Mechanisms of pathogenesis in allergic asthma: role of interleukin-23

A new Anticalin protein for IL-23 inhibits non-type 2 allergen-driven mouse lung inflammation and airway hyperresponsiveness

Severe asthma is a syndromic label assigned to patients based on clinical parameters, yet there are diverse underlying molecular endotypes in severe asthma pathobiology. Immunophenotyping of asthma biospecimens commonly includes a mixture of granulocytes and lymphocytes. Recently, a subset of patients with severe asthma was defined as non-type 2 with neutrophil-enriched inflammation associated with increased Th17 CD4+ T cells and IL-17 levels. Here, we used an allergen-driven mouse model of increased IL-17 and mixed granulocyte lung inflammation to determine the impact of upstream regulation by an Anticalin protein that specifically binds IL-23. Airway administration of the IL-23-binding Anticalin protein (AcIL-23) decreased lung neutrophils, eosinophils, macrophages, lymphocytes, IL-17+ CD4 T cells, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. Selective targeting of IL-23 with a monoclonal antibody (IL-23p19; αIL-23) also decreased macrophages, IL-17+ CD4 T cells, and airway hyperresponsiveness. In contrast, a monoclonal antibody against IL-17A (αIL-17A) had no significant effect on airway hyperresponsiveness but did decrease lung neutrophils, macrophages, and IL-17+ CD4 T cells. Targeting the IL-23 pathway did not significantly change IL-5+ or IL-13+ CD4 T cells. Together, these data indicate that airway AcIL-23 mirrored the activity of systemic anti-IL-23 antibody to decrease airway hyperresponsiveness in addition to mixed granulocytic inflammation and that these protective actions were broader than blocking IL-17A or IL-5 alone, which selectively decreased airway neutrophils and eosinophils, respectively.NEW & NOTEWORTHY This is the first report of an Anticalin protein engineered to neutralize IL-23 (AcIL-23). Airway administration of AcIL-23 in mice regulated allergen-driven airway inflammation, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. In mixed granulocytic allergic lung inflammation, immune regulation of IL-23 was broader than neutralization of either IL-17 or IL-5.

Precision medicine for severe asthma - Biological targeted therapy

Severe asthma is a complex and heterogeneous chronic airway inflammatory disease. Current treatment strategies are increasingly focused on disease classification, facilitating the transition towards personalized medicine by integrating biomarkers and monoclonal antibodies for tailored therapeutic approaches. Several approved biological agents, including anti-immunoglobulin E (IgE), anti-interleukin (IL)-4, anti-IL-5, and anti-thymic stromal lymphopoietin (TSLP) monoclonal antibodies, have demonstrated significant efficacy in reducing asthma exacerbations, eosinophil counts, improving lung function, minimizing oral corticosteroid usage, and enhancing patients' quality of life. The utilization of these biological agents has brought about profound transformations in the management of severe asthma. This article provides a comprehensive review on biomarkers and biological agents for severe asthma while emphasizing the increasing importance of further research into its pathogenesis and novel treatment modalities.

Comparative structural and immunological analysis of outer membrane proteins and dermonecrotic toxin in Bordetella bronchiseptica canine isolate

Bordetella bronchiseptica is a pathogen causing respiratory infections in mammals. With the improving understanding of companion animals' welfare, addressing the side effects of bordetella vaccine gains importance in dogs. Studies on diverse subunit vaccines are actively pursued in humans to safely and effectively control bordetellosis. Therefore, our objective was to develop a canine bordetella vaccine inspired by human vaccine development. We evaluated the immunogenicity of the two bacterial components: the outer membrane proteins (OMPs) and the dermonecrotic toxin (DNT) from a canine isolate of B. bronchiseptica. In-silico analysis identified eight domains of DNT, and Domain 3 was selected as the most promising antigen candidate. Additionally, the OMPs were extracted and examined using SDS-PAGE and Western blot analysis. The distinct immunological characteristic of OMPs and DNT-3 were examined individually and in combination. Gene expression and cytokine production were also evaluated in DH82 cells after stimulation with those antigens. Treatment with OMPs resulted in higher level of Th1 related cytokines, while DNT-3 induced a predominant response associated with Th17 and Th2 in the cytokine production. Synergistic effects were observed exclusively on IL-23, indicating increase of a potential risk of side effects when OMPs and DNT act together. These findings provide valuable insights into the reactogenicity of conventional Bordetella vaccines. Further, the presented preclinical data in this study offer an alternative method of the development for an optimal next-generation Bordetella vaccine for companion animals and humans, replacing the acellular vaccines containing both toxin and protein components.

Phytochemicals as treatment for allergic asthma: Therapeutic effects and mechanisms of action

BACKGROUND

Allergic asthma is an inflammatory disease caused by the immune system's reaction to allergens, inflammation and narrowing of the airways, and the production of more than normal mucus. One of the main reasons is an increased production of inflammatory cytokines in the lungs that leads to the appearance of symptoms of asthma, including inflammation and shortness of breath. On the other hand, it has been proven that phytochemicals with their antioxidant and anti-inflammatory properties can be useful in improving allergic asthma.

PURPOSE

Common chemical treatments for allergic asthma include corticosteroids, which have many side effects and temporarily relieve symptoms but are not a cure. Therefore, taking the help of natural compounds to improve the quality of life of asthmatic patients can be a valuable issue that has been evaluated in the present review.

STUDY DESIGN AND METHODS

In this study, three databases (Scopus, PubMed, and Cochrane) with the keywords: allergic asthma, phytochemical, plant, and herb were evaluated. The primary result was 5307 articles. Non-English, repetitive, and review articles were deleted from the study.

