Role of Interleukin-13 in Asthma

Cationic CaMKII Inhibiting Nanoparticles Prevent Allergic Asthma

Asthma is a common lung disease affecting over 300 million people worldwide and is associated with increased reactive oxygen species, eosinophilic airway inflammation, bronchoconstriction, and mucus production. Targeting of novel therapeutic agents to the lungs of patients with asthma may improve efficacy of treatments and minimize side effects. We previously demonstrated that Ca²⁺/calmodulin-dependent protein kinase (CaMKII) is expressed and activated in the bronchial epithelium of asthmatic patients. CaMKII inhibition in murine models of allergic asthma reduces key disease phenotypes, providing the rationale for targeted CaMKII inhibition as a potential therapeutic approach for asthma. Herein we developed a novel cationic nanoparticle (NP)-based system for delivery of the potent and specific CaMKII inhibitor peptide, CaMKIIN, to airways.1 CaMKIIN-loaded NPs abrogated the severity of allergic asthma in a murine model. These findings provide the basis for development of innovative, site-specific drug delivery therapies, particularly for treatment of pulmonary diseases such as asthma.

Predictors of response to therapy with omalizumab in patients with severe allergic asthma - a real life study

OBJECTIVES

Omalizumab is a recombinant humanized IgG1 monoclonal anti-IgE antibody, used for the treatment of severe refractory allergic asthma. However, not all patients with IgE levels within the limits of administration, respond to treatment. The aim of the present study, was to determine clinical and inflammatory characteristics that could predict response to omalizumab.

METHODS

We studied retrospectively patients treated with omalizumab as per GINA guidelines in one asthma tertiary referral center. Demographic and functional characteristics, level of asthma control, fractional exhaled nitric oxide, blood and eosinophils and IgE level, induced sputum cell count, eosinophil cationic protein and Interleukin-13 in sputum supernatant were recorded. All measurements were performed before starting treatment with omalizumab. Response to treatment was evaluated according to the physician's global evaluation of treatment effectiveness. Patients were characterized as early responders when improvement was achieved within 16 weeks and as late responders when improvement was achieved between 16 and 32 weeks. Patients who did not show any improvement after 32 weeks of therapy were considered as non-responders.

RESULTS

Forty-one patients treated with omalizumab were included in the study. 28 (68.3%) patients were characterized as responders while 13 patients (31.7%) were considered as non-responders. Among responders, 25 (89%) were early responders and 3 (n = 11%) were late responders. Responders were characterized by lower baseline FEV₁ and FEV₁/FVC and higher IL-13 levels in induced sputum supernatant compared to non-responders. Late responders had higher serum IgE levels, shorter disease duration and higher number of blood eosinophils. Finally, using ROC curve analysis, the best predictors of response to omalizumab were FEV₁ (AUC = 0.718) and IL-13 in sputum supernatant (AUC = 0.709).

CONCLUSION

Lower baseline FEV₁ and higher IL-13 levels in induced sputum supernatant were predictors of response to omalizumab. Patients with higher baseline serum IgE levels, shorter disease duration and higher blood eosinophils may experience a late response and might benefit from a more prolonged treatment before being characterized as non-responders.

Novel monoclonal treatments in severe asthma

AIM

To provide a general overview of the current biological treatments and discuss their potential anti-asthmatic effects.

DATA SOURCES

We reviewed articles in PubMed found using the search words "Asthma/therapy AND antibodies, monoclonal/therapeutic use AND cytokines."

STUDY SELECTIONS

Only articles published in English since 2000 were considered. The search identified 29 studies; 8 additional studies were found by hand search, generating 37 studies.

RESULTS

Of the 37 studies investigating biological treatments of asthma, 5 were on the effects of anti-IgE (omalizumab); 12 on anti-IL-5; 8 on anti-IL-13; 5 on anti-IL-4R-α; 3 on anti-IL-9; one on TNF-α; one on anti-IL-2R-α; one on TSLP (Thymic Stromal Lymphopoietin); and one on OX40L. Sample sizes ranged from 3 to 943 participants. Studies of therapies targeting IgE, IL-2, IL4R-α, IL-5, and IL-13 showed some efficacy, whereas those targeting TSLP, IL-9, and TNF-α lacked convincing effectiveness.

CONCLUSION

Research on the biological treatment of asthma shows promising results. While anti-IgE (omalizumab) has been used in the treatment of asthma for some years, anti-IL-5 has recently been approved for use. The efficacy of results of other large studies with a longer duration is needed to draw a firm conclusion. Such studies should not only focus on clinical outcomes, but also consider asthma-related quality of life. Knowledge on the asthma phenotypes and identification of biomarkers associated with these will be useful for physicians considering the right treatment for the asthma patient.

Inflammatory Disorders Associated with Allergy: Overview of Immunopathogenesis and Implications for Treatment

A number of chronic inflammatory diseases are associated with IgE-mediated immunologic hypersensitivity, including atopic dermatitis, chronic rhinosinusitis, and asthma. Pathogenetic studies of well-characterized patient groups has allowed investigators to more precisely define the molecular pathways involved in these diseases. Specific cytokines and chemokines, as well as other unique proteins, have now been identified in each of these common disorders and a number of medications are currently in development for inhibiting their actions. Continual refinement of our understanding of the pathogenesis of these diseases will undoubtedly yield increasingly precise, and potentially more effective, treatments.

Effect of waterpipe tobacco smoking on airway inflammation in murine model of asthma

OBJECTIVE

There has been an increase in the popularity of waterpipe tobacco smoking (WTS) worldwide, especially in the younger population, including asthma patients. In this study, we investigated the effects of waterpipe smoking on airway inflammation, cytokine levels and oxidative stress markers in an antigen-driven murine model of asthma.

