Interleukin-13: prospects for new treatments

A critical evaluation of suitability of tralokinumab for treatment of moderate-to-severe atopic dermatitis in adolescents and adults

INTRODUCTION

Atopic dermatitis (AD) is a chronic, intensely pruritic disease associated with significant patient burden. Recent advancements in AD pathogenesis have expanded its therapeutics pipeline. Tralokinumab is a fully human monoclonal antibody that binds specifically Interleukin (IL)-13, inhibiting the downstream IL-13 signaling. Phase 3 clinical trials and some real-world studies showed that tralokinumab, as monotherapy or in combination with topical corticosteroids, is efficacious and safe in adult patients with moderate-to-severe AD. Similar results were reported in a phase 3 trial in adolescents (aged ≥12 years).

AREAS COVERED

We review the role of IL-13 in AD and discuss the value of tralokinumab for treating moderate-to-severe AD, comparing efficacy and safety results derived from clinical trials and real-life data.

EXPERT OPINION

The role of IL-13 in AD supports a targeted therapeutic approach. Tralokinumab has proven efficacious and well-tolerated in a large proportion of patients confirming its value for treating moderate-to-severe AD from age 12 years onwards; it quickly improves itching and can maintain a high-level of response over time; it can be administered with flexible dosing schedules. Future studies will further clarify the role of IL-13 pathway and which patients would be best suited to tralokinumab, shifting AD treatment into an era of precision medicine.

The hidden sentinel of the skin: An overview on the role of interleukin-13 in atopic dermatitis

Recent evidence suggests that interleukin (IL)-13 is a crucial cytokine involved in the pathogenesis of atopic dermatitis (AD). It is a central driver of type-2 T-helper inflammation and is overexpressed in lesional skin of AD patients. Upon release in peripheral skin, IL-13 activates its receptors, recruits inflammatory cells, and modifies the skin microbiome. IL-13 also reduces the expression of epidermal barrier proteins and activates sensory nerve mediating the itch transmission signal. Novel therapeutics that target IL-13 seem to be efficacious and safe for the treatment of patients with moderate-to-severe AD. The aim of our manuscript is to review the role that IL-13 plays in AD immunopathogenesis.

Critical Players and Therapeutic Targets in Chronic Itch

Chronic itch is one of the most prominent clinical characteristics of diverse systematic diseases. It is a devastating sensation in pathological diseases. Despite its importance, there are no FDA-labelled drugs specifically geared toward chronic itch. The associated complex pathogenesis and diverse causes escalate chronic itch to being one of the top challenges in healthcare. Humanized antibodies against IL-13, IL-4, and IL-31 proved effective in treatment of itch-associated atopic dermatitis but remain to be validated in chronic itch. There are still no satisfactory anti-itch therapeutics available toward itch-related neuropeptides including GRP, BNP, SST, CGRP, and SP. The newly identified potential itch targets including OSM, NMB, glutamate, periostin, and Serpin E1 have opened new avenues for therapeutic development. Proof-of-principle studies have been successfully performed on antagonists against these proteins and their receptors in itch treatment in animal models. Their translational interventions in humans need to be evaluated. It is of great importance to summarize and compare the newly emerging knowledge on chronic itch and its pathways to promote the development of novel anti-itch therapeutics. The goal of this review is to analyze the different physiologies and pathophysiologies of itch mediators, whilst assessing their suitability as new targets and discussing future therapeutic development.

Type 2 Inflammation in Eosinophilic Esophagitis: From Pathophysiology to Therapeutic Targets

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease of the esophagus characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation, whose incidence is rising. It significantly affects patients’ quality of life and, if left untreated, results in fibrotic complications. Although broad consensus has been achieved on first-line therapy, a subset of patients remains non-responder to standard therapy. The pathogenesis of EoE is multifactorial and results from the complex, still mostly undefined, interaction between genetics and intrinsic factors, environment, and antigenic stimuli. A deep understanding of the pathophysiology of this disease is pivotal for the development of new therapies. This review provides a comprehensive description of the pathophysiology of EoE, starting from major pathogenic mechanisms (genetics, type 2 inflammation, epithelial barrier dysfunction, gastroesophageal reflux, allergens, infections and microbiota) and subsequently focusing on the single protagonists of type 2 inflammation (involved cells, cytokines, soluble effectors, surface proteins and transcription factors) that could represent present and future therapeutic targets, while summarizing previous therapeutic approaches in literature.