RESULTS AND DISCUSSION

Finally, after carefully reading the articles, 102 were included in the study (2006-2022). The results of this review state that phytochemicals suppress the inflammatory pathways via inhibition of inflammatory cytokines production/secretion, genes, and proteins involved in the inflammation process, reducing oxidative stress indicators and symptoms of allergic asthma, such as cough and mucus production in the lungs.

CONCLUSION

With their antioxidant effects, this study concluded that phytochemicals suppress cytokines and other inflammatory indicators and thus can be considered an adjunctive treatment for improving allergic asthma.

Biologic therapies for chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a disorder characterized by a complicated chronic inflammatory response that is resistant to corticosteroid therapy. As a result, there is a critical need for effective anti-inflammatory medications to treat people with COPD. Using monoclonal antibodies (mAbs) to inhibit cytokines and chemokines or their receptors could be a potential approach to treating the inflammatory component of COPD.

AREAS COVERED

The therapeutic potential that some of these mAbs might have in COPD is reviewed.

EXPERT OPINION

No mAb directed against cytokines or chemokines has shown any therapeutic impact in COPD patients, apart from mAbs targeting the IL-5 pathway that appear to have statistically significant, albeit weak, effect in patients with eosinophilic COPD. This may reflect the complexity of COPD, in which no single cytokine or chemokine has a dominant role. Because the umbrella term COPD encompasses several endotypes with diverse underlying processes, mAbs targeting specific cytokines or chemokines should most likely be evaluated in limited and focused populations.

Bullous pemphigoid-What do we know about the most recent therapies?

Introduction

Bullous pemphigoid (BP) is the most common subtype of autoimmune blistering diseases that primarily affects the elderly and is classically defined by the presence of IgG and/or complement C3 against the BP180 and BP230 hemidesmosome proteins. However, most recent studies have introduced the role of specific eosinophil receptors and chemokine mediators in the pathogenesis of BP which are helpful in identifying new targets for future treatments.

Areas covered

This review will focus on the involvement of eosinophils in BP, including the processes that lead to their recruitment, activation, and regulation. Subsequently, covering new therapeutic options in relation to the role of eosinophils. Eotaxin enhances the recruitment of eosinophils in BP, with CCR3 chemoreceptor that is expressed on eosinophils being identified as a key binding site for eotaxin-1. The pathogenic role of IgE and IL-4 in BP is corroborated by successful treatments with Omalizumab and Dupilumab, respectively. IL-5, IL-17 and IL-23 inhibitors may be effective given their roles in promoting eosinophilia.

Expert opinion

Further research into inhibitors of eotaxin, IL-4, IL-5, IL-17, IL-23, CCR3, and specific complement factors are warranted as preliminary studies have largely identified success in treating BP with these agents. Learning from novel treatments for other IgG-mediated autoimmune diseases may be beneficial.

Biologics in Asthma: A Molecular Perspective to Precision Medicine

Recent developments in therapeutic strategies have provided alternatives to corticosteroids as the cornerstone treatment for managing airway inflammation in asthma. The past two decades have witnessed a tremendous boost in the development of anti-cytokine monoclonal antibody (mAb) therapies for the management of severe asthma. Novel biologics that target eosinophilic inflammation (or type 2, T2 inflammation) have been the most successful at treating asthma symptoms, though there are a few in the drug development pipeline for treating non-eosinophilic or T2-low asthma. There has been significant improvement in clinical outcomes for asthmatics treated with currently available monoclonal antibodies (mAbs), including anti-immunoglobulin (Ig) E, anti-interleukin (IL)-4 receptor α subunit, anti-IL-5, anti-IL-5Rα, anti-IL-6, anti-IL-33, and anti-thymic stromal lymphopoietin (TSLP). Despite these initiatives in precision medicine for asthma therapy, a significant disease burden remains, as evident from modest reduction of exacerbation rates, i.e., approximately 40-60%. There are numerous studies that highlight predictors of good responses to these biologics, but few have focused on those who fail to respond adequately despite targeted treatment. Phenotyping asthmatics based on blood eosinophils is proving to be inadequate for choosing the right drug for the right patient. It is therefore pertinent to understand the underlying immunology, and perhaps, carry out immune endotyping of patients before prescribing appropriate drugs. This review summarizes the immunology of asthma, the cytokines or receptors currently targeted, the possible mechanisms of sub-optimal responses, and the importance of determining the immune make-up of individual patients prior to prescribing mAb therapy, in the age of precision medicine for asthma.

Oral administration of Lactobacillus plantarum CQPC11 attenuated the airway inflammation in an ovalbumin (OVA)-induced Balb/c mouse model of asthma

