The regulation of allergy and asthma

Mycobacterium vaccae alleviates allergic airway inflammation and airway hyper-responsiveness in asthmatic mice by altering intestinal microbiota

Host immunity can influence the composition of the gut microbiota and consequently affect disease progression. Previously, we reported that a Mycobacterium vaccae vaccine could ameliorate allergic inflammation in asthmatic mice by regulating inflammatory immune processes. Here, we investigated the anti-inflammatory effects of M. vaccae on allergic asthma via gut microbiota modulation. An ovalbumin (OVA)-induced asthmatic murine model was established and treated with M. vaccae. Gut microbiota profiles were determined in 18 BALB/c mice using 16S rDNA gene sequencing and metabolomic profiling was performed using liquid chromatography quadrupole time-of-flight mass spectrometry. Mycobacterium vaccae alleviated airway hyper-reactivity and inflammatory infiltration in mice with OVA-induced allergic asthma. The microbiota of asthmatic mice is disrupted and that this can be reversed with M. vaccae. Additionally, a total of 24 differential metabolites were screened, and the abundance of PI(14:1(9Z)/18:0), a glycerophospholipid, was found to be correlated with macrophage numbers (r = 0.52, p = 0.039). These metabolites may affect chemokine (such as macrophage chemoattractant protein-1) concentrations in the serum, and ultimately affect pulmonary macrophage recruitment. Our data demonstrated that M. vaccae might alleviate airway inflammation and hyper-responsiveness in asthmatic mice by reversing imbalances in gut microbiota. These novel mechanistic insights are expected to pave the way for novel asthma therapeutic strategies.

Maternal microbe-specific modulation of the offspring microbiome and development during pregnancy and lactation

The maternal microbiome is essential for the healthy growth and development of offspring and has long-term effects later in life. Recent advances indicate that the maternal microbiome begins to regulate fetal health and development during pregnancy. Furthermore, the maternal microbiome continues to affect early microbial colonization via birth and breastfeeding. Compelling evidence indicates that the maternal microbiome is involved in the regulation of immune and brain development and affects the risk of related diseases. Modulating offspring development by maternal diet and probiotic intervention during pregnancy and breastfeeding could be a promising therapy in the future. In this review, we summarize and discuss the current understanding of maternal microbiota development, perinatal microbial metabolite transfer, mother-to-infant microbial transmission during/after birth and its association with immune and brain development as well as corresponding diseases.

Duration of exposure to epidural anesthesia at delivery, DNA methylation in umbilical cord blood and their association with offspring asthma in Non-Hispanic Black women

Epidural anesthesia is an effective pain relief modality, widely used for labor analgesia. Childhood asthma is one of the commonest chronic medical illnesses in the USA which places a significant burden on the health-care system. We recently demonstrated a negative association between the duration of epidural anesthesia and the development of childhood asthma; however, the underlying molecular mechanisms still remain unclear. In this study of 127 mother-child pairs comprised of 75 Non-Hispanic Black (NHB) and 52 Non-Hispanic White (NHW) from the Newborn Epigenetic Study, we tested the hypothesis that umbilical cord blood DNA methylation mediates the association between the duration of exposure to epidural anesthesia at delivery and the development of childhood asthma and whether this differed by race/ethnicity. In the mother-child pairs of NHB ancestry, the duration of exposure to epidural anesthesia was associated with a marginally lower risk of asthma (odds ratio = 0.88, 95% confidence interval = 0.76-1.01) for each 1-h increase in exposure to epidural anesthesia. Of the 20 CpGs in the NHB population showing the strongest mediation effect, 50% demonstrated an average mediation proportion of 52%, with directional consistency of direct and indirect effects. These top 20 CpGs mapped to 21 genes enriched for pathways engaged in antigen processing, antigen presentation, protein ubiquitination and regulatory networks related to the Major Histocompatibility Complex (MHC) class I complex and Nuclear Factor Kappa-B (NFkB) complex. Our findings suggest that DNA methylation in immune-related pathways contributes to the effects of the duration of exposure to epidural anesthesia on childhood asthma risk in NHB offspring.