MATERIALS AND METHODS

Balb/c mice were divided into four groups; (1) control (received fresh air, ovalbumin sensitization and saline challenge), (2) WTS (received WTS, ovalbumin sensitization and saline challenge), (3) Ova S/C (received fresh air, ovalbumin sensitization and ovalbumin challenge) and (4) simultaneous WTS and Ova S/C (received WTS, ovalbumin sensitization and ovalbumin challenge). Airway inflammatory cells were evaluated in the broncho-alveolar lavage fluid. Cytokines [interleukin (IL)-13, 10 and 18] and oxidative stress markers [superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx)] were evaluated in the lung homogenates.

RESULTS

Chronic exposure to WTS significantly increased the number of airway inflammatory cells in mice, specifically: eosinophils, neutrophils, macrophages and lymphocytes. The level of IL-13 in the lungs was increased and the level of IL-10 was reduced (p < 0.05) by WTS. Chronic WTS potentiated the increase in inflammatory cells induced by Ova S/C (p < 0.05). The level of IL-13 in the lungs was increased by simultaneous WTS and Ova S/C (p < 0.05) while, levels of IL-10, IL-18, SOD, catalase and GPx in the lungs were not affected.

CONCLUSIONS

Chronic WTS exposure induced airway inflammation in control mice and enhanced airway inflammation in murine model of asthma.

Association between IL-13 +1923C/T polymorphism and asthma risk: a meta-analysis based on 26 case-control studies

Asthma is a serious and hereditary respiratory disorder affecting all age groups. Interleukin-13 (IL-13) is a central regulator of allergic inflammation. The purpose of the present study was to estimate the relationship between IL-13 +1923C/T polymorphism and asthma susceptibility. Relevant case-control studies published between January 2000 and July 2016 were searched in the online databases. Review Manage (RevMan) 5.3 was used to conduct the statistical analysis. The pooled odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the strength of association. A total of 26 articles were retrieved, including 17642 asthma patients and 42402 controls. Overall, our results found that IL-13 +1923C/T polymorphism was significantly associated with increased risk of asthma under each genetic model (P<0.00001). Subgroup analysis by ethnicity showed that alleles and genotypes of this variant correlated with asthma among Asians and Caucasians, but only TT genotype under the homozygote model in Africans. When stratified by age group, this variant highly correlated with asthma in children and moderately in adults. Furthermore, the TT, CT and CC genotypes in asthma group were all significantly associated with increased IgE levels in sera of asthma patients when compared with controls. Our results suggested that IL-13 +1923C/T polymorphism contributed to the development of asthma. Further case-control studies with more ethnicities are still needed.

Monoclonal antibody therapy for the treatment of asthma and chronic obstructive pulmonary disease with eosinophilic inflammation

Eosinophils have been linked with asthma for more than a century, but their role has been unclear. This review discusses the roles of eosinophils in asthma and chronic obstructive pulmonary disease (COPD) and describes therapeutic antibodies that affect eosinophilia. The aims of pharmacologic treatments for pulmonary conditions are to reduce symptoms, slow decline or improve lung function, and reduce the frequency and severity of exacerbations. Inhaled corticosteroids (ICS) are important in managing symptoms and exacerbations in asthma and COPD. However, control with these agents is often suboptimal, especially for patients with severe disease. Recently, new biologics that target eosinophilic inflammation, used as adjunctive therapy to corticosteroids, have proven beneficial and support a pivotal role for eosinophils in the pathology of asthma. Nucala® (mepolizumab; anti-interleukin [IL]-5) and Cinquair® (reslizumab; anti-IL-5), the second and third biologics approved, respectively, for the treatment of asthma, exemplifies these new treatment options. Emerging evidence suggests that eosinophils may contribute to exacerbations and possibly to lung function decline for a subset of patients with COPD. Here we describe the pharmacology of therapeutic antibodies inhibiting IL-5 or targeting the IL-5 receptor, as well as other cytokines contributing to eosinophilic inflammation. We discuss their roles as adjuncts to conventional therapeutic approaches, especially ICS therapy, when disease is suboptimally controlled. These agents have achieved a place in the therapeutic armamentarium for asthma and COPD and will deepen our understanding of the pathogenic role of eosinophils.

Inhalation of inactivated‑Mycobacterium phlei prevents asthma‑mediated airway hyperresponsiveness and airway eosinophilia in mice by reducing IL‑5 and IL‑13 levels

The present study aimed to investigate whether inhalation of inactivated‑Mycobacterium phlei could prevent airway hyperresponsiveness and airway eosinophilia. A total of 24 male Balb/c mice were randomly divided into three groups: Normal control group (group A), asthma model group (group B) and the intervention group (group C), (8 mice/group). Group A mice were sensitized and with challenged saline and group B with ovalbumin (OVA). Group C mice were administered with aerosol Mycobacterium phlei once daily prior to the allergen challenge. Airway responsiveness in each group was assessed. All the animals were sacrificed and lung tissues, blood samples and bronchoalveolar lavage fluid (BALF) were harvested. Cell fractionation and differential cells were counted in serum and BALF. HE staining and alcian blue/periodic acid Schiff staining were used to measure airway eosinophilic inflammation and mucus production. The levels of the cytokines IL‑5, IL‑13 and IgE were measured in lung and BALF as determined by ELISA and reverse transcription‑quantitative polymerase chain reaction assays. The results indicated that inactivated‑Mycobacterium phlei suppressed the airway hyperresponsiveness and mitigated airway eosinophilia induced by a methacholine challenge, and significantly reduced the levels of cytokines IL‑5 and IL‑13 in lung tissue and IgE level in BALF when compared with the OVA‑sensitized mice. In conclusion, inhalation of inactivated‑Mycobacterium phlei could reduce OVA‑induced airway hyperresponsiveness and may be a potential alternative therapy for allergic airway diseases.

