Advances in mechanisms of asthma, allergy, and immunology in 2011

Longitudinal Trajectories of Asthma and Allergic Comorbidities in the Korean Childhood Asthma Study

PURPOSE

Studies on the longitudinal clinical features of asthma or allergic comorbidities in children are limited. We aimed to examine the trajectories of asthma and allergic comorbidities and determine whether these trajectories differ according to clinical asthma phenotypes from birth to adolescence.

METHODS

We enrolled 958 children with physician-diagnosed asthma from the Korean childhood Asthma Study (KAS) cohort. Children with asthma were classified using hierarchical cluster analysis. Information on the diagnosis and treatment of allergic diseases before cohort entry was collected through linkage with national claims data from the Health Insurance Review and Assessment Service.

RESULTS

In the KAS cohort, approximately half had a history of atopic dermatitis (AD) before infancy, with its prevalence gradually decreasing during adolescence. The prevalence of allergic rhinitis (AR) increased with age. The prevalence of asthma increased during early childhood and decreased during adolescence. According to the natural progression of asthma, AD, and AR trajectories, 4 distinctive phenotypes were identified using latent class analysis: "almost controlled," "early-onset asthma with AD and late-onset AR," "early-onset asthma only," and "intermediate-onset asthma and late-onset AR." Four distinct clinical trajectory patterns of asthma, AD, and AR were identified among the 4 cluster phenotypes based on baseline characteristics. Cluster 1 comprised male-dominant, atopic asthma with early-onset AD and late-onset AR. Cluster 2 included early-onset, atopic asthma with AD" persistent into adolescence. Cluster 3 encompassed "puberty-onset, female-dominant atopic asthma" with early-onset and low remission rates. Cluster 4 comprised "early-onset asthma with less atopic features" and the lowest comorbidities of AD and AR.

CONCLUSIONS

The longitudinal trajectories of asthma and allergic comorbidities in Korean children can be classified into distinct clusters. Most phenotypes exhibited early-onset asthma with a varying prevalence of comorbidities. The persistence of AD, rather than its onset age, determines the phenotype.

Life Course of Asthma

Asthma is a heterogeneous chronic airway disease that can vary over a lifetime. Although broad categories of asthma by severity and type have been constructed, there remains a tremendous opportunity to discover an approach to managing asthma with additional factors in mind. Many in the field have suggested and are pursuing a novel paradigm shift in how asthma might be better managed, considering the life course of exposures, management priorities, and predicted trajectory of lung function growth. This approach will require a more holistic view of prenatal, postnatal, adolescence, hormonal and gender aspects, and the aging process. In addition, the environment, externally and internally, including in one's genetic code and epigenetic changes, are factors that affect how asthma progresses or becomes more stable in individuals. This chapter focuses on the various influences that may, to differing degrees, affect people with asthma, which can develop at any time in their lives. Shifting the paradigm of thought and strategies for care and advocating for public policies and health delivery that focus on this philosophy is paramount to advance asthma care for all.

Autoantibody of interleukin-17A induced by recombinant Mycobacterium smegmatis attenuates airway inflammation in mice with neutrophilic asthma

OBJECTIVE

Previous studies have shown Interleukin (IL)-17A as an important contributor to the development of severe asthma, which is mainly characterized by neutrophilic inflammation and less response to corticosteroids. Consequently, the IL-17A-neutrophil axis could be a potential therapeutic target. Previously, we constructed a recombinant Mycobacterium smegmatis (rMS) expressing fusion protein Ag85A-IL-17A, and confirmed it could induce production of IL-17A autoantibody in vivo. This study uses a murine model of neutrophilic asthma to further investigate the effects of rMS on airway inflammation.

METHODS

DO11.10 mice were divided into four groups: phosphate buffered saline (PBS), asthma, rMS and MS. This murine model of neutrophilic asthma was established with ovalbumin (OVA) challenge, whereby PBS, rMS and MS were administered intranasally. Anti-inflammatory effects on inflammatory cell infiltration and expression of inflammatory mediators in bronchoalveolar lavage fluid (BALF) were evaluated, along with histopathological changes in lung tissues.

RESULTS

A sustained high-titer IL-17A autoantibody was detected in sera of the rMS group. Compared to the asthma group, the number of neutrophils, IL-17A, CXCL-1 levels and MPO activity in the rMS group were all significantly reduced (p < 0.01). Histological analysis showed rMS remarkably suppressed inflammatory infiltration around bronchia. The inflammation score and the mucus score in the rMS group were both significantly lower than those in the asthma group (p < 0.001).

CONCLUSION

rMS ameliorated airway inflammation in mice with neutrophilic asthma caused by inducing IL-17A autoantibody and regulating the IL-17A-neutrophil axis, thus offering a possible novel treatment for neutrophilic asthma.

ASTHMA: ROLE OF THE ANGIOTENSIN-(1-7)/MAS PATHWAY IN PATHOPHYSIOLOGY AND THERAPY

The incidence of asthma is a global health problem, requiring studies aimed at developing new treatments to improve clinical management, thereby reducing personal and economic burdens on the health system. Therefore, the discovery of mediators that promote anti-inflammatory and pro-resolutive events are highly desirable to improve lung function and quality of life in asthmatic patients. In that regard, experimental studies have shown that the Angiotensin-(1-7)/Mas receptor of the renin-angiotensin system (RAS) is a potential candidate for the treatment of asthma. Therefore, we reviewed findings related to the function of the Angiotensin-(1-7)/Mas pathway in regulating the processes associated with inflammation and exacerbations in asthma, including leukocyte influx, fibrogenesis, pulmonary dysfunction and resolution of inflammation. Thus, knowledge of the role of the Angiotensin-(1-7)/Mas can help pave the way for the development of new treatments for this disease with high morbidity and mortality through new experimental and clinical trials.

