The role of IL-13 in IgE synthesis by allergic asthma patients

Suppressed transcript diversity and immune response in COVID-19 ICU patients: a longitudinal study

Understanding the dynamic changes in gene expression during Acute Respiratory Distress Syndrome (ARDS) progression in post-acute infection patients is crucial for unraveling the underlying mechanisms. Study investigates the longitudinal changes in gene/transcript expression patterns in hospital-admitted severe COVID-19 patients with ARDS post-acute SARS-CoV-2 infection. Blood samples were collected at three time points and patients were stratified into severe and mild ARDS, based on their oxygenation saturation (SpO2/FiO2) kinetics over 7 d. Decline in transcript diversity was observed over time, particularly in patients with higher severity, indicating dysregulated transcriptional landscape. Comparing gene/transcript-level analyses highlighted a rather limited overlap. With disease progression, a transition towards an inflammatory state was evident. Strong association was found between antibody response and disease severity, characterized by decreased antibody response and activated B cell population in severe cases. Bayesian network analysis identified various factors associated with disease progression and severity, viz. humoral response, TLR signaling, inflammatory response, interferon response, and effector T cell abundance. The findings highlight dynamic gene/transcript expression changes during ARDS progression, impact on tissue oxygenation and elucidate disease pathogenesis.

Identification and characterisation of anti-IL-13 inhibitory single domain antibodies provides new insights into receptor selectivity and attractive opportunities for drug discovery

Interleukin-13 (IL-13) is a cytokine involved in T-cell immune responses and is a well validated therapeutic target for the treatment of asthma, along with other allergic and inflammatory diseases. IL-13 signals through a ternary signalling complex formed with the receptors IL-13Rα1 and IL-4Rα. This complex is assembled by IL-13 initially binding IL-13Rα1, followed by association of the binary IL-13:IL-13Rα1 complex with IL-4Rα. The receptors are shared with IL-4, but IL-4 initially binds IL-4Rα. Here we report the identification and characterisation of a diverse panel of single-domain antibodies (VHHs) that bind to IL-13 (K_D 40 nM-5.5 μM) and inhibit downstream IL-13 signalling (IC₅₀ 0.2-53.8 μM). NMR mapping showed that the VHHs recognise a number of epitopes on IL-13, including previously unknown allosteric sites. Further NMR investigation of VHH204 bound to IL-13 revealed a novel allosteric mechanism of inhibition, with the antibody stabilising IL-13 in a conformation incompatible with receptor binding. This also led to the identification of a conformational equilibrium for free IL-13, providing insights into differing receptor signalling complex assembly seen for IL-13 compared to IL-4, with formation of the IL-13:IL-13Rα1 complex required to stabilise IL-13 in a conformation with high affinity for IL-4Rα. These findings highlight new opportunities for therapeutic targeting of IL-13 and we report a successful ¹⁹F fragment screen of the IL-13:VHH204 complex, including binding sites identified for several hits. To our knowledge, these ¹⁹F containing fragments represent the first small-molecules shown to bind to IL-13 and could provide starting points for a small-molecule drug discovery programme.

Differential inflammatory profile in the lungs of mice exposed to cannabis smoke with varying THC:CBD ratio

Cannabis contains cannabinoids including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC causes the psychoactive effects of cannabis, and both THC and CBD are thought to be anti-inflammatory. Cannabis is typically consumed by inhaling smoke that contains thousands of combustion products that may damage the lungs. However, the relationship between cannabis smoke exposure and alterations in respiratory health is poorly defined. To address this gap in knowledge, we first developed a mouse model of cannabis smoke exposure using a nose-only rodent inhalation exposure system. We then tested the acute effects of two dried cannabis products that differ substantially in their THC-CBD ratio: Indica-THC dominant (I-THC; 16-22% THC) and Sativa-CBD dominant (S-CBD; 13-19% CBD). We demonstrate that this smoke exposure regime not only delivers physiologically relevant levels of THC to the bloodstream, but that acute inhalation of cannabis smoke modulates the pulmonary immune response. Cannabis smoke decreased the percentage of lung alveolar macrophages but increased lung interstitial macrophages (IMs). There was also a decrease in lung dendritic cells as well as Ly6Cintermediate and Ly6Clow monocytes, but an increase in lung neutrophils and CD8+ T cells. These immune cell changes were paralleled with changes in several immune mediators. These immunological modifications were more pronounced when mice were exposed to S-CBD compared to the I-THC variety. Thus, we show that acute cannabis smoke differentially affects lung immunity based on the THC:CBD ratio, thereby providing a foundation to further explore the effect of chronic cannabis smoke exposures on pulmonary health.

Fenofibrate Attenuates Asthma Features in an Ovalbumin-induced Mouse Model Via Suppressing NF-κB Binding Activity

BACKGROUND/AIM

Asthma is a chronic inflammatory disease of the airways with a high prevalence. Asthma has a complex pathophysiology and about 5-10% of patients are not fully responsive to the currently available treatments. The aim of this study is to investigate the involvement of NF-κB in the effects of fenofibrate on a mouse model of allergic asthma.

MATERIALS AND METHODS

A total of 49 BALB/c mice were randomly distributed into 7 groups (n=7). Allergic asthma model was created by administering i.p. injections of ovalbumin on days 0, 14 and 21, followed by provocation with inhaled ovalbumin on days 28, 29 and 30. Fenofibrate was orally given in 3 different doses; 1, 10 and 30mg/kg through days 21 to 30 of the experiment. On day 31, pulmonary function test using whole body plethysmography was performed. The mice were sacrificed 24hours later. Blood samples were obtained, and serum of each sample was separated for IgE determination. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to measure IL-5 and IL-13 levels. Nuclear extracts of lung tissues were employed to assess nuclear factor kappa B (NF-κB) p65 binding activity.

RESULTS

Enhanced Pause (Penh) values were significantly increased in ovalbumin-sensitized and challenged mice (p<0.01). Administration of fenofibrate (10 and 30mg/kg) resulted in improved pulmonary function as shown by significantly lower Penh values (p<0.01). Interleukin (IL) -5 and IL-13 levels in BALF and lung tissues and immunoglobulin E (IgE) levels in serum were significantly elevated in the allergic mice. IL-5 levels in the lung tissues of mice treated with 1mg/kg fenofibrate (FEN1) group were significantly reduced (p<0.01). BALF and lung tissue IL-5 and IL-13 levels in mice treated with 10 and 30mg/kg fenofibrate, FEN10 and FEN30, respectively, were significantly diminished when compared to the ovalbumin-treated (OVA) group, whereas treatment with 1mg/kg fenofibrate resulted in insignificant changes. IgE levels in the serum of FEN30 group mice have shown a prominent reduction (p<0.01). NF-κB p65 binding activity was higher in mice sensitized and challenged with ovalbumin (p<0.01). NF-κB p65 binding activity was significantly reduced in allergic mice treated with 30mg/kg (p<0.01) fenofibrate.

CONCLUSIONS

In this study, we showed that administration of 10 and 30mg/kg fenofibrate effectively attenuated airway hyperresponsiveness and inflammation in a mouse model of allergic asthma, possibly through inhibition of NF-κB binding activity.