Association between DNA hypomethylation at IL13 gene and allergic rhinitis in house dust mite-sensitized subjects

BACKGROUND

Allergic rhinitis (AR) is a complex disease, in which gene-environment interactions contribute to its pathogenesis. Epigenetic modifications such as DNA methylation play an important role in the regulation of gene function. As IL13, a pleiotropic cytokine, may be important in conferring susceptibility to AR, the aim of the present work was to assess the relationship between a CpG island methylation status at the upstream of IL13 gene and house dust mite (HDM)-sensitized AR in Han Chinese subjects.

METHODS

A total of 60 patients with HDM-sensitized AR and 65 control subjects were enrolled as two independent cohorts from Beijing and Liaoning. MassARRAY EpiTYPER and pyrosequencing was used to systematically screen the status of DNA methylation in peripheral blood leucocytes. IL13 mRNA expression was measured by real-time quantitative PCR. Electrophoretic mobility shift assay was used to assess the function of methylation site.

RESULTS

The mean level of methylation was decreased in the AR patient group compared with the control group (P = 0.01). Two of a total of 33 IL13CpG units analysed (CpG units 24 : 25 : 26 and 38 : 39) showed significant differences in methylation status between the AR patient group and the control group, with DNA hypomethylation at CpG38 significantly associated with higher risk of HDM-sensitized AR in both independent cohorts and a combined cohort (Beijing: OR = 1.24, 95%CI = 1.01-1.52, P = 0.036; Liaoning: OR = 1.62, 95%CI = 1.11-2.38, P = 0.013; Combined: OR = 1.31, 95%CI = 1.10-1.56, P = 0.002). Methylation level of CpG38 correlated negatively with both IL13 mRNA expression and serum total IgE level and affected the binding affinity of SP1.

CONCLUSIONS

DNA hypomethylation of IL13 gene may be associated with increased risk of AR from HDM sensitization.

Anti-inflammatory potential of PI3Kδ and JAK inhibitors in asthma patients

Background

Phosphatidylinositol 3-kinase delta (PI3Kδ) and Janus-activated kinases (JAK) are both novel anti-inflammatory targets in asthma that affect lymphocyte activation. We have investigated the anti-inflammatory effects of PI3Kδ and JAK inhibition on cytokine release from asthma bronchoalveolar lavage (BAL) cells and T-cell activation, and measured lung PI3Kδ and JAK signalling pathway expression.

Method

Cells isolated from asthma patients and healthy subjects were treated with PI3Kδ or JAK inhibitors, and/or dexamethasone, before T-cell receptor stimulation. Levels of IFNγ, IL-13 and IL-17 were measured by ELISA and flow cytometry was used to assess T-cell activation. PI3Kδ, PI3Kγ, phosphorylated protein kinase B (pAKT) and Signal Transducer and Activator of Transcription (STAT) protein expression were assessed by immunohistochemistry in bronchial biopsy tissue from asthma patients and healthy subjects. PI3Kδ expression in BAL CD3 cells was measured by flow cytometry.

Results

JAK and PI3Kδ inhibitors reduced cytokine levels from both asthma and healthy BAL cells. Combining dexamethasone with either a JAK or PI3Kδ inhibitor showed an additive anti-inflammatory effect. JAK and PI3Kδ inhibitors were shown to have direct effects on T-cell activation. Immunohistochemistry showed increased numbers of PI3Kδ expressing cells in asthma bronchial tissue compared to controls. Asthma CD3 cells in BAL expressed higher levels of PI3Kδ protein compared to healthy cells.

Conclusions

Targeting PI3Kδ or JAK may prove effective in reducing T-cell activation and the resulting cytokine production in asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0436-2) contains supplementary material, which is available to authorized users.

Conjunctival Goblet Cell Function: Effect of Contact Lens Wear and Cytokines

This review focuses on conjunctival goblet cells and their essential function in the maintenance of eye health. The main function of goblet cells is to produce and secrete mucins that lubricate the ocular surface. An excess or a defect in those mucins leads to several alterations that makes goblet cells central players in maintaining the proper mucin balance and ensuring the correct function of ocular surface tissues. A typical pathology that occurs with mucous deficiency is dry eye disease, whereas the classical example of mucous hyperproduction is allergic conjunctivitis. In this review, we analyze how goblet cell number and function can be altered in these diseases and in contact lens (CL) wearers. We found that most published studies focused exclusively on the goblet cell number. However, recent advances have demonstrated that, along with mucin secretion, goblet cells are also able to secrete cytokines and respond to them. We describe the effect of different cytokines on goblet cell proliferation and secretion. We conclude that it is important to further explore the effect of CL wear and cytokines on conjunctival goblet cell function.