This study investigated the antiasthmatic and anti-inflammatory effects of Lactobacillus plantarum-CQPC11 (LP-CQPC11) on ovalbumin (OVA)-induced asthmatic Balb/c mice. Administration of different doses of LP-CQPC11 (10⁵ , 10⁷ , and 10⁹ colony-forming unit [CFU]/mouse) effectively reduced airway hyperresponsiveness (AHR) and the lung W/D ratio in asthmatic mice. LP-CQPC11 treatment reduced the accumulation of inflammatory cells in the BALF and attenuated histologic edema in asthmatic mice. Administration of LP-CQPC11 decreased the serum levels of OVA-specific IgE, IgE, and OVA-specific IgG1. LP-CQPC11 treatment decreased the levels of inflammatory cytokines (TNF-α, IL-4, IL-13, IL-5, and IL-6) in the BALF of asthmatic mice. In addition, LP-CQPC11 also elevated the mRNA levels of Foxp3 and T-bet and decreased the mRNA levels of Gata3 and RORγt in asthmatic mice lungs. Administration of LP-CQPC11 also reduced OVA-induced oxidative stress by improving the activities of GSH-Px, SOD, and catalase in the lungs. Finally, LP-CQPC11 treatment also significantly decreased the activation of the NF-κB pathway to modulate the inflammatory reaction in the lungs of asthmatic mice. The results from this study clearly demonstrated that oral administration of LP-CQPC11 exhibited outstanding activity in attenuating OVA-induced asthma in a mouse model. Furthermore, LP-CQPC11 may be an effective microecologic agent in preventing allergic asthma in the future. PRACTICAL APPLICATIONS: Allergic asthma is a common chronic inflammation-associated respiratory disease. Lactic acid bacteria (LAB) are known as a health product involved in modulating immune tolerance and play important roles in disease prevention and treatment. Many studies have reported that LAB, as probiotics, exhibits great antioxidation, anticancer, and anti-inflammatory activities and have health benefits in gastrointestinal disorders. In fact, human studies have confirmed that Lactobacillus rhamnosus strains have an effective activity to reduce the risk of allergic asthma. LP-CQPC11 was isolated from Sichuan pickled cabbages (a type of LAB-fermented vegetable product, also called Sichuan paocai) and was reported to reduce d-galactose-induced aging in mice in our previous study. However, the antiasthmatic and anti-inflammatory activities of LP-CQPC11 are unclear. The current study investigated the antiasthmatic and anti-inflammatory effects of LP-CQPC11 on OVA-induced asthmatic Balb/c mice.

Risankizumab in Severe Asthma - A Phase 2a, Placebo-Controlled Trial

BACKGROUND

Interleukin-23 has been implicated in airway inflammation that is mediated by type 2 and type 17 cytokines. Whether targeting interleukin-23 in the treatment of asthma improves disease control and reduces airway inflammation is unclear.

METHODS

We conducted a phase 2a, multicenter, randomized, double-blind, placebo-controlled, 24-week, parallel-group trial to assess the efficacy and safety of risankizumab, an anti-interleukin-23p19 monoclonal antibody, in adults with severe asthma. Patients were assigned to receive 90 mg of risankizumab or placebo, administered subcutaneously once every 4 weeks. The primary end point was the time to the first asthma worsening. Asthma worsening was defined as deterioration from baseline on 2 or more consecutive days; deterioration was considered to be a decrease of at least 30% in the morning peak expiratory flow or an increase from baseline of at least 50% in the number of puffs of rescue medication in a 24-hour period (equating to at least four additional puffs), a severe asthma exacerbation, or an increase of 0.75 or more points on the 5-item Asthma Control Questionnaire (ACQ-5; scores range from 0 to 6, with higher scores indicating less control). Secondary end points were the annualized rate of asthma worsening, the annualized rate of severe exacerbations, the ACQ-5 score, and the forced expiratory volume in 1 second. Exploratory end points were assessed with the use of sputum cytologic analysis and gene expression analysis, and safety was assessed.

RESULTS

A total of 105 patients received risankizumab and 109 received placebo. The clinical characteristics of the patients were similar in the two groups. The time to the first asthma worsening was shorter with risankizumab than with placebo (median, 40 days vs. 86 days; hazard ratio, 1.46; 95% confidence interval [CI], 1.05 to 2.04; P = 0.03). The rate ratio for annualized asthma worsening with risankizumab as compared with placebo was 1.49 (95% CI, 1.12 to 1.99), and the rate ratio for severe exacerbations was 1.13 (95% CI, 0.75 to 1.70). Sputum transcriptomic pathway analysis showed that genes involved in the activation of natural killer cells and cytotoxic T cells and the activation of the type 1 helper T and type 17 helper T transcription factors were down-regulated by risankizumab. No safety concerns were associated with risankizumab therapy.

CONCLUSIONS

Risankizumab treatment was not beneficial in severe asthma. The time to the first asthma worsening was shorter and the annualized rate of asthma worsening was higher with risankizumab than with placebo. (Funded by AbbVie and Boehringer Ingelheim; ClinicalTrials.gov number, NCT02443298.).

Insights into interplay of immunopathophysiological events and molecular mechanistic cascades in psoriasis and its associated comorbidities

Psoriasis is an inflammatory skin disease with complex pathogenesis and multiple etiological factors. Besides the essential role of autoreactive T cells and constellation of cytokines, the discovery of IL-23/Th17 axis as a central signaling pathway has unraveled the mechanism of accelerated inflammation in psoriasis. This has provided insights into psoriasis pathogenesis and revolutionized the development of effective biological therapies. Moreover, genome-wide association studies have identified several candidate genes and susceptibility loci associated with this disease. Although involvement of cellular innate and adaptive immune responses and dysregulation of immune cells have been implicated in psoriasis initiation and maintenance, there is still a lack of unifying mechanism for understanding the pathogenesis of this disease. Emerging evidence suggests that psoriasis is a high-mortality disease with additional burden of comorbidities, which adversely affects the treatment response and overall quality of life of patients. Furthermore, changing trends of psoriasis-associated comorbidities and shared patterns of genetic susceptibility, risk factors and pathophysiological mechanisms manifest psoriasis as a multifactorial systemic disease. This review highlights the recent progress in understanding the crucial role of different immune cells, proinflammatory cytokines and microRNAs in psoriasis pathogenesis. In addition, we comprehensively discuss the involvement of various complex signaling pathways and their interplay with immune cell markers to comprehend the underlying pathophysiological mechanism, which may lead to exploration of new therapeutic targets and development of novel treatment strategies to reduce the disastrous nature of psoriasis and associated comorbidities.

