IL-13 receptors and signaling pathways: an evolving web

Hataedock treatment has preventive therapeutic effects for atopic dermatitis through skin barrier protection in Dermatophagoides farinae-induced NC/Nga mice

ETHNOPHARMACOLOGICAL RELEVANCE

Hataedock treatment is traditionally used for the purpose of preventing the future skin disease by feeding herbal extracts to the newborn in traditional Chinese and Korean medicine.

AIM OF THE STUDY

This study investigated the preventive therapeutic effects of Hataedock (HTD) treatment for atopic dermatitis (AD) through skin barrier protection in Dermatophagoides farinae-induced NC/Nga mice.

MATERIALS AND METHODS

To the HTD treatment group, the extract of Coptis japonica Makino and Glycyrrhiza uralensis Fischer, which analyzed with High Performance Liquid Chromatography (HPLC)-fingerprint for quality consistency, was administered orally to the 3-week-old mice before inducing AD. After that, Dermatophagoides farinae was applied except the control group to induce AD-like skin lesions. We confirmed the effects of HTD on morphological changes, protection of skin barrier, regulation of Th2 differentiation, inflammation regulation and induction of apoptosis through histochemistry, immunohistochemistry, and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

RESULTS

HTD effectively reduced edema, angiogenesis and skin lesion. HTD also increased the levels of liver X receptor (LXR) and filaggrin but decreased the level of protein kinase C (PKC) (p<0.01). The levels of interleukin-4 (IL-4), IL-13, signal transducer and activator of transcription-6 (STAT-6) and Cluster of differentiation 40 (CD40) were significantly reduced in the HTD treated group (p<0.01). HTD also suppressed the mast cell degranulation and the level of the high-affinity IgE receptor (FcɛRI), substance P, Matrix metalloproteinases-9 (MMP-9) and 5-hydroxytryptamine (5-HT) (p<0.01). The levels of inflammatory factors such as nuclear factor-kappaB (NF-κB) p65, phosphorylated IκB (p-IκB) and inducible nitric oxide synthase (iNOS) were also decreased (p<0.01). Apoptosis of inflammatory cells was also found to increase (p<0.01).

CONCLUSION

Our results indicate that HTD effectively regulate the Th2 differentiation, mast cell activation and various inflammatory responses on AD-induced mice through protection of skin barrier. Therefore, HTD may have potential applications for alternative and preventive treatment in the management of AD.

Biomarkers in asthmatic patients: Has their time come to direct treatment?

Asthma is a heterogeneous disease with multiple phenotypes that have variable risk factors and responses to therapeutics. Mild-to-moderate asthma often responds to traditional medications, whereas severe disease can be refractory to inhaled corticosteroids, long-acting β-agonists, and leukotriene receptor antagonists. There is robust research into the variable phenotypes of asthma. Biomarkers help define the specific pathophysiology of different asthma phenotypes and identify potential therapeutic targets. The following review will discuss the current use of biomarkers for the diagnosis of asthma, triaging the severity of a patient's disease, and the potential efficacy of treatments. This information can be used to define certain patient populations that are more likely to respond to inhaled corticosteroids or biologics. As knowledge of patient phenotypes and endotypes and biological agents to target specific classes of asthma emerge, the ability to provide personalized care to asthmatic patients will follow.

RPC4046, A Novel Anti-interleukin-13 Antibody, Blocks IL-13 Binding to IL-13 α1 and α2 Receptors: A Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation First-in-Human Study

Introduction

A unique anti-interleukin (IL)-13 monoclonal antibody, RPC4046, was generated on the basis of differential IL-13 receptor (R) blockade as assessed in a murine asthma model; the safety, tolerability, pharmacokinetics, and pharmacodynamics of RPC4046 were evaluated in a first-in-human study.

Methods

Anti-IL-13 antibodies with varying receptor blocking specificity were evaluated in the ovalbumin-induced murine asthma model. A randomized, double-blind, placebo-controlled, dose-escalation first-in-human study (NCT00986037) was conducted with RPC4046 in healthy adults and patients with mild to moderate controlled asthma.

Results

In the ovalbumin model, blocking IL-13 binding to both IL-13Rs (IL-13Rα1 and IL-13Rα2) inhibited more asthma phenotypic features and more fully normalized the distinct IL-13 gene transcription associated with asthma compared with blocking IL-13Rα1 alone. In humans, RPC4046 exposure increased dose-dependently; pharmacokinetics were similar in healthy and asthmatic subjects, and blockade of both IL-13Rs uniquely affected IL-13 gene transcription. A minority of participants (28%) had antidrug antibodies, which were transient and appeared not to affect pharmacokinetics. Adverse event profiles were similar in healthy and asthmatic subjects, without dose-related or administration route differences, systemic infusion-related reactions, or asthma symptom worsening. Adverse events were mild to moderate, with none reported as probably related to RPC4046 or leading to discontinuations. Non-serious upper respiratory tract infections were more frequent with RPC4046 versus placebo.

Conclusion

RPC4046 is a novel anti-IL-13 antibody that blocks IL-13 binding to both receptors and more fully blocks the asthma phenotype. These results support further investigation of RPC4046 for IL-13-related allergic/inflammatory diseases (e.g., asthma and eosinophilic esophagitis).

Funding

AbbVie Inc. sponsored the studies and contributed to the design and conduct of the studies, data management, data analysis, interpretation of the data, and in the preparation and approval of the manuscript.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0525-8) contains supplementary material, which is available to authorized users.

New Role for Interleukin-13 Receptor α1 in Myocardial Homeostasis and Heart Failure

BACKGROUND

The immune system plays a pivotal role in myocardial homeostasis and response to injury. Interleukins-4 and -13 are anti-inflammatory type-2 cytokines, signaling via the common interleukin-13 receptor α1 chain and the type-2 interleukin-4 receptor. The role of interleukin-13 receptor α1 in the heart is unknown.

METHODS AND RESULTS

We analyzed myocardial samples from human donors (n=136) and patients with end-stage heart failure (n=177). We found that the interleukin-13 receptor α1 is present in the myocardium and, together with the complementary type-2 interleukin-4 receptor chain Il4ra, is significantly downregulated in the hearts of patients with heart failure. Next, we showed that Il13ra1-deficient mice develop severe myocardial dysfunction and dyssynchrony compared to wild-type mice (left ventricular ejection fraction 29.7±9.9 versus 45.0±8.0; P=0.004, left ventricular end-diastolic diameter 4.2±0.2 versus 3.92±0.3; P=0.03). A bioinformatic analysis of mouse hearts indicated that interleukin-13 receptor α1 regulates critical pathways in the heart other than the immune system, such as extracellular matrix (normalized enrichment score=1.90; false discovery rate q=0.005) and glucose metabolism (normalized enrichment score=-2.36; false discovery rate q=0). Deficiency of Il13ra1 was associated with reduced collagen deposition under normal and pressure-overload conditions.

CONCLUSIONS

The results of our studies in humans and mice indicate, for the first time, a role of interleukin-13 receptor α1 in myocardial homeostasis and heart failure and suggests a new therapeutic target to treat heart disease.

IL-4R suppresses airway inflammation in bronchial asthma by inhibiting the IL-4/STAT6 pathway

OBJECTIVE

This study aims to explore the mechanisms of how IL-4R suppresses airway inflammation in bronchial asthma by inhibiting the IL-4/STAT6 pathway.