A Critical Evaluation of Anti-IL-13 and Anti-IL-4 Strategies in Severe Asthma

Asthma is a high-prevalence disease, still accounting for mortality and high direct and indirect costs. It is now recognized that, despite the implementation of guidelines, a large proportion of cases remain not controlled. Certainly, adherence to therapy and the education of patients remain the primary objective, but the increasingly detailed knowledge about the pathogenic mechanisms and new biotechnologies offer the opportunity to better address and treat the disease. Interleukin (IL)-13 and IL-4 appear as the most suitable targets to treat the T helper 2 (TH2)-mediated forms (endotypes) of asthma. IL-13 and IL-4 partly share the same receptor and signaling pathways and both are deeply involved in immunoglobulin E (IgE) synthesis, eosinophil activation, mucus secretion and airways remodeling. Several anti-IL-13 strategies have been proposed (anrukinzumab, lebrikizunab and tralokinumab), with relevant clinical results reported with lebrikizumab. Such studies facilitate better definition of the possible predictive markers of response to a specific treatment (e.g. eosinophils, total IgE, fraction of exhaled nitric oxide and periostin). In parallel, anti-IL-4 strategies have been attempted (pascolizumab, pitakinra and dupilumab). So far, dupilumab was reported capable of reducing the severity of asthma and the rate of exacerbations. IL-13 and IL-4 are crucial in TH2-mediated inflammation in asthma, but it remains clear that only specific endotypes respond to these treatments. Although the use of anti-IL-14 and anti-IL-13 strategies is promising, the search for appropriate predictive biomarkers is urgently needed to better apply biological treatments.

Patient stratification and the unmet need in asthma

Asthma is often described as an inflammatory disease of the lungs and in most patients symptomatic treatment with bronchodilators or inhaled corticosteroids is sufficient to control disease. Unfortunately there are a proportion of patients who fail to achieve control despite treatment with the best current treatment. These severe asthma patients have been considered a homogeneous group of patients that represent the unmet therapeutic need in asthma. Many novel therapies have been tested in unselected asthma patients and the effects have often been disappointing, particularly for the highly specific monoclonal antibody-based drugs such as anti-IL-13 and anti-IL-5. More recently, it has become clear that asthma is a syndrome with many different disease drivers. Clinical trials of anti-IL-13 and anti-IL-5 have focused on biomarker-defined patient groups and these trials have driven the clinical progression of these drugs. Work on asthma phenotyping indicates that there is a group of asthma patients where T helper cell type 2 (Th2) cytokines and inflammation predominate and these type 2 high (T2-high) patients can be defined by biomarkers and response to therapies targeting this type of immunity, including anti-IL-5 and anti-IL-13. However, there is still a subset of T2-low patients that do not respond to these new therapies. This T2-low group will represent the new unmet medical need now that the T2-high-targeting therapies have made it to the market. This review will examine the current thinking on patient stratification in asthma and the identification of the T2-high subset. It will also look at the T2-low patients and examine what may be the drivers of disease in these patients.

Airborne Fine Particulate Matter Induces Oxidative Stress and Inflammation in Human Nasal Epithelial Cells

Airborne fine particulate matter with an aerodynamic diameter equal to or smaller than 2.5 μm is abbreviated as PM2.5, which is one of the main components in air pollution. Exposure to PM2.5 is associated with increased risk of many human diseases, including chronic and allergic rhinitis, but the underlying molecular mechanism for its toxicity has not been fully elucidated. We have hypothesized that PM2.5 may cause oxidative stress and enhance inflammatory responses in nasal epithelial cells. Accordingly, we used human RPMI 2650 cells, derived from squamous cell carcinoma of the nasal septum, as a model of nasal epithelial cells, and exposed them to PM2.5 that was collected at Fudan University (31.3°N, 121.5°E) in Shanghai, China. PM2.5 exposure decreased the viability of RPMI 2650 cells, suggesting that PM2.5 may impair the barrier function of nasal epithelial cells. Moreover, PM2.5 increased the levels of intracellular reactive oxygen species (ROS) and the nuclear translocation of NF-E2-related factor-2 (Nrf2). Importantly, PM2.5 also decreased the activities of superoxide dismutase, catalase and glutathione peroxidase. Pretreatment with N-Acetyl-L-cysteine (an anti-oxidant) reduced the degree of the PM2.5-induced oxidative stress in RPMI 2650 cells. In addition, PM2.5 increased the production of granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α, interleukin-13 and eotaxin (C-C motif chemokine ligand 11), each of which initiates and/or augments local inflammation. These results suggest that PM2.5 may induce oxidative stress and inflammatory responses in human nasal epithelial cells, thereby leading to nasal inflammatory diseases. The present study provides insights into cellular injury induced by PM2.5.

Lebrikizumab in the treatment of asthma

INTRODUCTION

Severe asthma continues to be a major clinical problem despite the availability of effective asthma medications such as inhaled corticosteroids. Several targeted biologic therapies are emerging to treat patients with severe asthma. Areas Covered: This review provides an update of information on lebrikizumab, a novel monoclonal antibody that targets IL-13 and is currently in advanced stages of development. It describes the role of IL-13, a key effector cytokine in Type 2 (T2) airway inflammation in asthma and discusses the results of recent phase 2 trials investigating lebrikizumab's efficacy and safety in patients with severe asthma. Furthermore, it provides insight into the current ongoing trials with lebrikizumab and outlines future research needs. Expert Opinion: Several emerging therapeutic targets have been identified for patients with severe asthma. By specifically targeting IL-13, lebrikizumab has the potential to block several downstream signals that play a role in disease progression including airway inflammation, mucous hypersecretion and airway remodeling. The effects of lebrikizumab have been more marked in individuals with high serum periostin levels which reflect underlying IL-13 activity and T2 airway inflammation. Ongoing trials with lebrikizumab aim to further examine its long-term safety and efficacy in a larger population and explore its effects on airway inflammation and function.

Sputum interleukin-13 as a biomarker for the evaluation of asthma control

BACKGROUND

Asthma control refers to the extent to which the manifestations of asthma have been reduced or eradicated by treatment. Interleukin-13 (IL-13) has a central role in Th2 response and serves as a possible therapeutic target in uncontrolled asthma. Fraction of exhaled nitric oxide (FeNO) and sputum eosinophils have modest performance in the evaluation of asthma control.

OBJECTIVE

To assess the diagnostic performance of sputum IL-13 for the evaluation of asthma control and furthermore to investigate the performance of sputum eosinophils and FeNO.