Lactoferrin Ameliorates Ovalbumin-Induced Asthma in Mice through Reducing Dendritic-Cell-Derived Th2 Cell Responses

Asthma is a chronic respiratory disease with symptoms such as expiratory airflow narrowing and airway hyperresponsiveness (AHR). Millions of people suffer from asthma and are at risk of life-threatening conditions. Lactoferrin (LF) is a glycoprotein with multiple physiological functions, including antioxidant, anti-inflammatory, antimicrobial, and antitumoral activities. LF has been shown to function in immunoregulatory activities in ovalbumin (OVA)-induced delayed type hypersensitivity (DTH) in mice. Hence, the purpose of this study was to investigate the roles of LF in AHR and the functions of dendritic cells (DCs) and Th2-related responses in asthma. Twenty 8-week-old male BALB/c mice were divided into normal control (NC), ovalbumin (OVA)-sensitized, and OVA-sensitized with low dose of LF (100 mg/kg) or high dose of LF (300 mg/kg) treatment groups. The mice were challenged by intranasal instillation with 5% OVA on the 21st to 27th day after the start of the sensitization period. The AHR, cytokines in bronchoalveolar lavage fluid, and pulmonary histology of each mouse were measured. Serum OVA-specific IgE and IgG1 and OVA-specific splenocyte responses were further detected. The results showed that LF exhibited protective effects in ameliorating AHR, as well as lung inflammation and damage, in reducing the expression of Th2 cytokines and the secretion of allergen-specific antibodies, in influencing the functions of DCs, and in decreasing the level of Th2 immune responses in a BALB/c mouse model of OVA-induced allergic asthma. Importantly, we demonstrated that LF has practical application in reducing DC-induced Th2 cell responses in asthma. In conclusion, LF exhibits anti-inflammation and immunoregulation activities in OVA-induced allergic asthma. These results suggest that LF may act as a supplement to prevent asthma-induced lung injury and provide an additional agent for reducing asthma severity.

Assessment of Selected Intestinal Permeability Markers in Children with Food Allergy Depending on the Type and Severity of Clinical Symptoms

Background: Food allergy (FA) has a broad range of symptoms, and clinical manifestations may concern several reactions from one system or organ. Aim: The aim of the study was to assess intestinal permeability (IP) based on the analysis of serum zonulin and bacterial lipopolysaccharides (LPS) levels in children with FA, taking into account the pathomechanism of immune reaction, clinical symptoms of FA and their severity. Material and methods: The study comprised 103 patients aged 7–60 months (median 34); 49 children with IgE-mediated allergy and 25 children with non-IgE-mediated allergy; the reference group comprised 29 children with functional gastrointestinal disorders. IP markers were determined using ELISA. Results: There was no correlation between the severity of clinical symptoms and the level of IP markers in children with FA. Zonulin and LPS levels were significantly higher in children with FA and gastrointestinal symptoms. Zonulin levels in the subgroup of children with non-IgE-mediated FA and gastrointestinal symptoms were significantly higher than in the subgroup of children with IgE-mediated FA and these symptoms. The level of LPS was significantly higher in the subgroup with IgE-mediated FA and atopic dermatitis. Conclusions: Zonulin and LPS levels were significantly higher in children with FA compared to children from the reference group. Zonulin levels were significantly higher in children with non-IgE-mediated FA than in children with IgE-mediated FA.

The Role of Noncoding RNA in Airway Allergic Diseases through Regulation of T Cell Subsets

Allergic rhinitis and asthma are common airway allergic diseases, the incidence of which has increased annually in recent years. The human body is frequently exposed to allergens and environmental irritants that trigger immune and inflammatory responses, resulting in altered gene expression. Mounting evidence suggested that epigenetic alterations were strongly associated with the progression and severity of allergic diseases. Noncoding RNAs (ncRNAs) are a class of transcribed RNA molecules that cannot be translated into polypeptides and consist of three major categories, microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Previous studies showed that ncRNAs were involved in the physiopathological mechanisms of airway allergic diseases and contributed to their occurrence and development. This article reviews the current state of understanding of the role of noncoding RNAs in airway allergic diseases, highlights the limitations of recent studies, and outlines the prospects for further research to facilitate the clinical translation of noncoding RNAs as therapeutic targets and biomarkers.

