Th17 and allergy

Bupleurum chinense extract ameliorates an OVA-induced murine allergic asthma through the reduction of the Th2 and Th17 cytokines production by inactivation of NFκB pathway

Bupleurum chinense belongs to the Bupleurum spp. family that has been used in traditional herbal medicine for over thousand years. It has been reported to have anti-inflammatory, anti-oxidant, hepato-protective, antipyretic, analgesic, anti-fibrotic and immunomodulatory effect. However, the effect of B. Chinense on allergic asthma remains unclear. This study investigated the immunomodulatory effects of B. Chinense extracts (BCE) on airway inflammation in asthmatic mice model. In the ovalbumin (OVA)-induced allergic asthma model, we evaluated the number of total cells, differential inflammatory cells and the production of proinflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung homogenate as well as histological structure. The levels of NFκB p65, IκBα, p-NFκB p65, p-IκBα and the total immunoglobulin (Ig) E, anti-OVA IgE, anti-OVA IgG were also examined. The oral administration of 200mg/kg BCE inhibited the accumulation of inflammatory cells especially eosinophils in BALF. Also, BCE regulated the imbalance of Th1, Th2 and Th17-related production, with attenuated the expression of GATA3, IL-1β, IL-4, IL-5, IL-6, TNF-α and RORγt, IL-17A in BALF and lung homogenate, meanwhile, up-regulated the secretion of INF-γ in lung homogenate. The levels of IgE, anti-OVA IgE, anti-OVA IgG1 and anti-OVA IgG2a were also suppressed by BCE treatment in serum. Futhermore, BCE inhibited the proinflammatory cytokines via inactivation of NFκB p65 phosphorylation and IκBα degradation in cytoplasm. The histological analysis showed that the infiltration of inflammatory cells, mucus hypersecretion and collagen fiber deposits were ameliorated in BCE treated mice. In addition, BCE induced the functional differentiation of naive CD4+ T cells forward to Th1 and Tr1 through producing INF-γ and IL-10. These results suggest that BCE may have therapeutic potential for treating allergic asthma through inhibiting Th2/Th17 cytokines production by inactivation of NFκB pathway.

Polysaccharide extracted from Chinese white wax scale ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like symptoms in BALB/c mice

Atopic dermatitis (AD) is a common inflammatory skin disease with high rates of morbidity and is associated with erythema, pruritus, scaling of affected areas of skin. It is extremely important to introduce a therapeutic agent which has significant anti-inflammatory effect with less side-effect for treatment of AD. This study evaluated the effect of a natural compound from herbal extracts, the crude polysaccharide extracted from the white wax scale (CWPS), on AD-like mice. Repeated applications of 2,4-dinitrochlorobenzene (DNCB) were performed on ear and dorsal skin of BALB/c mice to induce AD-like symptoms and skin lesions. Oral administration of CWPS decreased serum IgE level and limited the infiltration of mast cells and eosinophils to the dermal tissues in the DNCB-induced AD mice. In addition, CWPS reduced Th1 and Th17 responses, leading to an attenuated cutaneous inflammatory response. Furthermore, in vitro study also demonstrated that CWPS limited T cell activation and cytokines (i.e. IFN-γ and IL-17) production induced by DNCB. We conclude that CWPS attenuates DNCB-induced AD-like skin lesion through modulating T cell-elicited immune responses and CD4+ T cell polarization, and could be exploited as a new therapeutic approach for AD.

Caveolin-1 Promotes the Imbalance of Th17/Treg in Patients with Chronic Obstructive Pulmonary Disease

The imbalance of Th17/Treg cells plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Caveolin-1 (Cav-1) has been regarded as a potential critical regulatory protein in pathological mechanisms of chronic inflammatory respiratory diseases. Therefore, we investigated whether the loss of Cav-1 is involved in the homeostasis of Th17/Treg cells in COPD. We examined the expressions of plasma Cav-1 and circulating Th17, Treg cells, and the related cytokines in patients with COPD. Enzyme-linked immunosorbent assay (ELISA) analyses showed a significant reduction of plasma Cav-1 levels in patients with stable COPD (SCOPD) and acutely exacerbated COPD (AECOPD) compared to smokers without COPD. This loss was associated with an increase in frequency of Treg and decreased in frequency of Th17 cells. To further identify the role of Cav-1, we studied the effects of Cav-1 overexpression or downregulation on frequencies of Treg and Th17 cells in peripheral blood mononuclear cells (PBMCs) from subjects. Interestingly, small interfering RNA (siRNA) downregulation of Cav-1 was accompanied by an augmentation of Treg and reduction of Th17 expression. Together, our study demonstrated that the loss of Cav-1 contributed to the imbalance of Th17/Treg cells in patients with COPD.

Role of Interleukin-17A on the Chemotactic Responses to CCL7 in a Murine Allergic Rhinitis Model

BACKGROUND

The proinflammatory cytokine interleukin (IL)-17A is associated with eosinophil infiltration into the nasal mucosa in a mouse model of ovalbumin-induced allergic rhinitis. Chemotaxis of eosinophils is mediated primarily through C-C chemokine receptor type 3 (CCR3). However, the mechanism underlying the IL-17A-mediated enhancement of eosinophil recruitment via chemoattractants/chemokines remains unknown.

OBJECTIVES

In this study, we assessed the contribution of IL-17A to eosinophil-related inflammation via the CCL7/CCR3 pathway in experimental allergic rhinitis.

METHODS

IL-17A knockout (KO) and wild-type (WT) BALB/c mice were injected intraperitoneally and challenged intranasally with OVA to induce allergic rhinitis. Various parameters of the allergic response were evaluated, and mRNA and protein levels of CCL7 and CCR3 in nasal tissue and serum were compared between the two groups. The chemotactic response to CCL7 with or without IL-17A in bone marrow-derived eosinophils (bmEos) from BALB/c mice was measured.

RESULTS

In the allergic rhinitis model, IL-17A deficiency significantly decreased nasal symptoms, serum IgE levels, and eosinophil recruitment to the nasal mucosa. CCL7 and CCR3 mRNA and protein levels were decreased in the nasal mucosa of IL-17A KO mice compared with the WT mice. BmEos showed a significantly increased chemotactic response to -low concentration of CCL7 in the presence of IL-17A compared with its absence.

CONCLUSION

The suppression of nasal inflammation due of IL-17A deficiency in allergic rhinitis is partly responsible for the regulation of CCL7 secretion and eosinophil infiltration, which may be regulated via the CCL7/CCR3 pathway.

The Role of IL-17 in a Lipopolysaccharide-Induced Rhinitis Model

Purpose

Lipopolysaccharide (LPS) is a cell wall component of Gram-negative bacteria and important for pro-inflammatory mediators. This study aimed to establish a rhinitis model using ovalbumin (OVA) and LPS in order to evaluate the role of interleukin (IL)-17 in the pathogenesis of an LPS-induced non-eosionophilic rhinitis model.