Epidemiological evidence for the effect of environmental heavy metal exposure on the immune system in children

Heavy metals exist widely in daily life, and exposure to heavy metals caused by environmental pollution has become a serious public health problem worldwide. Due to children's age-specific behavioral characteristics and imperfect physical function, the adverse health effects of heavy metals on children are much higher than in adults. Studies have found that heavy metal exposure is associated with low immune function in children. Although there are reviews describing the evidence for the adverse effects of heavy metal exposure on the immune system in children, the summary of evidence from epidemiological studies involving the level of immune molecules is not comprehensive. Therefore, this review summarizes the current epidemiological study on the effect of heavy metal exposure on childhood immune function from multiple perspectives, emphasizing its risks to the health of children's immune systems. It focuses on the effects of six heavy metals (lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), nickel (Ni), and manganese (Mn)) on children's innate immune cells, lymphocytes and their subpopulations, cytokines, total and specific immunoglobulins, and explores the immunotoxicological effects of heavy metals. The review finds that exposure to heavy metals, particularly Pb, Cd, As, and Hg, not only reduced lymphocyte numbers and suppressed adaptive immune responses in children, but also altered the innate immune response to impair the body's ability to fight pathogens. Epidemiological evidence suggests that heavy metal exposure alters cytokine levels and is associated with the development of inflammatory responses in children. Pb, As, and Hg exposure was associated with vaccination failure and decreased antibody titers, and increased risk of immune-related diseases in children by altering specific immunoglobulin levels. Cd, Ni and Mn showed activation effects on the immune response to childhood vaccination. Exposure age, sex, nutritional status, and co-exposure may influence the effects of heavy metals on immune function in children.

Increased allergic and asthmatic risks in children residing in industrial areas by surveying the pre-inflammatory (IgE, IL-4 and IL-13) biomarkers

Toxic metal(loid)s can lead to high damages on human. This work was conducted to investigate the levels of metal(loid)s in PM2.5 and a total of 123 male children's (aged 6-9 years) blood chosen from different areas in Ahvaz and their association with the pre-inflammatory (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13) responses in serum cells. Six metal(loid)s (arsenic, cadmium, chromium, mercury, nickel and lead) in three regions including industrial (Padad), vehicle traffic (Golestan) and reference (Kianpars) areas were studied. Results showed the concentrations of As, Cr, Cd, Ni and Hg in the ambient air of industrial area (Padad) (P < 0.001), and Pb in vehicle traffic area (Golestan) were higher (p < 0.001). Moreover, the mean levels of IgE (mean = 146.44 pg/200landa, P < 0.003), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 53.21 pg/200landa, P < 0.001) in Padad were higher than Golestan and Kianpars. Our results suggest that living in industrial areas leads to accelerated synthesis of IgE, IL-4 and IL-13 in blood. The spatial distribution of children's serum IgE, IL-4 and IL-13 concentrations showed an abnormal increase of 240 to 400 pg/200landa for IgE, 950 to 1400 pg/200landa for IL-4 and 90 to 128 pg/200landa for IL-13. Our results indicate children in the industrial area are prone to asthma, allergy, miRNA mutation, and other chronic diseases.

Polyinosinic:polycytidylic acid aggravates calcipotriol-induced atopic dermatitis-like skin lesions in mice by increasing the expression of thymic stromal lymphopoietin

Background

Polyinosinic:polycytidylic acid [poly (I:C)] is a synthetic viral double-stranded RNA analog that can activate Toll-like receptor 3 (TLR3) and induce the release of thymic stromal lymphopoietin (TSLP). TSLP has been shown to contribute to atopic dermatitis (AD). This study explored the effects of poly (I:C) in a calcipotriol-induced model of murine AD.

Methods

Calcipotriol (MC903) was used to establish AD-like mice model. Mice in the MC903 + poly (I:C) group were then treated with poly (I:C) in a concentration of 5 µg/g bodyweight. The impact of poly (I:C) treatment on these animals was assessed based upon changes in lesions, bodyweight, ear thickness, and histopathological findings. In addition, serum interleukin 4 (IL-4), interferon-γ (IFN-γ), immunoglobulin E (IgE), IL-13, and TSLP levels were measured using enzyme-linked immunosorbent assay (ELISA), while tissue IL-13 and TSLP levels were assessed using ELISA, Western blotting, and immunohistochemical staining, and mast cell infiltration was assessed through toluidine blue (TBO) staining.

Results

Relative to vehicle control treatment, poly (I:C) administration was associated with a significant exacerbation of calcipotriol-induced AD-like murine skin lesions. In animals treated with poly (I:C), the levels of serum IL-4, IL-13 and TSLP increased significantly, while the level of IFN-γ did not change. It also increased IL-13 and TSLP levels in skin lesions relative to the control-group mice and increased dermal mast cell infiltration and IgE production.

Conclusions

These data indicate that poly (I:C) treatment and exogenous activation of TLR3 exacerbate murine calcipotriol-induced AD-like skin lesions in part by increasing the production of TSLP and other T-helper 2 (Th2)-related cytokines.

Keywords

Atopic dermatitis (AD); polyinosinic:polycytidylic acid [poly (I:C)]; thymic stromal lymphopoietin (TSLP); Toll-like receptor 3 (TLR3)

Effect of ambient air PM2.5-bound heavy metals on blood metal(loid)s and children's asthma and allergy pro-inflammatory (IgE, IL-4 and IL-13) biomarkers

BACKGROUND

We investigated the concentrations of metals in fine particulate matter PM_2.5 in the outdoor air around the home sites of 123 male children from Ahvaz, average age 7.56, along with their blood samples to measure pro-inflammatory responses (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13).

METHODS

We measured 6 metals (As, Cd, Cr, Hg, Ni and Pb) in three Ahvaz's regions including industrial (Padad), vehicle traffic (Golestan) and control (Kianpars).

RESULTS

The higher concentrations of metals in the Padad as the industrial ambient air i.e., arsenic, cadmium, chromium, mercury and nickel coincided with the higher concentrations of those metals in exposed children (P < 0.05) versus the controls. Children in Golestan, the high traffic air pollution area had the highest lead concentrations (p < 0.05). Also a significant association was shown in Padad between blood arsenic and IgE (β = 26.59, P < 0.001), IL-4 (β = 172.1, P < 0.001) and IL-13 (β = 14.84, P < 0.001), blood chromium and IgE (β = 10.38, P < 0.001), IL-4 (β = 75.27, P < 0.001) and IL-13 (β = 5.27, P < 0.001) and blood mercury and IgE (β = 13.11, P < 0.001), IL-4 (β = 108.09, P < 0.001) and IL-13 (β = 7.96, P < 0.001) and blood lead and IgE(β = 0.92, P = 0.025), IL-4(β = 7.16, P < 0.001) and IL-13(β = 0.58, P = 0.003). However, no significant relation was found for Cadmium, Nickel in blood with IgE, IL-4 and IL-13 levels. Moreover, children from industrial areas showed significantly higher concentrations of IgE (mean = 146.44 pg/200landa, P < 0.001), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 52.93 pg/200landa, P < 0.001) versus Golestan and Kianpars.

CONCLUSION

Children residing in an industrial area with high concentrations of metals in PM_2.5 had high metals in blood and high production of IgE, IL-4 and IL-13, reflecting an immune dysregulation and brisk inflammatory responses.

Miquelianin Inhibits Allergic Responses in Mice by Suppressing CD4+ T Cell Proliferation

Allergic diseases, including atopic dermatitis (AD), induce type 2 helper T (Th2) cell-dominant immune responses. Miquelianin (quercetin 3-O-glucuronide, MQL) is an active compound in Rosae multiflorae fructus extract with anti-allergic properties. Here, we investigate the anti-allergic effects of MQL in an ovalbumin (OVA)-induced Th2-dominant mouse model and the associated mechanisms. Oral MQL suppressed cytokine and IL-2 production and proliferation of Th2 cells and upregulated heme oxygenase-1 (HO-1) in splenocytes. Ex vivo MQL suppressed Th1- and Th2-related immune responses by inhibiting CD4⁺ T cell proliferation, and upregulated HO-1 in CD4⁺ T cells by activating C-Raf-ERK1/2-Nrf2 pathway via induction of reactive oxygen species generation. In a trimellitic anhydride-induced AD-like mouse model, both topical and oral MQL ameliorated AD symptoms by suppressing Th2 immune responses. Our results suggest that MQL is a potential therapeutic agent for CD4⁺ T cell-mediated diseases, including allergic diseases.