METHODS

One hundred and seventy patients with asthma were studied. All subjects underwent assessment of asthma control by asthma control test (ACT), lung function tests, FeNO measurement and sputum induction for cell count identification and IL-13 measurement in supernatants.

RESULTS

IL-13 (pg/mL) levels in sputum supernatant differed significantly among patients with well-controlled asthma and those with not well-controlled asthma [median IQR 78 (66-102) vs. 213 (180-265), P < 0.001]. Receiver operating characteristic (ROC) analysis showed that, for the whole study population, the diagnostic performance of IL-13 was superior to both sputum eosinophils and FeNO levels [area under the curve (AUC) 0.92, 95% CI 0.87 to 0.95 vs. AUC 0.65, 95% CI 0.58 to 0.72 vs. AUC 0.65, 95% CI 0.55 to 0.72, respectively].

CONCLUSION

The diagnostic performance of sputum IL-13 was superior to both sputum eosinophils and FeNO levels for the identification of well-controlled asthma. Sputum IL-13 levels could serve as a useful biomarker for asthma control assessment.

Genome-Wide Methylation Study Identifies an IL-13-induced Epigenetic Signature in Asthmatic Airways

RATIONALE

Epigenetic changes to airway cells have been proposed as important modulators of the effects of environmental exposures on airway diseases, yet no study to date has shown epigenetic responses to exposures in the airway that correlate with disease state. The type 2 cytokine IL-13 is a key mediator of allergic airway diseases, such as asthma, and is up-regulated in response to many asthma-promoting exposures.

OBJECTIVES

To directly study the epigenetic response of airway epithelial cells (AECs) to IL-13 and test whether IL-13-induced epigenetic changes differ between individuals with and without asthma.

METHODS

Genome-wide DNA methylation and gene expression patterns were studied in 58 IL-13-treated and untreated primary AEC cultures and validated in freshly isolated cells of subjects with and without asthma using the Illumina Human Methylation 450K and HumanHT-12 BeadChips. IL-13-mediated comethylation modules were identified and correlated with clinical phenotypes using weighted gene coexpression network analysis.

MEASUREMENTS AND MAIN RESULTS

IL-13 altered global DNA methylation patterns in cultured AECs and were significantly enriched near genes associated with asthma. Importantly, a significant proportion of this IL-13 epigenetic signature was validated in freshly isolated AECs from subjects with asthma and clustered into two distinct modules, with module 1 correlated with asthma severity and lung function and module 2 with eosinophilia.

CONCLUSIONS

These results suggest that a single exposure of IL-13 may selectively induce long-lasting DNA methylation changes in asthmatic airways that alter specific AEC pathways and contribute to asthma phenotypes.

Cellular signalling of cysteinyl leukotriene type 1 receptor variants CysLT₁-G300S and CysLT₁-I206S

Cysteinyl-leukotrienes are pro-inflammatory lipid mediators, involved in allergic asthma, that bind the G-protein-coupled receptors CysLT1, CysLT2 and GPR99. A polymorphism in one of these receptors, CysLT1-G300S was strongly associated with atopy, whereas the CysLT1-I206S polymorphism was not. In the present work, our aim was to characterize these two variants by studying their cellular signalling. Cell surface expression of mutant receptors in transfected HEK-293 cells was comparable to that of the wild-type receptor. Compared to CysLT1-WT, production of inositol phosphates as well as IL-8 and IL-13 promoter transactivation in response to either LTD4 or LTC4 was significantly increased in CysLT1-G300S-transfected cells. Moreover, LTD4-induced phosphorylation of the signalling effector Erk, but not p38, p65 or c-Jun was higher in CysLT1-G300S-transfected cells. On the other hand, the variant CysLT1-I206S did not show a significant difference in its signal transduction compared to the wild-type receptor. Taken together, our results indicate that the variant CysLT1-G300S can induce a greater signal than the CysLT1-WT receptor, a feature that may be relevant to its association with atopy.

Cytokines profile and peripheral blood mononuclear cells morphology in Rett and autistic patients

A potential role for immune dysfunction in autism spectrum disorders (ASD) has been well established. However, immunological features of Rett syndrome (RTT), a genetic neurodevelopmental disorder closely related to autism, have not been well addressed yet. By using multiplex Luminex technology, a panel of 27 cytokines and chemokines was evaluated in serum from 10 RTT patients with confirmed diagnosis of MECP2 mutation (typical RTT), 12 children affected by classic autistic disorder and 8 control subjects. The cytokine/chemokine gene expression was assessed by real time PCR on mRNA of isolated peripheral blood mononuclear cells (PBMCs). Moreover, ultrastructural analysis of PBMCs was performed using transmission electron microscopy (TEM). Significantly higher serum levels of interleukin-8 (IL-8), IL-9, IL-13 were detected in RTT compared to control subjects, and IL-15 shows a trend toward the upregulation in RTT. In addition, IL-1β and VEGF were the only down-regulated cytokines in autistic patients with respect to RTT. No difference in cytokine/chemokine profile between autistic and control groups was detected. These data were also confirmed by ELISA real time PCR. At the ultrastructural level, the most severe morphological abnormalities were observed in mitochondria of both RTT and autistic PBMCs. In conclusion, our study shows a deregulated cytokine/chemokine profile together with morphologically altered immune cells in RTT. Such abnormalities were not quite as evident in autistic subjects. These findings indicate a possible role of immune dysfunction in RTT making the clinical features of this pathology related also to the immunology aspects, suggesting, therefore, novel possible therapeutic interventions for this disorder.