The economic burden of medical treatment of children with asthma in China

Background

At present, there are few studies on the economic burden and medical treatment of children with asthma in China. Thus this study aimed to investigate the economic burden of medical treatment of children with asthma in China.

Method

The 2015 China Medical Insurance Research Association (CHIRA) database was searched for patients with asthma from 0 to 14 years old. A cross-sectional study with cost analysis was conducted.

Results

The annual per capita direct medical cost was RMB 525 (US$75) related to asthma. Totaling 58% of the medical expenditure for asthma was covered by insurance in China, the majority of which were direct medical costs. Those that have the highest rates of using antibiotics were central China (100.0%), children aged 3 years and under (63.6%), as well as fourth-tier and fifth-tier cities (77.1%). Outpatient clinics (98.58% vs 1.42%, P < 0.01), tertiary hospitals (62.08% vs 37.92%, P < 0.01), and general hospitals (72.27% vs 27.73%, P < 0.01) were more often visited than the inpatient clinics, secondary and primary as well as the specialized clinics, respectively.

Conclusion

The economic burden of childhood asthma in China is relatively low, and the national medical insurance reduces their economic burden to a large extent. Abuse of antibiotics in treating asthma was found in China. There remain opportunities to strengthen the hierarchical medical system, reducing hospitalization and emergency visits, and ultimately reducing the economic burden of children with asthma.

The Exposome and Asthma

This article on exposome and asthma focuses on the interaction of patients and their environments in various parts of their growth, development, and stages of life. Indoor and outdoor environments play a role in pathogenesis via levels and duration of exposure, with genetic susceptibility as a crucial factor that alters the initiation and trajectory of common conditions such as asthma. Knowledge of environmental exposures globally and changes that are occurring is necessary to function effectively as medical professionals and health advocates.

Recombinant pyrin domain protein attenuates allergic inflammation by suppressing NF-κB pathway in asthmatic mice

Pyrin domain (PYD), a subclass of protein motif known as the death fold, is frequently involved in inflammation and immune responses. PYD modulates nuclear factor-kappa B (NF-κB) signalling pathway upon various stimuli. Herein, a novel recombinant pyrin domain protein (RPYD) was generated. Its role and mechanism in inflammatory response in an ovalbumin (OVA) induced asthma model was investigated. After OVA challenge, there was inflammatory cell infiltration in the lung, as well as airway hyper-responsiveness (AHR) to inhaled methacholine. In addition, eosinophils increased in the bronchoalveolar lavage fluids, alone with the elevated levels of Th-2 type cytokines [interleukin (IL)-4, IL-5 and IL-13], eotaxin, and adhesion molecules. However, the transnasal administration of RPYD before the OVA challenge significantly inhibited these asthmatic reactions. Moreover, RPYD markedly suppressed NF-κB translocation, reduced phosphorylation of p38 MAPK, and thus attenuated the expression of intercellular adhesion molecule 1 and IL-6 in the BEAS-2B cells stimulated by proinflammatory cytokines in vitro. These findings indicate that RPYD can protect asthma host from OVA-induced airway inflammation and AHR via down-regulation of NF-κB and p38 MAPK activities. RPYD may be used as a potential medicine for the treatment of asthma in clinic.

Environmental determinants of allergy and asthma in early life

Allergic disease prevalence has increased significantly in recent decades. Primary prevention efforts are being guided by study of the exposome (or collective environmental exposures beginning during the prenatal period) to identify modifiable factors that affect allergic disease risk. In this review we explore the evidence supporting a relationship between key components of the external exposome in the prenatal and early-life periods and their effect on atopy development focused on microbial, allergen, and air pollution exposures. The abundance and diversity of microbial exposures during the first months and years of life have been linked with risk of allergic sensitization and disease. Indoor environmental allergen exposure during early life can also affect disease development, depending on the allergen type, dose, and timing of exposure. Recent evidence supports the role of ambient air pollution in allergic disease inception. The lack of clarity in the literature surrounding the relationship between environment and atopy reflects the complex interplay between cumulative environmental factors and genetic susceptibility, such that no one factor dictates disease development in all subjects. Understanding the effect of the summation of environmental exposures throughout a child's development is needed to identify cost-effective interventions that reduce atopy risk in children.

Benomyl-induced effects of ORMDL3 overexpression via oxidative stress in human bronchial epithelial cells

The respiratory system is a major site of exposure route during pesticide use. Although pesticide exposure is associated with chronic respiratory diseases including asthma, the underlying pathophysiological mechanism remains to be elucidated. In this study, we investigated the in vitro effects of benomyl-induced ORMDL3 overexpression on the toxicological mechanism using the human bronchial epithelial cell line 16HBE14o-. Benomyl increased reactive oxygen species and Ca²⁺ levels, and asthma-related ADAM33 and ORMDL3 expression in 16HBE14o- cells. Considering the change in Ca²⁺ level and protein expression, we focused on ORMDL3 to elucidate the mechanism of benomyl-induced asthma. Antioxidant treatment showed that benomyl-induced ORMDL3 and endoplasmic reticulum stress could be triggered by oxidative stress. Furthermore, ORMDL3 knockdown alleviated the effects of benomyl on intracellular Ca²⁺, and the expression of metalloproteinases, and proinflammatory cytokines involved in the pathogenesis of asthma. In conclusion, our results suggest that benomyl-induced ORMDL3 overexpression via oxidative stress might be a mechanism involved in asthma. Moreover, antioxidants and alleviating mechanisms that reduce ORMDL3 levels could serve as promising therapeutic targets for pesticide-induced asthma.