Mast Cells as Regulators of Adaptive Immune Responses in Food Allergy

Mast cells are a critical first line of defense against endogenous and environmental threats. Their participation in innate immunity is well characterized; activation of toll like receptors as well as receptors for complement, adenosine, and a host of other ligands leads to mast cell release of preformed mediators contained within granules along with newly synthesized arachidonic acid metabolites, cytokines, and chemokines. These confer protective effects including the induction of mucus secretion, smooth muscle contraction, and activation of common itch and pain sensations, all of which act to promote expulsion of noxious agents. While their innate immune role as sentinel cells is well established, recent research has brought into focus their separate but also critical function in adaptive immunity particularly in the setting of IgE mediated food allergies. Crosslinking of FcεR1, the high affinity receptor for IgE, when bound to IgE and antigen, triggers the release of the same factors and elicits the same physiologic responses that occur after activation by innate stimuli. Though IgE-activated mast cells are best known for their role in acute allergic reactions, including the most severe manifestation, anaphylaxis, accumulating evidence has suggested an immunoregulatory effect in T cell-mediated immunity, modulating the balance between type 2 immunity and tolerance. In this review, we outline how mast cells act as adjuvants for food antigen driven Th2 cell responses, while curtailing Treg function.

Surfactant Protein-A Protects against IL-13-Induced Inflammation in Asthma

The lung surfactant proteins are recognized as critical not only for their role in lowering lung surface tension but also in innate host defense. Reports have shown that some asthmatic patients have decreased levels of one member of this protein family in particular, surfactant protein-A (SP-A). Our studies set out to determine the contribution of SP-A to the response of a key effector cytokine in asthma, IL-13. Our studies employ both animal models sufficient and deficient in SP-A challenged with IL-13 and primary epithelial cells from participants with asthma that are exogenously treated with SP-A in the context of IL-13 challenge. The inflammatory response and mucin production were assessed in both model systems. As compared with WT mice, we show that the activity of IL-13 is dramatically augmented in SP-A-/- mice, which have significantly increased neutrophil and eosinophil recruitment, mucin production and asthma-associated cytokines in the bronchoalveolar lavage fluid. In parallel, we show asthma-associated factors are attenuated in human cells from asthma subjects when exogenous SP-A is added during IL-13 challenge. Although many of these phenotypes have previously been associated with STAT6 signaling, SP-A inhibited IL-13-induced STAT3 phosphorylation in mice and in human epithelial cells while having little effect on STAT6 phosphorylation. In addition, when either STAT3 or IL-6 were inhibited in mice, the phenotypes observed in SP-A-/- mice were significantly attenuated. These studies suggest a novel mechanism for SP-A in asthma as a modulator of IL-13-induced inflammation via mediating downstream IL-6/STAT3 signaling.

Exosomes from Human Adipose Tissue-Derived Mesenchymal Stem Cells Promote Epidermal Barrier Repair by Inducing de Novo Synthesis of Ceramides in Atopic Dermatitis

Atopic dermatitis (AD) is a multifactorial, heterogeneous disease associated with epidermal barrier disruption and intense systemic inflammation. Previously, we showed that exosomes derived from human adipose tissue-derived mesenchymal stem cells (ASC-exosomes) attenuate AD-like symptoms by reducing multiple inflammatory cytokine levels. Here, we investigated ASC-exosomes' effects on skin barrier restoration by analyzing protein and lipid contents. We found that subcutaneous injection of ASC-exosomes in an oxazolone-induced dermatitis model remarkably reduced trans-epidermal water loss, while enhancing stratum corneum (SC) hydration and markedly decreasing the levels of inflammatory cytokines such as IL-4, IL-5, IL-13, TNF-α, IFN-γ, IL-17, and TSLP, all in a dose-dependent manner. Interestingly, ASC-exosomes induced the production of ceramides and dihydroceramides. Electron microscopic analysis revealed enhanced epidermal lamellar bodies and formation of lamellar layer at the interface of the SC and stratum granulosum with ASC-exosomes treatment. Deep RNA sequencing analysis of skin lesions demonstrated that ASC-exosomes restores the expression of genes involved in skin barrier, lipid metabolism, cell cycle, and inflammatory response in the diseased area. Collectively, our results suggest that ASC-exosomes effectively restore epidermal barrier functions in AD by facilitating the de novo synthesis of ceramides, resulting in a promising cell-free therapeutic option for treating AD.

[Levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing]

OBJECTIVE

To examine the levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing and to study the possible pathogenesis of wheezing from the aspects of T helper cell 1 (Th1)/T helper cell 2 (Th2) imbalance and airway inflammation.

METHODS

A total of 50 children aged 1 month to 3 years with an acute wheezing episode were enrolled as the wheezing group, and 25 age-matched healthy infants were enrolled as the healthy control group. According to the number of wheezing episodes, the wheezing group was divided into a first-episode group (n=25) and a recurrent wheezing (number of episodes ≥2) group (n=25). According to the presence or absence of high-risk factors for asthma, the wheezing group was divided into a high-risk factor group (n=22) and a non-high-risk factor group (n=28). According to the results of pathogen detection, the wheezing group was divided into a positive pathogen group (n=23) and a negative pathogen group (n=27). Levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), transforming growth factor-β1 (TGF-β1), and total IgE (TIgE) in peripheral blood were measured for each group. For children with wheezing, eosinophil (EOS) count in peripheral blood was measured, and related samples were collected for respiratory pathogen detection.

RESULTS

The wheezing group had significantly higher levels of IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood than the healthy control group (P<0.05). There were no significant differences in the levels of IL-2, IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood between the first-episode and recurrent wheezing groups, between the high-risk factor and non-high-risk factor groups, and between the positive pathogen and negative pathogen groups (P>0.05). The correlation analysis showed that in children with wheezing, EOS count was positively correlated with IL-4 level (P<0.01), IL-4 level was positively correlated with IL-5 and IL-13 levels (P<0.01), IL-5 level was positively correlated with IL-13 level (P<0.01), and IL-2 level was positively correlated with TGF-β1 level (P<0.05).

CONCLUSIONS

Th1/Th2 imbalance with a predominance of Th2 is observed in infants and young children with wheezing. IL-4, IL-5, IL-13, TGF-β1, and IgE are involved in the pathogenesis of wheezing in these children. Airway inflammation is also observed in these children with wheezing, but it is not associated with the number of wheezing episodes, presence or absence of high-risk factors for asthma, or results of pathogen detection.

Hsa_circ_0005519 increases IL-13/IL-6 by regulating hsa-let-7a-5p in CD4+ T cells to affect asthma

BACKGROUND

Circular RNAs (circRNAs) are a class of non-coding RNAs that could serve as novel biomarkers for the diagnosis and treatment of diseases. We hypothesized that circRNAs of CD4⁺ T cells are involved in asthma.

OBJECTIVE

In this study, we investigated the circRNA expression profile and the possible mechanism by which hsa_circ_0005519 participates in asthma.

METHODS

The expression profiles of circRNAs in CD4⁺ T cells were revealed by circRNA microarray. Hsa_circ_0005519 expression in CD4⁺ T cells was confirmed in asthmatic patients (n = 65) and healthy subjects (n = 30). Hsa-let-7a-5p, the target of hsa_circ_0005519, was predicted by online algorithms and verified by a dual-luciferase reporter assay. Correlation assays between the expression of hsa_circ_0005519 and hsa-let-7a-5p, the mRNA levels of interleukin (IL)-13 and IL-6 in CD4⁺ T cells, and the clinical characteristics of asthmatic patients were performed. The role of hsa_circ_0005519 in proinflammatory cytokine expression was investigated in CD4⁺ T cells from asthmatic patients in vitro. Hsa_circ_0005519 expression in PBMCs was determined in another cohort including 30 asthmatic patients and 24 controls. Correlation assays of hsa_circ_0005519 expressions between CD4⁺ T cells and PBMCs were performed.

