but downregulated after the oral administration of high-dose atorvastatin. Atorvastatin also showed dose-dependent inhibition of ERK1/2 and downstream NF-κB phosphorylation in the nasal mucosa and liver of AR rats.

CONCLUSIONS

Atorvastatin inhibited allergic inflammation and attenuated AR nasal symptoms by downregulating PGD₂ and rate-limiting enzyme expression in PGD₂ biosynthesis, possibly by blocking the RAS/ERK/NF-κB signaling pathway.

Comprehensive analysis of protein phosphatase 1 regulatory inhibitor subunit 14B, a molecule related to tumorigenesis, poor prognosis, and immune cell infiltration in lung adenocarcinoma

OBJECTIVE

To explore the relationship between Protein Phosphatase 1 Regulatory Inhibitor Subunit 14B (PPP1R14B) and the occurrence of lung adenocarcinoma (LUAD).

METHOD

PPP1R14B expression was investigated using various databases, and its molecular functions and pathways were evaluated using Gene Set Variation Analysis (GSVA) and Gene Set Enrichment Analysis (GSEA). Then, the correlation between tumor mutations and PPP1R14B expression was analyzed. Furthermore, the regulation network and expression pathway axes of PPP1R14B were constructed. The correlation analysis between PPP1R14B and immune cell infiltration was performed using deconvolution algorithm analysis and the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical (IHC) staining of the clinical samples were used for expression validation.

RESULTS

PPP1R14B showed high expression in tumor tissue. PPP1R14B was associated with T and N stages and poor prognosis and was linked to the cell cycle, DNA repair, and low immune response. High PPP1R14B expression was associated with high tumor mutation rates. The upstream and downstream genes of PPP1R14B were identified, along with the construction of a protein-protein interaction network (PPI network) and the expression pathway axes of PPP1R14B. PPP1R14B expression was associated with poor immune cell infiltration and a negative correlation between PPP1R14B and mast cell and eosinophil infiltration.

CONCLUSION

This study reveals high PPP1R14B expression in LUAD, its contribution to poor prognosis, molecular function, biological pathways, and impact on immune cell infiltration, and provides great insight into the role of PPP1R14B in LUAD tumorigenesis.

Dachengqi Decoction alleviates intestinal inflammation in ovalbumin-induced asthma by reducing group 2 innate lymphoid cells in a microbiota-dependent manner

Background and aim

Dachengqi Decoction (DCQD) as a classic traditional Chinese medicine has been reported to be effective in treating asthma, but its mechanism remains unknown. This study aimed to reveal the mechanisms of DCQD on the intestinal complications of asthma mediated by group 2 innate lymphoid cells (ILC2) and intestinal microbiota.

Experimental procedure

Ovalbumin (OVA) was used to construct asthmatic murine models. IgE, cytokines (e.g., IL-4, IL-5), fecal water content, colonic length, histopathologic appearance, and gut microbiota were evaluated in asthmatic mice treated with DCQD. Finally, we administered DCQD to antibiotic-treated asthmatic mice to measure the ILC2 in the small intestine and colon.

Results and conclusion

DCQD decreased pulmonary IgE, IL-4, and IL-5 levels in asthmatic mice. The fecal water content, the colonic length weight loss, and the epithelial damage of jejunum, ileum, and colon of asthmatic mice were ameliorated by DCQD. Meanwhile, DCQD greatly improved intestinal dysbiosis by enriching Allobaculum, Romboutsia and Turicibacter in the whole intestine, and Lactobacillus gasseri only in the colon. However, DCQD caused less abundant Faecalibaculum and Lactobacillus vaginalis in the small intestine of asthmatic mice. A higher ILC2 proportion in different gut segments of asthmatic mice was reversed by DCQD. Finally, significant correlations appeared between DCQD-mediated specific bacteria and cytokines (e.g., IL-4, IL-5) or ILC2. These findings indicate that DCQD alleviated the concurrent intestinal inflammation in OVA-induced asthma by decreasing the excessive accumulation of intestinal ILC2 in a microbiota-dependent manner across different gut locations.

Louki Zupa decoction attenuates the airway inflammation in acute asthma mice induced by ovalbumin through IL-33/ST2-NF-κB/GSK3β/mTOR signalling pathway

CONTEXT

Asthma is a common respiratory system disease. Louki Zupa decoction (LKZP), a traditional Chinese medicine, presents a promising efficacy against lung diseases.