Eosinophil Peroxidase Catalyzed Protein Carbamylation Participates in Asthma

The biochemical mechanisms through which eosinophils contribute to asthma pathogenesis are unclear. Here we show eosinophil peroxidase (EPO), an abundant granule protein released by activated eosinophils, contributes to characteristic asthma-related phenotypes through oxidative posttranslational modification (PTM) of proteins in asthmatic airways through a process called carbamylation. Using a combination of studies we now show EPO uses plasma levels of the pseudohalide thiocyanate (SCN^-) as substrate to catalyze protein carbamylation, as monitored by PTM of protein lysine residues into N^ϵ-carbamyllysine (homocitrulline), and contributes to the pathophysiological sequelae of eosinophil activation. Studies using EPO-deficient mice confirm EPO serves as a major enzymatic source for protein carbamylation during eosinophilic inflammatory models, including aeroallergen challenge. Clinical studies similarly revealed significant enrichment in carbamylation of airway proteins recovered from atopic asthmatics versus healthy controls in response to segmental allergen challenge. Protein-bound homocitrulline is shown to be co-localized with EPO within human asthmatic airways. Moreover, pathophysiologically relevant levels of carbamylated protein either incubated with cultured human airway epithelial cells in vitro, or provided as an aerosolized exposure in non-sensitized mice, induced multiple asthma-associated phenotypes including induction of mucin, Th2 cytokines, IFNγ, TGFβ, and epithelial cell apoptosis. Studies with scavenger receptor-A1 null mice reveal reduced IL-13 generation following exposure to aerosolized carbamylated protein, but no changes in other asthma-related phenotypes. In summary, EPO-mediated protein carbamylation is promoted during allergen-induced asthma exacerbation, and can both modulate immune responses and trigger a cascade of many of the inflammatory signals present in asthma.

Intranasal Administration of Recombinant Mycobacterium smegmatis Inducing IL-17A Autoantibody Attenuates Airway Inflammation in a Murine Model of Allergic Asthma

Asthma is a chronic inflammatory disorder, previous studies have shown that IL-17A contributes to the development of asthma, and there is a positive correlation between the level of IL-17A and the severity of disease. Here, we constructed recombinant Mycobacterium smegmatis expressing fusion protein Ag85A-IL-17A (rMS-Ag85a-IL-17a) and evaluated whether it could attenuate allergic airway inflammation, and further investigated the underlying mechanism. In this work, the murine model of asthma was established with ovalbumin, and mice were intranasally vaccinated with rMS-Ag85a-IL-17a. Autoantibody of IL-17A in sera was detected, and the airway inflammatory cells infiltration, the local cytokines and chemokines production and the histopathological changes of lung tissue were investigated. We found that the administration of rMS-Ag85a-IL-17a induced the autoantibody of IL-17A in sera. The vaccination of rMS-Ag85a-IL-17a remarkably reduced the infiltration of inflammatory cells and the secretion of mucus in lung tissue and significantly decreased the numbers of the total cells, eosinophils and neutrophils in BALF. Th1 cells count in spleen, Th1 cytokine levels in BALF and supernatant of splenocytes and mediastinal lymph nodes, and T-bet mRNA in lung tissue were significantly increased with rMS-Ag85a-IL-17a administration. Meanwhile, rMS-Ag85a-IL-17a vaccination markedly decreased Th2 cells count, Th2 cytokine and Th17 cytokine levels in BALF and supernatant of splenocytes and mediastinal lymph nodes, and chemokines mRNA expression in lung tissue. These data confirmed that recombinant Mycobacterium smegmatis in vivo could induce autoantibody of IL-17A, which attenuated asthmatic airway inflammation.

meso-Dihydroguaiaretic acid attenuates airway inflammation and mucus hypersecretion in an ovalbumin-induced murine model of asthma

meso-Dihydroguaiaretic acid (MDGA), which is a dibenzylbutane lignin isolated from the ethyl acetate fraction of Saururus chinensis, has various biological activities, including anti-oxidative, anti-inflammatory, anti-bacterial, and neuroprotective effects. However, no report has examined the potential anti-asthmatic activity of MDGA. In this study, we evaluated the protective effects of MDGA on asthmatic responses, particularly airway inflammation and mucus hypersecretion in an ovalbumin (OVA)-induced murine model of asthma. Intragastric administration of MDGA significantly lowered the productions of interleukin (IL)-4, IL-5, IL-13, tumor necrosis-α (TNF-α), eotaxin, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and immunoglobulin (Ig)E in bronchoalveolar lavage fluid (BALF), plasma, or lung tissues. Histological studies showed that MDGA inhibited OVA-induced inflammatory cell infiltration and mucus production in the respiratory tract. Moreover, MDGA markedly attenuated the OVA-induced activations of nuclear factor kappa B (NF-κB), extracellular-signal-regulated kinases 1/2 (ERK1/2), and p38 mitogen-activated protein kinase (p38 MAPK). Together, these results suggest that MDGA effectively inhibits airway inflammation and mucus hypersecretion by downregulating the levels of T helper 2 (Th2) cytokines, chemokines, and adhesion molecules, and inhibiting the activations of NF-κB and MAPKs.

Eosinophil-mediated signalling attenuates inflammatory responses in experimental colitis

OBJECTIVE

Eosinophils reside in the colonic mucosa and increase significantly during disease. Although a number of studies have suggested that eosinophils contribute to the pathogenesis of GI inflammation, the expanding scope of eosinophil-mediated activities indicate that they also regulate local immune responses and modulate tissue inflammation. We sought to define the impact of eosinophils that respond to acute phases of colitis in mice.

DESIGN

Acute colitis was induced in mice by administration of dextran sulfate sodium, 2,4,6-trinitrobenzenesulfonic acid or oxazolone to C57BL/6J (control) or eosinophil deficient (PHIL) mice. Eosinophils were also depleted from mice using antibodies against interleukin (IL)-5 or by grafting bone marrow from PHIL mice into control mice. Colon tissues were collected and analysed by immunohistochemistry, flow cytometry and reverse transcription PCR; lipids were analysed by mass spectroscopy.