RESULTS

Hsa_circ_0005519 was up-regulated and negatively correlated with hsa-let-7a-5p expression in CD4⁺ T cells of asthmatic patients. Both the fraction of exhaled nitric oxide (FeNO) and the peripheral blood eosinophil ratio were positively correlated with hsa_circ_0005519 expression in CD4⁺ T cells. These outcomes were also different in asthmatic patients with low vs high hsa_circ_0005519 levels. Hsa_circ_0005519 expressions between CD4⁺ T cells and PBMCs were concordant in asthmatic patients. Mechanistically, hsa_circ_0005519 might bind to hsa-let-7a-5p and relieve suppression for IL-13/IL-6 in CD4⁺ T cells.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest that hsa_circ_0005519 may induce IL-13 and IL-6 expression by regulating hsa-let-7a-5p in CD4⁺ T cells to affect asthma. And hsa_circ_0005519 may be a potential biomarker of asthma.

Camellia japonica oil suppressed asthma occurrence via GATA-3 & IL-4 pathway and its effective and major component is oleic acid

BACKGROUND

In December 2016, WHO released a report stating that in 2015 there were 383,000 deaths caused by asthma and 235 million people suffering from asthma. As there are many adverse effects associated with the currently-used asthma drugs, new anti-asthmatic drugs need to be developed.

PURPOSE

In order to find new drug candidates with safe and low side effects, the anti-asthmatic function and mechanism of C. japonica oil were evaluated, and its active ingredients were analyzed for use in an ovalbumin asthma murine model.

STUDY DESIGN AND METHODS

The study consisted of six groups: control; ovalbumin group; and dexamethasone group as a positive control; and 10, 100, and 500 mg/kg C. japonica oil treatment groups. In order to measure the anti-asthmatic effect of C. japonica oil, WBC and differential cell count in BALF, IgE in serum, morphological changes in pulmonary system, and gene and protein levels such as IFN-γ, IL-12p40, IL-4, IL-5, IL-6, TNF-α, and IL-6 were all evaluated.

RESULTS

C. japonica oil had an anti-asthmatic effect and significantly controlled eosinophil in BALF, Th2-related factors such as GATA-3 that is Th2 cell transcription factor, IL-4, IL-5, and IL-13, and TNF-α in the lung. It also dose-dependently modulated inflammatory cells, T-bet, IL-12p40, and IL-6. Oleci acid was the major gradient (52.89%) in C. japonica oil and also had anti-asthmatic effects such as the downregulation of inflammatory cells, WBC, and eosinophil in BALF, IgE in serum, and morphological changes in the lung.

CONCLUSION

We concluded that C. japonica oil is a new anti-asthmatic drug candidate and that oleic acid is the major anti-asthmatic ingredient in C. japonica oil.

Anthriscus sylvestris root extract reduces allergic lung inflammation by regulating interferon regulatory factor 4-mediated Th2 cell activation

ETHNOPHARMACOLOGICAL RELEVANCE

Anthriscus sylvestris L. Hoffmann (AS) is a perennial plant that grows in Asia and Eastern Europe. Its dried root is used to treat conditions such as asthma, bronchitis, and cough.

AIM OF THE STUDY

The present study investigated the anti-inflammatory effects of whole AS extract (ASE) on allergic lung inflammation in vitro and in vivo as well as the underlying mechanisms.

MATERIALS AND METHODS

We used an ovalbumin (OVA)-induced asthma mouse model and in vitro primary T helper (Th)2 polarization system. Five groups of 8-week-old female C57BL/6 mice were divided into the following groups: saline control, or OVA-induced allergic asthma with vehicle, ASE (100 or 200 mg/kg), or dexamethasone (5 mg/kg) treatment for 7 days.

RESULTS

ASE attenuated mucus secretion in airway epithelial cells, inflammatory cell infiltration, eosinophilia, and Th2 cytokine levels in bronchoalveolar lavage fluid. Mice administered ASE showed reductions in the activated cluster of differentiation 4⁺ T cell population and GATA-binding protein-3 gene expression in the lung, and diminished Th2 cell differentiation and activation in vitro. Furthermore, ASE-treated mice showed decreased interleukin-6 and interferon regulatory factor (IRF)4 expression, with corresponding reductions in nitric oxide levels in the lungs of asthmatic mice and in stimulated RAW cells.

CONCLUSION

ASE exerts anti-asthmatic effects by inhibiting IRF4 expression and thereby suppressing Th2 cell activation.

Antiasthmatic Effects of Sanglong Pingchuan Decoction through Inducing a Balanced Th1/Th2 Immune Response

Objective

To investigate the antiasthmatic effects of Sanglong pingchuan decoction (SLPCD) and to explore its mechanisms of action.

Methods

The serum, bronchoalveolar lavage fluid (BALF), and lung tissues from OVA-induced allergic asthma mice were collected 24 h after the last administration. Lung pathological changes were observed by H&E staining. The inflammatory cells in BALF were counted by flow cytometry. The levels of total IgE in serum and cytokines in BALF were determined by ELISA. The expression levels of cytokine mRNA in lung were assayed by qRT-PCR.

Results

SLPCD significantly inhibited airway inflammation, reduced inflammatory cells in BALF, reduced the levels of total IgE in serum and Th2 cytokines (IL-10 and IL-13) in BALF, and downregulated the mRNA expression levels of Th2 cytokines (IL-4, IL-5, IL-10, and IL-13) in lung of asthmatic mice. However, SLPCD remarkably elevated the level of Th1 cytokine IFN-γ in BALF and upregulated the mRNA expression levels of Th1 cytokines (IL-2 and IFN-γ) in lung of asthmatic mice.

Conclusion

SLPCD could attenuate airway inflammation and alleviate the pathogenesis in asthma mice through inducing a balanced Th1/Th2 response and could act as an effective drug for treatment of asthma.

Opuntia humifusa modulates morphological changes characteristic of asthma via IL-4 and IL-13 in an asthma murine model

Asthma is a chronic pulmonary disease that affects an estimated 235 million people worldwide, but asthma drugs have many adverse effects. Opuntia humifusa (eastern prickly pear) has been used as a food and traditional medicine worldwide; however, its anti-asthmatic effects have not been reported. We evaluated O. humifusa as a potential therapeutic or preventive component of anti-asthmatic drugs. We divided ovalbumin-sensitized mice into the following groups: normal control, asthma-induced control, dexamethasone-treated group (positive control), 50 mg/kg O. humifusa-treated group, 100 mg/kg O. humifusa-treated group, and 500 mg/kg O. humifusa-treated group. Levels of Th1/Th2/Th17-related cytokines were evaluated using RT-PCR, ELISA, and immunohistochemistry. O. humifusa dose-dependently suppressed the morphological changes typically observed in asthma, such as goblet cell hyperplasia, inflammatory cell infiltration, mucous hypersecretion, and relative basement membrane thickening in the respiratory system. These results may be attributable to regulation of Th1-/Th2-/Th17-related factors, especially interleukin (IL)-4 and IL-13. We conclude that O. humifusa is a potential anti-asthmatic functional food.