METHODS

A total of 27 BALB/c male mice were selected and divided into control, asthma and IL-4R groups. Ovalbumin-induced mouse asthma model was established. Maximal pulmonary resistance was recorded. Hematoxylin and eosin (HE) and periodic acid Schiff (PAS) staining were conducted to observe the pathological changes in lung tissue. Optical microscope was used to detect numbers of total cells, mastocytes, eosinophils (EOS), neutrophils, and lymphocytes. Enzyme-linked immunosorbent assay (ELISA) was adopted for the levels of immunoglobulin (IgE), IL-4, IL-5, IL-13 and interferon (IFN)-γ, flow cytometry for the percentages of IL-4⁺ CD4⁺, IFN-γ⁺ CD4⁺ and IFN-γ⁺/IL-4⁺ in total thymus-derived (T) cells, qRT-PCR for the mRNA expressions of IL-4, IL-5, IL-13, STAT6, pSTAT6, suppressor of cytokine signaling (SOCS), inducible nitric oxide synthase (iNOS) and vascular cell adhesion molecule (VCAM)-1, and Western blotting for the protein expressions of STAT6 and pSTAT6.

RESULTS

Compared with the control group, the asthma group had irregular tissue structure and severe inflammation, increases in maximal pulmonary resistance, numbers of total cells, EOS, neutrophils, and lymphocytes, levels of IgE, IL-4, IL-5 and IL-13, percentages of IFN-γ⁺ CD4⁺ and IFN-γ⁺/IL-4⁺ in total T cells, mRNA expressions of IL-4, IL-5, IL-13, STAT6, pSTAT6, SOCS, iNOS and VCAM-1, and protein expressions of STAT6 and pSTAT6, but decreases in IFN-γ level and percentage of IL-4⁺ CD4⁺ in total T cells. Compared with the asthma group, the IL-4R group had relatively regular tissue structure and light inflammation, declined maximal RL, numbers of total cells, EOS, neutrophils, and lymphocytes, contents of IgE, IL-4, IL-5 and IL-13, percentages of IFN-γ⁺ CD4⁺ and IFN-γ⁺/IL-4⁺ in total T cells, mRNA expressions of IL-4, IL-5, IL-13, STAT6, pSTAT6, SOCS, iNOS and VCAM-1, and protein expressions of STAT6 and pSTAT6, but elevated IFN-γ content and percentage of IL-4⁺ CD4⁺ in total T cells.

CONCLUSION

Our results demonstrate that IL-4R can suppress airway inflammation in bronchial asthma by inhibited the IL-4/STAT6 pathway, which may provide a new therapeutic approach for the treatment of bronchial asthma.

Influence of IL13 on Periostin Secretion by Synoviocytes in Osteoarthritis

BACKGROUND

Our previous research provided evidence of periostin increase in parallel with interleukin-13 (IL13) increase in the synovial fluid of patients with osteoarthritis (OA). The reaction cascade from IL13 to periostin, however, remains unidentified. We, therefore, tested the hypothesis that periostin secretion is affected downstream of IL13.

MATERIALS AND METHODS

OA synoviocytes were cultured under different concentrations of IL13. Periostin content in culture supernatants and the level of signal transducer and activator of transcription 6 (STAT6) in the cultured cells were measured using enzyme-linked immunosorbent assay (ELISA). Moreover, the influence of dexamethasone and leflunomide on periostin production in relation to the effect of IL13 on the cells was also examined.

RESULTS

Periostin content in culture supernatants and the level of STAT6 in cultured cells were significantly increased by IL13. The increase of periostin was significantly inhibited by dexamethasone and leflunomide.

CONCLUSION

Periostin may be up-regulated in OA synoviocytes via STAT6 downstream of IL13.

Role of Transcription Factors in Pulmonary Artery Smooth Muscle Cells: An Important Link to Hypoxic Pulmonary Hypertension

Hypoxia, namely a lack of oxygen in the blood, induces pulmonary vasoconstriction and vasoremodeling, which serve as essential pathologic factors leading to pulmonary hypertension (PH). The underlying molecular mechanisms are uncertain; however, pulmonary artery smooth muscle cells (PASMCs) play an essential role in hypoxia-induced pulmonary vasoconstriction, vasoremodeling, and PH. Hypoxia causes oxidative damage to DNAs, proteins, and lipids. This damage (oxidative stress) modulates the activity of ion channels and elevates the intracellular calcium concentration ([Ca²⁺]_i, Ca²⁺ signaling) of PASMCs. The oxidative stress and increased Ca²⁺ signaling mutually interact with each other, and synergistically results in a variety of cellular responses. These responses include functional and structural abnormalities of mitochondria, sarcoplasmic reticulum, and nucleus; cell contraction, proliferation, migration, and apoptosis, as well as generation of vasoactive substances, inflammatory molecules, and growth factors that mediate the development of PH. A number of studies reveal that various transcription factors (TFs) play important roles in hypoxia-induced oxidative stress, disrupted PAMSC Ca²⁺ signaling and the development and progress of PH. It is believed that in the pathogenesis of PH, hypoxia facilitates these roles by mediating the expression of multiple genes. Therefore, the identification of specific genes and their transcription factors implicated in PH is necessary for the complete understanding of the underlying molecular mechanisms. Moreover, this identification may aid in the development of novel and effective therapeutic strategies for PH.

Mechanisms of immunomodulation by mammalian and viral decoy receptors: insights from structures

Immune responses are regulated by effector cytokines and chemokines that signal through cell surface receptors. Mammalian decoy receptors - which are typically soluble or inactive versions of cell surface receptors or soluble protein modules termed binding proteins - modulate and antagonize signalling by canonical effector-receptor complexes. Viruses have developed a diverse array of molecular decoys to evade host immune responses; these include viral homologues of host cytokines, chemokines and chemokine receptors; variants of host receptors with new functions; and novel decoy receptors that do not have host counterparts. Over the past decade, the number of known mammalian and viral decoy receptors has increased considerably, yet a comprehensive curation of the corresponding structure-mechanism relationships has not been carried out. In this Review, we provide a comprehensive resource on this topic with a view to better understanding the roles and evolutionary relationships of mammalian and viral decoy receptors, and the opportunities for leveraging their therapeutic potential.

Biological Modulators in Eosinophilic Diseases

Eosinophils can regulate local and systemic inflammation, and their presence in higher numbers appears to play an important role in the pathology of various atopic and inflammatory diseases. Eosinophil maturation, recruitment, and survival depend on several cytokine regulators, including interleukin (IL)-5, IL-4, and IL-13 as well as growth factors such as GM-CSF. Over the last decade, the approach to treating eosinophilic diseases has changed greatly. A number of biologic modulators have been developed to target eosinophilic inflammatory pathways, and their usage has resulted in variable clinical improvement in the treatment of eosinophilic-associated conditions. Novel targeted therapies that are safe and effective for treating these disorders are being investigated. This review summarizes the clinical use of biologic agents that have been studied in clinical trials or approved for treating eosinophilic diseases.

Modeling the chronic lymphocytic leukemia microenvironment in vitro

Microenvironments within the lymph node and bone marrow promote proliferation and drug resistance in chronic lymphocytic leukemia (CLL). Successful treatment of CLL must therefore target the leukemic cells within these compartments. A better understanding of the interaction between CLL cells and the tumor microenvironment has led to the development of in vitro models that mimic the mechanisms that support leukemic cell survival and proliferation in vivo. Employing these models as part of the pre-clinical evaluation of novel therapeutic agents enables a better approximation of their potential clinical efficacy. In this review we summarize the current literature describing how different aspects of the tumor microenvironment have been modeled in vitro and detail how these models have been employed to study the biology of the disease and potential efficacy of novel therapeutic agents.