OBJECTIVE

To investigate the pathogenic mechanism of asthma and reveal the intervention mechanism of LKZP.

MATERIALS AND METHODS

Forty-eight female Balb/c mice were randomly divided into 6 groups: normal control group (NC), ovalbumin (OVA)/saline asthma model group, OVA/LL group, OVA/LM group, OVA/LH group and OVA/DEX group (n = 8 per group). The asthmatic mice were modelled through intraperitoneal injecting and neutralizing OVA. LKZP decoction was administrated by gavage at the challenge stage for seven consecutive days (2.1, 4.2 and 8.4 g/kg/day). We investigated the change in lung function, airway inflammation, mucus secretion and TH-1/TH-2-related cytokines. We further verify the activated status of the IL-33/ST2/NF-κB/GSK3β/mTOR signalling pathway.

RESULTS

LKZP was proved to improve asthmatic symptoms, as evidenced by the down-regulated airway resistance by 36%, 58% and 53% (p < 0.01, p < 0.001 vs. OVA/saline group), up-regulated lung compliance by 102%, 114% and 111%, decreased airway inflammation and mucus secretion by 33%, 40% and 33% (p < 0.001 vs. OVA/saline group). Moreover, the content of cytokines in BALF related to airway allergy (such as IgE) and T helper 1/T helper 2 cells (like IL-2, IL-4, IL-5, IL-13, TNF-α and IFN-γ), were also markedly reduced by 13-65% on LKZP intervention groups compared with model group. Mechanistic research revealed that the IL-33/ST2-NF-κB/GSK3β/mTOR signalling pathway was activated in the OVA/saline group and LKZP significantly down-regulated this pathway.

DISCUSSION AND CONCLUSION

LKZP improves lung function, airway inflammation, mucus secretion and correct immune imbalance by intervening with the IL-33/ST2-NF-κB/GSK3β/mTOR signalling pathway, presenting a promising therapeutic choice for asthma.

Physiological microbial exposure transiently inhibits mouse lung ILC2 responses to allergens

Lung group 2 innate lymphoid cells (ILC2s) control the nature of immune responses to airway allergens. Some microbial products, including those that stimulate interferons, block ILC2 activation, but whether this occurs after natural infections or causes durable ILC2 inhibition is unclear. In the present study, we cohoused laboratory and pet store mice as a model of physiological microbial exposure. Laboratory mice cohoused for 2 weeks had impaired ILC2 responses and reduced lung eosinophilia to intranasal allergens, whereas these responses were restored in mice cohoused for ≥2 months. ILC2 inhibition at 2 weeks correlated with increased interferon receptor signaling, which waned by 2 months of cohousing. Reinduction of interferons in 2-month cohoused mice blocked ILC2 activation. These findings suggest that ILC2s respond dynamically to environmental cues and that microbial exposures do not control long-term desensitization of innate type 2 responses to allergens.

Mucosal-associated invariant T cells repress group 2 innate lymphoid cells in Alternaria alternata-induced model of allergic airway inflammation

Mucosal-associated invariant T (MAIT) cells, a blossoming member of the innate-like T cells, play a pivotal role in host defense through engaging the mucosal immunity. Although it has been suggested that MAIT cells are somehow implicated in the allergic airway inflammation mediated by group 2 innate lymphoid cells (ILC2s) such as asthma, the precise role(s) of MAIT cells in such inflammation has remained elusive. To explore the possible roles of MAIT cells in the inflammation, we examined whether MAIT cells suppressed the production of T helper (Th) 2 and inflammatory cytokines from ILC2s, and constrained the proliferation of ILC2s, both of which are prerequisite for airway inflammation. Given that laboratory mice are poor at MAIT cells, a novel mouse line rich in MAIT cells was used. We found that mice rich in MAIT cells showed alleviated airway inflammation as evidenced by reduced infiltration of the immune cells and hyperplasia in goblet cells in the lung concomitant with compromised production of Th2 and inflammatory cytokines, while wild type mice exhibited severe inflammation upon challenge with the fungal extracts. In vitro coculture experiments using purified ILC2s and MAIT cells unrevealed that cytokine-stimulated MAIT cells suppressed ILC2s to produce the cytokines as well as to proliferate most likely via production of IFN-γ. Furthermore, reconstitution of the allergic airway inflammation in the highly immunocompromised mice showed that ILC2-mediated inflammation was alleviated in mice that received MAIT cells along with ILC2s. We concluded that MAIT cells played a crucial role in suppressing the cytokine-producing capacity of ILC2s and ILC2 proliferation, that ultimately led to decrease in the allergic airway inflammation. The results open up a novel therapeutic horizon in ILC2-mediated inflammatory diseases by modulating MAIT cell activity.