Abbreviations: O. humifusa: Opuntia humifusa; Th: helper T; RT-PCR: real-time polymerase chain reaction; ELISA: enzyme-linked immunosorbent assay; IL: interleukin; WHO: World Health Organization; IFN-γ: interferon gamma; TNF-α: tumor necrosis factor-alpha; IgE: immunoglobulin E; CD: cluster of differentiation; OVA: ovalbumin; DEX: dexamethasone; BALF: bronchoalveolar fluid; H&E: hematoxylin and eosin; PAS: periodic acid-schiff; PBS: phosphate-buffered saline; BM: basement membrane; cDNA: complementary deoxyribonucleic acid; RNA: ribo nucleic acid; RIPA: radioimmunoprecipitation assay; IHC: immunohistochemistry; HPLC: high-performance liquid chromatography; SD: standard deviation; WBC: white blood cells; APCs: antigen-presenting cells

Synaptopodin is upregulated by IL-13 in eosinophilic esophagitis and regulates esophageal epithelial cell motility and barrier integrity

Eosinophilic esophagitis (EoE) is an allergic inflammatory disease of the esophagus mediated by an IL-13-driven epithelial cell transcriptional program. Herein, we show that the cytoskeletal protein synaptopodin (SYNPO), previously associated with podocytes, is constitutively expressed in esophageal epithelium and induced during allergic inflammation. In addition, we show that the SYNPO gene is transcriptionally and epigenetically regulated by IL-13 in esophageal epithelial cells. SYNPO was expressed in the basal layer of homeostatic esophageal epithelium, colocalized with actin filaments, and expanded into the suprabasal epithelium in EoE patients, where expression was elevated 25-fold compared with control individuals. The expression level of SYNPO in esophageal biopsies correlated with esophageal eosinophil density and was improved following anti-IL-13 treatment in EoE patients. In esophageal epithelial cells, SYNPO gene silencing reduced epithelial motility in a wound healing model, whereas SYNPO overexpression impaired epithelial barrier integrity and reduced esophageal differentiation. Taken together, we demonstrate that SYNPO is induced by IL-13 in vitro and in vivo, is a nonredundant regulator of epithelial cell barrier function and motility, and is likely involved in EoE pathogenesis.

Polymorphism of the IL13 gene may be associated with Uterine leiomyomas in Slovenian women

Uterine leiomyomas (ULM) are a common cause of solid pelvic tumors in women. Their etiopathogenesis remains unclear. Interleukins (ILs) and their receptors can influence tumor biology of ULM. The aim of this study was to evaluate single nucleotide polymorphisms (SNPs) exhibited in the genes IL4 (rs2070874), IL4R (rs1801275), IL12RB1 (rs11575934), IL12B (rs6887695), IL13 (rs20541) and IL23R (rs7517847) as risk factors for ULM in Slovenian women and to identify associations between corresponding clinical parameters and the analyzed SNPs. In addition, solitary and multiple ULM were compared to identify clinical and/or genetic parameters influencing their occurrence. We conducted a case-control study that included 181 women with leiomyomas and 133 control subjects. Genotyping of selected SNPs was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and high resolution melting (HRM) techniques. The TT genotype of rs20541 (IL13) was significantly associated with decreased risk of ULM compared to both the CC and CT genotypes [p = 0.018; odds ratio (OR) = 0.184; 95% confidence interval (95% CI) = 0.048-0.7121. Using genetic and clinical data to develop a predictive model with logistic regression, we found that adenomyosis, higher age at diagnosis, family history of ULM occurrence, earlier menarche, lower number of pregnancies and lower age at first sexual intercourse, the G allele and genotypes AG and GG of rs1801275 (IL4R) were associated with an increased risk of multiple ULM occurrence. We also found an association between rs20541 (IL13) and 17ß-estradiol serum levels in patients with multiple ULM (p 0.003). Our study showed, for the first time, that rs20541 (IL13) may contribute to susceptibility of ULM development and that rs1801275 (IL4R) can predispose patients to develop multiple ULM.

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

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

Anti-asthmatic and anxiolytic effects of Herissantia tiubae, a Brazilian medicinal plant

Herissantia tiubae (HtE) is a Brazilian plant used in folk medicine to treat inflammatory diseases. Our aim was to determine whether the HtE has anti-inflammatory and anxiolytic effects in a murine model of asthma. Ovalbumin (OVA)-sensitized BALB/c mice were treated with HtE (50, 100, or 200 mg/kg) or dexamethasone before each OVA challenge. After the last challenge, animals were subjected to anxiety tests and respiratory measurements. Following euthanasia, we quantified immune cells in the bronchoalveolar lavage (BAL), serum IgE titer and cytokine levels, cellular infiltration and mucus content in the lung tissues, and cellular composition of the mediastinal lymph nodes. OVA challenge in sensitized animals caused: (1) reduction of mean respiratory and dominant respiratory rate (from 398 ± 12 to 286 ± 20 cicles per minute (cpm) and from 320 ± 14 to 162 ± 15 cpm, respectively); (2) increase in behavioral markers of anxiety tests; (3) substantial pro-inflammatory effects, including rise in OVA-specific IgE titer (from 0 to 1:2048) and these inflammatory effect diminished the titer to 1:512 after HtE treatment; rise in plasma IL-13 (from 13 ng/mL in saline to 227 ng/mL in OVA and HtE treatment restored to 1.29 ng/mL; rise in total BAL cell count (from 0.742 cells/mL in saline to 11.77 cells/mL in OVA), with prominent eosinophilia. H. tiubae extract affected respiratory parameters similarly to aminophylline, behavioral changes comparable to diazepam, and inflammation being as efficient as dexamethasone. H. tiubae extract (HtE) possesses both anti-inflammatory and anxiolytic properties in the murine model of asthma.

Analysis of changes in expression of IL-4/IL-13/STAT6 pathway and correlation with the selected clinical parameters in patients with atopic asthma

INTRODUCTION

Asthma is associated with activation of interleukin-4 (IL-4)/interleukin-13 (IL-13)/signal transducer and activator of transcription factor-6(STAT6) inflammatory response via overexpression of all pathway components: IL-4, IL-13, and STAT6.

OBJECTIVES

To evaluate the association of IL-4, IL-13, and STAT6 expression and immunoexpression with atopic asthma development.

PATIENTS AND METHODS

Fifty patients with atopic asthma and 20 healthy controls were enrolled into the study. Relative gene expression was analyzed by qPCR method. Immunoexpression was assessed by ELISA method.

RESULTS

The expression levels of IL-4, IL-13, and STAT6 were higher in patients compared to the controls, but a statistically significant difference was observed only for IL-13 (P = 0.03). In immunoexpression analysis, a statistically significant difference between patients and controls was found for IgE (P = 0.03). Significant positive correlations in the patient group were found between IL-13 gene expression and total level of serum IgE (rho = 0.230, P = 0.033), STAT6 gene/STAT6 protein and total level of serum IgE (STAT6: rho = 0.077, P = 0.038; STAT6: rho = 0.049, P = 0.042), IL-4, and STAT6 expression (rho = 0.098, P = 0.048). Any significant correlations were found between expression/immunoexpression levels of the studied genes and clinical classification, clinical features, or lung function parameters.

CONCLUSIONS

Our data support the role of Th2 cytokines (IL-4, IL-13) and STAT6 in Th1/Th2 imbalance and highlight the etiological relationship between IL-4/IL-13/STAT6 signaling and atopy and asthma.

Lebrikizumab in the treatment of asthma

INTRODUCTION

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

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.

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.

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.

Development of an ultra-sensitive single molecule counting assay for the detection of interleukin-13 as a marker for asthmatic severity

OBJECTIVE

Interleukin-13 (IL-13) has been difficult to quantify within human serum due to low abundance. Available assays have not been sensitive enough to detect IL-13 at the femtogram level. Thus, there are inconsistencies within the published literature as to IL-13 concentrations in normal or disease populations. To better understand IL-13 serum concentrations, a highly sensitive immunoassay was developed and used to determine concentrations from asthmatics with varying clinical severities.

METHODS

A single molecule counting (SMC) method was used to analyze serum samples from a total of 145 individuals (60 severe asthma, 60 moderate asthma, 60 mild asthma and 23 healthy donors).