Sputum IL-25, IL-33 and TSLP, IL-23 and IL-36 in airway obstructive diseases. Reduced levels of IL-36 in eosinophilic phenotype

INTRODUCTION

Alarmins ((IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)) are known to promote Th2 inflammation and could be associated with eosinophilic airway infiltration. They may also play a role in airway remodeling in chronic airway obstructive diseases such as asthma and chronic obstructive pulmonary disease (COPD). IL-23 and IL-36 were shown to mediate the neutrophilic airway inflammation as seen in chronic airway obstructive diseases.

OBJECTIVES

The purpose of this project was to determine the expression and the production of these cytokines from induced sputum (IS) in patients with chronic airway obstructive diseases including asthmatics and COPD. The relationship of the mediators with sputum inflammatory cellular profile and the severity of airway obstruction was assessed.

METHODS

The alarmins (IL-25, IL-33 and TSLP) as well as IL-23 and IL-36 concentrations were measured in IS from 24 asthmatics and 20 COPD patients compared to 25 healthy volunteers. The cytokines were assessed by ELISA in the IS supernatant and by RT-qPCR in the IS cells.

RESULTS

At protein level, no difference was observed between controls and patients suffering from airway obstructive diseases regarding the different mediators. IL-36 protein level was negatively correlated with sputum eosinophil and appeared significantly decreased in patients with an eosinophilic airway inflammation compared to those with a neutrophilic profile and controls. At gene level, only IL-36, IL-23 and TSLP were measurable but none differed between controls and patients with airway obstructive diseases. IL-36 and IL-23 were significantly increased in patients with an neutrophilic inflammatory profile compared to those with an eosinophilic inflammation and were correlated with sputum neutrophil proportions. None of the mediators were linked to airway obstruction.

CONCLUSIONS

The main finding of our study is that patients with eosinophilic airway inflammation exhibited a reduced IL-36 level which could make them more susceptible to airway infections as IL-36 is implicated in antimicrobial defense. This study showed also an implication of IL-36 and IL-23 in airway neutrophilic inflammation in chronic airway obstructive diseases.

Insights Into Type I and III Interferons in Asthma and Exacerbations

Asthma is a highly prevalent, chronic respiratory disease that impacts millions of people worldwide and causes thousands of deaths every year. Asthmatics display different phenotypes with distinct genetic components, environmental causes, and immunopathologic signatures, and are broadly characterized into type 2-high or type 2-low (non-type 2) endotypes by linking clinical characteristics, steroid responsiveness, and molecular pathways. Regardless of asthma severity and adequate disease management, patients may experience acute exacerbations of symptoms and a loss of disease control, often triggered by respiratory infections. The interferon (IFN) family represents a group of cytokines that play a central role in the protection against and exacerbation of various infections and pathologies, including asthma. Type I and III IFNs in particular play an indispensable role in the host immune system to fight off pathogens, which seems to be altered in both pediatric and adult asthmatics. Impaired IFN production leaves asthmatics susceptible to infection and with uncontrolled type 2 immunity, promotes airway hyperresponsiveness (AHR), and inflammation which can lead to asthma exacerbations. However, IFN deficiency is not observed in all asthmatics, and alterations in IFN expression may be independent of type 2 immunity. In this review, we discuss the link between type I and III IFNs and asthma both in general and in specific contexts, including during viral infection, co-infection, and bacterial/fungal infection. We also highlight several studies which examine the potential role for type I and III IFNs as asthma-related therapies.

Immunomodulatory and Anti-Inflammatory Potential of Curcumin for the Treatment of Allergic Asthma: Effects on Expression Levels of Pro-inflammatory Cytokines and Aquaporins

Curcumin is well known for possessing anti-inflammatory properties and for its beneficial effects in the treatment of asthma. Current study investigates the immunomodulatory and anti-inflammatory effects of curcumin using mouse model of ovalbumin-induced allergic asthma. BALB/c mice were immunized with ovalbumin on day 0 and 14 to induce allergic asthma. Animals were treated with two different doses of curcumin (20 mg/kg and 100 mg/kg) and methylprednisolone from day 21 to 28. Mice were also daily challenged intranasally with ovalbumin during treatment period, and all groups were sacrificed at day 28. Histopathological examination showed amelioration of allergic asthma in treated groups as evident by the attenuation of infiltration of inflammatory cells, goblet cell hyperplasia, alveolar thickening, and edema and vascular congestion. Curcumin significantly reduced total and differential leukocyte counts in both bronchoalveolar lavage fluid and blood. Reverse transcription polymerase chain reaction analysis showed significantly suppressed mRNA expression levels of IL-4 and IL-5 (pro-inflammatory cytokines), TNF-α, TGF-β (pro-fibrotic cytokines), eotaxin (chemokine), and heat shock protein 70 (marker of airway obstruction) in treated groups. Attenuation of these pro-inflammatory markers might have led to the suppression of airway inflammation. The expression levels of aquaporin-1 (AQP) and AQP-5 were found significantly elevated in experimental groups which might be responsible for reduction of pulmonary edema. In conclusion, curcumin significantly ameliorated allergic asthma. The anti-asthmatic effect might be attributed to the suppression of pro-inflammatory cytokines, and elevation of aquaporin expression levels, suggesting further studies and clinical trials to establish its candidature in the treatment of allergic asthma.