Emerging Effects of IL-33 on COVID-19

Since the start of COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more than 6 million people have lost their lives worldwide directly or indirectly. Despite intensified efforts to clarify the immunopathology of COVID-19, the key factors and processes that trigger an inflammatory storm and lead to severe clinical outcomes in patients remain unclear. As an inflammatory storm factor, IL-33 is an alarmin cytokine, which plays an important role in cell damage or infection. Recent studies have shown that serum IL-33 is upregulated in COVID-19 patients and is strongly associated with poor outcomes. Increased IL-33 levels in severe infections may result from an inflammatory storm caused by strong interactions between activated immune cells. However, the effects of IL-33 in COVID-19 and the underlying mechanisms remain to be fully elucidated. In this review, we systematically discuss the biological properties of IL-33 under pathophysiological conditions and its regulation of immune cells, including neutrophils, innate lymphocytes (ILCs), dendritic cells, macrophages, CD4⁺ T cells, Th17/Treg cells, and CD8⁺ T cells, in COVID-19 phagocytosis. The aim of this review is to explore the potential value of the IL-33/immune cell pathway as a new target for early diagnosis, monitoring of severe cases, and clinical treatment of COVID-19.

Benralizumab in the management of rare primary eosinophilic lung diseases

Background: Eosinophils have a double-edged role in the human body, being essential in important physiologic functions but whose presence is conspicuous in a variety of diseases characterized by a T2 inflammation phenotype. Eosinophils are exquisitely sensitive to corticosteroids, and the latter have, until recently, represented the cornerstone of treatment of eosinophilic diseases. However, most patients remain dependent on oral corticosteroids, with a notable adverse effect burden and experience a chronic relapsing disease that leads to high morbidity and mortality. Treatment prospects have changed with the advent of biologic drugs that target the eosinotropic cytokine interleukin (IL) 5 or its receptor. The success of the latter drugs in severe eosinophilic asthma has paved the way for their use in other, rarer, eosinophilic lung diseases. Recently, mepolizumab, a humanized monoclonal antibody that works against IL-5, was approved for the add-on treatment of relapsing-remitting or refractory eosinophilic granulomatosis with polyangiitis (EGPA) in patients ages ≥ 6 years. Benralizumab, a humanized antibody that binds to the α portion of the IL-5 receptor, is also being tested for its efficacy in EGPA in two clinical trials, after a growing number of case reports and case series supported its use as a steroid-sparing agent in the treatment of EGPA. Methods: In this review, we summarized the scientific literature evaluating the efficacy of benralizumab treatment in patients afflicted with rare primary eosinophilic lung diseases. Results: The literature we found, largely case reports, reported that the use of benralizumab in EGPA, chronic eosinophilic pneumonia (CEP) and allergic bronchopulmonary aspergillosis (ABPA) often led to a depletion of eosinophils, less exacerbations and a decreased systemic corticosteroid burden. No adverse effects were reported. Conclusion: Benralizumab has a prospective role in the treatment of rare eosinophilic lung diseases, which needs to be further elucidated in randomized controlled trials.

Ambient ozone, and urban PM2.5 co-exposure, aggravate allergic asthma via transient receptor potential vanilloid 1-mediated neurogenic inflammation