Inhalative Nanoparticulate CpG Immunotherapy in Severe Equine Asthma: An Innovative Therapeutic Concept and Potential Animal Model for Human Asthma Treatment

Simple Summary

Severe equine asthma is the most common globally widespread non-infectious equine respiratory disease (together with its mild and moderate form), which is associated with exposure to hay dust and mold spores, has certain similarities to human asthma, and continues to represent a therapeutic problem. Immunomodulatory DNA sequences (CpG) bound to nanoparticles were successfully administered by inhalation to severe asthmatic horses in several studies. It was possible to demonstrate a significant, sustained, one-to-eight-week improvement in important clinical parameters: partial oxygen pressure in the blood, quantity and viscosity of tracheal mucus secretion in the airways, and the amount of inflammatory cells in the respiratory tracts of severe asthmatic horses. The immunotherapy with CpG is performed independent of specific allergens. At an immunological level, the treatment leads to decreases in allergic and inflammatory parameters. This innovative therapeutic concept thus opens new perspectives in severe equine asthma treatment and possibly also in human asthma treatment.

Abstract

Severe equine asthma is the most common globally widespread non-infectious equine respiratory disease (together with its mild and moderate form), which is associated with exposure to hay dust and mold spores, has certain similarities to human asthma, and continues to represent a therapeutic problem. Immunomodulatory CpG-ODN, bound to gelatin nanoparticles as a drug delivery system, were successfully administered by inhalation to severe equine asthmatic patients in several studies. It was possible to demonstrate a significant, sustained, and allergen-independent one-to-eight-week improvement in key clinical parameters: the arterial partial pressure of oxygen, the quantity and viscosity of tracheal mucus, and neutrophilic inflammatory cells in the respiratory tracts of the severe equine asthmatic subjects. At the immunological level, an upregulation of the regulatory antiallergic and anti-inflammatory cytokine IL-10 as well as a downregulation of the proallergic IL-4 and proinflammatory IFN-γ in the respiratory tracts of the severe equine asthmatic patients were identified in the treatment groups. CD4⁺ T lymphocytes in the respiratory tracts of the asthmatic horses were demonstrated to downregulate the mRNA expression of Tbet and IL-8. Concentrations of matrix metalloproteinase-2 and -9 and tissue inhibitors of metalloproteinase-2 were significantly decreased directly after the treatment as well as six weeks post-treatment. This innovative therapeutic concept thus opens new perspectives in the treatment of severe equine asthma and possibly also that of human asthma.

Probiotics Function in Preventing Atopic Dermatitis in Children

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard.

Assessment of Allergen-Responsive Regulatory T Cells in Experimental Asthma Induced in Different Mouse Strains

Background

Regulatory T cells (Tregs) are important in regulating responses to innocuous antigens, such as allergens, by controlling the Th2 response, a mechanism that appears to be compromised in atopic asthmatic individuals. Different isogenic mouse strains also have distinct immunological responses and susceptibility to the experimental protocols used to develop lung allergic inflammation. In this work, we investigated the differences in the frequency of Treg cell subtypes among A/J, BALB/c, and C57BL/6, under normal conditions and following induction of allergic asthma with ovalbumin (OVA).

Methods

Subcutaneous sensitization followed by 4 consecutive intranasal OVA challenges induced asthma characteristic changes such as airway hyperreactivity, inflammation, and production of Th2 cytokines (IL-4, IL-13, IL-5, and IL-33) in the lungs of only A/J and BALB/c but not C57BL/6 strain and evaluated by invasive whole-body plethysmography, flow cytometry, and ELISA, respectively.

Results

A/J strain naturally showed a higher frequency of CD4⁺IL-10⁺ T cells in the lungs of naïve mice compared to the other strains, accompanied by higher frequencies of CD4⁺IL-4⁺ T cells. C57BL/6 mice did not develop lung inflammation and presented higher frequency of CD4⁺CD25⁺Foxp3⁺ Treg cells in the bronchoalveolar lavage fluid (BALF) after the allergen challenge. In in vitro settings, allergen-specific stimulation of mediastinal LN (mLN) cells from OVA-challenged animals induced higher frequency of CD4⁺IL-10⁺ Treg cells from A/J strain and CD4⁺CD25⁺Foxp3⁺ from C57BL/6.

Conclusions

The observed differences in the frequencies of Treg cell subtypes associated with the susceptibility of the animals to experimental asthma suggest that CD4⁺CD25⁺Foxp3⁺ and IL-10-producing CD4⁺ Treg cells may play different roles in asthma control. Similar to asthmatic individuals, the lack of an efficient regulatory response and susceptibility to the development of experimental asthma in A/J mice further suggests that this strain could be preferably chosen in experimental models of allergic asthma.