RESULTS

Eosinophil-deficient mice developed significantly more severe colitis, and their colon tissues contained a greater number of neutrophils, than controls. This compensatory increase in neutrophils was accompanied by increased levels of the chemokines CXCL1 and CXCL2, which attract neutrophils. Lipidomic analyses of colonic tissue from eosinophil-deficient mice identified a deficiency in the docosahexaenoic acid-derived anti-inflammatory mediator 10, 17- dihydroxydocosahexaenoic acid (diHDoHE), namely protectin D1 (PD1). Administration of an exogenous PD1-isomer (10S, 17S-DiHDoHE) reduced the severity of colitis in eosinophil-deficient mice. The PD1-isomer also attenuated neutrophil infiltration and reduced levels of tumour necrosis factor-α, IL-1β, IL-6 and inducible NO-synthase in colons of mice. Finally, in vitro assays identified a direct inhibitory effect of PD1-isomer on neutrophil transepithelial migration.

CONCLUSIONS

Eosinophils exert a protective effect in acute mouse colitis, via production of anti-inflammatory lipid mediators.

Toll-like receptor 4 plays significant roles during allergic rhinitis

Allergic rhinitis is a nasal hypersensitivity and allergic disease which leads to inflammation of nasal mucosa. Previous investigations revealed that innate immune receptors play a key role in the pathogenesis of inflammatory diseases including allergic diseases. Toll-like receptors (TLRs), which are important innate immune receptors, play crucial roles in the recognition of foreign antigens, including allergens, and subsequently for the induction of immune responses such as inflammation. There are several controversial reports regarding the roles of TLR4 in the pathogenesis of allergic rhinitis. This review presents current information regarding the roles of TLR4 in the pathogenesis of allergic rhinitis and the plausible mechanisms which lead to the expression and function of TLR4 in this disease.

Asthma Bronchiale and Exercise-Induced Bronchoconstriction

Exercising regularly has a wide range of beneficial health effects; in particular, it has been well documented to help in the management of chronic illnesses including asthma. However, in some individuals, exertion can also trigger an exacerbation of asthmatic episodes and subsequent acute attacks of breathlessness, coughing, tightness of the chest and wheezing. This physiological process is called exercise-induced bronchoconstriction (EIB) whereby post-exercise forced expiratory volume in 1 s is reduced by 10-15% from baseline. While EIB is highly prevalent in asthmatics and presents with similar respiratory symptoms, asthma and EIB are not mutually exclusive. The aim of this review is to present a broad overview of both conditions in order to enhance the understanding of the similarities and differences distinguishing them as two separate entities. The pathophysiology and mechanisms underlying asthma are well described with research now focussing on defining phenotypes for targeted management strategies. Conversely, the mechanistic understanding of EIB remains largely under-described. Diagnostic pathways for both are established and similar, as are pharmacologic and non-pharmacologic treatments and management approaches, which have enhanced success with early detection. Given the potential for exacerbation of asthma, exercise avoidance is common but counterproductive as current evidence indicates that it is well tolerated and improves quality of life. Literature supporting the benefit of exercise for EIB sufferers is at present favourable, yet extremely limited; therefore, future research should be directed in this area as well as towards further developing the understanding of the pathophysiology and mechanisms underpinning both EIB and asthma.

IL-17A Autoantibody Induced by Recombinant Mycobacterium smegmatis Expressing Ag85A-IL-17A Fusion Protein

Interleukin-17A is a newly described proinflammatory cytokine, which plays important roles in autoimmune diseases as well as asthma. In current work, we constructed a recombinant plasmid pMFA42S-Ag85a-IL-17a by inserting fusion gene Ag85a-IL-17a into shuttle vector pMFA42S, which was transformed to Mycobacterium smegmatis by electroporation to obtain recombinant M. smegmatis named rMS-Ag85a-IL-17a. The comparison of growth pattern between M. smegmatis and rMS-Ag85a-IL-17a suggested fusion gene had no significant influence on the growth of strains, and rMS-Ag85a-IL-17a expressed fusion protein Ag85A-IL-17A which had good immunogenicity revealed by Western blot. M. smegmatis and rMS-Ag85a-IL-17a were performed to intranasally immunize mice; then, antibody response in sera was detected by enzyme-linked immunosorbent assay. Our findings demonstrated that rMS-Ag85a-IL-17a could induce specific IL-17A autoantibody in mice, which laid the foundation for further study.

Salidroside attenuates allergic airway inflammation through negative regulation of nuclear factor-kappa B and p38 mitogen-activated protein kinase

Salidroside is a biologically active ingredient of Rhodiola rosea, which has several interesting biological properties, including anti-oxidant and anti-inflammatory; however, its anti-allergic effects are poorly understood. The objective of this study is to determine whether salidroside attenuates the inflammatory response in an ovalbumin (OVA)-induced asthma model. OVA-sensitized/challenged mice show airway hyperresponsiveness (AHR) to inhaled methacholine and have an increased amount of T-helper2 type cytokines [interleukin (IL)-4, IL-5, and IL-13] and eosinophils in their bronchoalveolar lavage fluids and lung tissues. However, three successive intraperitoneal administrations of salidroside before the last OVA challenge result in significant inhibition of these asthmatic reactions. Moreover, OVA significantly increases the activation of nuclear factor-kappa B (NFκB) and p38 mitogen-activated protein kinase (MAPK) in lung tissues, whereas salidroside markedly suppresses NF-κB translocation and reduces phosphorylation of p38 MAPK. Furthermore, salidroside attenuates the expression of intercellular adhesion molecule 1 and IL-6 through modulating the activities of p38 MAPK and NF-κB in the BEAS-2B cells stimulated by proinflammatory cytokines. These findings indicate that salidroside protects against OVA-induced airway inflammation and AHR, at least in part via downregulation of NF-κB and p38 MAPK activities. Our data support the utility of salidroside as a potential medicine for the treatment of asthma.