Allergic asthma is the most common pulmonary inflammatory disease, and epidemiological studies have revealed that PM_2.5 or ambient ozone (O₃) exposure contribute to the higher prevalence of allergic asthma. Current experimental evidence focus principally on the pathogenic effect of exposure to a single air pollutant, ignoring the possible synergistic effect of combined exposure to a mix of these pollutants, which is a more realistic scenario. In this study, allergic mice and a nociceptor antagonist were used to explore the mechanisms of co-exposure to these two important air pollutants. Compared with exposure to either PM_2.5 or O₃, combined exposure to both greatly aggravated allergic asthma in a dose dependent manner, including increased airway hyperresponsiveness, goblet cell metaplasia, more severe airway inflammation and higher oxidative stress levels. In addition, co-exposure in the allergic mice resulted in elevation of the expression of transient receptor potential vanilloid 1 (TRPV1), and of the production of substance P (SP), which exacerbated lung inflammation by neurogenic inflammation. TRPV1 antagonist (capsazepine, CPZ) treatment for the co-exposed allergic mice, markedly attenuated TRPV1 expression and SP release, and reduced airway inflammation and oxidative damage, further alleviating airway hyperresponsiveness. We conclude that neuro-immune interactions might be involved in PM_2.5 and O₃ co-exposure aggravated allergic asthma.

Is Strongyloides stercoralis hyperinfection induced by glucocorticoids a result of both suppressed host immunity and altered parasite genetics?

The gastrointestinal (GI) nematode Strongyloides stercoralis (S.s.) causes human strongyloidiasis, a potentially life-threatening disease that currently affects over 600 million people globally. The uniquely pernicious aspect of S.s. infection, as compared to all other GI nematodes, is its autoinfective larval stage (L3a) that maintains a low-grade chronic infection, allowing undetectable persistence for decades. Infected individuals who are administered glucocorticoid therapy can develop a rapid and often lethal hyperinfection syndrome within days. Hyperinfection patients often present with dramatic increases in first- and second-stage larvae and L3a in their GI tract, with L3a widely disseminating throughout host organs leading to sepsis. How glucocorticoid administration drives hyperinfection remains a critical unanswered question; specifically, it is unknown whether these steroids promote hyperinfection through eliminating essential host protective mechanisms and/or through dysregulating parasite development. This current deficiency in understanding is largely due to the previous absence of a genetically defined mouse model that would support all S.s. life-cycle stages and the lack of successful approaches for S.s. genetic manipulation. However, there are currently new possibilities through the recent demonstration that immunodeficient NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ (NSG) mice support sub-clinical infections that can be transformed to lethal hyperinfection syndrome following glucocorticoid administration. This is coupled with advances in transcriptomics, transgenesis, and gene inactivation strategies that now allow rigorous scientific inquiry into S.s. biology. We propose that combining in vivo manipulation of host immunity and deep immunoprofiling strategies with the latest advances in S.s. transcriptomics, piggyBac transposon-mediated transgene insertion, and CRISPR/Cas-9-mediated gene inactivation will facilitate new insights into the mechanisms that could be targeted to block lethality in humans with S.s. hyperinfection.

Osteopontin mediated eosinophils activation by group II innate lymphoid cells

Background

Osteopontin (OPN) can regulate Th2 inflammation in allergic rhinitis (AR). A recent study suggested that group II innate lymphoid cells (ILC2s) were very important for airway inflammation. But the role of OPN in ILC2s regulation is not explored.

Methods

Purified ILC2s were stimulated by human recombinant OPN. The expression of GATA3 and RORα was assayed using real-time polymerase chain reaction (PCR) and enzyme linked immunosorbent assay. MiR-181a was transfected into eosinophils to test the OPN production. The protein concentrations of interleukin (IL)-5 and IL-13 were examined using ELISA. Purified eosinophils and ILC2s were cocultured and stimulated by OPN and the activation of eosinophils was detected by ELISA.

Results

After OPN stimulation, the ILC2s proliferation, the mRNA levels of GATA3 and RORα, the protein of GATA3, RORα, IL-5 and IL-13 expression were up-regulated significantly in a dose dependent manner. Eosinophils cultured alone transfected with miR-181a mimics produced less OPN protein compared with eosinophils transfected with miR-control, whereas OPN production was significantly promoted when miR-181a inhibitor was transfected. In the eosinophils and ILC2s coculture system, eosinophil cationic protein (ECP) production induced by OPN or IL-33 were significantly higher than ECP production in eosinophils culture system. OPN presented similar potency with IL-33 in the activation of eosinophils. When anti-IL-5 antibody was added, the production of ECP was significantly inhibited.

Conclusions

Our data for the first time provided new evidence that OPN played important roles in innate immunity of AR by regulation of ILC2s and the interaction between ILC2s and eosinophils.