The HLA-G Immune Checkpoint Plays a Pivotal Role in the Regulation of Immune Response in Autoimmune Diseases

The human G-leukocyte antigen (HLA-G) molecule is a non-classical major histocompatibility complex (MHC) class I molecule. The pertinence of HLA-G has been investigated in numerous studies which have sought to elucidate the relevance of HLA-G in pathologic conditions, such as autoimmune diseases, cancers, and hematologic malignancies. One of the main goals of the current research on HLA-G is to use this molecule in clinical practice, either in diagnostics or as a therapeutic target. Since HLA-G antigens are currently considered as immunomodulatory molecules that are involved in reducing inflammatory and immune responses, in this review, we decided to focus on this group of antigens as potential determinants of progression in autoimmune diseases. This article highlights what we consider as recent pivotal findings on the immunomodulatory function of HLA-G, not only to establish the role of HLA-G in the human body, but also to explain how these proteins mediate the immune response.

Thrombin induces pro-inflammatory and anti-inflammatory cytokines secretion from human mast cell line (HMC-1) via protease-activated receptors

Thrombin-induced mast cell activation represents cross-talk between coagulation and inflammation. However, there is still controversy concerning the pro- or anti-inflammatory effects mast cells have in response to thrombin signaling. Human mast cell HMC-1 was incubated with 0.2 U/mL thrombin. Cells and supernatants were collected. Production of pro- and anti-inflammatory mediators was determined by quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). Expression of proteinase-activated receptor-1 (PAR1) and -4 (PAR4) mRNA in HMC-1 cells was analyzed by qPCR. Activation of mitogen-activated protein kinases (MAPKs) was measured by immunoblotting. Furthermore, the impact of PAR1 inhibitor (SCH79797) and agonist (TFLLR-NH₂), PAR4 inhibitor (BMS986120) and agonist (AYPGKF-NH₂), and MAPK inhibitors (SB203580, PD98059, and SP600125) on the production of mediators was evaluated using qPCR and ELISA. Thrombin exposure increased pro- and anti-inflammatory mediators, expression of PAR1 and PAR4 mRNA, and phosphorylation of JNK, p38, and ERK1/2 MAPKs in HMC-1 cells. SCH79797, BMS986120, and MAPK inhibitors (SB203580, PD98059, and SP600125) were inhibited, while TFLLR-NH₂ and AYPGKF-NH₂ promoted pro- and anti-inflammatory cytokines in this process. HMC-1 produces pro- and anti-inflammatory cytokines after thrombin incubation, namely PAR1 and PAR4. Alongside HMC-1, MAPK signaling pathways are involved in the production of these mediators. The mast cells showed dual activation after thrombin stimulation.

CD4 + T cells in inflammatory diseases : pathogenic T-helper cells and the CD69-Myl9 system

CD4 + T cells direct immune responses against infectious microorganisms but are also involved in the pathogenesis of inflammatory diseases. In the last two to three decades, various researchers have identified and characterized several functional CD4 + T cell subsets, including T-helper 1 (Th1), Th2, Th9 and Th17 cells and regulatory T (Treg) cells. In this mini-review, we introduce the concept of pathogenic Th cells that induce inflammatory diseases with a model of disease induction by a population of pathogenic Th cells; "pathogenic Th population disease-induction model". We will focus on Th2 cells that induce allergic airway inflammation-pathogenic Th2 cells (Tpath2 cells)-and discuss the nature of Tpath2 cells that shape the pathology of chronic inflammatory diseases. Various Tpath2 cell subsets have been identified and their unique features are summarized in mouse and human systems. Second, we will discuss how Th cells migrate and are maintained in chronic inflammatory lesions. We propose a model known as the "CD69-Myl9 system". CD69 is a cell surface molecule expressed on activated T cells and interaction with its ligand myosin light chain 9 (Myl9) is required for the induction of inflammatory diseases. Myl9 molecules in the small vessels of inflamed lungs may play a crucial role in the migration of activated T cells into inflammatory lesions. Emerging evidence may provide new insight into the pathogenesis of chronic inflammatory diseases and contribute to the development of new therapeutic strategies for intractable inflammatory disorders.