Role of Serum Vitamin D, Interleukin 13, and microRNA-135a in Hepatocellular Carcinoma and Treatment Failure in Egyptian HCV-Infected Patients Receiving Direct Antiviral Agents

Direct-acting antivirals (DAAs) are used for hepatitis C virus (HCV) treatment. However, treatment failure and hepatocellular carcinoma (HCC) development following treatment was reported. In this study, we assessed the role of serum vitamin D, interleukin 13 (IL-13), and microRNA-135a in the prediction of treatment failure with DAA and HCC development among Egyptian HCV-infected patients. A total of 950 patients with HCV-related chronic liver disease underwent DAA treatment. Before DAAs, serum vitamin D and IL-13 were determined by ELISA, and gene expression of miRNA-135a was assessed in serum by real-time PCR. The predictive abilities of these markers were determined using the receiver operating characteristic (ROC) curve. Sustained virological response (SVR) was achieved in 92.6% of HCV-infected patients (responders). High viral load, IL-13, miRNA-135a, and low vitamin D levels were associated with treatment failure and HCC development. HCC development was recorded in non-responders, but not in the responders (35.7% vs. 0% p < 0.001). In conclusion: serum IL-13, Vitamin D, and miRNA-135a could be potential biomarkers in monitoring DAA treatment and HCC prediction. DAAs-induced SVR may decrease the incidence of HCC.

Development of Aldose Reductase Inhibitors for the Treatment of Inflammatory Disorders and Cancer: Current Drug Design Strategies and Future Directions

Aldose Reductase (AR) is an enzyme that converts glucose to sorbitol during the polyol pathway of glucose metabolism. AR has been shown to be involved in the development of secondary diabetic complications due to its involvement in causing osmotic as well as oxidative stress. Various AR inhibitors have been tested for their use to treat secondary diabetic complications, such as retinopathy, neuropathy, and nephropathy in clinical studies. Recent studies also suggest the potential role of AR in mediating various inflammatory complications. Therefore, the studies on the development and potential use of AR inhibitors to treat inflammatory complications and cancer besides diabetes are currently on the rise. Further, genetic mutagenesis studies, computer modeling, and molecular dynamics studies have helped design novel and potent AR inhibitors. This review discussed the potential new therapeutic use of AR inhibitors in targeting inflammatory disorders and cancer besides diabetic complications. Further, we summarized studies on how AR inhibitors have been designed and developed for therapeutic purposes in the last few decades.

Targeted therapy in eosinophilic chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common and preventable airway disease causing significant worldwide mortality and morbidity. Lifetime exposure to tobacco smoking and environmental particles are the two major risk factors. Over recent decades, COPD has become a growing public health problem with an increase in incidence. COPD is defined by airflow limitation due to airway inflammation and small airway remodelling coupled to parenchymal lung destruction. Most patients exhibit neutrophil-predominant airway inflammation combined with an increase in macrophages and CD8⁺ T-cells. Asthma is a heterogeneous chronic inflammatory airway disease. The most studied subtype is type 2 (T2) high eosinophilic asthma, for which there are an increasing number of biologic agents developed. However, both asthma and COPD are complex and share common pathophysiological mechanisms. They are known as overlapping syndromes as approximately 40% of patients with COPD present an eosinophilic airway inflammation. Several studies suggest a putative role of eosinophilia in lung function decline and COPD exacerbation. Recently, pharmacological agents targeting eosinophilic traits in uncontrolled eosinophilic asthma, especially monoclonal antibodies directed against interleukins (IL-5, IL-4, IL-13) or their receptors, have shown promising results. This review examines data on the rationale for such biological agents and assesses efficacy in T2-endotype COPD patients.

Patients with severe COPD and eosinophilic inflammation experience uncontrolled symptoms despite optimal pharmaceutical treatment. The development of new biomarkers is needed for better phenotyping of patients to propose innovative targeted therapy.https://bit.ly/2KzWuNO

Systemic Cytokine Profiles of CD4+ T Lymphocytes Correlate with Clinical Features and Functional Status in Stable COPD

Aims

To evaluate the expressions of intracellular cytokines in CD4+ T lymphocytes and to investigate the correlation between biomarker expressions and clinical and functional characteristics of stable COPD patients.

Patients and Methods

Peripheral blood was collected from 36 COPD patients, and the expression of cytokines (IL-8, IL-13, IL-17, IL-6, IL-2, IL-10, and TNF-α) in T lymphocytes CD4 + was investigated. In addition, lung function, dyspnea symptoms, quality of life, vital signs, body composition, level of physical activity, peripheral muscle strength, and functional capacity were assessed.