Methods

Mice were divided into 4 groups and each group consisted of 10 mice (negative control group, allergic rhinitis model group, 1-µg LPS treatment group, and 10-µg LPS treatment group). BALB/c mice were sensitized with OVA and 1 or 10 µg of LPS, and challenged intranasally with OVA. Multiple parameters of rhinitis were also evaluated to establish the LPS-induced rhinitis model. IL-17 knockout mice were used to check if the LPS-induced rhinitis model were dependent on IL-17. Eosinophil and neutrophil infiltration, and mRNA and protein expression profiles of cytokine in nasal mucosa or spleen cell culture were evaluated using molecular, biochemical, histopathological, and immunohistological methods.

Results

In the LPS-induced rhinitis model, neutrophil infiltration increased in the nasal mucosa, and systemic and nasal IL-17 and interferon-gamma (IFN-γ) levels also increased as compared with the OVA-induced allergic rhinitis model. These findings were LPS-dose-dependent. In IL-17 knockout mice, those phenotypes (neutrophil infiltration, IL-17, and IFN-γ) were reversed, showing IL-17 dependency of LPS-induced rhinitis. The expression of vascular endothelial growth factor (VEGF), an important mediator for inflammation and angiogenesis, decreased in IL-17 knockout mice, showing the relationship between IL-17 and VEGF.

Conclusions

This study established an LPS-induced rhinitis model dependent on IL-17, characterized by neutrophil infiltration and increased expression of IL-17.

Atopy and Inhaled Corticosteroid Use Associate with Fewer IL-17+ Cells in Asthmatic Airways

Background

Interleukin (IL)-17 plays a critical role in numerous immune and inflammatory responses and was recently suggested to contribute to the pathogenesis of nonatopic (non-eosinophil/neutrophil-dominant) asthma. We aimed to compare expression of IL-17 in bronchial airways between atopic and nonatopic asthmatics, with/without inhaled corticosteroid (ICS) use and to identify its major cellular source.

Methods

Bronchial biopsies from 114 patients with mild-to-moderate asthma were investigated: 33 nonatopic, 63 non-corticosteroid users, 90 nonsmokers. IL-17 expression was correlated with atopy and inflammatory cell counts (EPX, NP57, CD3, CD4, CD8, CD20, CD68), taking ICS use and smoking into account. Multiple linear regression analyses were used to determine the independent factors as well as the most relevant inflammatory cells contributing to IL-17 expression. Double immunostainings were performed to confirm the major cellular source of IL-17.

Results

In non-ICS users, nonatopic asthmatics had more IL-17⁺ cells in the airway wall than atopic asthmatics. In both atopic and nonatopic asthmatics, ICS use was associated with lower numbers of IL-17⁺ cells, independent of smoking. The number of IL-17⁺ cells was associated with the number of neutrophils (B: 0.26, 95% CI: 0.17–0.35) and eosinophils (B: 0.18, 95% CI: 0.07–0.29). The majority of IL-17⁺ cells were neutrophils, as confirmed by double immunostaining.

Conclusions

We show for the first time that atopy and ICS use are associated with lower numbers of IL-17⁺ cells in asthmatic airways. Importantly, IL-17⁺ cells were mostly neutrophils which conflicts with the paradigm that lymphocytes (Th17) are the main source of IL-17.

The Study of Interleukin-17 Level in Vernal Keratoconjunctivitis Disease and its Relationship between Symptom and Sign Severity

INTRODUCTION

Vernal keratoconjunctivitis (VKC) is a bilateral multi-factorial disease. The pathogenesis of this disease is not obviously determined, but the role of various inflammatory cytokines has been specified. This study has provided a comparison between the level of interleukin-17 (IL17) in the serum and tears of case and control groups, and also the relationship between the level of this interleukin with severity of signs and symptoms of the disease.

MATERIALS AND METHODS

This case-control study has been accomplished on 40 individuals (20 healthy people and 20 patients who suffer from VKC) in Al-Zahra Eye Center in 2014. The level of interleukin was isolated in an individual's tear by Schirmer strips; moreover, serum interleukin has been measured.

RESULTS

The average of interleukin 17 in serum in the case group was 25.5±4.1 pg/dl and in the control group was 12.5±5.7 pg/dl. The average of interleukin 17 in the case group was 259.6±91.4 pg/dl in the tear and was 50.6±20.8 pg/dl for the control group; the signs and symptoms of the IL-17 disease were associated with the severity of Trantas dots.

CONCLUSIONS

Interleukin-17 has a role in the pathogenesis of VKC and also has been proven in the former studies.

Chinese herbal medicine formula Gu-Ben-Fang-Xiao-Tang attenuates airway inflammation by modulating Th17/Treg balance in an ovalbumin-induced murine asthma model

Gu-Ben-Fang-Xiao-Tang (GBFXT) is a traditional Chinese medicine formula consisting of 11 medicinal plants, which has been used in the treatment of asthma. The present study aimed to determine the protective effects and the underlying mechanisms of GBFXT on ovalbumin (OVA)-induced allergic inflammation in a mouse model of allergic asthma. A total of 50 mice were randomly assigned to the following five experimental groups: Normal, model, montelukast (2.6 mg/kg), 12 g/kg GBFXT and 36 g/kg GBFXT groups. Airway responsiveness was measured using the forced oscillation technique, while differential cell count in the bronchoalveolar lavage fluid (BALF) was measured by Wright-Giemsa staining. Histological assessment was performed by hematoxylin and eosin staining, while BALF levels of Th17/Treg cytokines were measured by enzyme-linked immunosorbent assay, and the proportions of Th17 and Treg cells were evaluated by flow cytometry. The results showed that GBFXT suppressed airway hyperresponsiveness during methacholine-induced constriction, reduced the percentage of leukocytes and eosinophils, and resulted in decreased absolute neutrophil infiltration in lung tissue. In addition, GBFXT treatment significantly decreased the IL-17A cytokine level and increased the IL-10 cytokine level in the BALF. Furthermore, GBFXT significantly suppressed Th17 cells and increased Treg cells in asthmatic mice. In conclusion, the current results demonstrated that GBFXT may effectively inhibit the progression of airway inflammation in allergic asthma, partially by modulating the Th17/Treg cell balance.

Role of interleukin-17A in early graft rejection after orthotopic lung transplantation in mice

BACKGROUND

The cellular and molecular mechanisms underlying lung allograft rejection remain poorly understood. We investigated the potential role of interleukin (IL)-17A in lung transplant rejection in a mouse model, because previous studies in clinical and rodent models have implicated IL-17A in both acute and chronic rejection.

METHODS

To generate an orthotopic lung transplantation model, lungs from C57BL/6 or BALB/c mice were transplanted into C57BL/6 mice (isograft and allograft models, respectively). The effects of anti-IL-17A treatment in allograft recipients were investigated. The histological features and rejection status of isografts and allografts were assessed at 3, 7, and 28 days after transplantation, and differences in graft infiltrating cells and mRNA expression of relevant cytokines were quantified at 3 and 7 days after transplantation.