Pannexin 1 channels facilitate communication between T cells to restrict the severity of airway inflammation

Allergic airway inflammation is driven by type-2 CD4⁺ T cell inflammatory responses. We uncover an immunoregulatory role for the nucleotide release channel, Panx1, in T cell crosstalk during airway disease. Inverse correlations between Panx1 and asthmatics and our mouse models revealed the necessity, specificity, and sufficiency of Panx1 in T cells to restrict inflammation. Global Panx1^-/- mice experienced exacerbated airway inflammation, and T-cell-specific deletion phenocopied Panx1^-/- mice. A transgenic designed to re-express Panx1 in T cells reversed disease severity in global Panx1^-/- mice. Panx1 activation occurred in pro-inflammatory T effector (Teff) and inhibitory T regulatory (Treg) cells and mediated the extracellular-nucleotide-based Treg-Teff crosstalk required for suppression of Teff cell proliferation. Mechanistic studies identified a Salt-inducible kinase-dependent phosphorylation of Panx1 serine 205 important for channel activation. A genetically targeted mouse expressing non-phosphorylatable Panx1^S205A phenocopied the exacerbated inflammation in Panx1^-/- mice. These data identify Panx1-dependent Treg:Teff cell communication in restricting airway disease.

SERPINB10 contributes to asthma by inhibiting the apoptosis of allergenic Th2 cells

BACKGROUND

Serine peptidase inhibitor, clade B, member 10 (SERPINB10) contributes to allergic inflammation in asthma. However, its role in the T-helper type 2 (Th2) response of allergic asthma is not known. The goal of this study was to unveil the function of SERPINB10 in the Th2 response of allergic asthma and the mechanism by which SERPINB10 affects the viability of Th2 cells.

METHODS

Th2 cytokines and serum levels of house dust mite (HDM)-specific IgE in bronchoalveolar lavage fluid were examined by ELISA in an HDM-induced asthma model. The number and apoptosis of Th1 and Th2 cells in mouse lungs were measured by flow cytometry. Naïve CD4 T cells from patients with asthma were cultured under appropriate polarizing conditions to generate Th1 and Th2 cells. SERPINB10 expression in polarized Th1 and Th2 cells was quantified by real-time reverse transcription-quantitative polymerase chain reaction. SERPINB10 expression was knocked down in human CD4 T cells with lentivirus.

RESULTS

Knockdown of SERPINB10 expression significantly diminished HDM-induced Th2 cytokine secretion and level of HDM-specific IgE. After HDM exposure, SERPINB10-knockdown mice had diminished numbers of Th2 cells, but similar numbers of Th1 cells, compared with those in negative-control mice. Th2 cells of SERPINB10-knockdown mice were more susceptible to apoptosis than that of control mice. Stimulating T-cell receptors (TCRs) with anti-CD3 antibody caused upregulation of SERPINB10 expression in polarized Th2 cells, but not polarized Th1 cells. Knockdown of SERPINB10 expression resulted in fewer numbers and greater apoptosis of polarized Th2 cells.

CONCLUSION

Our results suggest that SERPINB10 may contribute to allergic inflammation and the Th2 response of asthma by inhibiting the apoptosis of Th2 cells.

Understanding Asthma and Allergies by the Lens of Biodiversity and Epigenetic Changes

Exposure to different organisms (bacteria, mold, virus, protozoan, helminths, among others) can induce epigenetic changes affecting the modulation of immune responses and consequently increasing the susceptibility to inflammatory diseases. Epigenomic regulatory features are highly affected during embryonic development and are responsible for the expression or repression of different genes associated with cell development and targeting/conducting immune responses. The well-known, "window of opportunity" that includes maternal and post-natal environmental exposures, which include maternal infections, microbiota, diet, drugs, and pollutant exposures are of fundamental importance to immune modulation and these events are almost always accompanied by epigenetic changes. Recently, it has been shown that these alterations could be involved in both risk and protection of allergic diseases through mechanisms, such as DNA methylation and histone modifications, which can enhance Th2 responses and maintain memory Th2 cells or decrease Treg cells differentiation. In addition, epigenetic changes may differ according to the microbial agent involved and may even influence different asthma or allergy phenotypes. In this review, we discuss how exposure to different organisms, including bacteria, viruses, and helminths can lead to epigenetic modulations and how this correlates with allergic diseases considering different genetic backgrounds of several ancestral populations.