Results

Individuals with greater bronchial obstruction present a higher proportion of CD4 + IL-2 + lymphocytes compared to individuals with less severe bronchial obstruction. We found a positive correlation between the expression of the cytokines IL-13, IL-17, IL-6, IL-2, IL-10, and TNF-α in CD4+ T lymphocytes. In addition, we found a positive correlation between CD4+ IL-10+ T lymphocytes and lower limb muscle strength and a negative correlation between CD4+ IL-8+ T lymphocytes and peripheral oxygen saturation and steps per day.

Conclusion

Systemic CD4+IL-2+, IL-8+, and IL-10+ T lymphocytes presented a correlation with clinical characteristics and functional status in stable COPD.

Intranasal administration of Lignosus rhinocerotis (Cooke) Ryvarden (Tiger Milk mushroom) extract attenuates airway inflammation in murine model of allergic asthma

Asthma is a chronic inflammatory disorder in the airways that involves the activation of cells and mediators. Lignosus rhinocerotis (Cooke) Ryvardan or Tiger Milk mushroom is a medicinal mushroom that is traditionally used to treat inflammatory diseases including asthma. In this study, the protective effects of intranasal administration of L. rhinocerotis extract (LRE) in ovalbumin (OVA)-induced airway inflammation mouse model were investigated. Mice were sensitized by intraperitoneal (i.p) injection on days 0 and 14, followed by a daily challenge with 1% OVA from days 21 to 27. Following OVA challenge, LRE and dexamethasone were administered via intranasal and i.p. injection respectively. On day 28, the level of serum immunoglobulin (Ig)E, differential cell counts and T-helper (Th) 2 cytokines in bronchoalveolar lavage fluid (BALF) fluid, cell subset population in lung-draining lymph nodes (LNs), leukocytes infiltration and mucus production in the lungs of the animals was measured. Results demonstrated that intranasal administration of LRE significantly suppressed the level of inflammatory cell counts in BALF as well as populations of CD4⁺ T-cells in lung draining LNs. Apart from that, LRE also significantly reduced the level of Th2 cytokines in BALF and IgE in the serum in OVA-induced asthma. Histological analysis also demonstrated the amelioration of leukocytes infiltration and mucus production in the lungs. Overall, these findings demonstrated the attenuation of airway inflammation in the LRE-treated mice therefore suggesting a promising alternative for the management of allergic airway inflammation.

Variation in doses and duration of particulate matter exposure in bronchial epithelial cells results in upregulation of different genes associated with airway disorders

Exposure to particulate matter < 2.5 μm (PM2.5) is associated with a variety of airway diseases. Although studies have demonstrated that high doses of PM2.5 cause cytotoxicity and changes to gene expression in bronchial epithelial cells, the effect of lower doses and repeated exposure to PM2.5 are less well studied. Here, we treated BEAS-2B cells with varying doses of PM2.5 for 1-7 days and examined the expression of a variety of genes implicated in airway disorders. At high doses, PM2.5 increased the expression of IL6, TNF, TSLP, CSF2, PTGS2, IL4R, and SPINK5. Other genes such as ADAM33, ORMDL3, DPP10 and CYP1A1, however, were increased by PM2.5 at much lower doses (≤1 μg/cm2). Repeated exposure to PM2.5 at 1 or 5 μg/cm2 every day for 7 days increased the sensitivity and magnitude of change for all of the aforementioned genes. Genes such as IL13 and TGFB1, increased only when cells were repeatedly exposed to PM2.5. Treatment with an antioxidant, or inhibitors to aryl hydrocarbon receptor or NF-κB attenuated the effect of PM2.5. These data demonstrate that PM2.5 exerts pleiotropic actions that differ by dose and duration that affect a variety of genes important to the development of airway disease.

Association of Air Pollution Exposure and Interleukin-13 Haplotype with the Risk of Aggregate Bronchitic Symptoms in Children

Interleukin-13(IL-13) might play an important role in driving aggregate bronchitic symptoms pathogenesis. However, none of the studies assessed the interaction between air pollutants exposure and IL-13 gene on the risk of aggregate bronchitic symptoms in non-asthma children. To assess the independent and joint effects of the exposure to air pollution and IL-13 haplotypes on the risk of aggregate bronchitic symptoms, we conducted a cross-sectional study and focused on non-asthma children. The study population consisted of 2944 children. The effect of each air pollutant on the risk of aggregate bronchitic symptoms was estimated as odds ratios per interquartile range (IQR) change. In the multiple logistic regressions, adjusted for confounding factors, the risk of chronic phlegm was associated with PM_2.5 exposure (aOR, 1.59; 95% CI, 1.07–2.37 per 12.51 μg/m3 change), O₃ exposure (aOR, 1.54 95% CI, 1.05–2.27 per 8.28 ppb change) and SO₂ exposure (aOR, 1.19; 95% CI, 1.02–1.39 per 0.98 ppb change). Our study further provides the evidence that gene-environment interactions between IL-13 haplotype and O₃ exposure on chronic phlegm (95% CI for interaction, 1.01–1.38). Identifying children who are more sensitive to air pollution helps us to provide them an efficient prevention to avoid aggregate bronchitic symptoms.