RESULTS

As expected, isografts showed no obvious signs of rejection, whereas allografts exhibited minimal-to-mild rejection (grade A1-A2) by day 3 and moderate-to-severe rejection (grade A3-A4) by day 7, without evidence of obliterative bronchiolitis (OB). However, by 28 days, evidence of OB was observed in 67% (2/3) of allografts and severe rejection (grade A4) was observed in all. IL-17 mRNA expression in allografts was increased with rejection, and interferon (IFN)-γ and IL-6 mRNA expression levels followed a similar pattern. In contrast, IL-22 expression in allografts was only slightly increased. Antibody (Ab) neutralization of IL-17A diminished the signs of acute rejection at 7 days after transplantation in allografts, and this early protection was accompanied by a decrease in cellular stress according to histological evaluation, suggesting the involvement of IL-17A in the development of early post-transplantation lesions.

CONCLUSIONS

Our data indicate that IL-17A is important in the pathophysiology of allograft rejection, and neutralization of IL-17A is a potential therapeutic strategy to preventing lung transplant rejection.

Paeoniflorin suppresses IL-6/Stat3 pathway via upregulation of Socs3 in dendritic cells in response to 1-chloro-2,4-dinitrobenze

Mounting evidence has suggested that inflammation is associated with IL-6/Stat3 pathway in dendritic cells (DCs) and Th17 cells, which are critical for development of allergic contact dermatitis (ACD). Paeoniflorin (PF) has been clinically proved to be effective in the treatment of inflammatory skin diseases such as ACD. We have previously demonstrated the effect of PF on DCs stimulated with 1-chloro-2,4-dinitrobenze (DNCB) and naïve CD4(+)CD45RA(+) T cells for Th17 cell differentiation. However, whether PF down-regulates IL-6/Stat3 in DCs and Th17 cells remains to be explored. In this study, we show clearly that PF markedly decreases IL-6/Stat3 in DCs stimulated with DNCB at both gene and protein levels compared with control DCs in vitro. Meanwhile, PF up-regulates suppressor of cytokine signaling 3 (Socs3). Such decreased expression of IL-6/Stat3 is abolished in DCs that were transfected with Socs3 short interfering RNA (siRNA). When mice CD4(+)CD45 RA(+) T cells were co-cultured with PF-treated DCs stimulated with/without DNCB, the gene expression of the Th17 cell markers such as retinoic acid-related orphan nuclear hormone receptor γt (RORγt), IL-17A, and IL-23R decreased, in accordance with the less secretions of IL-17 and IL-23 in vitro and in vivo. Finally, the suppressed Th17 differentiation induced by PF can be abolished by additional recombinant mouse IL-6. Our results suggest that the anti-inflammatory mechanisms introduced by depletion of Socs3 expression or inactivation of the negative regulator such as Socs3 may represent a promising strategy for the prevention of ACD.

Regulatory roles of mast cells in immune responses

Mast cells are important immune cells for host defense through activation of innate immunity (via toll-like receptors or complement receptors) and acquired immunity (via FcεRI). Conversely, mast cells also act as effector cells that exacerbate development of allergic or autoimmune disorders. Yet, several lines of evidence show that mast cells act as regulatory cells to suppress certain inflammatory diseases. Here, we review the mechanisms by which mast cells suppress diseases.

CXCR4 inhibitor attenuates ovalbumin-induced airway inflammation and hyperresponsiveness by inhibiting Th17 and Tc17 cell immune response

Accumulating evidence suggests that chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor chemokine (C-X-C motif) receptor 4 (CXCR4) may contribute to the pathogenesis of allergic asthma. However, the underlying molecular mechanisms remain to be fully understood. T-helper 17 cells (Th17) and T-cytotoxic 17 cells (Tc17) have been implicated in the development of several allergic disorders, including asthma. The present study aimed to explore the association between CXCL12 signaling and Th17/Tc17 cells in the development of asthma. Ovalbumin (OVA)-sensitized BALB/c mice were treated with AMD3100, a specific CXCR4 antagonist, prior to OVA challenge. Following the final allergen (OVA) challenge, airway responsiveness to methacholine, influx of inflammatory cells to the airway, and cytokine levels in the bronchoalveolar lavage fluids (BALF) and lung homogenate were assessed. Interleukin (IL)-17-expressing CD3⁺CD8^- lymphocytes (Th17 cells) and IL-17⁺CD3⁺CD8⁺ lymphocytes (Tc17 cells) isolated from lung tissue samples were detected by flow cytometry. The results of the present study demonstrated that administration of AMD3100 significantly decreased airway responsiveness to methacholine, attenuated the influx of inflammatory cells to the airway and reduced the levels of IL-4, IL-5 and IL-13 in the BALF. Furthermore, AMD3100 significantly reduced the increased number of lung Th17 and Tc17 cells as well as the levels of IL-17 in the lung homogenate induced by OVA challenge. In conclusion, the CXCR4 inhibitor suppresses the asthmatic response, which is associated with attenuation of the Th17 and Tc17 cell immune response.

Antibiotics and the Human Gut Microbiome: Dysbioses and Accumulation of Resistances

The human microbiome is overly exposed to antibiotics, due, not only to their medical use, but also to their utilization in farm animals and crops. Microbiome composition can be rapidly altered by exposure to antibiotics, with potential immediate effects on health, for instance through the selection of resistant opportunistic pathogens that can cause acute disease. Microbiome alterations induced by antibiotics can also indirectly affect health in the long-term. The mutualistic microbes in the human body interact with many physiological processes, and participate in the regulation of immune and metabolic homeostasis. Therefore, antibiotic exposure can alter many basic physiological equilibria, promoting long-term disease. In addition, excessive antibiotic use fosters bacterial resistance, and the overly exposed human microbiome has become a significant reservoir of resistance genes, contributing to the increasing difficulty in controlling bacterial infections. Here, the complex relationships between antibiotics and the human microbiome are reviewed, with focus on the intestinal microbiota, addressing (1) the effects of antibiotic use on the composition and function of the gut microbiota, (2) the impact of antibiotic-induced microbiota alterations on immunity, metabolism, and health, and (3) the role of the gut microbiota as a reservoir of antibiotic resistances.