Specific Immune Response to Phospholipase B-Like 2 Protein, a Host Cell Impurity in Lebrikizumab Clinical Material

Host cell proteins are manufacturing process-related impurities that may co-purify with the product despite extensive efforts to optimize the purification process. The risks associated with these impurities can vary and may be patient and/or therapeutic dependent. Therefore, it is critical to monitor and control the levels of these impurities in products and their potential impact on safety and efficacy. Lebrikizumab is a humanized immunoglobulin G4 monoclonal antibody (mAb) that binds specifically to soluble interleukin 13. This mAb is currently in phase III clinical development for the treatment of asthma. Following initial phase III studies, the material used in lebrikizumab clinical trials was found to have a process-related impurity identified as Chinese hamster ovary phospholipase B-like 2 (PLBL2) which co-purified with lebrikizumab. The immunogenic potential of PLBL2 and its potential impact on the immunogenicity of lebrikizumab in clinical studies were therefore evaluated. Data from the clinical studies demonstrated that ∼90% of subjects developed a specific and measurable immune response to PLBL2. Given the high incidence of antibodies to PLBL2 as well as the comparable safety profile observed between placebo- and drug-treated subjects, no correlation between safety events and anti-PLBL2 antibodies could be made. Additionally, no impact on the incidence of anti-lebrikizumab antibodies was observed, suggesting the lack of an adjuvant effect from PLBL2. Interim analysis from ongoing phase III studies using material with substantially reduced levels of PLBL2 with patients having had longer exposure shows significantly less and dose-dependent frequency of immune responses to PLBL2.

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.

Pycnogenol Ameliorates Asthmatic Airway Inflammation and Inhibits the Function of Goblet Cells

Pycnogenol^® (PYC) is utilized in the treatment of various diseases ranging from chronic inflammation to circulatory diseases, but its efficacy and functional mechanism in pediatric asthma continue to remain obscure. Therefore, the purpose of this study was to investigate the effectiveness and molecular mechanism of PYC on regulation of asthmatic airway inflammation. We found that PYC with tail intravenous injection of 50 mg/kg or intragastric administration of 100 mg/kg all reduced ovalbumin (OVA)-induced airway injury. Pharmacokinetics of PYC was evaluated by high-performance liquid chromatography assay, indicating that PYC was quickly absorbed into the blood after intragastric administration, and PYC metabolism was later improved gradually with increase of time after PYC administration. PYC has a higher bioavailability of 71.96%, and it was more easily absorbed by the body. PYC inhibited the number of total inflammatory cells and levels of interleukin (IL)-4, IL-5, IL-9, and IL-13 in bronchoalveolar lavage fluid of OVA-induced mice. PYC inhibited IL-13 secretion from the Th2 cells, thereby causing a reduction in expression of the signaling molecules in JAK/STAT6 pathway in airway epithelial cells. STAT6 silence suppressed IL-13-increased acetylcholine level. STAT6 overexpression promoted expression of goblet cell metaplasia-associated molecules (FOXA3, SPDEF, and Muc5ac). PYC suppressed OVA-induced expression of FOXA3, SPDEF, and Muc5ac in lung. Our findings indicate that PYC has a higher bioavailability and it prevents emergence of OVA-induced airway injury and airway inflammation in mice by inhibiting IL-13/JAK/STAT6 pathway and blocking release of acetylcholine to reduce goblet cell metaplasia.

Efficacy and safety of lebrikizumab in patients with uncontrolled asthma (LAVOLTA I and LAVOLTA II): replicate, phase 3, randomised, double-blind, placebo-controlled trials

BACKGROUND

In phase 2 trials, lebrikizumab, an anti-interleukin-13 monoclonal antibody, reduced exacerbation rates and improved FEV₁ in patients with uncontrolled asthma, particularly in those with high concentrations of type 2 biomarkers (eg, periostin or blood eosinophils). We undertook replicate phase 3 studies to assess the efficacy and safety of lebrikizumab in patients with uncontrolled asthma despite inhaled corticosteroids and at least one second controller medication.

METHODS

Adult patients with uncontrolled asthma, pre-bronchodilator FEV₁ 40-80% predicted, and stable background therapy were randomly assigned (1:1:1) with an interactive voice-web-based response system to receive lebrikizumab 37·5 mg or 125 mg, or placebo subcutaneously, once every 4 weeks. Randomisation was stratified by screening serum periostin concentration, history of asthma exacerbations within the last 12 months, baseline asthma medications, and country. The primary efficacy endpoint was the rate of asthma exacerbations over 52 weeks in biomarker-high patients (periostin ≥50 ng/mL or blood eosinophils ≥300 cells per μL), analysed with a Poisson regression model corrected for overdispersion with Pearson χ² that included terms for treatment group, number of asthma exacerbations within the 12 months before study entry, baseline asthma medications, geographic region, screening periostin concentration, and blood eosinophil counts as covariates. Both trials are registered at ClinicalTrials.gov, LAVOLTA I, number NCT01867125, and LAVOLTA II, number NCT01868061.

FINDINGS

1081 patients were treated in LAVOLTA I and 1067 patients in LAVOLTA II. Over 52 weeks, lebrikizumab reduced exacerbation rates in biomarker-high patients in the 37·5 mg dose group (rate ratio [RR] 0·49 [95% CI 0·34-0·69], p<0·0001) and in the 125 mg dose group (RR 0·70 [0·51-0·95], p=0·0232) versus placebo in LAVOLTA I. Exacerbation rates were also reduced in biomarker-high patients in both dose groups versus placebo in LAVOLTA II (37·5 mg: RR 0·74 [95% CI 0·54-1·01], p=0·0609; 125 mg: RR 0·74 [0·54-1·02], p=0·0626). Pooling both studies, the proportion of patients who experienced treatment-emergent adverse events (79% [1125 of 1432 patients] for both lebrikizumab doses vs 80% [576 of 716 patients] for placebo), serious adverse events (8% [115 patients] for both lebrikizumab doses vs 9% [65 patients] for placebo), and adverse events leading to study drug discontinuation (3% [49 patients] for both lebrikizumab doses vs 4% [31 patients] for placebo) were similar between lebrikizumab and placebo. The following serious adverse events were reported in the placebo-controlled period: one event of aplastic anaemia and five serious adverse events related to raised concentrations of eosinophils in patients treated with lebrikizumab and one event of eosinophilic pneumonia in the placebo group.

INTERPRETATION

Lebrikizumab did not consistently show significant reduction in asthma exacerbations in biomarker-high patients. However, it blocked interleukin-13 as evidenced by the effect on interleukin-13-related pharmacodynamic biomarkers, and clinically relevant changes could not be ruled out.

FUNDING

F Hoffmann-La Roche.

Interleukin-13 Pathway Alterations Impair Invariant Natural Killer T-Cell-Mediated Regulation of Effector T Cells in Type 1 Diabetes

Many studies have shown that human natural killer T (NKT) cells can promote immunity to pathogens, but their regulatory function is still being investigated. Invariant NKT (iNKT) cells have been shown to be effective in preventing type 1 diabetes in the NOD mouse model. Activation of plasmacytoid dendritic cells, modulation of B-cell responses, and immune deviation were proposed to be responsible for the suppressive effect of iNKT cells. We studied the regulatory capacity of human iNKT cells from control subjects and patients with type 1 diabetes (T1D) at disease clinical onset. We demonstrate that control iNKT cells suppress the proliferation of effector T cells (Teffs) through a cell contact-independent mechanism. Of note, suppression depended on the secretion of interleukin-13 (IL-13) by iNKT cells because an antibody blocking this cytokine resulted from the abrogation of Teff suppression; however, T1D-derived iNKT cells showed impaired regulation that could be attributed to the decrease in IL-13 secretion. Thus, alteration of the IL-13 pathway at disease onset may lead to the progression of the autoimmune response in T1D. Advances in the study of iNKT cells and the selection of agonists potentiating IL-13 secretion should permit new therapeutic strategies to prevent the development of T1D.