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Limited studies explored the interactions between IL-13 gene and air pollutants exposure on the risk of bronchitic symptoms.

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Genetic susceptibility of IL-13 may interact with O₃ exposure causing the pathogenesis of bronchitic symptoms.

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Identifying children susceptible to air pollutants helps us to provide them an efficient prevention of bronchitic symptoms.

Genetic susceptibility may interact with specific environmental factors causing the pathogenesis of aggregate bronchitic symptoms. Limited studies have explored the interactions between Interleukin-13 (IL-13) gene and air pollutants exposure on the risk of aggregate bronchitic symptoms. Our study further provides the evidence that gene-environment interactions between IL-13 gene and O₃ exposure may play an important role in aggregate bronchitic symptoms. Identifying children who are more sensitive to air pollutants helps us to provide them an efficient prevention to avoid aggregate bronchitic symptoms.

Overexpression of miR-155-5p Inhibits the Proliferation and Migration of IL-13-Induced Human Bronchial Smooth Muscle Cells by Suppressing TGF-β-Activated Kinase 1/MAP3K7-Binding Protein 2

Purpose

Molecular mechanisms leading to asthma is still ill-defined. Though the function of microRNAs (miRNAs) in asthma was previously reported, the involvement of miR-155 in important features of this disease remains unknown. The present study was designed to uncover the probable involvement of miR-155-5p in the proliferation and migration of IL-13-induced human bronchial smooth muscle cells (BSMCs) and the intrinsic regulatory mechanism.

Methods

The effects of different concentrations of IL-13 on the proliferation and migration of BSMCs as well as the expression of miR-155-5p and its predicted target transforming growth factor (TGF)-β-activated kinase 1/MAP3K7-binding protein 2 (TAB2) were investigated. The effects of miR-155-5p on the proliferation and migration of interleukin (IL)-13-induced BSMCs was determined in vitro using BSMCs transfected with miR-155 mimic/inhibitor and induced by a high concentration of IL-13. The quantitative real-time polymerase chain reaction (qRTPCR) was employed for determining the expression of miR-155-5p and TAB2. Western blotting was applied to analyze the expression of TAB2 at the protein level. Cell proliferation and migration were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays, respectively.

Results

The proliferation and migration of BSMCs were dose-dependently increased with IL-13 treatment. Contrariwise, IL-13 dose-dependently inhibited the expression of miR-155-5p in BSMCs. Mechanistic studies showed that inhibition of miR-155-5p further promoted the stimulatory effects of IL-13, whereas overexpression of miR-155 significantly inhibited these effects. In silico studies and luciferase reporter assays indicated that TAB2 was a negatively regulated miR-155-5p target.

Conclusions

These results suggested that miR-155-5p-inhibit the IL-13-induced proliferation and migration of BSMCs by targeting TAB2 and that the IL-13/miR-155/TAB2 pathway could serve as a therapeutic target for pulmonary diseases, especially asthma.

A novel anti-IL4Rα nanoparticle efficiently controls lung inflammation during asthma

Drug resistance and the harmful side effects accompanying the prolonged corticosteroid treatment of chronic pulmonary diseases prompted the development of more specific anti-inflammatory approaches. Several strategies aiming to block IL4Rα, the receptor for a key pro-inflammatory pathway, were investigated. However, their efficiency was limited, mostly due to the systemic or subcutaneous route of administrations. In this paper, we examined the ability of an intranasal treatment with biocompatible nanoparticles targeting IL4Rα to control lung inflammation in ovalbumin (OVA)-sensitized mice. OVA-sensitized mice were treated with anti-IL4Rα-conjugated nanoparticles. The levels of pro-inflammatory cytokines in the lungs and broncho-alveolar lavage fluid (BALF) were determined using a cytokine array assay. The effects of nanoparticle treatment on the activation of lung inflammatory cells and their ability to proliferate and produce cytokines were determined using fluorescence-activated cell sorting (FACS) analysis. Lung inflammation was also monitored using immunohistochemical staining. Treatment with the anti-IL4Rα nanoparticles significantly decreased pro-inflammatory cytokine expression and release in BALF and airway lung tissue in mice. The numbers of lung tissue lymphocytes, neutrophils and eosinophils were also decreased. Interestingly, anti-IL4Rα nanoparticles deactivated CD4 and CD8 T cells in lung tissue and inhibited their ability to produce pro-inflammatory cytokines to a significantly lower level than the treatment with free anti-IL4Rα. Moreover, they induced a sustained low level of lung inflammation for 1 week following the last instillation compared with the treatment with free anti-IL4Rα antibodies. Together, this data suggested that the enhanced tissue penetrability and sustainability of these nanoparticles improved the strength and durability of the immunosuppressive effects of anti-IL4Rα.