Angiotensin-(1-7) attenuates airway remodelling and hyperresponsiveness in a model of chronic allergic lung inflammation

BACKGROUND AND PURPOSE

A long-term imbalance between pro- and anti-inflammatory mediators leads to airway remodelling, which is strongly correlated to most of the symptoms, severity and progression of chronic lung inflammation. The Angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis of the renin-angiotensin system is associated with attenuation of acute and chronic inflammatory processes. In this study, we investigated the effects of Ang-(1-7) treatment in a model of chronic allergic lung inflammation.

EXPERIMENTAL APPROACH

Mice were sensitized to ovalbumin (OVA; 4 injections over 42 days, 14 days apart) and were challenged three times per week (days 21-46). These mice received Ang-(1-7) (1 μg·h(-1) , s.c.) by osmotic mini-pumps, for the last 28 days. Histology and morphometric analysis were performed in left lung and right ventricle. Airway responsiveness to methacholine, analysis of Ang-(1-7) levels (RIA), collagen I and III (qRT-PCR), ERK1/2 and JNK (Western blotting), IgE (elisa), cytokines and chemokines (elisa multiplex), and immunohistochemistry for Mas receptors were performed.

KEY RESULTS

Infusion of Ang-(1-7) in OVA-sensitized and challenged mice decreased inflammatory cell infiltration and collagen deposition in the airways and lung parenchyma, and prevented bronchial hyperresponsiveness. These effects were accompanied by decreased IgE and ERK1/2 phosphorylation, and decreased pro-inflammatory cytokines. Mas receptors were detected in the epithelium and bronchial smooth muscle, suggesting a site in the lung for the beneficial actions of Ang-(1-7).

CONCLUSIONS AND IMPLICATIONS

Ang-(1-7) exerted beneficial attenuation of three major features of chronic asthma: lung inflammation, airway remodelling and hyperresponsiveness. Our results support an important protective role of Ang-(1-7) in lung inflammation.

IL-33/ST2 axis controls Th2/IL-31 and Th17 immune response in allergic airway diseases

IL-33 targeting ST2 receptor (T1/ST2), expressed on Th2 cell surface, regulates the production of cytokines like IL-17A and IL-31. We studied the role of IL-33/ST2 axis in IL-31 and IL-17A production in patients with allergic rhinitis (AR) and with concomitant allergic asthma and rhinitis (AAR). 20 healthy control subjects (HC), 14 AR and 17 AAR subjects were recruited and blood samples collected. IL-33, soluble ST2 (sST2), IL-17A and IL-31 plasma concentrations were measured by ELISA method. T1/ST2, IL-31 and IL-17A cellular expression were studied in peripheral blood mononuclear cells (PBMC) from HC, AR and AAR (n=6 for each group) by flow-cytometry. In vitro, we also evaluated the effect of beclomethasone dipropionate (BDP) on T1/ST2, IL-31 and IL-17A expression in CD3(+)T-cells from PBMC of AAR (n=6). Plasma levels of IL-33, IL-31 and IL-17A were significantly higher and sST2 was lower in patients with AR and AAR than in HC. IL-31 and IL-17A intracellular levels significantly increased, whereas T1/ST2 expression was significantly lower, in CD3(+)T-cells from AR and AAR compared to HC. Positive correlations were observed between plasmatic components of IL-33/ST2 axis and IL-31 in both AR and AAR and IL-17A in AAR. In vitro IL-31 and IL-17A intracellular levels decreased after BDP treatment, whereas T1/ST2 expression increased in cultured CD3(+)T-cells obtained from AAR. IL-33/ST2 axis is involved in Th2/IL-31 and Th17 immune response during the progression of allergic airway disease. In vitro BDP is able to control Th2/IL-31 and Th17 immune response in PBMC from allergic patients.

Association between promoter polymorphisms of interleukin-4 gene and allergic rhinitis risk: a meta-analysis

The relationship of interleukin-4 (IL-4) C-33T and C-590T (C-589T) gene polymorphisms with allergic rhinitis was analyzed. Data about the case control studies of IL-4 gene promoter polymorphisms [C-33T and C-590T (C-589T)] and their association with allergic diseases and correlation between serum IL-4 levels and allergic rhinitis were retrieved. The Stata 12.0 statistical software was applied to analyze the correlation between IL-4 gene polymorphisms and allergic rhinitis. The meta-analysis result of TT/CC genotype of -590 (-589) polymorphism showed a significant association with allergic diseases [OR=1.93, 95% CI (1.61-2.31), P=0.00]. Meta-analysis of the TT+TC versus CC genotype of IL-4 C-33/T polymorphism revealed significant associations with allergic diseases [OR=3.23, 95% CI (1.13-9.25), P=0.03]. Meanwhile, there was a significant correlation between serum IL-4 levels and allergic rhinitis [OR=2.52, 95% CI=(1.80-3.23), P=0.00]. IL-4 gene -590 TT genotype may increase the risk of allergic rhinitis and the T allele mutation of -33 might be correlated with allergic rhinitis.

Phellinus linteus Extract Exerts Anti-asthmatic Effects by Suppressing NF-κB and p38 MAPK Activity in an OVA-induced Mouse Model of Asthma

Phellinus linteus has been used as a traditional herbal medicine in Asian countries and is known to have anti-tumor, immunomodulatory, anti-inflammatory, and anti-allergic activities. However, the protective effects of P. linteus against experimental asthma have not been fully investigated. The objective of this study was to determine whether P. linteus ethanol extract (PLE) suppresses inflammatory response in an OVA-induced asthma model. As expected, the oral administration of PLE significantly inhibited eosinophilic airway inflammation and airway hyperresponsiveness in OVA-challenged BALB/c mice. Supporting these data, the augmentation of Th2 cytokines (IL-4, IL-5, and IL-13), eotaxin, and adhesion molecules in lung tissues and bronchoalveolar lavage fluid after OVA inhalation was markedly attenuated by PLE. Furthermore, PLE reduced OVA-induced activation of NF-κB and p38 MAPK in lung tissues. Therefore, our results suggest the potential of P. linteus as a therapeutic agent for asthma.