What lies beneath the airway mucosal barrier? Throwing the spotlight on antigen-presenting cell function in the lower respiratory tract

The global prevalence of respiratory infectious and inflammatory diseases remains a major public health concern. Prevention and management strategies have not kept pace with the increasing incidence of these diseases. The airway mucosa is the most common portal of entry for infectious and inflammatory agents. Therefore, significant benefits would be derived from a detailed understanding of how immune responses regulate the filigree of the airways. Here, the role of different antigen‐presenting cells (APC) in the lower airways and the mechanisms used by pathogens to modulate APC function during infectious disease is reviewed. Features of APC that are unique to the airways and the influence they have on uptake and presentation of antigen to T cells directly in the airways are discussed. Current information on the crucial role that airway APC play in regulating respiratory infection is summarised. We examine the clinical implications of APC dysregulation in the airways on asthma and tuberculosis, two chronic diseases that are the major cause of illness and death in the developed and developing world. A brief overview of emerging therapies that specifically target APC function in the airways is provided.

Immunomodulatory asthma therapy in the equine animal model: A dose-response study and evaluation of a long-term effect

INTRODUCTION

Equine asthma represents a naturally occurring animal model for human allergic neutrophilic asthma. Inhalative nanoparticle-bound cytosine-phosphate-guanosine (CpG-GNP) immunotherapy, independent of specific allergens, has already shown promising clinical and immunological results in previous studies and offers the possibility to treat the underlying cause of the disease. This study analyses the relationship between dose and response, and evaluates a possible long-term effect.

METHODS

In the prospective, randomised, double-blind clinical field study, 29 horses suffering from equine asthma received 10 inhalation treatments with either 187.5 µg CpG-GNP (CpG single dose [CpGsd]; n = 11), 375 µg CpG-GNP double dose (CpG double dose [CpGdd]; n = 9) (q48h for 20 days) or 1600 µg beclomethasone (n = 9) (q24h for 10 days). Each horse was examined three times: before the treatment (I), immediately after the 10 inhalations (II), and 8 weeks after the final inhalation (III). The three groups were compared according to clinical and laboratory parameters. The study examined the sustainability of the long-term effect of the treatment after 8 weeks, as well as the tolerability of the formula as a double dose.

RESULTS

The CpGsd resulted in a significant improvement in 82% of the parameters, the CpGdd in 72%. In the long-term evaluation, the CpGsd showed a significant improvement in 100% of the parameters in comparison to the initial values, the CpGdd in 67%. On the immunological level, the bronchoalveolar lavage revealed a significant reduction of IL-4, IL-8, and interferon-γ.

CONCLUSION

Both CpG groups displayed significant improvements in clinical and laboratory parameters, especially regarding the long-term effect of CpGsd. Doubling the CpG dose did not result in any improvement in comparison to the original single dose. On the immunological level, an anti-inflammatory, as well as an immunomodulatory effect, apart from a Th2-dominated immune response, could be observed. This immunomodulatory inhalation treatment could indicate a new possibility for human allergic asthma therapy.

Glucocorticoids-All-Rounders Tackling the Versatile Players of the Immune System

Glucocorticoids regulate fundamental processes of the human body and control cellular functions such as cell metabolism, growth, differentiation, and apoptosis. Moreover, endogenous glucocorticoids link the endocrine and immune system and ensure the correct function of inflammatory events during tissue repair, regeneration, and pathogen elimination via genomic and rapid non-genomic pathways. Due to their strong immunosuppressive, anti-inflammatory and anti-allergic effects on immune cells, tissues and organs, glucocorticoids significantly improve the quality of life of many patients suffering from diseases caused by a dysregulated immune system. Despite the multitude and seriousness of glucocorticoid-related adverse events including diabetes mellitus, osteoporosis and infections, these agents remain indispensable, representing the most powerful, and cost-effective drugs in the treatment of a wide range of rheumatic diseases. These include rheumatoid arthritis, vasculitis, and connective tissue diseases, as well as many other pathological conditions of the immune system. Depending on the therapeutically affected cell type, glucocorticoid actions strongly vary among different diseases. While immune responses always represent complex reactions involving different cells and cellular processes, specific immune cell populations with key responsibilities driving the pathological mechanisms can be identified for certain autoimmune diseases. In this review, we will focus on the mechanisms of action of glucocorticoids on various leukocyte populations, exemplarily portraying different autoimmune diseases as heterogeneous targets of glucocorticoid actions: (i) Abnormalities in the innate immune response play a crucial role in the initiation and perpetuation of giant cell arteritis (GCA). (ii) Specific types of CD4+ T helper (Th) lymphocytes, namely Th1 and Th17 cells, represent important players in the establishment and course of rheumatoid arthritis (RA), whereas (iii) B cells have emerged as central players in systemic lupus erythematosus (SLE). (iv) Allergic reactions are mainly triggered by several different cytokines released by activated Th2 lymphocytes. Using these examples, we aim to illustrate the versatile modulating effects of glucocorticoids on the immune system. In contrast, in the treatment of lymphoproliferative disorders the pro-apoptotic action of glucocorticoids prevails, but their mechanisms differ depending on the type of cancer. Therefore, we will also give a brief insight into the current knowledge of the mode of glucocorticoid action in oncological treatment focusing on leukemia.