Eosinophilic airway inflammation: role in asthma and chronic obstructive pulmonary disease

The chronic lung diseases, asthma and chronic obstructive pulmonary disease (COPD), are common affecting over 500 million people worldwide and causing substantial morbidity and mortality. Asthma is typically associated with Th2-mediated eosinophilic airway inflammation, in contrast to neutrophilic inflammation observed commonly in COPD. However, there is increasing evidence that the eosinophil might play an important role in 10-40% of patients with COPD. Consistently in both asthma and COPD a sputum eosinophilia is associated with a good response to corticosteroid therapy and tailored strategies aimed to normalize sputum eosinophils reduce exacerbation frequency and severity. Advances in our understanding of the multistep paradigm of eosinophil recruitment to the airway, and the consequence of eosinophilic inflammation, has led to the development of new therapies to target these molecular pathways. In this article we discuss the mechanisms of eosinophilic trafficking, the tools to assess eosinophilic airway inflammation in asthma and COPD during stable disease and exacerbations and review current and novel anti-eosinophilic treatments.

Neurotrophic tyrosine kinase receptor 1 is a direct transcriptional and epigenetic target of IL-13 involved in allergic inflammation

Although interleukin (IL)-13 and neurotrophins are functionally important for the pathogenesis of immune responses, the interaction of these pathways has not been explored. Herein, by interrogating IL-13-induced responses in human epithelial cells we show that neurotrophic tyrosine kinase receptor, type 1 (NTRK1), a cognate, high-affinity receptor for nerve growth factor (NGF), is an early transcriptional IL-13 target. Induction of NTRK1 was accompanied by accumulation of activating epigenetic marks in the promoter; transcriptional and epigenetic changes were signal transducer and activator of transcription 6 dependent. Using eosinophilic esophagitis as a model for human allergic inflammation, we found that NTRK1 was increased in inflamed tissue and dynamically expressed as a function of disease activity and that the downstream mediator of NTRK1 signaling early growth response 1 protein was elevated in allergic inflammatory tissue compared with control tissue. Unlike NTRK1, its ligand NGF was constitutively expressed in control and disease states, indicating that IL-13-stimulated NTRK1 induction is a limiting factor in pathway activation. In epithelial cells, NGF and IL-13 synergistically induced several target genes, including chemokine (C-C motif) ligand 26 (eotaxin-3). In summary, we have demonstrated that IL-13 confers epithelial cell responsiveness to NGF by regulating NTRK1 levels by a transcriptional and epigenetic mechanism and that this process likely contributes to allergic inflammation.

Gene susceptibility in Iranian asthmatic patients: a narrative review

As environmental factors are important in the development of asthma, genetic factors could have a critical role in the expression of the disease. Hence, we carried out a systematic review to assess the susceptible genes for asthma in Iranian population. We conducted a literature search by using the electronic database PubMed, Biological Abstracts Web of Science, Current Contents Connect, Cinahl, ScienceDirect, Scopus, IranMedex, and Scientific Information Database to identify articles that evaluated the association between genetic variants and the risk of asthma in Iranian population (until April 30, 2012). The search terms were used include: Asthma and gene in combination with Iran for international database. The following criteria were used for selecting literatures in this review: The study should evaluate the association between gene polymorphism and risk of asthma in Iranian population, and the study should be a case-control design with normal subject as ac control group that published in a journal. Finally, 14 case-control studies were extracted from local and international database. In this study, we reviewed 38 polymorphisms in 19 genes. Polymorphism in interleukin-13 (IL-13), IL-10, IL-1, IL-2, IL-12, E-Selectin, S128R and Exon 9 Vitamin D Receptor were susceptible for asthma and polymorphism in chemokine receptor 5, transforming growth factor-a (TGF-a), Intron 8 of the Vitamin D Receptor, angiotensin-converting enzyme gene, IL-6 and interferon-c were not susceptible for asthma in Iranian population. Polymorphism in IL-4, tumor necrosis factor-α and TGF-b had inconsistent findings. This systematic review indicated that three polymorphisms (IL-13, IL-10, and IL-1) are associated with risk of asthma in Iranian population.