Bifidobacterium breve and Lactobacillus rhamnosus treatment is as effective as budesonide at reducing inflammation in a murine model for chronic asthma

Background

Asthma is estimated to affect as many as 300 million people worldwide and its incidence and prevalence are rapidly increasing throughout the world, especially in children and within developing countries. Recently, there has been a growing interest in the use of potentially beneficial bacteria for allergic diseases. This study is aimed at exploring the therapeutic effects of long-term treatment with two different beneficial bacterial strains (Bifidobacterium breve M-16 V and Lactobacillus rhamnosus NutRes1) and a glucocorticoid (budesonide), as a reference treatment, on inflammatory response in a murine model for chronic allergic asthma.

Methods

To mimic the chronic disease in asthmatic patients, we used the murine ovalbumin-induced asthma model combined with prolonged allergen exposure. Airway function; pulmonary airway inflammation; airway remodelling, mRNA expression of pattern recognition receptors, Th-specific cytokines and transcription factors in lung tissue; mast cell degranulation; in vitro T cell activation; and expression of Foxp3 in blood Th cells were examined.

Results

Lactobacillus rhamnosus reduced lung resistance to a similar extent as budesonide treatment in chronically asthmatic mice. Pulmonary airway inflammation, mast cell degranulation, T cell activation and airway remodelling were suppressed by all treatments. Beneficial bacteria and budesonide differentially modulated the expression of toll-like receptors (TLRs), nod-like receptors (NLRs), cytokines and T cell transcription factors. Bifidobacterium breve induced regulatory T cell responses in the airways by increasing Il10 and Foxp3 transcription in lung tissue as well as systemic by augmenting the mean fluorescence intensity of Foxp3 in blood CD4+ T cells.

Conclusion

These findings show that Bifidobacterium breve M-16 V and Lactobacillus rhamnosus NutRes1 have strong anti-inflammatory properties that are comparable to budesonide and therefore may be beneficial in the treatment of chronic asthma.

Cysteinyl leukotriene receptor antagonist regulates allergic airway inflammation in an organ- and cytokine-specific manner

Background

Cysteinyl leukotrienes (cys-LTs) are very important factors in the pathophysiology of bronchial asthma. Cys-LT receptor antagonists (LTRAs) decrease allergic airway inflammation. The aim of the present study was to determine the differential effects of LTRAs and corticosteroids on allergic airway inflammation and allergen-specific cytokine production from lymphoid tissues using a murine model of asthma.

Material/Methods

Four groups of female BALB/c mice [control (Cont); Dermatophagoides farinae allergen-sensitized (AS); pranlukast (Prl), an LTRA-treated AS; and dexamethasone (Dex)-treated AS] were examined. Lung pathology and cytokine production by prepared mononuclear cells isolated from mediastinal lymph nodes (MLNs) and spleen were compared among these groups.

Results

AS mice exhibited allergic airway inflammation and significant increases in allergen-specific Th1 and Th2 cytokines in MLNs and spleen. Prl-treated mice showed significant attenuation of allergic airway inflammation concomitant with reduction of Th2 cytokines and IFN-γ in MLNs but not in spleen. In contrast, Dex significantly decreased Th1 and Th2 cytokines in MLNs and also decreased them (except IL-13 and IL-2) in spleen.

Conclusions

The inflammatory effects of cys-LTs could differ in lymphoid organs. LTRAs potentially regulate allergic airway inflammation in an organ- and cytokine-specific manner, while systemic corticosteroid shows nonspecific effects.

Fungi: the neglected allergenic sources

Allergic diseases are considered the epidemics of the twentieth century estimated to affect more than 30% of the population in industrialized countries with a still increasing incidence. During the past two decades, the application of molecular biology allowed cloning, production and characterization of hundreds of recombinant allergens. In turn, knowledge about molecular, chemical and biologically relevant allergens contributed to increase our understanding of the mechanisms underlying IgE-mediated type I hypersensitivity reactions. It has been largely demonstrated that fungi are potent sources of allergenic molecules covering a vast variety of molecular structures including enzymes, toxins, cell wall components and phylogenetically highly conserved cross-reactive proteins. Despite the large knowledge accumulated and the compelling evidence for an involvement of fungal allergens in the pathophysiology of allergic diseases, fungi as a prominent source of allergens are still largely neglected in basic research as well as in clinical practice. This review aims to highlight the impact of fungal allergens with focus on asthma and atopic dermatitis.

The combination of Bifidobacterium breve with non-digestible oligosaccharides suppresses airway inflammation in a murine model for chronic asthma

Over the last decade, there has been a growing interest in the use of interventions that target the intestinal microbiota as a treatment approach for asthma. This study is aimed at exploring the therapeutic effects of long-term treatment with a combination of Bifidobacterium breve with non-digestible oligosaccharides on airway inflammation and remodeling. A murine ovalbumin-induced chronic asthma model was used. Pulmonary airway inflammation; mRNA expression of pattern recognition receptors, Th-specific cytokines and transcription factors in lung tissue; expression of Foxp3 in blood Th cells; in vitro T cell activation; mast cell degranulation; and airway remodeling were examined. The combination of B. breve with non-digestible oligosaccharides suppressed pulmonary airway inflammation; reduced T cell activation and mast cell degranulation; modulated expression of pattern recognition receptors, cytokines and transcription factors; and reduced airway remodeling. The treatment induced regulatory T cell responses, as shown by increased Il10 and Foxp3 transcription in lung tissue, and augmented Foxp3 protein expression in blood CD4+CD25+Foxp3+ T cells. This specific combination of beneficial bacteria with non-digestible oligosaccharides has strong anti-inflammatory properties, possibly via the induction of a regulatory T cell response, resulting in reduced airway remodeling and, therefore, may be beneficial in the treatment of chronic inflammation in allergic asthma.