Expression of IL-17A concentration and effector functions of peripheral blood neutrophils in food allergy hypersensitivity patients

Lymphocytes Th17 and other types of immune system cells produce IL17. By induction of cytokines and chemokines, the IL17 cytokine is involved in mechanisms of allergic reaction with participation of neutrophil granulocytes. It affects activation, recruitment, and migration of neutrophils to the tissues, regulating inflammatory reaction intensity. Excited neutrophils secrete inter alia elastase and reactive oxygen species (ROS)--significant mediators of inflammation process responsible for tissues damage.The aim of the study was to evaluate the concentrations of serum interleukin 17A, serum neutrophil elastase, and ROS production by neutrophils in patients with food allergy.The study included 30 patients with food allergy diagnosed based on interview, clinical symptoms, positive SPT, placebo controlled double-blind oral provocation trial, and the presence of asIgE in blood serum against selected food allergens using fluoro-immuno-enzymatic method FEIA UNICap 100. The control group consisted of 10 healthy volunteers. The concentrations of IL17A were determined in all patients using ELISA method with eBioscience kits, and elastase using BenderMed Systems kits. Chemiluminescence of non-stimulated neutrophils was evaluated using luminol-dependent kinetic method for 40 min on Luminoskan (Labsystems luminometer).The results of serum IL-17A concentrations and the values of chemiluminescence obtained by non-activated neutrophils, as well as elastase concentrations, were higher in patients with food allergic hypersensitivity compared to healthy volunteers.This study demonstrates a significance of IL-17A and activated neutrophil granulocytes in the course of diseases with food allergic hypersensitivity.

Advances in asthma pathophysiology: stepping forward from the Maurizio Vignola experience

Maurizio Vignola was a superb and innovative researcher, who wrote seminal papers on the biology of airway epithelium in asthma. Inflammation and remodelling were the main topics of his research, mostly conducted in biopsy specimens from patients with asthma of variable severity, encompassing the entire spectrum of the disease from mild to severe asthma. His observations contributed to define the biology of asthma as we know it today, and opened the way to the personalised treatment of asthma. His group has successfully continued to investigate the biology and clinical aspects of bronchial asthma, with major interest in the clinical use of biomarkers to monitor disease activity, and in the development of new therapeutic perspectives. This review summarises the latest work on these topics proudly conducted by Maurizio's closest collaborators. The results indicate significant progress in our understanding of asthma in the last 10 years, in particular increased knowledge of the complex interaction between inflammatory and remodelling pathways, improved recognition of biological and clinical asthma phenotypes, and development of new treatment strategies, especially for patients with severe corticosteroid-resistant asthma.

Biomarkers may help to define disease phenotypes and new treatment strategies for asthmahttp://ow.ly/G2Fl6

Th17 response and its regulation in inflammatory upper airway diseases

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) are two widely prevalent inflammatory diseases in the upper airways. T cell immunity has been suggested to play an important pathogenic role in many chronic inflammatory diseases including inflammatory upper airway diseases. Inappropriate CD4(+) T cell responses, especially the dysregulation of the Th1/Th2 balance leading to excessive Th1 or Th2 cell activation, have been associated with allergic rhinitis and chronic rhinosinusitis. Nevertheless, recent studies suggest that IL-17A and IL-17A-producing Th17 cell subset, a distinct pro-inflammatory CD4(+) T cell lineage, may also play an important role in the pathophysiology of inflammatory upper airway diseases. Th17 cells may promote both eosinophilic and neutrophilic inflammation in AR and CRS. In addition, a few, but accumulating evidence shows that the Th17 responses can be tightly regulated by endogenous and exogenous substances in the context of AR and CRS. This review discusses recent advances in our understanding of the expression and function of the Th17 response and its regulation in inflammatory upper airway diseases, and the perspective for future investigation and clinical utility.

Cytokine profiles in nasal fluid of patients with seasonal or persistent allergic rhinitis

Background

New therapeutic approaches with biologic agents such as anti-cytokine antibodies are currently on trial for the treatment of asthma, rhinosinusitis or allergic diseases necessitating patient selection by biomarkers. Allergic rhinitis (AR), affecting about 20 % of the Canadian population, is an inflammatory disease characterised by a disequilibrium of T-lymphocytes and tissue eosinophilia. Aim of the present study was to describe distinct cytokine patterns in nasal secretion between seasonal and perennial AR (SAR/PAR), and healthy controls by comparing cytokines regulating T-cells or stimulating inflammatory cells, and chemokines.

Methods

Nasal secretions of 44 participants suffering from SAR, 45 participants with PAR and 48 healthy controls were gained using the cotton wool method, and analysed for IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, GM-CSF, G-CSF, IFN-γ, MCP-1, MIP-1α, MIP-1β, eotaxin, and RANTES by Bio-Plex Cytokine Assay as well as for ECP and tryptase by UniCAP-FEIA.

Results

Participants with SAR or PAR presented elevated levels of tryptase, ECP, MCP-1, and MIP-1β, while values of GM-CSF, G-CSF, IL-1β, and IL-6 did not differ from the controls. Increased levels of IL-5, eotaxin, MIP-1α, and IL-17 and decreased levels of IFN-γ, IL-12 and IL-10 were found in SAR only. RANTES was elevated in SAR in comparison to PAR. Interestingly, we found reduced levels of IL-4 in PAR and of IL-13 in SAR.

Conclusions

Elevated levels of proinflammatory cytokines were seen in both disease entities. They were, however, more pronounced in SAR, indicating a higher degree of inflammation. This study suggests a downregulation of T_H1 and T_reg-lymphocytes and an upregulation of T_H17 in SAR. Moreover, the results display a prominent role of eosinophils and mast cells in AR. The observed distinct cytokine profiles in nasal secretion may prove useful as a diagnostic tool helping to match patients to antibody therapies.

Hyperoxia promotes polarization of the immune response in ovalbumin-induced airway inflammation, leading to a TH17 cell phenotype

Previous studies have demonstrated that hyperoxia-induced stress and oxidative damage to the lungs of mice lead to an increase in IL-6, TNF-α, and TGF-β expression. Together, IL-6 and TGF-β have been known to direct T cell differentiation toward the TH17 phenotype. In the current study, we tested the hypothesis that hyperoxia promotes the polarization of T cells to the TH17 cell phenotype in response to ovalbumin-induced acute airway inflammation. Airway inflammation was induced in female BALB/c mice by intraperitoneal sensitization and intranasal introduction of ovalbumin, followed by challenge methacholine. After the methacholine challenge, animals were exposed to hyperoxic conditions in an inhalation chamber for 24 h. The controls were subjected to normoxia or aluminum hydroxide dissolved in phosphate buffered saline. After 24 h of hyperoxia, the number of macrophages and lymphocytes decreased in animals with ovalbumin-induced airway inflammation, whereas the number of neutrophils increased after ovalbumin-induced airway inflammation. The results showed that expression of Nrf2, iNOS, T-bet and IL-17 increased after 24 of hyperoxia in both alveolar macrophages and in lung epithelial cells, compared with both animals that remained in room air, and animals with ovalbumin-induced airway inflammation. Hyperoxia alone without the induction of airway inflammation lead to increased levels of TNF-α and CCL5, whereas hyperoxia after inflammation lead to decreased CCL2 levels. Histological evidence of extravasation of inflammatory cells into the perivascular and peribronchial regions of the lungs was observed after pulmonary inflammation and hyperoxia. Hyperoxia promotes polarization of the immune response toward the TH17 phenotype, resulting in tissue damage associated with oxidative stress, and the migration of neutrophils to the lung and airways. Elucidating the effect of hyperoxia on ovalbumin-induced acute airway inflammation is relevant to preventing or treating asthmatic patients that require oxygen supplementation to reverse the hypoxemia.