A generally applicable translational strategy identifies S100A4 as a candidate gene in allergy

The identification of diagnostic markers and therapeutic candidate genes in common diseases is complicated by the involvement of thousands of genes. We hypothesized that genes co-regulated with a key gene in allergy, IL13, would form a module that could help to identify candidate genes. We identified a T helper 2 (TH2) cell module by small interfering RNA-mediated knockdown of 25 putative IL13-regulating transcription factors followed by expression profiling. The module contained candidate genes whose diagnostic potential was supported by clinical studies. Functional studies of human TH2 cells as well as mouse models of allergy showed that deletion of one of the genes, S100A4, resulted in decreased signs of allergy including TH2 cell activation, humoral immunity, and infiltration of effector cells. Specifically, dendritic cells required S100A4 for activating T cells. Treatment with an anti-S100A4 antibody resulted in decreased signs of allergy in the mouse model as well as in allergen-challenged T cells from allergic patients. This strategy, which may be generally applicable to complex diseases, identified and validated an important diagnostic and therapeutic candidate gene in allergy.

Genetic polymorphisms and asthma: findings from a case-control study in the Madeira island population

BACKGROUND

Asthma is a complex disease influenced by multiple genetic and environmental factors. While Madeira has the highest prevalence of asthma in Portugal (14.6%), the effect of both genetic and environmental factors in this population has never been assessed. We categorized 98 asthma patients according to the Global Initiative for Asthma (GINA) guidelines, established their sensitization profile, and measured their forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) indexes. Selected single nucleotide polymorphisms (SNPs) were analysed as potential markers for asthma susceptibility and severity in the interleukin 4 (IL4), interleukin 13 (IL13), beta-2-adrenergic receptor (ADRB2), a disintegrin and metalloprotease 33 (ADAM33), gasdermin-like (GSDML) and the signal transducer and activator of transcription 6 (STAT6) genes comparatively to a population reference set.

RESULTS

Although mites are the major source of allergic sensitization, no significant difference was found amongst asthma severity categories. IL4-590*CT/TT and IL4-RP2*253183/183183 were found to predict the risk (2-fold) and severity (3 to 4-fold) of asthma and were associated with a lower FEV1 index. ADRB2-c.16*AG is a risk factor (3.5-fold), while genotype GSDML-236*TT was protective (4-fold) for moderate-severe asthma. ADAM33-V4*C was associated to asthma and mild asthma by the transmission disequilibrium test (TDT). Finally, ADAM33-V4*CC and STAT6-21*TT were associated with higher sensitization (mean wheal size ≥10 mm) to house dust (1.4-fold) and storage mite (7.8-fold).

CONCLUSION

In Madeira, IL4-590C/T, IL4-RP2 253/183, GSDML-236C/T and ADAM33-V4C/G SNPs are important risk factors for asthma susceptibility and severity, with implications for asthma healthcare management.

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.

Identification and validation of shrimp-tropomyosin specific CD4 T cell epitopes

BACKGROUND

Shellfish allergy is an immune-mediated adverse reaction to allergenic shellfish and is responsible for significant morbidity and mortality. CD4 T cell responses play an important role in the pathophysiological mechanisms of sensitization and in production of IgE.

OBJECTIVE

We sought to identify and validate CD4 T cell shrimp tropomyosin-derived epitopes and characterize CD4 T cell responses in subjects with a clinical history of shellfish allergy.

METHOD

Using an in vitro MHC-peptide binding assay, we screened 91 overlapping peptides and identified 28 epitopes with moderate and strong binding capacities; 3 additional peptides were included based on MHC binding prediction score. These peptides were then examined in proliferation and cytokine release assays with T cells from allergic subjects.

RESULT

17 epitopes restricted to DRB(∗)01:01, DRB1(∗)03:01, DRB1(∗)04:01, DRB1(∗)09:01, DQB1(∗)02:01, DQB1(∗)03:02 and DQB1(∗)05:01 alleles were identified and validated by both the MHC binding and the functional assays. Two peptides showed specificities to more than one MHC class II allele. We demonstrated that these peptides exert functional responses in an epitope specific manner, eliciting predominantly IL-6 and IL-13.