Allergen-specific immunotherapy in asthmatic children: from the basis to clinical applications

Atopic asthma in childhood with the tendency to persist into adult life is an important issue in pediatrics. Allergen-specific immunotherapy (SIT) is the only curative treatment option for these children, being directed to the causes of the disease. The Th2 phenotype is a predominant immunological pattern in atopic asthma and SIT leads to apoptosis/anergy of T cells and induces immune-regulatory responses and immune deviation towards Th1. Many factors can affect the safety and efficacy of SIT, such as pattern of sensitization, allergy vaccine (allergen extracts, adjuvants and conjugated molecules), route of administration (subcutaneous or sublingual) and different treatment schedules. Overall, asthma symptoms and medication scores usually decrease following a SIT course and the most common observed side effects are restricted to local swelling, erythema and pruritus. Compared with conventional pharmacotherapy, SIT may be more cost effective, providing a benefit after discontinuation and a steroid-sparing effect. In addition, it can prevent new sensitizations in monosensitized asthmatic children. Microbial supplements such as probiotics, immunomodulatory substances like anti-IgE/leukotrienes, antibodies and newer allergen preparations such as recombinant forms have been tested to improve the efficacy and safety of SIT with inconclusive results. In conclusion, SIT provides an appropriate solution for childhood asthma that should be employed more often in clinical practice. Further studies are awaited to improve current knowledge regarding the mechanisms behind SIT and determine the most appropriate materials and schedule of immunotherapy for children with asthma.

MicroRNAs act complementarily to regulate disease-related mRNA modules in human diseases

MicroRNAs (miRNAs) play a key role in regulating mRNA expression, and individual miRNAs have been proposed as diagnostic and therapeutic candidates. The identification of such candidates is complicated by the involvement of multiple miRNAs and mRNAs as well as unknown disease topology of the miRNAs. Here, we investigated if disease-associated miRNAs regulate modules of disease-associated mRNAs, if those miRNAs act complementarily or synergistically, and if single or combinations of miRNAs can be targeted to alter module functions. We first analyzed publicly available miRNA and mRNA expression data for five different diseases. Integrated target prediction and network-based analysis showed that the miRNAs regulated modules of disease-relevant genes. Most of the miRNAs acted complementarily to regulate multiple mRNAs. To functionally test these findings, we repeated the analysis using our own miRNA and mRNA expression data from CD4+ T cells from patients with seasonal allergic rhinitis. This is a good model of complex diseases because of its well-defined phenotype and pathogenesis. Combined computational and functional studies confirmed that miRNAs mainly acted complementarily and that a combination of two complementary miRNAs, miR-223 and miR-139-3p, could be targeted to alter disease-relevant module functions, namely, the release of type 2 helper T-cell (Th2) cytokines. Taken together, our findings indicate that miRNAs act complementarily to regulate modules of disease-related mRNAs and can be targeted to alter disease-relevant functions.

Differential regulation of inflammation and immunity in mild and severe experimental asthma

This study aimed at exploring innate and adaptive immunity in allergic asthma by investigation of mRNA expression of pattern recognition receptors, T-cell-specific cytokines, and transcription factors. Mouse models for mild and severe asthma, with similar pathological characteristics observed in humans, were used to study the involved inflammatory markers as a first step in the development of phenotype-directed treatment approaches. In the mild model, mice were sensitized to ovalbumin-Imject Alum and challenged with ovalbumin. In the severe model, mice were sensitized to trinitrophenyl-conjugated ovalbumin and challenged with trinitrophenyl-ovalbumin/IgE immune complex. Pulmonary airway inflammation and mRNA expression of Toll-like receptors (TLRs), NOD-like receptors (NLRs), T cell cytokines, and transcription factors in lung tissue were examined. Different mRNA expression profiles of TLRs, NLRs, T cell cytokines, and transcription factors were observed. In the mild model, Il10 showed the largest increase in expression, whereas in the severe model, it was Infγ with the largest increase. Expression of Tbet was also significantly increased in the severe model. Inflammation and immunity are differentially regulated in mild and severe experimental asthma. This preclinical data may help in directing clinical research towards a better understanding and therapy in mild and severe asthmatic patients.

Differential effects of dexamethasone and itraconazole on Aspergillus fumigatus-exacerbated allergic airway inflammation in a murine model of mite-sensitized asthma

BACKGROUND

Fungal exposure is associated with particularly severe asthma. Nevertheless, the effects of anti-fungal treatments on fungus-exacerbated asthma need to be determined.

OBJECTIVES

The present study aimed to compare the effects of itraconazole (ITCZ) and dexamethasone (Dex) on Aspergillus fumigatus (Af)-exacerbated preexisting Dermatophagoides farinae (Df) allergen-sensitized allergic airway inflammation.

METHODS

Four groups of BALB/c mice were prepared: control, Df-sensitized plus Af-infected mice (Df-Af), and Df-Af mice treated with Dex (Df-Af-Dex) or with ITCZ (Df-Af-ITCZ). Pulmonary pathology and cytokine profiles in the airway were evaluated. In a different set of experiments, the effects of Dex on alveolar macrophage (AM) phagocytosis of Af conidia were determined in Df-sensitized mice.

RESULTS

Af infection significantly increased the level of eosinophils and neutrophils in the airway of Df-sensitized mice. While Dex significantly decreased eosinophils, ITCZ significantly decreased both eosinophils and neutrophils in Df-Af mice. Dex significantly decreased IL-5, whereas ITCZ significantly reduced MIP-2 in the airway. Compared to controls, AM isolated from Df-sensitized mice had significantly reduced phagocytotic activity of Af conidia. However, Dex significantly improved phagocytotic activity of AM in Df-sensitized mice.