Rubusoside alleviates the ovalbumin-induced mice allergic asthma by modulating the NF-κB activation

The anti-inflammatory and anti-asthmatic effects of rubusoside (Rbs) were investigated in the ovalbumin (OVA)-induced asthmatic mice, followed by effective attenuation of Rbs treatment on the airway hyperresponsiveness and reduction of inflammatory cells inside the bronchoalveolar lavage fluid (BALF). The mitigation of inflammatory infiltration as a result of Rbs treatment was histologically observed in these mice lungs. Rbs contributed to the decrease of inflammatory cytokines (TNF-α, IL-13, IL-6, IL-5, and IL-4) inside the BALF of mice with asthma. A decline of OVA-dependent IgE and IgG1 inside the serum was also noticed in these mice. Rbs was proved to enhance the mRNA level of Foxp3 inside the mice lung affected with asthma while decrease that of IL-17A, IL-23, and RORγt. NF-κB pathway activation elicited by OVA was suppressed by Rbs inside the pulmonary tissues. Rbs played significantly in the reduction of airway inflammation induced by OVA which with modulating NF-κB pathway activation. PRACTICAL APPLICATIONS: Simultaneous therapy with medicine and food is strategically significant for disease prevention and treatment in traditional Chinese medicine. Rbs is a diterpene glycoside isolated from Rubus suavissimus. The anti-inflammatory and anti-asthmatic mechanism dependent of Rbs need further study clinically. The goal of current investigation is to explore the anti-inflammatory as well as anti-asthmatic activity of Rbs in mouse models of OVA-induced experimental allergic asthma. Results of the present study are scientifically supportive for the use of Rbs as an adjunctive reagent for clinical treatment of allergic asthma.

Protective activity of mogroside V against ovalbumin-induced experimental allergic asthma in Kunming mice

We investigated the antiasthmatic effect of mogroside V (Mog V) in mice with ovalbumin (OVA)-induced asthma. Administration of Mog V effectively attenuated OVA-induced airway hyperresponsiveness and reduced the number of inflammatory cells in bronchoalveolar lavage fluid (BALF). Histological examination showed that Mog V reduced the inflammatory infiltration of the lungs in the asthmatic mice. ELISAs suggested that Mog V effectively decreased the levels of IL-4, IL-5, and IL-13 in BALF and serum levels of OVA-specific IgE and IgG1 in the asthmatic mice. A quantitative reverse-transcription PCR assay also indicated that Mog V decreased the mRNA levels of IL-17A, IL-23, and RORγt in the lungs of the asthmatic mice (the opposite effect on Foxp3 mRNA). Furthermore, Mog V significantly reduced the OVA-induced activation of NF-κB in the lungs. This study indicates that Mog V alleviates OVA-induced inflammation in airways, and this effect is associated with a reduction in NF-κB activation. PRACTICAL APPLICATIONS: A traditional Chinese medicine herb has been reported to have a strong curative effect on asthma in clinical practice. Siraitia grosvenorii is known in China as a functional food product with the ability to improve lung function. Mogroside V is a triterpene glycoside isolated from S. grosvenorii. Nonetheless, the antiasthmatic effect of mogroside V has not been evaluated yet. The aim of this study was to investigate the antiasthmatic activity of mogroside V in mice with chemically induced asthma. The data from this study will provide some scientific evidence supporting wider use of S. grosvenorii in functional foods.

Efficacy of add-on sublingual immunotherapy for adults with asthma: A meta-analysis and systematic review

BACKGROUND

Sublingual immunotherapy (SLIT) reduces symptom scores and the use of rescue medication in children with allergic asthma, but the effect of SLIT therapy in adult patients has not been reported.

OBJECTIVE

To examine the efficacy and adverse effects of SLIT add-on vs conventional medication in adult patients with mild to moderate asthma.

METHODS

We systematically searched the MEDLINE, Embase, Cochrane, and Central databases. Eligible studies included adult patients with allergic asthma who received either SLIT or standard care. Standard mean differences were used as measures of efficacy in a random-effects model.

RESULTS

Twenty trials that included 2,288 patients in the SLIT add-on group and 1,268 patients in the traditional therapy group were identified as eligible for final analysis. Compared with traditional therapy, SLIT add-on therapy was associated with significant improvements in lower and upper airway scores, a higher forced expiratory volume in 1 second, and maximal expiratory flow at 25% of forced vital capacity, and improved bronchial reactivity. Drug consumptions were significantly decreased as well. Airway inflammatory parameters, such as nasal eosinophil infiltration, were markedly improved.

CONCLUSION

The findings of this study suggested that long-term SLIT add-on therapy is a complementary treatment for adults with asthma in addition to conventional medicine. It not only reduces symptom scores but also improves lung function and airway inflammation.

The current and future role of biomarkers in type 2 cytokine-mediated asthma management

Assessment and management of asthma is complicated by the heterogeneous pathophysiological mechanisms that underlie its clinical presentation, which are not necessarily reflected in standardized management paradigms and which necessitate an individualized approach to treatment. This is particularly important with the emerging availability of a variety of targeted forms of therapy that may only be appropriate for use in particular patient subgroups. The identification of biomarkers can potentially aid diagnosis and inform prognosis, help guide treatment decisions and allow clinicians to predict and monitor response to treatment. Biomarkers for asthma have been identified from a variety of sources, including airway, exhaled breath and blood. Biomarkers from exhaled breath include fractional exhaled nitric oxide, measurement of which can help identify patients most likely to benefit from inhaled corticosteroids and targeted anti-immunoglobulin E therapy. Biomarkers measured in blood are relatively non-invasive and technically more straightforward than those measured from exhaled breath or directly from the airway. The most well established of these are the blood eosinophil count and serum periostin, both of which have demonstrated utility in identifying patients most likely to benefit from targeted anti-interleukin and anti-immunoglobulin E therapies, and in monitoring subsequent treatment response. For example, serum periostin appears to be a biomarker for responsiveness to inhaled corticosteroid therapy and may help identify patients as suitable candidates for anti-IL-13 treatment. The use of biomarkers can therefore potentially help avoid unnecessary morbidity from high-dose corticosteroid therapy and allow the most appropriate and cost-effective use of targeted therapies. Ongoing clinical trials are helping to further elucidate the role of established biomarkers in routine clinical practice, and a range of other circulating novel potential biomarkers are currently being investigated in the research setting.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

Severe Asthma: Have We Made Progress?