The association of vitamin D with inflammatory cytokines in diabetic peripheral neuropathy

[Purpose] The effects of vitamin D on the circulating levels of IL-17 and IL-13 were investigated in patients with diabetic peripheral neuropathy, patients with diabetes mellitus type 2 without neuropathy, and healthy controls. [Subjects and Methods] A single-blind controlled clinical study was performed, including70 type 2 diabetic patients with or without diabetic peripheral neuropathy and 33 healthy volunteer controls. The 25(OH)D levels were evaluated using ultra-performance liquid chromatography, and IL-17 and IL-13 levels were assessed using enzyme-linked immunosorbent assays. [Results] The 25(OH) vitamin D concentration was lower in diabetic peripheral neuropathy patients than in diabetes mellitus patients without neuropathy and healthy controls. Similarly, 25(OH)D levels were lower in diabetes mellitus patients than healthy controls. IL-17 and IL-13 levels were higher in diabetes mellitus patients than in controls. Additionally, IL-13 levels were higher in diabetic peripheral neuropathy patients than in diabetes mellitus patients without neuropathy. These differences were statistically significant. There was a significant positive correlation between 25(OH)D and IL-13,and a negative correlation between 25(OH)D andIL-17 in the diabetic and diabetic neuropathy groups. [Conclusion] Vitamin D is a potential modifiable risk factor for diabetic peripheral neuropathy and may regulate inflammatory mediators, e.g., IL-17 and IL-13.

IL-13 from intraepithelial lymphocytes regulates tissue homeostasis and protects against carcinogenesis in the skin

The skin is under constant renewal and exposure to environmental challenges. How homeostasis is maintained alongside protective mechanisms against damage is unclear. Among the basal epithelial cells (ECs) is a population of resident intraepithelial lymphocytes (IELs) that provide host-protective immune surveillance. Here we show that IELs cross-communicate with ECs via the production of IL-13. Skin ECs are activated by IEL-derived IL-13, enabling a canonical EC stress response. In the absence of IL-13, or canonical IEL, the skin has decreased ability to repair its barrier and increased susceptibility to cutaneous carcinogenesis. IL-13 controls the rate of EC movement through the epidermis, which might explain the importance of IL-13 for epidermal integrity and its suppressive effect on skin carcinogenesis. These findings show that IL-13 acts as a molecular bridge between IELs and ECs, and reveal a critical host-defensive role for type-2 immunity in regulating EC tissue homeostasis and carcinogenesis.

Exposure to Aedes aegypti Bites Induces a Mixed-Type Allergic Response following Salivary Antigens Challenge in Mice

Classical studies have shown that Aedes aegypti salivary secretion is responsible for the sensitization to mosquito bites and many of the components present in saliva are immunogenic and capable of inducing an intense immune response. Therefore, we have characterized a murine model of adjuvant-free systemic allergy induced by natural exposure to mosquito bites. BALB/c mice were sensitized by exposure to A. aegypti mosquito bites and intranasally challenged with phosphate-buffered saline only or the mosquito’s salivary gland extract (SGE). Blood, bronchoalveolar lavage (BAL) and lung were collected and evaluated for cellularity, histopathological analyses, cytokines and antibody determination. Respiratory pattern was analyzed by Penh measurements and tracheal segments were obtained to study in vitro reactivity to methacholine. BAL recovered from sensitized mice following challenge with SGE showed an increased number of eosinophils and Th2 cytokines such as IL-4, IL-5 and IL-13. Peribronchoalveolar eosinophil infiltration, mucus and collagen were also observed in lung parenchyma of sensitized mice, suggesting the development of a typical Th2 response. However, the antibody profile in serum of these mice evidenced a mixed-type response with presence of both, IgG1/IgE (Th2-related) and IgG2a (Th1-related) isotypes. In addition, changes in breathing pattern and tracheal reactivity to methacholine were not found. Taken together, our results show that A. aegypti bites trigger an atypical allergic reaction, with some classical cellular and soluble Th2 components in the lung, but also systemic Th1 and Th2 antibody isotypes and no change in either the respiratory pattern or the trachea responsiveness to agonist.

Distal airways are protected from goblet cell metaplasia by diminished expression of IL-13 signalling components

BACKGROUND

Increased mucus production is a critical factor impairing lung function in patients suffering from bronchial asthma, the most common chronic inflammatory lung disease worldwide.

OBJECTIVE

This study aimed at investigating whether goblet cell (GC) metaplasia and mucus production are differentially regulated in proximal and distal airways.

METHODS

Female Balb/c mice were sensitized to ovalbumin (OVA) and challenged with an OVA-aerosol on two consecutive days for 1 week (acute) or 12 weeks (chronic). Real-time RT-PCR analysis was applied on microdissected airways.

RESULTS

In acutely and chronically OVA-challenged mice, GC metaplasia and mucus production were observed in proximal but not in distal airways. In contrast, inflammation reflected by the infiltration of eosinophils and expression of the TH2-type cytokines IL-4 and IL-13 was increased in both proximal and distal airways. Abundance of IL-13Rα1 was lower in distal airways of healthy control mice. Under acute and chronic OVA-exposure, activation of IL-13Rα1-dependent signalling cascade, reflected by Spdef and Foxo3A transcription factors, was attenuated in distal compared to proximal airways.

CONCLUSION AND CLINICAL RELEVANCE

These data indicate that distal airways might be less sensitive to IL-13-induced GC metaplasia and mucus production through lower expression of IL-13Rα1 and attenuated activation of downstream signalling. This might represent a protective strategy to prevent mucus plugging of distal airways and thus impaired ventilation of attached alveoli.

Cytokine and anti-cytokine therapies in prevention or treatment of fibrosis in IBD

The frequency of fibrosing Crohn's disease (CD) is significant, with approximately 40% of CD patients with ileal disease developing clinically apparent strictures throughout their lifetime. Although strictures may be subdivided into fibrotic, inflammatory, or mixed forms, despite immunosuppressive therapy in CD patients in the form of steroids or immunomodulators, the frequency of fibrostenosing complications has still remained significant. A vast number of genetic and epigenetic variables are thought to contribute to fibrostenosing disease, including those that affect cytokine biology, and therefore highlight the complexity of disease, but also shed light on targetable pathways. Exclusively targeting fibrosis may be difficult, however, because of the relatively slow evolution of fibrosis in CD, and the potential adverse effects of inhibiting pathways involved in tissue repair and mucosal healing. Acknowledging these caveats, cytokine-targeted therapy has become the mainstay of treatment for many inflammatory conditions and is being evaluated for fibrotic disorders. The question of whether anti-cytokine therapy will prove useful for intestinal fibrosis is, therefore, acutely relevant. This review will highlight some of the current therapeutics targeting cytokines involved in fibrosis.

Antiasthmatic Effects of Eugenol in a Mouse Model of Allergic Asthma by Regulation of Vitamin D3 Upregulated Protein 1/NF-κB Pathway

The aim of the study was to investigate the antiasthmatic effects of eugenol (EUG) and the possible mechanisms. Asthma model was established by ovalbumin induction. A total of 50 mice were randomly assigned to five experimental groups: control, OVA, OVA + dexamethasone (2 mg/kg), OVA + EUG (10 mg/kg), and OVA + EUG (20 mg/kg). Airway resistance (Raw) were measured, histological studies were evaluated by the hematoxylin and eosin (HE) staining, interleukin-4 (IL-4) and interleukin-5 (IL-5) were evaluated by enzyme-linked immunosorbent assay (ELISA), Vitamin D3 upregulated protein 1 (VDUP1), IκBα, P-IκBα, NF-κBP65, and p-NF-κBP65 were measured by Western blotting. Our study demonstrated that EUG inhibited OVA-induced increases in Raw and eosinophil count; IL-4 and IL-5 were recovered. Histological studies demonstrated that EUG substantially inhibited OVA-induced eosinophilia in the lung tissue. Western blotting studies demonstrated that EUG substantially inhibited P-IκBα, NF-κBP65, and p-NF-κBP65 protein levels and increased VDUP1 and IκBα protein levels. These findings suggest that EUG may effectively ameliorate the progression of asthma and could be used as a therapy for patients with allergic asthma.