CONCLUSION

The identified epitopes are specific to common MHC class II alleles in the general population. Our study provides important data for the design of peptide-based immunotherapy of shrimp-allergic patients.

Allergenicity and toxicology of inhaled silver nanoparticles in allergen-provocation mice models

Silver nanoparticles (AgNP) have been associated with the exacerbation of airway hyperresponsiveness. However, the allergenicity and toxicology of AgNP in healthy and allergic individuals are unclear. We investigated the pathophysiological responses to AgNP inhalation in a murine model of asthma. Continuous and stable levels of 33 nm AgNP were maintained at 3.3 mg/m³ during the experimental period. AgNP exposure concomitant with ovalbumin challenge increased the enhanced pause (Penh) in the control and allergic groups. AgNP evoked neutrophil, lymphocyte and eosinophil infiltration into the airways and elevated the levels of allergic markers (immunoglobulin E [IgE] and leukotriene E₄ [LTE₄]), the type 2 T helper (Th2) cytokine interleukin-13 (IL-13), and oxidative stress (8-hydroxy-2′-deoxyguanosine [8-OHdG]) in healthy and allergic mice. Bronchocentric interstitial inflammation was observed after AgNP inhalation. After inhalation, the AgNP accumulated predominantly in the lungs, and trivial amounts of AgNP were excreted in the urine and feces. Furthermore, the AgNP induced inflammatory responses in the peritoneum. The inhalation of AgNP may present safety concerns in healthy and susceptible individuals.

IL-13 and STAT6 signaling involve in low dose lipopolysaccharide induced murine model of asthma

Background

We reported that level of lipopolysaccharide (LPS) exposure determined the type of airway inflammation in a murine model of asthma.

Objective

The purpose of this study is to evaluated the role of IL-13 in low dose LPS induced murine model of asthma using IL-13 and signal transducer and activator of transcription 6 (STAT6) deficient mice.

Methods

Mice were sensitized with an intranasal application of LPS-depleted ovalbumin (OA) and different doses of LPS (0.1 and 10 µg), and then challenged intranasally with OA alone. The phenotype changes between wild type (WT) and IL-13^-/- mice and between WT and STAT6^-/- mice were evaluated.

Results

We confirmed again that low and high dose LPS resulted in different phenotypes of murine asthma. In the present study, we observed that phenotypes of murine asthma induced by low dose LPS were abolished in the homozygous null mutation of the IL-13 and STAT6 gene. However, those changes were not shown in mice sensitized OA plus high dose LPS.

Conclusion

IL-13 plays an important role in low dose LPS induced murine model of asthma. Our results provided a new insight in understanding of the potential role of IL-13 in innate immunity in human allergic asthma.

Development of a human IgG4 bispecific antibody for dual targeting of interleukin-4 (IL-4) and interleukin-13 (IL-13) cytokines

Human bispecific antibodies have great potential for the treatment of human diseases. Although human IgG1 bispecific antibodies have been generated, few attempts have been reported in the scientific literature that extend bispecific antibodies to other human antibody isotypes. In this paper, we report our work expanding the knobs-into-holes bispecific antibody technology to the human IgG4 isotype. We apply this approach to generate a bispecific antibody that targets IL-4 and IL-13, two cytokines that play roles in type 2 inflammation. We show that IgG4 bispecific antibodies can be generated in large quantities with equivalent efficiency and quality and have comparable pharmacokinetic properties and lung partitioning, compared with the IgG1 isotype. This work broadens the range of published therapeutic bispecific antibodies with natural surface architecture and provides additional options for the generation of bispecific antibodies with differing effector functions through the use of different antibody isotypes.

Interleukin-13 -1112 C/T promoter polymorphism confers risk for COPD: a meta-analysis

Background

Interleukin (IL)-13, a T-helper type 2 cytokine, plays a critical role in the development of chronic obstructive pulmonary disease (COPD). This meta-analysis was performed to assess the association of IL-13 −1112 C/T promoter polymorphism with COPD susceptibility.

Methods

Published case-control studies from Pubmed and China National Knowledge Infrastructure (CNKI) databases were retrieved. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.