Tremendous efforts have been invested in research to (1) discover risk factors, biomarkers, and clinical characteristics; (2) understand the pathophysiology and treatment response variability in severe asthma; and (3) design new therapies. However, to combat severe asthma, many questions concerning the pathogenesis of severe asthma, including its natural history, genetic and environmental risk factors, and disease mechanisms, must be answered. In this article we highlight some of the major discoveries concerning the pathogenesis of severe asthma and its therapeutic development. We conclude that discoveries on numerous fronts of severe asthma, from disease heterogeneity, features of airway remodeling, cytokine mediators and signaling pathways underlying disease pathogenesis, disease mechanisms, potential biomarkers, to new therapeutic targets, demonstrate that progress has been made in understanding and developing more effective treatments for this difficult-to-treat disease.

Identification of IL-17F/frequent exacerbator endotype in asthma

BACKGROUND

Severe asthma might be associated with overexpression of T_h17 cytokines, which induce neutrophil recruitment via neutrophil-mobilizing cytokines in airways.

OBJECTIVE

To study IL-17-related cytokines in nasal/bronchial biopsies from controls and mild asthmatics (MAs) to severe asthmatics (SAs) in relation to exacerbation rate.

METHODS

Inflammatory cells and IL-17A⁺, IL-17F⁺, IL-21⁺, IL-22⁺, and IL-23⁺ cells were examined by immunohistochemistry in cryostat sections of bronchial/nasal biopsies obtained from 33 SAs (21 frequent exacerbators [FEs]), 31 MAs (3 FEs), and 14 controls. IL-17F protein was also measured by ELISA in bronchial/nasal lysates and by immunohistochemistry in bronchial tissue obtained from subjects who died because of fatal asthma. Immunofluorescence/confocal microscopy was used for IL-17F colocalization.

RESULTS

Higher number (P < .05) of neutrophils, IL-17A⁺, IL-17F⁺, and IL-21⁺ cells in bronchial biopsies and higher numbers (P < .01) of IL-17F⁺ and IL-21⁺ cells in nasal biopsies were observed in SAs compared with MAs. Bronchial IL-17F⁺ cells correlated with bronchial neutrophils (r = 0.54), exacerbation rate (r = 0.41), and FEV₁ (r = -0.46). Nasal IL-17F⁺ cells correlated with bronchial IL-17F (r = 0.35), exacerbation rate (r = 0.47), and FEV₁ (r = -0.61). FEs showed increased number of bronchial neutrophils/eosinophils/CD4⁺/CD8⁺ cells and bronchial/nasal IL-17F⁺ cells. Receiver operating characteristic curve analysis evidenced predictive cutoff values of bronchial neutrophils and nasal/bronchial IL-17F for discriminating between asthmatics and controls, between MAs and SAs and between FEs and non-FEs. IL-17F protein increased in bronchial/nasal lysates of SAs and FEs and in bronchial tissue of fatal asthma. IL-17F colocalized in CD4⁺/CD8⁺ cells.

CONCLUSIONS

IL-17-related cytokines expression was amplified in bronchial/nasal mucosa of neutrophilic asthma prone to exacerbation, suggesting a pathogenic role of IL-17F in FEs.

Th-17 regulatory cytokines inhibit corticosteroid induced airway structural cells apoptosis

Background

Although corticosteroid is a powerful anti-inflammatory drug that is used widely to control asthma, still severe asthmatics can develop steroid resistance. Airway fibroblasts are quite resistant to steroids during Idiopathic pulmonary fibrosis (IPF) and fibrosis in asthmatic lungs is not always controlled. Th-17 regulatory cytokine which are elevated in lung tissues of asthmatics were shown to enhance the survival of various types of cells. STAT factors are central to this anti-apoptotic function. However, it is not yet clear whether these cytokines contribute to steroid hypo-responsiveness in asthma. Therefore, in this study, we investigated the ability of Th-17 regulatory cytokines, specifically IL-21, IL22 and IL23, to protect structural airway cells against dexamethasone-induced apoptosis.

Methods

Primary human fibroblasts, ASM cells, and lung endothelial cells line were treated with IL-21, IL-22, and IL-23 cytokines before incubation with dexamethasone and the level of apoptosis was determined by measuring cellular Annexin-V using Flow cytometry.

Results

Our data indicated that treatment with Th-17 regulatory cytokines was effective in inhibiting induced apoptosis for both fibroblasts and endothelial cells but not ASM cells. STAT3 phosphorylation levels were also upregulated in fibroblasts and endothelial upon treatment with these cytokines. Interestingly, inhibiting STAT3 phosphorylation abrogated IL-21, IL-22, and IL-23 anti-apoptotic effect on fibroblasts and endothelial cells.