Combined allergic rhinitis and asthma syndrome (CARAS)

Combined allergic rhinitis and asthma syndrome (CARAS) is a concept of "one airway - one disease" or "unified airway disease ". The upper and lower airway inflammation characterizes allergic rhinitis and asthma, respectively and both diseases have shown an intimate connection in their genesis, coexistence and similarities as triggered by the same etiological agents; the same inflammatory cell profile and share therapeutic treatment. This review highlights the concept of CARAS by its phenotype, endotype and biomarker classification. Indeed, rhinitis is divided into four major phenotypes: allergic rhinitis; infectious rhinitis; non-infective/non-allergic rhinitis and mixed rhinitis. On the other hand, asthma has no common consensus yet; however, the most accepted classification is based on the stage of life (early- or late- onset asthma) in which the clinical symptoms are presented. Experimental researches where animals develop a syndrome similar to CARAS have been contributed to better understand the pathogenesis of the syndrome. Therefore, the aim of this review is to clarify current terms related to CARAS as definition, phenotypes, endotypes/biomarkers, physiopathology and treatments.

Radon Therapy for Autoimmune Diseases Pemphigus and Diabetes: 2 Case Reports

We report on the application of radon therapy to relieve the suffering of 2 patients with autoimmune diseases, one with pemphigus with an old myocardial infarction and diabetes mellitus and the other with type I diabetes. We include a lengthy discussion of the biological mechanisms that we believe produced the observed benefits. During the 6 to 9 months of the treatments, the marker values decreased to the upper limit of their normal ranges and the symptoms of the diseases were alleviated. Disorders of Th1/Th2 balance are implicated in the onset of many diseases, including autoimmune diseases. Our decision to give radon (222Rn) therapy to these patients was based on the results of 2 similar case reports and our earlier mouse experiments, which indicated that low doses of radiation induce regulatory T cells. Regulatory T cells regulate the T helper 1 cell and the T helper 2 cell balance. There are more than 80 different autoimmune diseases that are treated with anti-inflammatory agents or immune-suppressing drugs because the exact causes of these diseases and the cures are unknown. These and other case reports indicate that proper radon therapy is an effective treatment. We urge physicians to consider radon as a standard therapy for refractory autoimmune diseases.

The Role of Autophagy in Eosinophilic Airway Inflammation

Autophagy is a homeostatic mechanism that discards not only invading pathogens but also damaged organelles and denatured proteins via lysosomal degradation. Increasing evidence suggests a role for autophagy in inflammatory diseases, including infectious diseases, Crohn's disease, cystic fibrosis, and pulmonary hypertension. These studies suggest that modulating autophagy could be a novel therapeutic option for inflammatory diseases. Eosinophils are a major type of inflammatory cell that aggravates airway inflammatory diseases, particularly corticosteroid-resistant inflammation. The eosinophil count is a useful tool for assessing which patients may benefit from inhaled corticosteroid therapy. Recent studies demonstrate that autophagy plays a role in eosinophilic airway inflammatory diseases by promoting airway remodeling and loss of function. Genetic variant in the autophagy gene ATG5 is associated with asthma pathogenesis, and autophagy regulates apoptotic pathways in epithelial cells in individuals with chronic obstructive pulmonary disease. Moreover, autophagy dysfunction leads to severe inflammation, especially eosinophilic inflammation, in chronic rhinosinusitis. However, the mechanism underlying autophagy-mediated regulation of eosinophilic airway inflammation remains unclear. The aim of this review is to provide a general overview of the role of autophagy in eosinophilic airway inflammation. We also suggest that autophagy may be a new therapeutic target for airway inflammation, including that mediated by eosinophils.