Assessing biomarkers in a real-world severe asthma study (ARIETTA)

The prognostic value of asthma biomarkers in routine clinical practice is not fully understood. ARIETTA (NCT02537691) is an ongoing, prospective, longitudinal, international, multicentre real-world study designed to assess the relationship between asthma biomarkers and disease-related health outcomes. The trial aims to enrol and follow for 52 weeks approximately 1200 severe asthma patients from approximately 160 sites in more than 20 countries. Severe asthmatics, treated with daily inhaled corticosteroid (≥500 μg of fluticasone propionate or equivalent) and at least 1 second controller medication are to be included. In this real-world study, patients will be treated according to the investigator's routine clinical practices and no treatment regimen will be implemented as part of the trial. At baseline and again at 26 and 52 weeks, FEV1, FeNO, serum periostin, blood eosinophil count and serum IgE will be measured. Asthma-related symptom and quality of life questionnaires will be administered at the visits and during telephone interviews at Weeks 13 and 39. Data about medication use, asthma exacerbation data, asthma-related healthcare utilization and events raising safety concerns will also be collected. This study design, unique in both its scope and scale, will address fundamental unanswered questions regarding asthma biomarkers and their interrelationship, as well as predict deviations in the course of asthma in a real-world setting.

A mechanistic PK/PD model for two anti-IL13 antibodies explains the difference in total IL-13 accumulation observed in clinical studies

IMA-638 and IMA-026 are humanized IgG1 monoclonal antibodies (mAbs) that target non-overlapping epitopes of IL-13. Separate first-in-human single ascending dose studies were conducted for each mAb. These studies had similar study designs, but mild to moderate asthmatics were recruited for the IMA-638 study and healthy subjects were recruited for the IMA-026 study. IMA-638 and IMA-026 showed similar pharmacokinetic (PK) profiles, but very different total IL-13 (free and drug bound IL-13) profiles; free IL13 was not measured. IMA-026 treatment induced a dose-dependent accumulation of total IL-13, while IMA-638 treatment led to a much smaller accumulation without any clear dose-response. To understand the differences between the two total IL-13 profiles and to predict the free IL-13 profiles for each mAb treatment, a mechanistic PK/pharmacodynamic model was developed. PK-related parameters were first fit to the mean PK profiles of each mAb separately; thereafter, the target-related parameters were fit to both total IL-13 profiles simultaneously. The IL-13 degradation rate was assumed to be the same for asthma patients and healthy subjects. The model suggests that an approximately 100× faster elimination of IL-13-IMA-638 complex than IL-13-IMA-026 complex could be responsible for the differences observed in total IL-13 profiles for the two mAbs. Furthermore, the model predicts that IMA-638 administration results in greater and more prolonged free IL-13 inhibition than equivalent dosing of IMA-026 despite similar binding KD and PK profile. In conclusion, joint modeling of two similar molecules provided mechanistic insight that the elimination rate of mAb-target complex can regulate the degree of free target inhibition.

Erythronium japonicum attenuates histopathological lung abnormalities in a mouse model of ovalbumin-induced asthma

Asthma is a chronic lung condition that can induce mucus hypersecretion and pulmonary obstruction and may even cause death, particularly in children and older individuals. Erythronium japonicum (E. japonicum) is a traditional herb used in Korea and East Asian countries that has been found to exert free radical scavenging activity and anti-proliferative effects in human colorectal carcinoma cells. In the present study, we evaluated the anti-asthmatic effects of an extract of E. japonicum in a mouse model of ovalbumin (OVA)-induced asthma. Female BALB/c mice were sensitized with an intraperitoneal injection of OVA and aluminum hydroxide hydrate on days 1 and 8 and then received the following treatments on days 21 to 25: i) control (no treatment), ii) sterilized tap water (given orally), iii) 1 mg/kg/day dexamethasone (administered orally), iv) 60 mg/kg/day E. japonicum extract, and v) 600 mg/kg/day E. japonicum extract. On the same days, all the mice except those in the control group were challenged 1 h later with nebulized 5% OVA for 30 min. We found that treatment with E. japonicum extract suppressed the OVA-induced increase in the number of white blood cells and decreased the IgE level in the bronchoalveolar lavage fluid samples obtained from the mice. Histopathological analysis of the lung tissues revealed that E. japonicum attenuated the asthma-related morphological changes in the mouse lung tissue, including the increased secretion of mucus in the bronchioles, eosinophil infiltration around the bronchioles and vessels, and goblet cell and epithelial cell hyperplasia. Immunohistochemical analysis revealed that treatment with E. japonicum extract suppressed the OVA-induced proliferation of T helper cells (CD4⁺) and B cells (CD19⁺) in the mouse lung tissue. Furthermore, treatment with E. japonicum extract modulated the expression of both T helper 2 cell-related factors [GATA binding protein 3 (GATA-3), tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-5, IL-6 and IL-13], as well as that of T helper 1 cell-related factors [(interferon-γ (IFN-γ), IL-12p35 and IL-12p40]. These findings suggest that E. japonicum may potentially be used as an anti-asthmatic treatment.

An Interleukin 13 Polymorphism Is Associated with Symptom Severity in Adult Subjects with Ever Asthma

Different genes are associated with categorical classifications of asthma severity. However, continuous outcomes should be used to catch the heterogeneity of asthma phenotypes and to increase the power in association studies. Accordingly, the aim of this study was to evaluate the association between single nucleotide polymorphisms (SNPs) in candidate gene regions and continuous measures of asthma severity, in adult patients from the general population. In the Gene Environment Interactions in Respiratory Diseases (GEIRD) study (www.geird.org), 326 subjects (aged 20–64) with ever asthma were identified from the general population in Verona (Italy) between 2007 and 2010. A panel of 236 SNPs tagging 51 candidate gene regions (including one or more genes) was analysed. A symptom and treatment score (STS) and pre-bronchodilator FEV₁% predicted were used as continuous measures of asthma severity. The association of each SNP with STS and FEV₁% predicted was tested by fitting quasi-gamma and linear regression models, respectively, with gender, body mass index and smoking habits as potential confounders. The Simes multiple-test procedure was used for controlling the false discovery rate (FDR). SNP rs848 in the IL13 gene region (IL5/RAD50/IL13/IL4) was associated with STS (TG/GG vs TT genotype: uncorrected p-value = 0.00006, FDR-corrected p-value = 0.04), whereas rs20541 in the same gene region, in linkage disequilibrium with rs848 (r² = 0.94) in our sample, did not reach the statistical significance after adjusting for multiple testing (TC/CC vs TT: uncorrected p-value = 0.0003, FDR-corrected p-value = 0.09). Polymorphisms in other gene regions showed a non-significant moderate association with STS (IL12B, TNS1) or lung function (SERPINE2, GATA3, IL5, NPNT, FAM13A) only. After adjusting for multiple testing and potential confounders, SNP rs848 in the IL13 gene region is significantly associated with a continuous measure of symptom severity in adult subjects with ever asthma.