Conclusions

This data suggest that Th-17 regulatory cytokines may play a critical role in regulating the survival of fibroblasts during asthma, IPF as well as other chronic lung inflammatory diseases leading to enhanced fibrosis. Accordingly, findings of this paper may pave the way for more extensive research on the role of these regulatory cytokines in fibrosis development in various chronic inflammatory diseases.

Hyperoxia promotes polarization of the immune response in ovalbumin-induced airway inflammation, leading to a TH17 cell phenotype

Previous studies have demonstrated that hyperoxia-induced stress and oxidative damage to the lungs of mice lead to an increase in IL-6, TNF-α, and TGF-β expression. Together, IL-6 and TGF-β have been known to direct T cell differentiation toward the TH17 phenotype. In the current study, we tested the hypothesis that hyperoxia promotes the polarization of T cells to the TH17 cell phenotype in response to ovalbumin-induced acute airway inflammation. Airway inflammation was induced in female BALB/c mice by intraperitoneal sensitization and intranasal introduction of ovalbumin, followed by challenge methacholine. After the methacholine challenge, animals were exposed to hyperoxic conditions in an inhalation chamber for 24 h. The controls were subjected to normoxia or aluminum hydroxide dissolved in phosphate buffered saline. After 24 h of hyperoxia, the number of macrophages and lymphocytes decreased in animals with ovalbumin-induced airway inflammation, whereas the number of neutrophils increased after ovalbumin-induced airway inflammation. The results showed that expression of Nrf2, iNOS, T-bet and IL-17 increased after 24 of hyperoxia in both alveolar macrophages and in lung epithelial cells, compared with both animals that remained in room air, and animals with ovalbumin-induced airway inflammation. Hyperoxia alone without the induction of airway inflammation lead to increased levels of TNF-α and CCL5, whereas hyperoxia after inflammation lead to decreased CCL2 levels. Histological evidence of extravasation of inflammatory cells into the perivascular and peribronchial regions of the lungs was observed after pulmonary inflammation and hyperoxia. Hyperoxia promotes polarization of the immune response toward the TH17 phenotype, resulting in tissue damage associated with oxidative stress, and the migration of neutrophils to the lung and airways. Elucidating the effect of hyperoxia on ovalbumin-induced acute airway inflammation is relevant to preventing or treating asthmatic patients that require oxygen supplementation to reverse the hypoxemia.

Treatment of severe asthma: entering the era of targeted therapy

INTRODUCTION

It is estimated that 5 - 10% of asthma patients suffer from severe asthma. Severe asthma is associated with increased morbidity and mortality. These patients are not controlled with currently available treatments and therefore additional treatment options are needed. Asthma is a heterogeneous disease, and different asthma patient groups probably have different underlying pathophysiology. Novel therapies with, for example, monoclonal antibodies that target certain immunological pathways have become available. These novel treatments are not effective in all patients but only in certain phenotypes.

AREAS COVERED

This review covers the current evidence and novel developments in treatment with monoclonal antibodies in different asthma phenotypes. This includes monoclonal antibodies against IgE, against interleukin (IL)-5 and antibodies targeting IL-13 pathways. Although there is a certain overlap between patient groups benefiting from these treatments, a more detailed identification of responder profiles for these therapies is needed for personalized therapy.

EXPERT OPINION

In recent years, novel monoclonal antibodies have been developed, which are a promising addition to existing therapy in the treatment of severe asthma with eosinophilic inflammation and Th2-driven disease. We expect that several of the new antibodies will become available for clinical practice. In addition, it must be acknowledged that so far no effective strategies are available for patients with non-eosinophilic asthma and further research and development is necessary for this patient group.

Bronchial lesions of mouse model of asthma are preceded by immune complex vasculitis and induced bronchial associated lymphoid tissue (iBALT)

We systematically examined by immune histology the lungs of some widely used mouse models of asthma. These models include sensitization by multiple intraperitoneal injections of soluble ovalbumin (OVA) or of OVA with alum, followed by three intranasal or aerosol challenges 3 days apart. Within 24 h after a single challenge there is fibrinoid necrosis of arterial walls with deposition of immunoglobulin (Ig) and OVA and infiltration of eosinophilic polymorphonuclear cells that lasts for about 3 days followed by peribronchial B-cell infiltration and slight reversible goblet cell hypertrophy (GCHT). After two challenges, severe eosinophilic vasculitis is present at 6 h, increases by 72 h, and then declines; B-cell proliferation and significant GCHT and hyperplasia (GCHTH) and bronchial smooth muscle hypertrophy recur more prominently. After three challenges, there is significantly increased induced bronchus-associated lymphoid tissue (iBALT) formation, GCHTH, and smooth muscle hypertrophy. Elevated levels of Th2 cytokines, IL-4, IL-5, and IL-13, are present in bronchial lavage fluids. Sensitized mice have precipitating antibody and positive Arthus skin reactions but also develop significant levels of IgE antibody to OVA but only 1 week after challenge. We conclude that the asthma like lung lesions induced in these models is preceded by immune complex-mediated eosinophilic vasculitis and iBALT formation. There are elevations of Th2 cytokines that most likely produce bronchial lesions that resemble human asthma. However, it is unlikely that mast cell-activated atopic mechanisms are responsible as we found only a few presumed mast cells by toluidine blue and metachromatic staining limited to the most proximal part of the main stem bronchus, and none in the remaining main stem bronchus or in the lung periphery.