Th17/Treg balance in children with obstructive sleep apnea syndrome and the relationship with allergic rhinitis

OBJECTIVE

This study aims to explore the role of the Th17 to Treg cell ratio in children with OSA and its relationship with allergic rhinitis.

METHODS

The study included 127 children diagnosed with OSA by polysomnography (PSG) testing and 29 children without OSA. The 127 children with OSA were divided into the following groups: OSA with moderate adenoidal hypertrophy (n=47), OSA with severe adenoidal hypertrophy (n=49), and OSA complicated by allergic rhinitis (AR) (n=31). The adenoids of the 29 children without OSA were mildly hypertrophic. We measured the number of Th17 and Treg cells, the levels of related serum cytokines in cellular secretions, and the expression of key transcription factors in both the peripheral blood and adenoid tissue. The Th17/Treg ratio was calculated and analyzed between groups. The numbers of Th17 and Treg cells were measured by flow cytometry; the secreted IL-17, IL-10, and TGF-β were measured by ELISA; and the expression levels of RORγt and Foxp3 were measured by RT-PCR.

RESULTS

Compared with the control group, OSA children exhibited a significant increase in the number of peripheral Th17 cells, Th17-related cytokine secretion (IL-17), and RORγt mRNA levels, whereas they exhibited a decrease in the number of Treg cells, Treg-related cytokine secretions (IL-10, TGF-β) and Foxp3 mRNA levels. The Th17/Treg ratio was higher (p<0.05) in the OSA groups than in the control group. The Th17/Treg ratio was correlated with the size of the adenoids. We also found that the Th17/Treg balance in OSA patients was complicated by allergic rhinitis; the increase was significantly larger in the AR group (p<0.05, p=0.021) than in OSA groups without AR. These results were observed in both the peripheral blood and local adenoid tissue.

CONCLUSION

The Th17/Treg imbalance may increase the risk of developing OSA, and AR may promote the development of the disease. These results provide an alternative explanation for OSA pathogenesis that warrants additional research and presents new directions for the prevention and treatment of OSA in children.

Clinical Parameters vs Cytokine Profiles as Predictive Markers of IgE-Mediated Allergy in Young Children

Background

Allergy afflicts one third of children, negatively impacting their quality of life and generating a significant socio-economic burden. To this day, this disorder remains difficult to diagnose early in young patients, with no predictive test available.

Objective

This study was designed to correlate cytokine profiles with clinical phenotypes of allergy development.

Methods

Three hundred patients were recruited and followed from birth to 18 months of age. They were given a clinical exam at birth and at 2, 6, 12, and 18 months of age, with skin prick tests at 6, and 18 months, in order to have a record of their medical history and determine their allergic status. In addition, mononuclear cells from 131 patients were isolated from cord blood and from peripheral blood samples at 2, 6 and 18 months of age, to analyse their cytokine and chemokine production.

Results

Cord blood mononuclear cells (CBMCs) from future Immunoglobulin (Ig) E-mediated allergic children produced significantly less Interleukin (IL)-12p70 and IL-15 than cells from the rest of the cohort. Multivariate analyses revealed that the best predictive model of allergy was built on cytokine data, whereas the best predictive model of IgE-mediated allergy was built on clinical parameters.

Conclusions and clinical relevance

Although univariate analyses can yield interesting information regarding the immune responses of allergic children, finding predictive markers of the disorder will likely rely on monitoring multiple parameters. Nonetheless these analyses suggest a potential key role for IL-15 in the development of atopic disease. In addition, the study highlights the importance of clinical parameters in predicting the development of IgE-mediated allergy.

Risk of psoriasis in patients with childhood asthma: a Danish nationwide cohort study

BACKGROUND

Psoriasis and asthma are disorders driven by inflammation. Psoriasis may carry an increased risk of asthma, but the reverse relationship has not been investigated.

OBJECTIVES

To investigate the risk of psoriasis in subjects with childhood asthma in a nationwide Danish cohort.

METHODS

Data on all Danish individuals aged 6-14 years at study entry between 1 January 1997 and 31 December 2011 (n = 1,478,110) were linked at an individual level in nationwide registers. Incidence rates per 10,000 person-years were calculated, and incidence rate ratios (IRRs) adjusted for age, sex, concomitant medication and comorbidity were estimated by Poisson regression models.

RESULTS

There were 21,725 cases of childhood asthma and 6586 incident cases of psoriasis. There were 5697 and 889 incident cases of mild and severe psoriasis, respectively. The incidence rates of overall, mild and severe psoriasis were 4.49, 3.88 and 0.61 for the reference population, and 5.95, 5.18 and 0.83 for subjects with childhood asthma, respectively. The IRRs for overall, mild and severe psoriasis were 3.94 [95% confidence interval (CI) 2.16-7.17], 5.03 (95% CI 2.48-10.21) and 2.27 (95% CI 0.61-8.42) for patients with childhood asthma.

CONCLUSIONS

Childhood asthma was associated with a significantly increased risk of psoriasis. Further studies are warranted to determine the clinical significance and effects of therapeutic interventions on this association.

Differential induction of total IgE by two Salmonella enterica serotypes

The main goal of this study was to establish how the inflammation caused by infection with two different Salmonella enterica serotypes, S. Typhimurium and S. Enteritidis, may lead to the predisposition to allergy as measured by total IgE level in the blood. Infection by S. Typhimurium did not affect the systemic IgE concentration while in S. Enteritidis-infected patients there was a significant 3.5-fold increase. This effect was especially profound in patients >4 years old, with up to the 8-fold increase above the norm. The degree of dysbiosis in these two infections measured with the comparative counts of cultivated bacteria showed an inverse relationship with the IgE concentration. Earlier we reported the elevated level of IL-17 in patients infected by S. Enteritidis. In the current study a significant correlation was found between the concentrations of IL-17 and IgE suggesting a possible role played by this cytokine in triggering the production of IgE in response to S. Enteritidis infection.

The CD4 T cell response to respiratory syncytial virus infection

Respiratory syncytial virus (RSV) can induce severe lower respiratory tract infections in infants and is the leading cause of bronchiolitis in children worldwide. RSV-induced inflammation is believed to contribute substantially to the severity of disease. T helper (Th)2-, Th9-, and Th17-related cytokines are all observed in infants hospitalized following a severe RSV infection. These cytokines cause an influx of inflammatory cells, resulting in mucus production and reduced lung function. Consistent with the data from RSV-infected infants, CD4 T cell production of Interleukin (IL)-9, IL-13, and IL-17 has all been shown to contribute to RSV-induced disease in a murine model of RSV infection. Conversely, murine studies indicate that the combined actions of regulatory factors such as CD4 regulatory T cells and IL-10 inhibit the inflammatory cytokine response and limit RSV-induced disease. In support of this, IL-10 polymorphisms are associated with susceptibility to severe disease in infants. Insufficient regulation and excess inflammation not only impact disease following primary RSV infection it can also have a major impact following vaccination. Prior immunization with a formalin-inactivated (FI-RSV) vaccine resulted in enhanced disease in infants following a natural RSV infection. A Th2 CD4 T cell response has been implicated to be a major contributor in mediating vaccine-enhanced disease. Thus, future RSV vaccines must induce a balanced CD4 T cell response in order to facilitate viral clearance while inducing proper regulation of the immune response.