Role of T2 inflammation biomarkers in severe asthma

PURPOSE OF REVIEW

Severe asthma is a heterogeneous syndrome. Classification of asthma into phenotypes and endotypes can improve understanding and treatment of the disease. Identification and utilization of biomarkers, particularly those linked to T2 inflammation, can help group patients into phenotypes, predict those who will respond to a specific therapy, and assess the response to treatment.

RECENT FINDINGS

Biomarkers are present in sputum, exhaled breath, and blood of patients with asthma. These include sputum eosinophils and neutrophils, fractional excretion of nitric oxide, blood eosinophilia, IgE, and periostin. Many of these biomarkers are associated with eosinophilic inflammation propagated mainly by T2 cytokines such as IL-5 and IL-13, which are released from Th2 cells and Type 2 innate lymphoid cells. Biomarkers have been utilized in recent trials of novel biologic agents targeted at T2 inflammation and may contribute to the defining population who would respond to these therapies.

SUMMARY

Despite advances in the identification and utilization of asthma biomarkers, further studies are needed to better clarify the role of biomarkers, individually or in combination, in the diagnosis and treatment of severe asthma. Future therapeutic trials should include the use of biomarkers in their design, which may lead to a more personalized approach to therapy and improved outcomes.

Platycodin D Attenuates Airway Inflammation in a Mouse Model of Allergic Asthma by Regulation NF-κB Pathway

In this work, the anti-asthma potential of platycodin D (PLD) was studied by investigation of its effect to suppress airway inflammation, a murine model of asthma and the possible mechanisms. A total of 50 mice were randomly assigned to five experimental groups: control, ovalbumin (OVA), OVA+dexamethasone (2 mg/kg) and OVA+PLD (40, 80 mg/kg). Airway resistance (Raw) were measured; airway histological studies were evaluated by the hematoxylin and eosin (HE) staining; interleukin-4 (IL-4), interleukin-5(IL-5), and interleukin-13 in bronchoalveolar lavage fluid (BALF) were evaluated by enzyme-linked immunosorbent assay (ELISA); NF-κBp65, p-NF-κBp65, p-IKKα, IKKα, p-IKKβ, p-IкBα, and IкBα of airway were measured by Western blotting. Our study demonstrated that PLD inhibited OVA-induced increases in Raw and eosinophil count in airway; IL-4, IL-5, and IL-13 were recovered in BALF. Histological studies demonstrated that PLD substantially inhibited OVA-induced eosinophilia in airway tissue. Western blotting studies demonstrated that PLD substantially inhibited NF-κB pathway. These findings suggest that PLD may effectively ameliorate the progression of asthma and could be used as a therapy for patients with allergic asthma.

Activin-A is overexpressed in severe asthma and is implicated in angiogenic processes

Activin-A is a pleiotropic cytokine that regulates allergic inflammation. Its role in the regulation of angiogenesis, a key feature of airways remodelling in asthma, remains unexplored. Our objective was to investigate the expression of activin-A in asthma and its effects on angiogenesis in vitro.Expression of soluble/immunoreactive activin-A and its receptors was measured in serum, bronchoalveolar lavage fluid (BALF) and endobronchial biopsies from 16 healthy controls, 19 patients with mild/moderate asthma and 22 severely asthmatic patients. In vitro effects of activin-A on baseline and vascular endothelial growth factor (VEGF)-induced human endothelial cell angiogenesis, signalling and cytokine release were compared with BALF concentrations of these cytokines in vivo.Activin-A expression was significantly elevated in serum, BALF and bronchial tissue of the asthmatics, while expression of its protein receptors was reduced. In vitro, activin-A suppressed VEGF-induced endothelial cell proliferation and angiogenesis, inducing autocrine production of anti-angiogenic soluble VEGF receptor (R)1 and interleukin (IL)-18, while reducing production of pro-angiogenic VEGFR2 and IL-17. In parallel, BALF concentrations of soluble VEGFR1 and IL-18 were significantly reduced in severe asthmatics in vivo and inversely correlated with angiogenesis.Activin-A is overexpressed and has anti-angiogenic effects in vitro that are not propagated in vivo, where reduced basal expression of its receptors is observed particularly in severe asthma.

Monoclonal antibodies: the new magic bullets for allergy: IUPHAR Review 17

Allergic diseases and conditions are widespread and their incidence is on the increase. They are characterized by the activation of mast cells resident in tissues and the consequent infiltration and stimulation of several inflammatory cells, predominantly eosinophils. Cell-cell cross-talk and the release of mediators are responsible for the symptoms and for the modulation of the response. The gold standard of therapeutic intervention is still glucocorticosteroids, although they are not effective in all patients and may cause numerous side effects. Symptomatic medications are also widespread. As research has led to deeper insights into the mechanisms governing the diseases, new avenues have been opened resulting in recent years in the development of monoclonal antibodies (mAbs) such as anti-IgE mAbs (omalizumab) and others still undergoing clinical trials aimed to specifically target molecules involved in the migration and stimulation of inflammatory cells. In this review, we summarize new developments in the field of anti-allergic mAbs with special emphasis on the treatment of asthma, particularly severe forms of this condition, and atopic dermatitis, which are two unmet clinical needs.

Anti-asthmatic effects of oxymatrine in a mouse model of allergic asthma through regulating CD40 signaling

The aim of the study was to investigate the anti-asthmatic effects of oxymatrine (OXY) and the possible underlying mechanisms. The mouse asthma model was established by ovalbumin (OVA) intraperitoneal injection. A total of fifty mice were randomly assigned to five groups: control, OVA, OVA + dexamethasone (Dex, 2 mg · kg(-1)), and OVA + OXY (40 mg · kg(-1)), and OVA + OXY (80 mg · kg(-1)), respectively. Histological studies were conducted by the hematoxylin and eosin (HE) staining, the levels of interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13, and IgE were evaluated by enzyme-linked immunosorbent assay (ELISA), and the protein level of CD40 was analyzed by Western blotting. OXY inhibited OVA-induced increases in eosinophil count; the levels of IL-4, IL-5, IgE, and IL-13 were recovered. It also substantially inhibited OVA-induced eosinophilia in lung tissues and the expression of CD40 protein. These findings suggest that OXY may effectively ameliorate the progression of asthma and could be explored as a possible therapy for patients with allergic asthma.

The Causal Role of IL-4 and IL-13 in Schistosoma mansoni Pulmonary Hypertension

RATIONALE

The etiology of schistosomiasis-associated pulmonary arterial hypertension (PAH), a major cause of PAH worldwide, is poorly understood. Schistosoma mansoni exposure results in prototypical type-2 inflammation. Furthermore, transforming growth factor (TGF)-β signaling is required for experimental pulmonary hypertension (PH) caused by Schistosoma exposure.

OBJECTIVES

We hypothesized type-2 inflammation driven by IL-4 and IL-13 is necessary for Schistosoma-induced TGF-β-dependent vascular remodeling.

METHODS

Wild-type, IL-4(-/-), IL-13(-/-), and IL-4(-/-)IL-13(-/-) mice (C57BL6/J background) were intraperitoneally sensitized and intravenously challenged with S. mansoni eggs to induce experimental PH. Right ventricular catheterization was then performed, followed by quantitative analysis of the lung tissue. Lung tissue from patients with schistosomiasis-associated and connective tissue disease-associated PAH was also systematically analyzed.