Ferulic Acid Induces Th1 Responses by Modulating the Function of Dendritic Cells and Ameliorates Th2-Mediated Allergic Airway Inflammation in Mice

This study investigated the immunomodulatory effects of ferulic acid (FA) on antigen-presenting dendritic cells (DCs) in vitro and its antiallergic effects against ovalbumin- (OVA-) induced Th2-mediated allergic asthma in mice. The activation of FA-treated bone marrow-derived DCs by lipopolysaccharide (LPS) stimulation induced a high level of interleukin- (IL-) 12 but reduced the expression levels of the proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor- (TNF-) α. Compared to control-treated DCs, FA significantly enhanced the expressions of Notch ligand Delta-like 4 (Dll4), MHC class II, and CD40 molecules by these DCs. Furthermore, these FA-treated DCs enhanced T-cell proliferation and Th1 cell polarization. In animal experiments, oral administration of FA reduced the levels of OVA-specific immunoglobulin E (IgE) and IgG₁ and enhanced IgG_2a antibody production in serum. It also ameliorated airway hyperresponsiveness and attenuated eosinophilic pulmonary infiltration in dose-dependent manners. In addition, FA treatment inhibited the production of eotaxin, Th2 cytokines (IL-4, IL-5, and IL-13), and proinflammatory cytokines but promoted the Th1 cytokine interferon- (IFN-) γ production in bronchoalveolar lavage fluid (BALF) and the culture supernatant of spleen cells. These findings suggest that FA exhibits an antiallergic effect via restoring Th1/Th2 imbalance by modulating DCs function in an asthmatic mouse model.

Tiotropium attenuates IL-13-induced goblet cell metaplasia of human airway epithelial cells

BACKGROUND

It has been shown that acetylcholine is both a neurotransmitter and acts as a local mediator, produced by airway cells including epithelial cells. In vivo studies have demonstrated an indirect role for acetylcholine in epithelial cell differentiation. Here, we aimed to investigate direct effects of endogenous non-neuronal acetylcholine on epithelial cell differentiation.

METHODS

Human airway epithelial cells from healthy donors were cultured at an air-liquid interface (ALI). Cells were exposed to the muscarinic antagonist tiotropium (10 nM), interleukin (IL)-13 (1, 2 and 5 ng/mL), or a combination of IL-13 and tiotropium, during or after differentiation at the ALI.

RESULTS

Human airway epithelial cells expressed all components of the non-neuronal cholinergic system, suggesting acetylcholine production. Tiotropium had no effects on epithelial cell differentiation after air exposure. Differentiation into goblet cells was barely induced after air exposure. Therefore, IL-13 (1 ng/mL) was used to induce goblet cell metaplasia. IL-13 induced MUC5AC-positive cells (5-fold) and goblet cells (14-fold), as assessed by histochemistry, and MUC5AC gene expression (105-fold). These effects were partly prevented by tiotropium (47-92%). Goblet cell metaplasia was induced by IL-13 in a dose-dependent manner, which was inhibited by tiotropium. In addition, tiotropium reversed goblet cell metaplasia induced by 2 weeks of IL-13 exposure. IL-13 decreased forkhead box protein A2 (FoxA2) expression (1.6-fold) and increased FoxA3 (3.6-fold) and SAM-pointed domain-containing ETS transcription factor (SPDEF) (5.2-fold) expression. Tiotropium prevented the effects on FoxA2 and FoxA3, but not on SPDEF.

CONCLUSIONS

We demonstrate that tiotropium has no effects on epithelial cell differentiation after air exposure, but inhibits and reverses IL-13-induced goblet cell metaplasia, possibly via FoxA2 and FoxA3. This indicates that non-neuronal acetylcholine contributes to goblet cell differentiation by a direct effect on epithelial cells.

Interleukin-13 promotes expression of Alix to compromise renal tubular epithelial barrier function

The epithelial barrier dysfunction plays a critical role in a number of kidney diseases. The mechanism is unclear. Alix is a protein involving in protein degradation in epithelial cells. This study aims to investigate that interleukin (IL)-13 inhibits Alix to compromise the kidney epithelial barrier function. In this study, the murine collecting duct cell line (M-1) was cultured in Transwell inserts to investigate the significance of Alix in compromising the epithelial barrier functions. T cell (Teff cells) proliferation assay was employed to assess the antigenicity of ovalbumin (OVA) that was transported across the M-1 monolayer barrier. The results showed that M-1 cells express Alix. Exposure to interleukin (IL)-13 markedly decreased the expression of Alix in M-1 cells, which compromised the M-1 monolayer barrier functions by showing the increases in the permeability to OVA. Over-expression of Alix abolished the IL-13-induced M-1 monolayer barrier dysfunction. Knockdown of Alix significantly increased M-1 monolayer permeability. The OVA collected from the Transwell basal chambers induced the OVA-specific T cell proliferation. We conclude that IL-13 compromises M-1 epithelial barrier functions via inhibiting Alix expression.