RESULTS

IL-13 concentrations correlated with severity of asthma, with overlapping ranges. Mean IL-13 levels were highest in severe asthma. Mean IL-13 levels in moderate asthma population were second highest followed by mild asthma with the lowest IL-13 concentration. IL-13 concentrations in healthy donors were similar to the mild asthmatic population. The average concentrations of IL-13 in severe, moderate, mild and healthy donors were 1.286pg/mL, 0.672pg/mL, 0.508pg/mL and 0.155pg/mL respectively.

CONCLUSION

Severe asthma patients have elevated levels of IL-13.

Profile of lebrikizumab and its potential in the treatment of asthma

Interleukin (IL)-13 has been associated with multiple inflammatory features of asthma. It affects multiple cellular lines in asthma and is a key mediator in airway hyperreactivity and remodeling. Periostin, an extracellular protein, has been used as a surrogate marker of IL-13 activity and has been linked to airway remodeling by inducing subepithelial fibrosis. Lebrikizumab is a humanized monoclonal antibody that targets IL-13. Studies have demonstrated promising results with lebrikizumab therapy in asthma with regard to pulmonary function and exacerbation rates, especially on those patients with surrogate markers of T helper cell type 2-driven inflammation (ie, elevated immunoglobulin E levels, eosinophil counts, periostin levels). Lebrikizumab appears to be a safe therapy, but there are ongoing studies evaluating its efficacy and safety profile. Other therapies that target IL-13 and the receptor of IL-4/IL-13 have been studied, but future studies are needed to determine their role in the treatment of asthma.

Adjuvant-dependent regulation of interleukin-17 expressing γδ T cells and inhibition of Th2 responses in allergic airways disease

Background

Th2 immune responses are linked primarily to mild and moderate asthma, while Th17 cells, Interleukin-17A (IL-17) and neutrophilia have been implicated in more severe forms of disease. How Th2-dependent allergic reactions are influenced by Th17 and IL-17-γδ T cells is poorly understood. In murine models, under some conditions, IL-17 promotes Th2-biased airway inflammatory responses. However, IL-17-γδ T cells have been implicated in the inhibition and resolution of allergic airway inflammation and hyperresponsiveness (AHR).

Methods

We compared airway responses in Balb/c mice sensitized to OVA with (and without) a Th2-skewing aluminum-based adjuvant and the IL-17 skewing, complete Freund’s adjuvant (CFA). AHR was measured invasively by flexiVent, while serum OVA-IgE was quantified by an enzyme immunoassay. Airway inflammatory and cytokine profiles, and cellular sources of IL-17 were assessed from bronchoalveolar lavage and/or lungs. The role of γδ T cells in these responses was addressed in OVA/CFA sensitized mice using a γδ T cell antibody.

Results

Following OVA challenge, all mice exhibited mixed eosinophilic/neutrophilic airway inflammatory profiles and elevated serum OVA-IgE. Whereas OVA/alum sensitized mice had moderate inflammation and AHR, OVA/CFA sensitized mice had significantly greater inflammation but lacked AHR. This correlated with a shift in IL-17 production from CD4⁺ to γδ T cells. Additionally, OVA/CFA sensitized mice, given a γδ TCR stimulatory antibody, showed increased frequencies of IL-17-γδ T cells and diminished airway reactivity and eosinophilia.

Conclusions

Thus, the conditions of antigen sensitization influence the profile of cells that produce IL-17, the balance of which may then modulate the airway inflammatory responses, including AHR. The possibility for IL-17-γδ T cells to reduce AHR and robust eosinophilic inflammation provides evidence that therapeutic approaches focused on stimulating and increasing airway IL-17-γδ T cells may be an effective alternative in treating steroid resistant, severe asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0090-5) contains supplementary material, which is available to authorized users.

Periostin, a novel biomarker of TH2-driven asthma

PURPOSE OF REVIEW

Asthma is a heterogeneous disease with multiple, overlapping phenotypes. Biomarkers are currently being investigated to better characterize the disease phenotypes and to identify the responders to specific targeted therapies. This review focuses on the emerging data surrounding the use of one such biomarker for T helper 2 (TH2)-driven asthma: periostin.

RECENT FINDINGS

Periostin is an extracellular matrix protein that is induced by interleukin (IL)-4 and IL-13 in airway epithelial cells and lung fibroblasts. It has proven to be an important biomarker of TH2-associated airway inflammation and a potential predictor of airway eosinophilia. It has also been shown to predict response to treatment with inhaled corticosteroids in patients with these characteristics. Furthermore, recent asthma clinical trials have established that serum periostin may have value in predicting the response to targeted therapy with biologic agents such as lebrikizumab and omalizumab.

SUMMARY

Emerging data suggest a role for periostin in refining asthma phenotypes and predicting the response to targeted therapy. Although early data are promising, further investigations are needed to confirm these findings and to identify other clinical applications in which periostin may be valuable.

Which biomarkers are effective for identifying Th2-driven inflammation in asthma?

Recognition of asthma as a heterogeneous disease revealed different potential molecular targets and urged the development of targeted, customized treatment modalities. Evidence was provided for different inflammatory subsets of asthma and more recently, further refined to T helper (Th)2-high and Th2-low subphenotypes with different responsiveness to standard and targeted pharmacotherapy. Given these differences in immunology and pathophysiology, proof of concept studies of novel treatment modalities for asthma should be performed in adequate, well-defined phenotypes. In this review, we describe both existing and novel biomarkers of Th2-inflammation in asthma that can be applied to classify asthma subphenotypes in clinical studies and for treatment monitoring.

Association between IL13 gene polymorphisms and susceptibility to cancer: a meta-analysis

BACKGROUND/AIMS

Interleukin-13 (IL13) is an immunoregulatory cytokine which plays an important role in carcinogenesis through affecting tumor immunosurveillance. Many studies had reported the influence of IL13 rs1800925 and rs20541 polymorphisms on cancer risk, however, with inconclusive results. The aim of the present study was to conduct a meta-analysis to clarify the relationship.

METHODS

Twenty studies including a total of 6713 cancer cases and 8693 controls for IL13 rs20541 polymorphism and 4081 cancer cases and 6202 controls for IL13 rs1800925 polymorphism were included in the meta-analysis. Data were extracted from these studies and odds ratios with corresponding 95% confidence intervals were computed to estimate the strength of the association.

RESULTS

Overall, the IL13 rs20541 polymorphism were associated with significantly decreased cancer risk in all genetic models (AA vs. GG: OR=0.82, 95%CI=0.71-0.95; GA vs. GG: OR=0.92, 95%CI=0.85-0.99; GA/AA vs. GG: OR=0.90, 95%CI=0.85-0.97; AA vs. GG/GA: OR=0.85, 95CI%=0.74-0.98). In the stratified analyses, significant effects were found among European populations, studies with population-based controls and studies of glioma. No influence of the IL13 rs1800925 polymorphism on the overall cancer risk was observed. However, in the stratified analyses, we found the IL13 rs1800925 polymorphism was significantly associated with decreased risk for glioma (CT vs. TT: OR=0.72, 95%CI=0.55-0.93; CT/TT vs. TT: OR=0.76, 95%CI=0.62-0.89).

CONCLUSION

Our meta-analysis suggests that the IL13 rs20541 polymorphism contributes to susceptibility to cancer, especially for glioma; and the IL13 rs1800925 polymorphism may be associated with glioma risk.

Polyphenols and their components in experimental allergic asthma

The aim of the study was to investigate the potential anti-inflammatory effects in -experimental allergic asthma of natural polyphenolic compounds or their single major components. The experiment was performed after 21-days sensitization of guinea pigs with ovalbumin suspension. Changes in airway reactivity after the long-term treatment with the polyphenolic compounds Provinol and Flavin-7 and their single major components quercetin and resveratrol during were assessed using a whole body plethysmography. Reactivity of tracheal smooth muscle was studied in vitro in response to cumulative doses of the bronchoconstrictive mediators histamine and acetylcholine. Furthermore, concentrations of the inflammatory cytokines IL-4 and IL-5 were measured in bronchoalveolar lavage fluid. The results demonstrate significant anti-inflammatory effects of Provinol and Flavin-7 exerted in the airways. In contrast, chronic treatment with quercetin and resveratrol, single components of the two polyphenols, did not show such activity. We conclude that polyphenolic compounds are more effective in the anti-inflammatory effects in the airways than their separate components.