MEASUREMENTS AND MAIN RESULTS

Mice with experimental Schistosoma-induced PH had evidence of increased IL-4 and IL-13 signaling. IL-4(-/-)IL-13(-/-) mice, but not single knockout IL-4(-/-) or IL-13(-/-) mice, were protected from Schistosoma-induced PH, with decreased right ventricular pressures, pulmonary vascular remodeling, and right ventricular hypertrophy. IL-4(-/-)IL-13(-/-) mice had less pulmonary vascular phospho-signal transducer and activator of transcription 6 (STAT6) and phospho-Smad2/3 activity, potentially caused by decreased TGF-β activation by macrophages. In vivo treatment with a STAT6 inhibitor and IL-4(-/-)IL-13(-/-) bone marrow transplantation also protected against Schistosoma-PH. Lung tissue from patients with schistosomiasis-associated and connective tissue disease-associated PAH had evidence of type-2 inflammation.

CONCLUSIONS

Combined IL-4 and IL-13 deficiency is required for protection against TGF-β-induced pulmonary vascular disease after Schistosoma exposure, and targeted inhibition of this pathway is a potential novel therapeutic approach for patients with schistosomiasis-associated PAH.

Glycomacropeptide administration attenuates airway inflammation and remodeling associated to allergic asthma in rat

OBJECTIVE

Glycomacropeptide (GMP) is a bioactive peptide derived from milk that has been reported to exhibit a range of anti-inflammatory and immunomodulatory properties. The aim of this study was to analyze the prophylactic effect of GMP administration on airway inflammation and remodeling in an experimental model of asthmatic rat.

METHODS

Animals treated orally with or without GMP (500 mg/kg/day) were ovalbumin-sensitized and -nebulized and several indicators of Th2 response, airway structural changes and inflammatory cells recruitment were evaluated.

RESULTS

Treatment with GMP prior and during asthma development resulted in reduction of allergen-specific IgE titers in serum and blood eosinophilia. Also, GMP substantially suppressed the recruitment of inflammatory cells to bronchoalveolar compartment. Histological studies demonstrated that GMP markedly inhibits eosinophils infiltration, goblet cells hyperplasia and collagen deposit in lung tissue. The latter effect was related with an inhibition in transforming growth factor-β expression. In addition, expression of interleukin-5 and -13 were substantially inhibited in lung while that of interleukin-10 was increased.

CONCLUSION

Our results suggest that administration of GMP may prevent the development of an excessive Th2 response in asthma and effectively ameliorates the progression of the disease.

Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol

Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications.

Serum anti-inflammatory cytokines for the evaluation of inflammatory status in endometriosis

Background:

Endometriosis is a frequent gynecologic disease with a severe impact on the quality of life in the affected women; its pathogenesis is yet to be fully understood, with an altered immunity as a possible key factor. The present study aimed to investigate the serum anti-inflammatory cytokine profile in the patients with endometriosis compared with the healthy controls.

Materials and Methods:

One hundred and sixty women were included, divided into two study groups (Group I — endometriosis; Group 2 — healthy women). We evaluated the serum levels of interleukin-1 receptor antagonist (IL-1Ra), IL-2, IL-2R, IL-4, IL-10, IL-13, and IL-15 with the use of Human multiplex cytokine panels. Statistical analyses (normality distribution analysis, independent t-test, Mann–Whitney U-test) were performed using IBM SPSS software (version 22.0) and GraphPad Prism (version 5.00); receiver operating characteristic curve were used to demonstrate the diagnostic performance of the studied markers.

Results:

The mean serum level of IL-1Ra, IL-4, and IL-10 were significantly higher in women with endometriosis compared to women free of disease from the control group (30.155, 138.459, and 1.489, respectively, compared to 14.109, 84.710, and 0.688, respectively; P < 0.001, P < 0.001, and P = 0.002, respectively.). No significant differences in the mean serum levels of IL-2, IL-13, and IL-15 were observed between the studied groups and IL-2R had a very low detection rate.

Conclusion:

Endometriosis is associated with elevated levels of anti-inflammatory cytokines, IL-1Ra, IL-4, and IL-10, markers that have a potential role as a prognostic factor for endometriosis.

Pleiotropic Effects of Immune Responses Explain Variation in the Prevalence of Fibroproliferative Diseases

Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to helminthic infections, and concurrently increases susceptibility to fibrosis due to the profibrotic action of Th2 cytokines. Many studies on selection of Th2-related genes for host resistance to helminths have been reported, but the pleiotropic impact of this selection on the distribution of fibrotic disorders has not been explicitly investigated. We discuss the disproportionate occurrence of fibroproliferative diseases in individuals of African ancestry and provide evidence that adaptation of the immune system has shaped the genetic structure of these human populations in ways that alter the distribution of multiple fibroproliferative diseases.

Interleukin-13 affects the epithelial sodium channel in the intestine by coordinated modulation of STAT6 and p38 MAPK activity

KEY POINTS

Interleukin-13 (IL-13) causes intestinal epithelial barrier dysfunction, and is implicated in the pathogenesis of Th2-driven intestinal inflammation (e.g. ulcerative colitis). However, it is unclear whether the epithelial sodium channel (ENaC) - the main limiting factor for sodium absorption in the distal colon - is also influenced by IL-13 and if so, by what mechanism(s). We demonstrate in an intestinal cell model as well as in mouse distal colon that IL-13 causes reduced ENaC activity. We show that IL-13 impairs ENaC-dependent sodium transport by activating the JAK1/2-STAT6 signalling pathway. These results improve our understanding of the mechanisms through which IL-13 functions as a key effector cytokine in ulcerative colitis, thereby contributing to the distinct pathology of this disease.

ABSTRACT

Interleukin-13 (IL-13) has been strongly implicated in the pathogenesis of ulcerative colitis, possibly by disrupting epithelial integrity. In the distal colon, the epithelial sodium channel (ENaC) is an important factor in the regulation of sodium absorption, and therefore plays a critical role in minimizing intestinal sodium and water losses. In the present study, we investigated whether IL-13 also acts as a potent modulator of epithelial sodium transport via ENaC, and the signalling components involved. The effect of IL-13 on ENaC was examined in HT-29/B6-GR/MR human colon cells, as well as in mouse distal colon, by measuring amiloride-sensitive short-circuit current (ISC ) in Ussing chambers. The expression levels of ENaC subunits and the cellular components that contribute to ENaC activity were analysed by qRT-PCR and promoter gene assay. We show that IL-13, in both the cell model and in native intestinal tissue, impaired epithelial sodium absorption via ENaC (JNa ) as a result of decreased transcription levels of β- and γ-ENaC subunits and SGK1, a post-translational regulator of ENaC activity, due to impaired promoter activity. The reduction in JNa was prevented by inhibition of JAK1/2-STAT6 signalling. This inhibition also affected the IL-13-induced decrease in p38 MAPK phosphorylation. The contribution of STAT6 to IL-13-mediated ENaC inactivation was confirmed in a STAT6(-/-) mouse model. In conclusion, these results indicate that IL-13, the levels of which are elevated in ulcerative colitis, contributes to impaired ENaC activity via modulation of the STAT6/p38 MAPK pathways.