Titanium allergy: a literature review

Titanium has gained immense popularity and has successfully established itself as the material of choice for dental implants. In both medical and dental fields, titanium and its alloys have demonstrated success as biomedical devices. Owing to its high resistance to corrosion in a physiological environment and the excellent biocompatibility that gives it a passive, stable oxide film, titanium is considered the material of choice for intraosseous use. There are certain studies which show titanium as an allergen but the resources to diagnose titanium sensivity are very limited. Attention is needed towards the development of new and precise method for early diagnosis of titanium allergy and also to find out the alternative biomaterial which can be used in place of titanium. A review of available articles from the Medline and PubMed database was done to find literature available regarding titanium allergy, its diagnosis and new alternative material for titanium.

Characteristics of eosinophilic and non-eosinophilic asthma during treatment with inhaled corticosteroids

OBJECTIVE

Eosinophilic inflammation in the respiratory tract is a hallmark of bronchial asthma. In naïve cases, the inflammatory profile is associated with disease severity and reactivity to inhaled corticosteroids (ICS). Sustained airway eosinophilia has been reported during ICS treatment. However, the immunological characteristics of these cases are not known and it is unclear if this situation contributes to asthma control. This study was performed to determine the answer of these questions.

METHODS

To compare phenotypes of eosinophilic and non-eosinophilic asthma (EA and NEA, respectively) under ICS treatment, clinical data were obtained from asthmatic subjects (n = 22) and healthy controls (n = 10), and the leukocyte compositions of induced sputum and peripheral blood were determined. T lymphocyte profiles in systemic blood were assessed by flow cytometry.

RESULTS

A higher frequency of emergency room visits was observed in the NEA group, which had a higher neutrophil count relative to the total inflammatory cell population in induced sputum than the EA group (59.5 versus 36.6%; p < 0.01). The fraction of helper T (Th)17 lymphocytes as well as the ratio of Th17 to regulatory T cells (Treg) in the peripheral blood was higher in the NEA than in the EA group (0.24 versus 0.13; p < 0.05).

CONCLUSIONS

Th17 were more prevalent than Treg cells in the peripheral blood of NEA patients under ICS treatment, corresponding to neutrophil-dominant airway inflammation and a severe asthmatic phenotype. Thus, an imbalance in Th17/Treg may be associated with the pathogenesis of NEA in patients undergoing ICS treatment.

Increased IL-22 level in allergic rhinitis significantly correlates with clinical severity

BACKGROUND

IL-22 regulates various processes and has been linked to diverse effects. However, the importance of IL-22 in the pathogenesis of allergic rhinitis (AR) remains poorly understood. This study sought to evaluate the levels of IL-22 and IL-17A in AR patients and their association with clinical severity ofN AR.

METHODS

Thirty-six AR patients and 22 normal controls were enrolled in this study. The frequencies of IL-22(+), IL-17A(+), and IL-9(+) T helper (Th) cells in peripheral blood of AR patients and normal controls were examined by flow cytometry. Serum levels of IL-22 and IL-17A in AR patients and normal controls were determined by ELISA. The clinical relevance of the percentages of IL-22(+) and IL-17A(+) Th cells as well as serum IL-22 and IL-17A levels were evaluated.

RESULTS

The frequencies of IL-22(+) and IL-17A(+) Th cells, but not IL-9(+) Th cells, were significantly increased compared with those in normal controls (p < 0.05). Frequencies of IL-22(+) and IL-17A(+) Th cells in peripheral blood of AR patients significantly correlated with visual analog scale scores of nasal symptoms (nasal congestion and rhinorrhea; p < 0.05). Moreover, the serum levels of IL-22 and IL-17A were significantly increased compared with those in normal controls (p < 0.05) and significantly correlated with the levels of Dermatophagoides pteronyssinus and Dermatophagoides farinae specific IgE in AR patients.

CONCLUSION

Our findings suggested that IL-22 as well as IL-17A may play an important role in the regulation of Th2-skewed inflammation in AR patients.

Non-celiac gluten sensitivity: literature review

BACKGROUND

A significant percentage of the general population report problems caused by wheat and/or gluten ingestion, even though they do not have celiac disease (CD) or wheat allergy (WA), because they test negative both for CD-specific serology and histopathology and for immunoglobulin E (IgE)-mediated assays. Most patients report both gastrointestinal and nongastrointestinal symptoms, and all report improvement of symptoms on a gluten-free diet. This clinical condition has been named non-celiac gluten sensitivity (NCGS).

AIM

We attempt to define the current pathogenic, clinical, and diagnostic criteria of this "new" disease, to provide a practical view that might be useful to evaluate, diagnose, and manage NCGS patients.

METHODS

We reviewed the international literature through PubMed and Medline, using the search terms "wheat (hyper)sensitivity," "wheat allergy," "wheat intolerance," "gluten (hyper)sensitivity," and "gluten intolerance," and we discuss current knowledge about NCGS.

RESULTS

It has been demonstrated that patients suffering from NCGS are a heterogeneous group, composed of several subgroups, each characterized by different pathogenesis, clinical history, and, probably, clinical course. NCGS diagnosis can be reached only by excluding CD and WA. Recent evidence shows that a personal history of food allergy in infancy, coexistent atopy, positive for immunoglobulin G (IgG) antigliadin antibodies and flow cytometric basophil activation test, with wheat and duodenal and/or ileum-colon intraepithelial and lamina propria eosinophil counts, could be useful to identify NCGS patients.

CONCLUSIONS

Future research should aim to identify reliable biomarkers for NCGS diagnosis and to better define the different NCGS subgroups. Key teaching points: • Most patients report both gastrointestinal and nongastrointestinal symptoms, and all agree that there is an improvement of symptoms on a gluten-free diet. • NCGS diagnosis can be reached only by excluding celiac disease and wheat allergy. • Patients suffering from NCGS are a heterogeneous group, composed of several subgroups, each characterized by different pathogenesis, clinical history, and, probably, clinical course. • A personal history of food allergy in infancy, coexistent atopy, positive IgG antigliadin antibodies (AGA) and flow cytometric basophil activation test, with wheat and duodenal and/or ileum-colon intraepithelial and lamina propria eosinophil counts, could be useful to identify NCGS patients. • Future research should aim to identify reliable biomarkers for NCGS diagnosis and to better define the different NCGS subgroup.