Pretreatment with glycomacropeptide reduces allergen sensitization, alleviates immediate cutaneous hypersensitivity and protects from anaphylaxis

Allergic disorders are characterized by the involvement of allergen-specific immunoglobulin (Ig)E antibodies and T helper type 2 (Th2) cells. The search for new therapies for allergic diseases has been the primary focus of interest for many investigators in recent years. Glycomacropeptide (GMP) is a biologically active component of milk that exhibits a range of immunomodulatory functions. We examined whether oral administration of GMP could affect the development of allergic sensitization and the severity of immediate cutaneous hypersensitivity reactions and of anaphylaxis. Rats treated with or without GMP were ovalbumin (OVA)-sensitized and several indicators of allergy were evaluated. Pretreatment with GMP resulted in reduction of antigen-specific IgE titre in rats when sensitized with OVA. GMP administration also markedly suppressed the proliferative response of splenocytes to antigen and the production of interleukin (IL)-13 by splenocytes of sensitized animals. In addition, GMP pretreatment attenuated the intensity of the immediate cutaneous reaction induced by antigen and protected the sensitized rats from severe anaphylaxis. These data demonstrate, for the first time, that the administration of GMP prevents allergen sensitization and reduces the severity of the early-phase reaction induced by antigen in cutaneous hypersensitivity and in anaphylaxis. GMP may be used as a novel prophylactic agent for the control of allergic diseases.

IL-13 in asthma and allergic disease: asthma phenotypes and targeted therapies

Decades of research in animal models have provided abundant evidence to show that IL-13 is a key T(H)2 cytokine that directs many of the important features of airway inflammation and remodeling in patients with allergic asthma. Several promising focused therapies for asthma that target the IL-13/IL-4/signal transducer and activator of transcription 6 pathway are in development, including anti-IL-13 mAbs and IL-4 receptor antagonists. The efficacy of these new potential asthma therapies depends on the responsiveness of patients. However, an understanding of how IL-13-directed therapies might benefit asthmatic patients is confounded by the complex heterogeneity of the disease. Recent efforts to classify subphenotypes of asthma have focused on sputum cellular inflammation profiles, as well as cluster analyses of clinical variables and molecular and genetic signatures. Researchers and clinicians can now evaluate biomarkers of T(H)2-driven airway inflammation in asthmatic patients, such as serum IgE levels, sputum eosinophil counts, fraction of exhaled nitric oxide levels, and serum periostin levels, to aid decision making in clinical trials and drug development and to identify subsets of patients who might benefit from therapies. Although it is unlikely that these therapies will benefit all asthmatic patients with this heterogeneous disease, advances in understanding asthma subphenotypes in relation to clinical variables and T(H)2 cytokine responses offer the opportunity to improve the efficacy and safety of proposed therapies for asthma.

Gene-gene interactions between candidate gene polymorphisms are associated with total IgE levels in Korean children with asthma

OBJECTIVE

To investigate associations between total serum immunoglobulin E (IgE) levels and single nucleotide polymorphisms (SNPs) from eight candidate genes (IL-4 rs2243250, IL-4Rα rs1805010, IL-13 rs20541, IL-13Rα1 rs2495636, CD14 rs2569190, tumor necrosis factor-alpha (TNF-α) rs1800629, cytotoxic T lymphocyte-associated antigen (CTLA4) rs231775, FCER1B rs1441585) in children with asthma and to evaluate gene-gene interactions.

METHODS

A total of 669 Korean children with asthma (n = 544 atopic n = 125 non-atopic) were included. Asthma phenotypes, total serum IgE levels, and methacholine challenge test results were evaluated. SNPs were genotyped using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method. Multi-factor dimensionality reduction (MDR) was used to analyze gene-gene interactions.

RESULTS

The combination of the IL-13, IL-13Rα1, and CTLA4 polymorphisms was selected through MDR analysis of the data pertaining to children with atopic and non-atopic asthma (accuracy = 0.5459, cross validation consistency (CVC) = 10/10). The IL-4Rα, IL-13, IL-13Rα1, CD14, and CTLA4 polymorphisms were selected as the best model of increased total serum IgE levels in non-atopic and atopic asthma (asthma: accuracy = 0.4726, CVC = 10/10; atopic asthma: accuracy = 0.4573, CVC = 10/10). Both the IL-4Rα and the IL-13 polymorphisms were correlated with the IgE level. ANOVA analysis revealed that the combinations of the CTLA4 and IL-13, IL-13 and IL-13Rα1, IL-4Rα and IL-13, and CD14 and IL-13 polymorphisms were all significantly associated with increased total serum IgE levels.

CONCLUSIONS

The best model of increased IgE level included the IL-4Rα, IL-13, IL-13Rα1, CD14, and CTLA4 polymorphisms. Of the various interactions between these polymorphisms, the combinations of the CTLA4 and IL-13 polymorphisms and the IL-13 and IL-13Rα1 polymorphisms showed synergistic effects in terms of increased total serum IgE levels in the present cohort.

IL-13 polymorphisms contribute to the risk of asthma: a meta-analysis

OBJECTIVES

The purpose of this study was to evaluate the effects of interleukin-13 (IL-13) polymorphisms on the risk of asthma using a meta-analysis.

DESIGN AND METHODS

Fifteen publications were identified by searching Pubmed, Embase, ISI, OVID, and EBSCO databases. Odds ratios with corresponding 95% confidence intervals were computed to estimate the association between IL-13 polymorphisms and risk of asthma.

RESULTS

The polymorphisms of R130Q (rs20541) and -1112C/T (rs1800925) in IL-13 gene were associated with significantly increased risks of asthma in overall analyses. Subgroup analyses showed that the elevated risks occurred in adult-onset asthma, Caucasians, and high quality studies.

CONCLUSIONS

This meta-analysis provides evidence that the R130Q and -1112C/T polymorphisms in IL-13 are risk factors for asthma.

Paeonol attenuates airway inflammation and hyperresponsiveness in a murine model of ovalbumin-induced asthma

Paeonol, the main active component isolated from Moutan Cortex, possesses extensive pharmacological activities such as anti-inflammatory, anti-allergic, and immunoregulatory effects. In the present study, we examined the effects of paeonol on airway inflammation and hyperresponsiveness in a mouse model of allergic asthma. BALB/c mice sensitized and challenged with ovalbumin were administered paeonol intragastrically at a dose of 100 mg/kg daily. Paeonol significantly suppressed ovalbumin-induced airway hyperresponsiveness to acetylcholine chloride. Paeonol administration significantly inhibited the total inflammatory cell and eosinophil count in bronchoalveolar lavage fluid. Treatment with paeonol significantly enhanced IFN-γ levels and decreased interleukin-4 and interleukin-13 levels in bronchoalveolar lavage fluid and total immunoglobulin E levels in serum. Histological examination of lung tissue demonstrated that paeonol significantly attenuated allergen-induced lung eosinophilic inflammation and mucus-producing goblet cells in the airway. These data suggest that paeonol exhibits anti-inflammatory activity in allergic mice and may possess new therapeutic potential for the treatment of allergic bronchial asthma.