Lung CD200 Receptor Activation Abrogates Airway Hyperresponsiveness in Experimental Asthma

In allergic asthma, homeostatic pathways are dysregulated, which leads to an immune response toward normally innocuous antigens. The CD200-CD200 receptor pathway is a central regulator of inflammation, and CD200 expression was recently found to be down-regulated in circulating leukocytes of patients with asthma. Given the antiinflammatory properties of CD200, we investigated whether local delivery of recombinant CD200 (rCD200) could reinstate lung homeostasis in an experimental model of asthma. Brown Norway rats were sensitized with ovalbumin (OVA) and alum. rCD200 was intratracheally administered 24 hours before OVA challenge, and airway responsiveness to methacholine was measured 24 hours after the allergen challenge. Inflammation was also assessed by measuring cell recruitment and cytokine levels in bronchoalveolar lavages, as well as lung and draining lymph node accumulation of dendritic cells (DCs) and T cells. In sensitized rats, rCD200 abolished airway hyperresponsiveness, whereas the sham treatment had no effect. In addition, rCD200 strongly reduced OVA-induced lung accumulation of myeloid DCs, CD4(+) T cells, and T helper type 2 cells. This was associated with a strong reduction of OVA-induced IL-13 level and with an increase of IL-10 in supernatants of bronchoalveolar lavages. Lung eosinophilia and draining lymph node accumulation of myeloid DCs and T cells were not affected by rCD200. Overall, these data reveal that rCD200 can inhibit airway hyperresponsiveness in a model of asthma by a multistep mechanism associated with local alterations of the T cell response and the cytokine milieu.

CXCR3 Requirement for the Interleukin-13-Mediated Up-Regulation of Interleukin-13Rα2 in Pulmonary Fibroblasts

Idiopathic pulmonary fibrosis (IPF) is a progressive disease characterized by fibrosis and abnormal vascularity. IL-13, a profibrotic cytokine that plays a role in IPF, functions through the Jak/STAT pathway after binding to the IL-13 receptor α1 (IL-13Rα1)/IL-4Rα complex. IL-13 also binds to IL-13Rα2, which has been thought to function as a nonsignaling decoy receptor, although possible signaling roles of this receptor have been proposed. CXCR3 and its IFN-inducible ligands-CXCL9, CXCL10, and CXCL11-have been implicated in vascular remodeling and fibroblast motility during the development of IPF. In this study, CXCR3 expression was demonstrated in cultured pulmonary fibroblasts from wild-type BALB/c mice and was found to be necessary for the IL-13-mediated gene and protein up-regulation of IL-13Rα2. In fibroblasts from CXCR3-deficient mice, STAT6 activation was prolonged. This study is the first to demonstrate the expression of CXCR3 in fibroblasts and its association with the expression of IL-13Rα2. Taken together, the results from this study point strongly to a requirement for CXCR3 for IL-13-mediated IL-13Rα2 gene expression. Understanding the function of CXCR3 in IL-13-mediated lung injury may lead to novel approaches to combat the development of pulmonary fibrosis, whether by limiting the effects of IL-13 or by manipulation of angiostatic pathways. The elucidation of the complex relationship between these antifibrotic receptors and manipulation of the CXCR3-mediated regulation of IL-13Rα2 may represent a novel therapeutic modality in cases of acute lung injury or chronic inflammation that may progress to fibrosis.

Targeting key proximal drivers of type 2 inflammation in disease

Systemic type 2 inflammation encompassing T helper 2 (TH2)-type responses is emerging as a unifying feature of both classically defined allergic diseases, such as asthma, and a range of other inflammatory diseases. Rather than reducing inflammation with broad-acting immunosuppressants or narrowly targeting downstream products of the TH2 pathway, such as immunoglobulin E (IgE), efforts to target the key proximal type 2 cytokines - interleukin-4 (IL-4), IL-5 and IL-13 - represent a promising strategy to achieve therapeutic benefit across multiple diseases. After several initial disappointing clinical results with therapies targeting IL-4, IL-5 or IL-13 in asthma, applying a personalized approach achieved therapeutic benefit in an asthma subtype exhibiting an 'allergic' phenotype. More recently, efficacy was extended into a broad population of people with asthma. This argues that the Type 2 inflammation is broadly relevant across the severe asthma population if the key upstream drivers are properly blocked. Moreover, the simultaneous inhibition of IL-4 and IL-13 has shown significant clinical activity in diseases that are often co-morbid with asthma - atopic dermatitis and chronic sinusitis with nasal polyps - supporting the hypothesis that targeting a central 'driver pathway' could benefit multiple allergic diseases.

Loss of IL-4Rα-mediated PI3K signaling accelerates the progression of IgE/mast cell-mediated reactions

Clinical and experimental evidence indicate that polymorphisms within the interleukin 4 (IL‐4) receptor (IL‐4R) chain are sufficient for altered strength of IL‐4/IL‐13 signaling, leading to an exaggerated allergic inflammatory response and increase susceptibility to allergic phenotypes. In the present study, we show that ablation of IL‐4Rα–induced phosphatidylinositol 3‐kinase (PI3K) activating signal by germline point mutation within the IL‐4Rα motif (Y500F) did not alter susceptibility to IgE‐mediated, food‐induced experimental anaphylaxis. Moreover, diarrhea occurrence, antigen‐specific IgE and intestinal mastocytosis were comparable between WT and IL‐4Rα^Y500F mice. However, mice unable to stimulate IL‐4Rα–mediated PI3K signaling had accelerated disease progression. Notably, the accelerated anaphylactic response was associated with more rapid histamine‐induced hypovolemia. Mechanistic in vitro and in vivo analyses revealed that endothelial IL‐4Rα PI3K signaling negatively regulates the histamine‐induced endothelial leak response. These results define an unanticipated role for IL‐4Rα–mediated PI3K signaling in negative regulation of IgE‐mediated anaphylactic reactions.

GdCl3 Attenuates Schistosomiasis japonicum Egg-Induced Granulomatosis Accompanied by Decreased Macrophage Infiltration in Murine Liver

Early-stage hepatic granuloma and advanced-stage fibrosis are important characteristics of schistosomiasis. The direct consequences of gadolinium chloride (GdCl₃) in egg-induced granuloma formation have not been reported, although GdCl₃ is known to block the macrophages. In present study, mice were infected with 15 Schistosoma japonicum (S. japonicum) cercariae and treated with GdCl₃ (10 mg/kg body weight) twice weekly from day 21 to day 42 post-infection during the onset of egg-laying towards early granuloma formation. Histochemical staining showed that repeated injection of GdCl₃ decreased macrophages infiltration in liver of mice infected with S. japonicum. Macrophage depletion by GdCl₃ during the initial phase attenuated liver pathological injury characterized by smaller granuloma size and decreased immune inflammation as well as less fibrogenesis. In addition, IL-13Rα2 expression was reduced by GdCl₃ in liver of mice infected with S. japonicum. The results suggest that GdCl₃ depleted macrophages, which attenuated helminth infected immune responses involving with IL-13Rα2 signal. These findings would highlight a therapeutic potential via manipulating IL-13Rα2+ macrophage in schistosomiasis.

Association of IL13R alpha 1 +1398A/G polymorphism in a North Indian population with asthma: A case-control study

Background:

Interleukin 13 (IL13) is directly involved in the secretion of total serum immunoglobulin E (IgE), which plays a major role in the asthma pathogenesis.

Objective:

One of the polymorphic receptor of IL13 is IL13Rα1, which after binding to IL13, initiates signal transduction that results in mucin secretion, airway hyperreactivity, fibrosis, and chitinase up-regulation, which increases asthma risk.

Methods:

In the present study, the role of IL13Rα1 +1398A/G gene polymorphisms in asthma was detected with a total of 964 individuals, including 483 healthy controls and 481 asthma patients from a North Indian population using polymerase chain reaction-restriction fragment length polymorphism method.

Results:

Statistical analysis revealed that the mutant allele (G) is predominant in asthma patients (42.7%) than the controls (38.2%), which shows an increased risk toward asthma with odds ratio = 1.21, 95% confidence interval (1.00–1.45), χ² = 4.10 and p = 0.043. Furthermore, the phenotypic characteristics also reveal a significant association with the disease (p < 0.05).

Conclusions:

This is the first study conducted in India and +1398A/G polymorphism in noncoding region of IL13Rα1 confer risk toward asthma in the studied population.