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

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

Early development of the gut microbiota and immune health

In recent years, the increase in human microbiome research brought about by the rapidly evolving “omic” technologies has established that the balance among the microbial groups present in the human gut, and their multipronged interactions with the host, are crucial for health. On the other hand, epidemiological and experimental support has also grown for the ‘early programming hypothesis’, according to which factors that act in utero and early in life program the risks for adverse health outcomes later on. The microbiota of the gut develops during infancy, in close interaction with immune development, and with extensive variability across individuals. It follows that the specific process of gut colonization and the microbe-host interactions established in an individual during this period have the potential to represent main determinants of life-long propensity to immune disease. Although much remains to be learnt on the progression of events by which the gut microbiota becomes established and initiates its intimate relationships with the host, and on the long-term repercussions of this process, recent works have advanced significatively in this direction.

Potential role of myeloid cell/eosinophil-derived IL-17 in LPS-induced endotoxin shock

IL-17RA is a shared receptor subunit for several cytokines of the IL-17 family, including IL-17A, IL-17C, IL-17E (also called IL-25) and IL-17F. It has been shown that mice deficient in IL-17RA are more susceptible to sepsis than wild-type mice, suggesting that IL-17RA is important for host defense against sepsis. However, it is unclear which ligands for IL-17RA, such as IL-17A, IL-17C, IL-17E/IL-25 and/or IL-17F, are involved in the pathogenesis of sepsis. Therefore, we examined IL-17A, IL-17E/IL-25 and IL-17F for possible involvement in LPS-induced endotoxin shock. IL-17A-deficient mice, but not IL-25- or IL-17F-deficient mice, were resistant to LPS-induced endotoxin shock, as compared with wild-type mice. Nevertheless, studies using IL-6-deficient, IL-21Rα-deficient and Rag-2-deficient mice, revealed that neither IL-6 and IL-21, both of which are important for Th17 cell differentiation, nor Th17 cells were essential for the development of LPS-induced endotoxin shock, suggesting that IL-17A-producing cells other than Th17 cells were important in the setting. In this connection, IL-17A was produced by macrophages, DCs and eosinophils after LPS injection. Taken together, these findings indicate that IL-17A, but not IL-17F or IL-25, is crucial for LPS-induced endotoxin shock. In addition, macrophages, DCs and eosinophils, but not Th17 cells or γδ T cells, may be sources of IL-17A during LPS-induced endotoxin shock.

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.

Atopic dermatitis, STAT3- and DOCK8-hyper-IgE syndromes differ in IgE-based sensitization pattern

BACKGROUND

Increased serum IgE levels are characteristic but not specific for allergic diseases. Particularly, severe atopic dermatitis (AD) overlaps with hyper-IgE syndromes (HIES) regarding eczema, eosinophilia, and increased serum IgE levels. HIES are primary immunodeficiencies due to monogenetic defects such as in the genes DOCK8 and STAT3. As it is not known to date why allergic manifestations are not present in all HIES entities, we assessed the specificity of serum IgE of AD and HIES patients in the context of clinical and immunological findings.

METHODS

Clinical data, skin prick tests, specific IgE to aero- and food allergens, and T helper (Th) subpopulations were compared in AD and molecularly defined HIES patients.

RESULTS

Total serum IgE levels were similarly increased in STAT3-HIES, DOCK8-HIES, and AD patients. The ratio of aeroallergen-specific IgE to total IgE was highest in AD, whereas DOCK8-HIES patients showed the highest specific serum IgE against food allergens. Overall, clinical allergy and skin prick test results complied with the specific IgE results. Th2-cell numbers were significantly increased in DOCK8-HIES and AD patients compared to STAT3-HIES patients and controls. AD patients showed significantly higher nTreg-cell counts compared to STAT3-HIES and control individuals. High Th17-cell counts were associated with asthma. Specific IgE values, skin prick test, and T-cell subsets of STAT3-HIES patients were comparable with those of healthy individuals except decreased Th17-cell counts.

CONCLUSION

Hyper-IgE syndromes and atopic dermatitis patients showed different sensitization pattern of serum IgE corresponding to the allergic disease manifestations and Th-cell subset data, suggesting a key role of DOCK8 in the development of food allergy.

Regulatory role of CD4(+)CD25 (+)Foxp3 (+) regulatory T cells on IL-17-secreting T cells in chronic hepatitis B patients

BACKGROUND

Both interleukin (IL)-17-secreting CD4(+) T (Th17) and CD4(+)CD25(+)Foxp3(+) T regulatory (Treg) cells have been shown to be associated with disease progression or liver damage in chronic hepatitis B (CHB) patients. However, the relationship between Treg cells and IL-17-secreting T cells in hepatitis B virus (HBV) infections is unclear.

METHODS

The frequencies of Treg cells and IL-17-secreting T cells in hepatitis B e antigen (HBeAg)-positive CHB patients and healthy subjects were measured by flow cytometric analysis. The role of Treg cells on the differentiation of Ag-specific IL-17-secreting T cells was determined by removing the Treg cells from peripheral blood mononuclear cells (PBMCs) in HBeAg-positive CHB patients.

RESULTS

The frequencies of both Th17 (1.71 ± 0.58 vs. 1.08 ± 0.36 %; P < 0.01) and Treg cells (8.92 ± 4.11 vs. 6.45 ± 1.56 %; P < 0.01) were increased in the peripheral blood of HBeAg-positive CHB patients compared with healthy controls, but in not the IL-17-secreting CD8(+) T (Tc17) cells. The frequency of Treg cells was significantly associated with that of Th17 cells (r = 0.625, P = 0.001) in CHB patients. Spearman analysis showed a positive correlation between the frequency of Treg cells and HBV DNA load (r = 0.508, P = 0.008), as well as between the frequency of Th17 cells and serum alanine aminotransferase level (r = 0.516, P = 0.007). The deletion of Treg cells significantly enhanced both Th17 and Tc17 cell development in PBMCs following recombinant HBV core antigen stimulation.

CONCLUSIONS

Our data indicate a clear inverse relationship between Th17 cells and Treg cells and that Treg cells can inhibit Th17 cell development in CHB patients.

Serum periostin: a novel biomarker for asthma management

Chronic airway inflammation and remodeling are fundamental features of asthma. Even with adequate inhaled corticosteroid (ICS) treatment, there are still patients who exhibit Th2/eosinophilic inflammation and develop airflow limitation, a functional consequence of airway remodeling. There are few biomarkers that are applicable in the clinical setting that reflect refractory Th2/eosinophilic inflammation and remodeling of the asthmatic airways. Therefore, establishing such biomarkers is essential for managing patients who suffer from these conditions. This review addresses the importance of serum periostin measurements by describing observations made in a KiHAC multicenter cohort with periostin used as a marker of pulmonary function decline and refractory Th2/eosinophilic inflammation in patients with asthma receiving long-term ICS treatment. Furthermore, serum periostin could be a companion diagnostic for targeted therapy against refractory Th2/eosinophilic inflammation. Finally, the distinct characteristics of serum periostin as compared to conventional biomarkers are addressed.