Increase systemic levels of IL-23 as a possible constitutive marker in schizophrenia

Inflammation appears to play significant role in schizophrenia. IL-23 is key molecule in mediating IL-17 dependent inflammatory response. Therefore, we analyzed the serum concentrations of IL-23 levels in patients with first episode psychosis (78 subjects), in patients with acute exacerbation of schizophrenia who were already treated with antipsychotics (47 subjects) and healthy controls (35 subjects). Diagnoses were established using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). Psychopathology was evaluated using the Positive and Negative Syndrome Scale (PANSS) and serum levels of IL-23 were measured using sensitive enzyme-linked immunosorbent assay (ELISA). Serum levels of IL-23 were higher in patients with first psychotic episode and in patients with schizophrenia in relapse than in healthy subjects (p=0.000) and no difference was established between these two groups of patients before therapy. Also, after 4 weeks of antipsychotic therapy levels of IL-23 remains elevated in both groups of patients with no differences between two groups. It appears that increased level of IL-23 in psychotic patients independently of antipsychotic therapy can be a constitutive marker in this disorder.

AT-RvD1 modulates CCL-2 and CXCL-8 production and NF-κB, STAT-6, SOCS1, and SOCS3 expression on bronchial epithelial cells stimulated with IL-4

Bronchial epithelial cells represent the first line of defense against microorganisms and allergens in the airways and play an important role in chronic inflammatory processes such as asthma. In an experimental model, both RvD1 and AT-RvD1, lipid mediators of inflammation resolution, ameliorated some of the most important phenotypes of experimental asthma. Here, we extend these results and demonstrate the effect of AT-RvD1 on bronchial epithelial cells (BEAS-2B) stimulated with IL-4. AT-RvD1 (100 nM) decreased both CCL2 and CXCL-8 production, in part by decreasing STAT6 and NF-κB pathways. Furthermore, the effects of AT-RvD1 were ALX/FRP2 receptor dependent, as the antagonist of this receptor (BOC1) reversed the inhibition of these chemokines by AT-RvD1. In addition, AT-RvD1 decreased SOCS1 and increased SOCS3 expression, which play important roles in Th1 and Th17 modulation, respectively. In conclusion, AT-RvD1 demonstrated significant effects on the IL-4-induced activation of bronchial epithelial cells and consequently the potential to modulate neutrophilic and eosinophilic airway inflammation in asthma. Taken together, these findings identify AT-RvD1 as a potential proresolving therapeutic agent for allergic responses in the airways.

Association between psoriasis and asthma: a population-based retrospective cohort analysis

BACKGROUND

Both psoriasis and asthma are chronic immune-mediated inflammatory diseases.

OBJECTIVES

To evaluate the risk of developing asthma in patients with psoriasis compared with controls.

METHODS

This cohort study was conducted using data from the Taiwan National Health Insurance Research Database. Patients with psoriasis (n = 10,288) and matched comparison patients without psoriasis (n = 41,152) were evaluated. A Cox proportional hazard regression analysis was used to determine the risk of asthma in patients with and without psoriasis.

RESULTS

The risk of asthma was 1·38-fold higher [95% confidence interval (CI) 1·23-1·54] in the cohort with psoriasis than in the reference cohort, after adjusting for age, sex and comorbidities. The incidence of asthma in men and women with psoriasis exhibited nonsignificant differences. Among all patients aged > 50 years, psoriasis was associated with a higher risk of asthma compared with not having psoriasis [adjusted hazard ratio (HR) 1·49; 95% CI 1·18-1·88 (in patients aged 50-64 years); adjusted HR 1·63; 95% CI 1·34-1·99 (in patients aged > 65 years)].

CONCLUSIONS

Our results indicate that patients with psoriasis are associated with a increased risk of developing asthma.

Regulation of Th17/Treg function contributes to the attenuation of chronic airway inflammation by icariin in ovalbumin-induced murine asthma model

Icariin which is a flavonoid glucoside isolated from Epimedium brevicornu Maxim, has been reported to have anti-osteoporotic, anti-inflammatory and anti-depressant-like activities. In this study, we observed the effect of icariin on airway inflammation of ovalbumin (OVA)-induced murine asthma model and the associated regulatory mode on T-helper (Th)17 and regulatory T (Treg) cell function. Our data revealed that chronic OVA inhalation induced a dramatic increase in airway resistance (RL) and decrease in the lung dynamic compliance (Cdyn), and icariin and DEX treatment caused significant attenuation of such airway hyperresponsiveness (AHR). BALF cell counts demonstrated that icariin and DEX led to a prominent reduction in total leukocyte as well as lymphocyte, eosinophil, neutrophil, basophil and monocyte counts. Histological analysis results indicated that icariin and DEX alleviated the inflammatory cells infiltrating into the peribronchial tissues and goblet cells hyperplasia and mucus hyper-production. Flow cytometry test demonstrated that icariin or DEX administration resulted in a significant percentage reduction in CD4+RORγt+ T cells and elevation of CD4+Foxp3+ T cells in BALF. Furthermore, icariin or DEX caused a significant reduction in IL-6, IL-17 and TGF-β level in BALF. Unfortunately, icariin had no effect on IL-10 level in BALF. Western blot assay found that icariin or DEX suppressed RORγt and promoted Foxp3 expression in the lung tissue. qPCR analysis revealed that icariin and DEX resulted in a notable decrease in RORγt and increase in Foxp3 mRNA expression in isolated spleen CD4+ T cell. In conclusion, our results suggested that icariin was effective in the attenuation of AHR and chronic airway inflammatory changes in OVA-induced murine asthma model, and this effect was associated with regulation of Th17/Treg responses, which indicated that icariin may be used as a potential therapeutic method to treat asthma with Th17/Treg imbalance phenotype.