Results

Eight case-control studies in seven articles were included in this meta-analysis. Pooled effect size showed IL-13 −1112 C/T was associated with COPD susceptibility in a codominant genetic model (TT vs CT, OR: 1.82, 95% CI: 1.14–2.92 and TT vs CC, OR: 2.02, 95% CI: 1.10–3.72), indicating individuals with TT genotype had an increased risk for COPD compared with those with CT or CC genotype. According to ethnicity, results indicated IL-13 −1112 C/T was correlated with COPD susceptibility in Arabians (TT vs CT, OR: 2.94, 95% CI: 1.03–8.42 and TT vs CC, OR: 3.05, 95% CI: 1.08–8.59). Moreover, after excluding the study without Hardy-Weinberg equilibrium, the pooled results were robust and no publication bias was found in this study.

Conclusions

This meta-analysis suggests IL-13 −1112 C/T promoter polymorphism is associated with the risk of COPD in Arabians.

Cytokine immunopathogenesis of enterovirus 71 brain stem encephalitis

Enterovirus 71 (EV71) is one of the most important causes of herpangina and hand, foot, and mouth disease. It can also cause severe complications of the central nervous system (CNS). Brain stem encephalitis with pulmonary edema is the severe complication that can lead to death. EV71 replicates in leukocytes, endothelial cells, and dendritic cells resulting in the production of immune and inflammatory mediators that shape innate and acquired immune responses and the complications of disease. Cytokines, as a part of innate immunity, favor the development of antiviral and Th1 immune responses. Cytokines and chemokines play an important role in the pathogenesis EV71 brain stem encephalitis. Both the CNS and the systemic inflammatory responses to infection play important, but distinctly different, roles in the pathogenesis of EV71 pulmonary edema. Administration of intravenous immunoglobulin and milrinone, a phosphodiesterase inhibitor, has been shown to modulate inflammation, to reduce sympathetic overactivity, and to improve survival in patients with EV71 autonomic nervous system dysregulation and pulmonary edema.

Treatment of allergic asthma: modulation of Th2 cells and their responses

Atopic asthma is a chronic inflammatory pulmonary disease characterised by recurrent episodes of wheezy, laboured breathing with an underlying Th2 cell-mediated inflammatory response in the airways. It is currently treated and, more or less, controlled depending on severity, with bronchodilators e.g. long-acting beta agonists and long-acting muscarinic antagonists or anti-inflammatory drugs such as corticosteroids (inhaled or oral), leukotriene modifiers, theophyline and anti-IgE therapy. Unfortunately, none of these treatments are curative and some asthmatic patients do not respond to intense anti-inflammatory therapies. Additionally, the use of long-term oral steroids has many undesired side effects. For this reason, novel and more effective drugs are needed. In this review, we focus on the CD4+ Th2 cells and their products as targets for the development of new drugs to add to the current armamentarium as adjuncts or as potential stand-alone treatments for allergic asthma. We argue that in early disease, the reduction or elimination of allergen-specific Th2 cells will reduce the consequences of repeated allergic inflammatory responses such as lung remodelling without causing generalised immunosuppression.

Distinct host cell proteins incorporated by SIV replicating in CD4+ T cells from natural disease resistant versus non-natural disease susceptible hosts

BACKGROUND

Enveloped viruses including the simian immunodeficiency virus (SIV) replicating within host cells acquire host proteins upon egress from the host cells. A number of studies have catalogued such host proteins, and a few have documented the potential positive and negative biological functions of such host proteins. The studies conducted herein utilized proteomic analysis to identify differences in the spectrum of host proteins acquired by a single source of SIV replicating within CD4+ T cells from disease resistant sooty mangabeys and disease susceptible rhesus macaques.

RESULTS

While a total of 202 host derived proteins were present in viral preparations from CD4+ T cells from both species, there were 4 host-derived proteins that consistently and uniquely associated with SIV replicating within CD4+ T cells from rhesus macaques but not sooty mangabeys; and, similarly, 28 host-derived proteins that uniquely associated with SIV replicating within CD4+ T cells from sooty mangabeys, but not rhesus macaques. Of interest was the finding that of the 4 proteins uniquely present in SIV preparations from rhesus macaques was a 26 S protease subunit 7 (MSS1) that was shown to enhance HIV-1 'tat' mediated transactivation. Among the 28 proteins found in SIV preparations from sooty mangabeys included several molecules associated with immune function such as CD2, CD3ε, TLR4, TLR9 and TNFR and a bioactive form of IL-13.

CONCLUSIONS

The finding of 4 host proteins that are uniquely associated with SIV replicating within CD4+ T cells from disease susceptible rhesus macaques and 28 host proteins that are uniquely associated with SIV replicating within CD4+ T cells from disease resistant sooty mangabeys provide the foundation for determining the potential role of each of these unique host-derived proteins in contributing to the polarized clinical outcome in these 2 species of nonhuman primates.