Interleukin 13-positive mast cells are increased in immunoglobulin G4-related sialadenitis

Interleukin (IL)-13 is a T helper 2 (Th2) cytokine that plays important roles in the pathogenesis of asthma. IL-13 induces hypersensitivity of the airways, increased mucous production, elevated serum immunoglobulin (Ig) E levels, and increased numbers of eosinophils. Many patients with IgG4-related disease have allergic backgrounds and show elevated serum IgE levels and an increase in the number of eosinophils. Upregulation of Th2/regulatory T (Treg) cytokines, including IL-13, has been detected in affected tissues of patients with IgG4-related disease. We previously reported that mast cells might be responsible for the production of the Th2/Treg cytokines IL-4, IL-10, and transforming growth factor (TGF)-β1 in IgG4-related disease. In this study, immunohistochemical analysis showed increased numbers of IL-13-positive mast cells in IgG4-related disease, which suggests that mast cells also produce IL-13 and contribute to elevation of serum IgE levels and eosinophil infiltration in IgG4-related disease.

miR-143 inhibits interleukin-13-induced inflammatory cytokine and mucus production in nasal epithelial cells from allergic rhinitis patients by targeting IL13Rα1

Allergic rhinitis (AR) is a common chronic inflammatory condition of the nasal mucosal tissue. The interleukin-13 (IL-13) signaling pathway is of great importance in the pathogenesis of AR. However, how the signaling molecules in this pathway are regulated, particularly through microRNAs (miRNAs), remains unclear. In the present study, we investigated the regulatory role and mechanism of miRNA-143 (miR-143) in IL-13-induced inflammatory cytokine and mucus production in nasal epithelial cells (NECs) from AR patients. Our results showed that forced expression of miR-143 significantly decreased the mRNA and protein expression levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), eotaxin and mucin 5AC (MUC5AC) in IL-13-stimulated NECs. Moreover, we confirmed that miR-143 directly targeted and significantly suppressed IL-13 receptor α1 chain (IL13Rα1) gene expression. This study thus suggests that miR-143 regulation of IL-13-induced inflammatory cytokine and mucus production in NECs from AR patients probably partly depends on inhibition of IL13Rα1. Therefore, the IL13Rα1 signaling pathway may be a potential target for the prevention and treatment of AR by miR-143.

Beyond TGFβ--novel ways to target airway and parenchymal fibrosis

Within the lungs, fibrosis can affect both the parenchyma and the airways. Fibrosis is a hallmark pathological change in the parenchyma in patients with idiopathic pulmonary fibrosis (IPF), whilst in asthma or chronic obstructive pulmonary disease (COPD) fibrosis is a component of the remodelling of the airways. In the past decade, significant advances have been made in understanding the disease behaviour and pathogenesis of parenchymal and airway fibrosis and as a result a variety of novel therapeutic targets for slowing or preventing progression of these fibrotic changes have been identified. This review highlights a number of these targets and discusses the potential for treating parenchymal or airway fibrosis through these mediators/pathways in the future.

Dupilumab: a novel treatment for asthma

Simultaneously with the steady progress towards a better knowledge of the pathobiology of asthma, the potential usefulness of anticytokine therapies is emerging as one of the key concepts in the newly developing treatments of this widespread airway disease. In particular, given the key role played by interleukin (IL)-4 and IL-13 in the pathophysiology of the most typical aspects of asthma, such as chronic airway inflammation, tissue remodeling, and bronchial hyperresponsiveness, these pleiotropic cytokines are now considered as suitable therapeutic targets. Among the recently developed antiasthma biologic drugs, the monoclonal antibody dupilumab is very promising because of its ability to inhibit the biological effects of both IL-4 and IL-13. Indeed, dupilumab prevents IL-4/13 interactions with the α-subunit of the IL-4 receptor complex. A recent trial showed that in patients with difficult-to-control asthma, dupilumab can markedly decrease asthma exacerbations and improve respiratory symptoms and lung function; these effects were paralleled by significant reductions in T-helper 2-associated inflammatory biomarkers. However, further larger and longer trials are required to extend and validate these preliminary results, and also to carefully study the safety and tolerability profile of dupilumab.

Effect of Kuwanon G isolated from the root bark of Morus alba on ovalbumin-induced allergic response in a mouse model of asthma

The root bark of Morus alba L. (Mori Cortex Radicis; MCR) is traditionally used in Korean medicine for upper respiratory diseases. In this study, we investigated the antiasthmatic effect of kuwanon G isolated from MCR on ovalbumin (OVA)-induced allergic asthma in mice. Kuwanon G (1 and 10 mg/kg) was administered orally in mice once a day for 7 days during OVA airway challenge. We measured the levels of OVA-specific IgE and Th2 cytokines (IL-4, IL-5, and IL-13) in the sera or bronchoalveolar lavage (BAL) fluids and also counted the immune cells in BAL fluids. Histopathological changes in the lung tissues were analyzed. Kuwanon G significantly decreased the levels of OVA-specific IgE and IL-4, IL-5, and IL-13 in the sera and BAL fluids of asthma mice. Kuwanon G reduced the numbers of inflammatory cells in the BAL fluids of asthma mice. Furthermore, the pathological feature of lungs including infiltration of inflammatory cells, thickened epithelium of bronchioles, mucus, and collagen accumulation was inhibited by kuwanon G. These results indicate that kuwanon G prevents the pathological progression of allergic asthma through the inhibition of lung destruction by inflammation and immune stimulation.

Key mediators in the immunopathogenesis of allergic asthma

Asthma is described as a chronic inflammatory disorder of the conducting airways. It is characterized by reversible airway obstruction, eosinophil and Th2 infiltration, airway hyper-responsiveness and airway remodeling. Our findings to date have largely been dependent on work done using animal models, which have been instrumental in broadening our understanding of the mechanism of the disease. However, using animals to model a uniquely human disease is not without its drawbacks. This review aims to examine some of the key mediators and cells of allergic asthma learned from animal models and shed some light on emerging mediators in the pathogenesis allergic airway inflammation in acute and chronic asthma.