ASK1 promotes the contact hypersensitivity response through IL-17 production

Contact hypersensitivity (CHS) is a form of delayed-type hypersensitivity triggered by the response to reactive haptens (sensitization) and subsequent challenge (elicitation). Here, we show that ASK1 promotes CHS and that suppression of ASK1 during the elicitation phase is sufficient to attenuate CHS. ASK1 knockout (KO) mice exhibited impaired 2,4-dinitrofluorobenzene (DNFB)-induced CHS. The suppression of ASK1 activity during the elicitation phase through a chemical genetic approach or a specific inhibitory compound significantly reduced the CHS response to a level similar to that observed in ASK1 KO mice. The reduced response was concomitant with the strong inhibition of production of IL-17, a cytokine that plays an important role in CHS and other inflammatory diseases, from sensitized lymph node cells. These results suggest that ASK1 is relevant to the overall CHS response during the elicitation phase and that ASK1 may be a promising therapeutic target for allergic contact dermatitis and other IL-17-related inflammatory diseases.

Allergic responses and aryl hydrocarbon receptor novel pathway of mast cell activation

The activation of the transcription factor aryl hydrocarbon receptor (AhR) is modulated by a wide variety of xenobiotics and ligands deriving from products of metabolism. The study of the contribution of AhR to allergic diseases has gained much interest in recent years. Here we discuss the role that environmental factors and metabolic products, particularly acting on AhR-expressing mast cells (MCs), could have in the development of local allergic/atopic response. Thus, this review will cover: a brief overview of the AhR mechanism of action in the immune system; a description of different AhR ligands and their effects to IgE-mediated MC activation in the allergic response, with particular attention to the role of IL-17; a discussion about the potential involvement of AhR in immune tolerance; and a conclusion on human diseases in which direct AhR activation of MC might have a major impact.

β-Glucans in the treatment and prevention of allergic diseases

β-glucans are a group of biologically active polysaccharides of natural origin with a proven pleiotropic immunomodulation effect. Their efficacy has been confirmed in the therapeutic treatment and prevention of various infectious diseases, secondary immune defects and also of oncologic disorders. Allergic diseases are one of the most frequent diseases and their prevalence continues to increase. They develop as a consequence of dysregulation of the immune system, especially when there is failure in the equilibrium of the response of TH1/TH2 lymphocytes towards TH2. New therapeutic approaches in the treatment of immunopathological conditions (e.g. allergic or oncologic) are directed to restoring the equilibrium among different T lymphocyte subpopulations. Based on in vitro experiments, and also on animal and human clinical studies, there is much evidence for the importance of β-glucans in the treatment and also prevention of allergic diseases; this opens new perspectives on the use of this widespread and popular group of natural substances.

Infant 7-valent pneumococcal conjugate vaccine immunization alters young adulthood CD4(+)T cell subsets in allergic airway disease mouse model

7-Valent pneumococcal conjugate vaccine (PCV7) immunization in adulthood can inhibit allergic asthma in mouse model. The aim of this study is to investigate the effects of infant PCV7 immunization on young adulthood CD4(+)T cell subsets in a murine allergic airway disease (AAD) model. Our study indicated that infant PCV7 immunization can inhibit young adulthood airway inflammation and airway hyperresponsiveness (AHR) by inducing the production of Foxp3(+)Treg, Th1 cells and their cytokines IL-10 and IFN-γ, inhibiting the production of Th2, Th17 cells and their cytokines IL-13 and IL-17A in BALB/c mice model. These results suggested that infant PCV7 immunization may serve as an effective measure to prevent young adulthood mice AAD.

Heme oxygenase-1 exerts a protective role in ovalbumin-induced neutrophilic airway inflammation by inhibiting Th17 cell-mediated immune response

Allergic asthma is conventionally considered as a Th2 immune response characterized by eosinophilic inflammation. Recent investigations revealed that Th17 cells play an important role in the pathogenesis of non-eosinophilic asthma (NEA), resulting in steroid-resistant neutrophilic airway inflammation. Heme oxygenase-1 (HO-1) has anti-inflammation, anti-oxidation, and anti-apoptosis functions. However, its role in NEA is still unclear. Here, we explore the role of HO-1 in a mouse model of NEA. HO-1 inducer hemin or HO-1 inhibitor tin protoporphyrin IX was injected intraperitoneally into ovalbumin-challenged DO11.10 mice. Small interfering RNA (siRNA) was delivered into mice to knock down HO-1 expression. The results show that induction of HO-1 by hemin attenuated airway inflammation and decreased neutrophil infiltration in bronchial alveolar lavage fluid and was accompanied by a lower proportion of Th17 cells in mediastinal lymph nodes and spleen. More importantly, induction of HO-1 down-regulated Th17-related transcription factor retinoic acid-related orphan receptor γt (RORγt) expression and decreased IL-17A levels, all of which correlated with a decrease in phosphorylated STAT3 (p-STAT3) level and inhibition of Th17 cell differentiation. Consistently, the above events could be reversed by tin protoporphyrin IX. Also, HO-1 siRNA transfection abolished the effect of hemin induced HO-1 in vivo. Meanwhile, the hemin treatment promoted the level of Foxp3 expression and enhanced the proportion of regulatory T cells (Tregs). Collectively, our findings indicate that HO-1 exhibits anti-inflammatory activity in the mouse model of NEA via inhibition of the p-STAT3-RORγt pathway, regulating kinetics of RORγt and Foxp3 expression, thus providing a possible novel therapeutic target in asthmatic patients.

Dexamethasone reduces IL-17 and Tim-3 expression in BALF of asthmatic mice

This study investigated the expression of interleukin-17 (IL-17) and T cell immunoglobulin mucin and domain-containing molecule-3 (Tim-3) in bronchoalveolar lavage fluid (BALF) of asthmatic mice and the effect of dexamethasone (DEX) on these factors. Thirty-six mice were randomly divided into three groups: normal group, asthmatic group and DEX group. The mouse model of asthma was established by sensitization with ovalbumin in both the asthmatic and DEX groups. The levels of IL-6, IL-10, IL-17 and TGF-β were measured in BALF by enzyme-linked immunesorbent assay (ELISA). The mRNA expression level of Tim-3 was detected by reverse transcription polymerase chain reaction (RT-PCR). The ratio of Tim-3+CD4+ cells to total CD4+ cells in BALF was determined by flow cytometry. Differential inflammatory cells in BALF were detected. The correlations among IL-17, IL-6, IL-10, Tim-3 and inflammatory cells were analyzed. The results showed that the levels of IL-17, IL-6 and Tim-3 were substantially increased and the IL-10 level decreased in BALF in the asthmatic mice, which was significantly reversed by DEX treatment. IL-17 expression was positively correlated with IL-6 and Tim-3 expression and the number of inflammatory cells but negatively with IL-10 expression. These results indicate that the increased expression of IL-17 and Tim-3 in BALF may be implicated in the occurrence and development of asthmatic inflammation; the mechanism by which DEX suppresses asthmatic airway inflammation involves down-regulation of IL-17 and Tim-3 levels.