Eczema in early life: genetics, the skin barrier, and lessons learned from birth cohort studies

Eczema is a chronic inflammatory disorder of the skin that affects up to 30% of children. It often afflicts infants in the first few months of life and can be the first indicator of the atopic march. Recent results from birth cohort studies have uncovered novel information regarding genetic and environmental factors that promote the development of eczema. Birth cohort studies provide an optimal study design to elucidate these associations and prospectively track longitudinal data including exposure assessment and health outcomes from birth into early life and childhood. This is especially relevant for eczema given the age specific emergence of this disease. In this review, we will provide a general overview of pediatric eczema and discuss the important findings in the literature with respect to genetics and environmental exposures, highlighting those derived from birth cohort studies. Additionally, we will review how these relate to the atopic march, the hygiene hypothesis and the integrity of the skin barrier.

Allergen-specific subcutaneous immunotherapy in allergic asthma: immunologic mechanisms and improvement

Allergic asthma is a disease characterized by persistent allergen-driven airway inflammation, remodeling, and airway hyperresponsiveness. CD4(+) T-cells, especially T-helper type 2 cells, play a critical role in orchestrating the disease process through the release of the cytokines IL-4, IL-5, and IL-13. Allergen-specific immunotherapy (SIT) is currently the only treatment with a long-term effect via modifying the natural course of allergy by interfering with the underlying immunological mechanisms. However, although SIT is effective in allergic rhinitis and insect venom allergy, in allergic asthma it seldom results in complete alleviation of the symptoms. Improvement of SIT is needed to enhance its efficacy in asthmatic patients. Herein, the immunoregulatory mechanisms underlying the beneficial effects of SIT are discussed with the ultimate aim to improve its treatment efficacy.

Association of IL-13 polymorphisms with leukotriene receptor antagonist drug responsiveness in Korean children with exercise-induced bronchoconstriction

BACKGROUND

IL-13 is a pivotal cytokine in allergic inflammation and bronchial hyperresponsiveness, and is known to influence leukotriene levels.

OBJECTIVE

We investigated whether IL-13 polymorphisms may be associated with clinical phenotypes and drug responsiveness to the leukotriene receptor antagonist (LTRA) in Korean asthmatic children with exercise-induced bronchoconstriction (EIB).

METHODS

We enrolled 242 normal controls and 374 patients with asthma. Of the asthmatic patients, 100 performed exercise challenge tests before and after receiving montelukast (5 mg/day) for 8 weeks and included 80 subjects in drug responsiveness analysis. We assessed IL-13 polymorphisms (-1512A/C, -1112C/T, +2044G/A) through PCR-restriction fragment length polymorphism analysis.

RESULTS

Significantly higher total IgE levels and maximum percent fall in forced expiratory volume in 1 s (FEV1) (%) after exercise challenge test were found in asthmatic patients carrying one or two copies of the IL-13 +2044A versus those homozygous for +2044G (P=0.011 and 0.040, respectively). We further noted a correlation of total IgE with maximum percent fall in FEV1 (%) in asthmatic patients, as well as a reverse correlation with improvement of maximum percent fall in FEV1 (%) after exercise challenge tests. Finally, we observed a significant association between responsiveness to montelukast and IL-13 -1112C/T polymorphism and the haplotype of IL-13 polymorphisms.

CONCLUSION

The IL-13 +2044G/A polymorphism may be associated with atopy and EIB severity in Korean children with EIB, and thus could potentially be considered as a disease-modifying gene. Moreover, the IL-13 -1112C/T polymorphism and the haplotype of IL-13 polymorphisms seem to be associated with LTRA drug responsiveness, and thus might prove useful as a target for modulation of LTRA drug responsiveness.

Regulation of IL-13 receptor α1 expression and signaling on human tonsillar B-lymphocyte subsets

BACKGROUND

T(H)2 cytokines play crucial roles in driving human B lymphocytes to produce IgE. However, it is unclear whether IL-4 and IL-13 have parallel or sequential roles in the development of B lymphocytes.

OBJECTIVE

We investigated IL-13 receptor (IL-13R) expression and regulation in mature and immature human B cells.

METHODS

Purified B cells were isolated from human tonsils. We evaluated IL-13Ralpha1 mRNA expression using real-time PCR and IL-13Ralpha1 and IL-4 receptor (IL-4R) alpha expression using flow cytometry and microscopy. Signal transduction was assessed on the basis of signal transducer and activator of transcription 6 phosphorylation.

RESULTS

IL13Ralpha1 mRNA was induced after stimulation with anti-CD40 antibodies, anti-CD40 plus IL-4, or anti-IgM/IgG. Baseline surface IL13Ralpha1 levels were low in unstimulated B cells but increased significantly at 24 hours and were sustained for 5 to 14 days. In contrast, IL4R alpha was constitutively expressed on tonsillar B cells, and levels did not significantly vary after stimulation. B cells activated by CD40 ligation or B-cell receptor cross-linking, but not resting B cells, showed significant increases in signal transducer and activator of transcription 6 phosphorylation in response to IL-13. IL-13Ralpha1 expression was induced on mature and memory B cells, as well as on naive subsets.

CONCLUSIONS

There is lower constitutive expression and signaling of IL13Ralpha1 in resting tonsillar B lymphocytes compared with that of IL4R alpha. IL-13 is induced on both immature and mature B lymphocytes.

CLINICAL IMPLICATIONS

This implies different roles for IL-4 and IL-13 in B-cell development, which would allow for specific targeting of IL-13 in IgE-mediated diseases.

Gene-gene interaction between IL-13 and IL-13Ralpha1 is associated with total IgE in Korean children with atopic asthma

Interleukin (IL)-13, which is essential for IgE synthesis, mediates its effects by binding with a receptor composed of IL-4Ralpha and IL-13Ralpha1. We investigated the effects of IL-13 and IL-13Ralpha1 polymorphisms in Korean children with asthma, and whether these have been associated with IgE production. We enrolled 358 atopic asthmatic, 111 non-atopic asthmatic, and 146 non-atopic healthy children. IL-13 and IL-13Ralpha1 genotypes were identified using the PCR-RFLP method. There was an association between the asthma susceptibility and homozygosity for risk allele of IL-13 G+2044A. In children with atopic asthma, risk alleles in IL-13 (A-1512C and C-1112T) and IL-13Ralpha1 (A+1398G) showed increased total IgE (P=0.012, 0.015 and 0.017, respectively). Three-loci haplotype analysis for IL-13 showed that the haplotype composed of -1512C, -1112T and +2044A was associated with higher total IgE than other tested haplotypes in children with atopic asthma (P=0.003). The gene-gene interaction between risk alleles of each IL-13 promoter polymorphism and IL-13Ralpha1 polymorphism was associated with higher total IgE in children with atopic asthma (P=0.002, 0.010). These findings indicate that the IL-13 G+2044A is associated with asthma development and the IL-13 and IL-13Ralpha1 polymorphisms may interact to enhance IgE production.

Downregulation of leukotriene biosynthesis by thymoquinone attenuates airway inflammation in a mouse model of allergic asthma

Chronic airway inflammation is a key feature of bronchial asthma. Leukotrienes are potent inflammatory mediators that play a role in the pathophysiology of asthma, and their levels are elevated in the airways in response to allergen challenge. We examined the anti-inflammatory effect of thymoquinone (TQ), the active principle in the volatile oil of Nigella sativa seeds, on leukotriene (LT) biosynthesis in a mouse model of allergic asthma. Mice sensitized and challenged with ovalbumin (OVA) antigen had an increased amounts of leukotriene B4 and C4, Th2 cytokines, and eosinophils in bronchoalveolar lavage (BAL) fluid. In addition, there was also a marked increase in lung tissue eosinophilia and goblet cell numbers. Administration of TQ before OVA challenge inhibited 5-lipoxygenase, the main enzyme in leukotriene biosynthesis, expression by lung cells and significantly reduced the levels of LTB4 and LTC4. This was accompanied by a marked decrease in Th2 cytokines and BAL fluid and lung tissue eosinophilia, all of which are characteristics of airway inflammation. These results demonstrate the anti-inflammatory effect of TQ in experimental asthma.