Plasma membrane Ca2+-ATPase regulates Ca2+ signaling and the proliferation of airway smooth muscle cells

Plasma membrane Ca2+-ATPase (PMCA) plays an important role in regulating intracellular Ca2+ homeostasis by extruding excessive Ca2+ to extracellular spaces. PMCA has four isoforms and is widely expressed in different tissues and cells including airway smooth muscle cells (ASMCs). In the present study, we investigated the role of PMCA in the maintenance of Ca2+ homeostasis and regulation of ASMCs proliferation. By using Ca2+ fluorescence, we found that inhibition of PMCA with LaCl3 or carboxyeosin (CE) decreased the decay rate of Ca2+ transient induced by bradykinin (BK). No obvious decay was observed when SERCA was inhibited by thapsigargin (TpG). LaCl3 and CE also induced a spontaneous [Ca2+]i increase in the presence of TpG even in Ca2+-free bath solution. Both LaCl3 and CE inhibited UTP-induced Ca2+ oscillations in ASMCs. PCR assay found that PMCA1 and PMCA4 mRNA were expressed in rat ASMCs. The expression of PMCA4 was downregulated in proliferating ASMCs when compared to resting cells. Both the isoform-nonselective PMCA inhibitor caloxin 2a1 and PMCA4-selective inhibitor caloxin 1b1 decreased the decay rate of Ca2+ transient induced by TpG or BK. PMCA inhibitors except caloxin 2a1 promoted ASMCs proliferation. Annexin-V apoptosis assay detected that caloxin 2a1 increased ASMCs apoptosis, suggesting that inhibition of PMCA with different blockers results in different [Ca2+]i and thus different cellular response. Our results provide evidences to support the hypothesis that PMCA is involved in the regulation of Ca2+ homeostasis and ASMCs proliferation. These data suggest that PMCA may be a new target in the treatment of chronic asthma.

Due diligence in the characterization of matrix effects in a total IL-13 Singulex™ method

After obtaining her PhD in Cellular and Molecular biology from the University of Nevada, Reno, Stephanie has spent the last 15 years in the field of bioanalysis. She has held positions in academia, biotech, contract research and large pharma where she has managed ligand binding assay (discovery to Phase IIb clinical) and flow cytometry (preclinical) laboratories as well as taken the lead on implementing new/emergent technologies. Currently Stephanie leads Pfizer’s Regulated Bioanalysis Ligand Binding Assay group, focusing on early clinical biomarker support.

Interleukin (IL)-13, a Th2 cytokine, drives a range of physiological responses associated with the induction of allergic airway diseases and inflammatory bowel diseases. Analysis of IL-13 as a biomarker has provided insight into its role in disease mechanisms and progression. Serum IL-13 concentrations are often too low to be measured by standard enzyme-linked immunosorbent assay techniques, necessitating the implementation of a highly sensitive assay. Previously, the validation of a Singulex™ Erenna® assay for the quantitation of IL-13 was reported. Herein we describe refinement of this validation; defining the impact of matrix interference on the lower limit of quantification, adding spiked matrix QC samples, and extending endogenous IL-13 stability. A fit-for-purpose validation was conducted and the assay was used to support a Phase II clinical trial.

Qu Feng Xuan Bi Formula attenuates anaphylactic rhinitis-asthma symptoms via reducing EOS count and regulating T cell function in rat ARA models

ETHNOPHARMACOLOGICAL RELEVANCE

Aqueous extract of Qu Feng Xuan Bi Formula (QFXBF, a Chinese herb formula) which composed of Radix Glycyrrhizae, Radix Glycyrrhizae Preparata, Paeonia sterniana Fletcher in Journ, Pheretima, Allium macrostemon Bunge, Astragalus membranaceus (Fisch) Bunge and Divaricate Saposhnikovia Root has been used in treatment of allergic rhinitis and asthma (ARA) as an approved hospital prescription for many years in Jiangsu Province Hospital of Traditional Chinese Medicine, China. The present study was designed to investigate the effect of the aqueous extract of QFXBF in the gene expression of Toll-like receptor 9 (TLR9) and the manners of immune modulation of T cell-associated interleukin (IL-4 and IL-13) in rat ARA models.

MATERIALS AND METHODS

Fifty SD male rats were divided into five groups: not treated group, OVA only group (treated only with OVA), dexamethasone (DXM) group, low dose QFXBF group and high dose QFXBF group randomly (n=10 per group). Rat allergic rhinitis and asthma model was developed by ovalbumin (OVA) sensitization and nose infusion. Pathological changes of nasal tissue and lungs were examined by H&E staining. Gene expressions of TLR9, Stat 3, Jak-1 and C-Jun in nasal tissue were assayed by real-time polymerase chain reaction (RT-PCR). The serum and broncho-alveolar lavage fluid (BALF) levels of T cell-associated interleukin (IL-4 and IL-13) were determined by enzyme-linked immunosorbent assay (ELISA).

RESULT

The ARA model was successfully established. Marked EOS count was observed in BALF from ARA models. The aqueous extract of QFXBF could reduce EOS levels and increase TLR9 expression, but did not affect the gene expression of Stat-3 and Jak-1 and C-Jun. The reduction of IL-13 concentration in serum from high dose QFXBF group was observed in BALF, albeit not significantly. Despite the not treated group, serum levels of IL-4 had significantly increased in other four groups (P<0.001, n=4-6) but made higher in low dose QFXBF group and DXM group (P<0.05, n=4-6).

CONCLUSION

This study originally provides the evidence that the aqueous extract of Qu Feng Xuan Bi Formula alone is effective in the treatment of anaphylactic rhinitis-asthma symptoms. The extract of Qu Feng Xuan Bi Formula was effective to reduce the eosophil recruitment to the lung. In addition it increased the IL-4 concentration in the BALF and expression of TLR9 in the nasal tissue. No alteration was observed in the IL-13 concentration in the BALF and expression of STAT-3, JAK-1 and C-Jun in nasal tissue. The results thereby scientifically provided mechanism of these aqueous extract of QFXBF in improvement of ARA and supported its clinical use.