CONCLUSIONS

The present study showed that Dex and ITCZ differently regulated Af-exacerbated allergic airway inflammation; the former inhibits eosinophilic inflammation and the latter inhibits neutrophilic as well as eosinophilic inflammation by regulating different cytokines. Additionally, Dex enhanced the phagocytotic activity of AM in allergic asthma. Thus, a combination of Dex and ITCZ might be effective for the management of fungus-exacerbated asthma.

Mfge8 suppresses airway hyperresponsiveness in asthma by regulating smooth muscle contraction

Airway obstruction is a hallmark of allergic asthma and is caused primarily by airway smooth muscle (ASM) hypercontractility. Airway inflammation leads to the release of cytokines that enhance ASM contraction by increasing ras homolog gene family, member A (RhoA) activity. The protective mechanisms that prevent or attenuate the increase in RhoA activity have not been well studied. Here, we report that mice lacking the gene that encodes the protein Milk Fat Globule-EGF factor 8 (Mfge8(-/-)) develop exaggerated airway hyperresponsiveness in experimental models of asthma. Mfge8(-/-) ASM had enhanced contraction after treatment with IL-13, IL-17A, or TNF-α. Recombinant Mfge8 reduced contraction in murine and human ASM treated with IL-13. Mfge8 inhibited IL-13-induced NF-κB activation and induction of RhoA. Mfge8 also inhibited rapid activation of RhoA, an effect that was eliminated by an inactivating point mutation in the RGD integrin-binding site in recombinant Mfge8. Human subjects with asthma had decreased Mfge8 expression in airway biopsies compared with healthy controls. These data indicate that Mfge8 binding to integrin receptors on ASM opposes the effect of allergic inflammation on RhoA activity and identify a pathway for specific inhibition of ASM hypercontractility in asthma.

Advances in pediatric asthma in 2012: moving toward asthma prevention

Last year's "Advances in pediatric asthma: moving forward" concluded the following: "Now is also the time to utilize information recorded in electronic medical records to develop innovative disease management plans that will track asthma over time and enable timely decisions on interventions in order to maintain control that can lead to disease remission and prevention." This year's summary will focus on recent advances in pediatric asthma on modifying disease activity, preventing asthma exacerbations, managing severe asthma, and risk factors for predicting and managing early asthma, as indicated in Journal of Allergy and Clinical Immunology publications in 2012. Recent reports continue to shed light on methods to improve asthma management through steps to assess disease activity, tools to standardize outcome measures in asthma, genetic markers that predict risk for asthma and appropriate treatment, and interventions that alter the early presentation of asthma to prevent progression. We are well on our way to creating a pathway around wellness in asthma care and also to use new tools to predict the risk for asthma and take steps to not only prevent asthma exacerbations but also to prevent the early manifestations of the disease and thus prevent its evolution to severe asthma.

Iron supplementation decreases severity of allergic inflammation in murine lung

The incidence and severity of allergic asthma have increased over the last century, particularly in the United States and other developed countries. This time frame was characterized by marked environmental changes, including enhanced hygiene, decreased pathogen exposure, increased exposure to inhaled pollutants, and changes in diet. Although iron is well-known to participate in critical biologic processes such as oxygen transport, energy generation, and host defense, iron deficiency remains common in the United States and world-wide. The purpose of these studies was to determine how dietary iron supplementation affected the severity of allergic inflammation in the lungs, using a classic model of IgE-mediated allergy in mice. Results showed that mice fed an iron-supplemented diet had markedly decreased allergen-induced airway hyperreactivity, eosinophil infiltration, and production of pro-inflammatory cytokines, compared with control mice on an unsupplemented diet that generated mild iron deficiency but not anemia. In vitro, iron supplementation decreased mast cell granule content, IgE-triggered degranulation, and production of pro-inflammatory cytokines post-degranulation. Taken together, these studies show that iron supplementation can decrease the severity of allergic inflammation in the lung, potentially via multiple mechanisms that affect mast cell activity. Further studies are indicated to determine the potential of iron supplementation to modulate the clinical severity of allergic diseases in humans.

Epoxyeicosatrienoic acids are involved in the C(70) fullerene derivative-induced control of allergic asthma

BACKGROUND

Fullerenes are molecules being investigated for a wide range of therapeutic applications. We have shown previously that certain fullerene derivatives (FDs) inhibit mast cell (MC) function in vitro, and here we examine their in vivo therapeutic effect on asthma, a disease in which MCs play a predominant role.

OBJECTIVE

We sought to determine whether an efficient MC-stabilizing FD (C(70)-tetraglycolate [TGA]) can inhibit asthma pathogenesis in vivo and to examine its in vivo mechanism of action.

METHODS

Asthma was induced in mice, and animals were treated intranasally with TGA either simultaneously with treatment or after induction of pathogenesis. The efficacy of TGA was determined through the measurement of airway inflammation, bronchoconstriction, serum IgE levels, and bronchoalveolar lavage fluid cytokine and eicosanoid levels.

RESULTS

We found that TGA-treated mice have significantly reduced airway inflammation, eosinophilia, and bronchoconstriction. The TGA treatments are effective, even when given after disease is established. Moreover, we report a novel inhibitory mechanism because TGA stimulates the production of an anti-inflammatory P-450 eicosanoid metabolites (cis-epoxyeicosatrienoic acids [EETs]) in the lung. Inhibitors of these anti-inflammatory EETs reversed TGA inhibition. In human lung MCs incubated with TGA, there was a significant upregulation of CYP1B gene expression, and TGA also reduced IgE production from B cells. Lastly, MCs incubated with EET and challenged through FcεRI had a significant blunting of mediator release compared with nontreated cells.

CONCLUSION

The inhibitory capabilities of TGA reported here suggest that FDs might be used a platform for developing treatments for asthma.