Stem cells from human exfoliated deciduous teeth correct the immune imbalance of allergic rhinitis via Treg cells in vivo and in vitro

Background

Several studies have demonstrated that mesenchymal stem cells can ameliorate the inflammation of allergic rhinitis (AR) and correct the Th1/Th2 immune imbalance.

Methods

This study was performed to explore the immunomodulation properties of stem cells from human exfoliated deciduous teeth (SHEDs) in the treatment of AR in vivo and in vitro. BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injection, and then SHEDs or bone marrow mesenchymal stem cells (BMMSCs) were injected intravenously before challenge. We evaluated nasal symptoms, inflammatory infiltration of nasal mucosa, immunoglobulin secretion, cytokine production, and mRNA expression in the spleen. In addition, peripheral blood mononuclear cells (PBMCs) from AR patients were cultured with SHEDs or BMMSCs in the presence of phytohemagglutinin (PHA). PBMCs cultured alone with or without PHA served as controls. After 3 days of culture, we examined the effect of SHEDs on T lymphocyte proliferation, cytokine secretion, and the proportion of Foxp3⁺ Treg cells via flow cytometry. Finally, to determine the role of soluble factors (TGF-β₁, PGE₂) in the immunomodulatory mechanism, a cytokine neutralization assay was performed.

Results

Nasal symptoms and inflammatory infiltration were significantly reduced after SHED administration. The OVA-specific IgE and IgG₁ levels in serum were significantly decreased, and the increased IL-4, IL-5, IL-13, and IL-17A levels in the spleen after OVA challenge were markedly downregulated, while the level of IFN-γ was upregulated by SHED administration. The mRNA expression levels also changed correspondingly. SHEDs significantly inhibited the proliferation of T lymphocytes; increased the levels of IFN-γ, IL-10, PGE₂, and TGF-β₁; decreased the levels of IL-4 and IL-17A; and induced the expansion of Treg cells in the coculture system. The neutralization of TGF-β₁ partly relieved the immunosuppression of SHEDs, but blocking PGE₂ did not. In addition, SHEDs were superior to BMMSCs in inhibiting the Th2 immune response in vivo and inducing the expansion of Treg cells in vitro.

Conclusion

These results suggest that SHEDs could correct the CD4⁺ T cell immune imbalance via Treg cells and may be potential therapeutic agents for the treatment of allergic diseases, such as AR, in the future.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1134-z) contains supplementary material, which is available to authorized users.

The immunomodulatory role of probiotics in allergy therapy

The increased incidence of allergic disorders may be the result of a relative fall in microbial induction in the intestinal immune system during infancy and early childhood. Probiotics have recently been proposed as viable microorganisms for the prevention and treatment of specific allergic diseases. Different mechanisms have been considered for this probiotic property, such as generation of cytokines from activated pro-T-helper type 1 after bacterial contact. However, the effects of its immunomodulatory potential require validation for clinical applications. This review will focus on the currently available data on the benefits of probiotics in allergy disease.

Influence of rutin on the effects of neonatal cigarette smoke exposure-induced exacerbated MMP-9 expression, Th17 cytokines and NF-κB/iNOS-mediated inflammatory responses in asthmatic mice model

Allergic asthma is one of the most enduring diseases of the airway. The T-helper cells and regulatory T-cells are critically involved in inflammatory responses, mucus hypersecretion, airway remodelling and in airway hyper-responsiveness. Cigarette smoke (CS) has been found to aggravate inflammatory responses in asthma. Though currently employed drugs are effective, associated side effects demand identification and development of novel drugs with negligible or no adverse effects. Rutin, plant-derived flavonoid has been found to possess antioxidant and anti-inflammatory effects. We investigated the ability of rutin to modulate T-cells and inhibit inflammation in experimentally-induced asthma in cigarette smoke exposed mice. Separate groups of neonatal mice were exposed to CS for 10 days from post-natal days 2 to 11. After 2 weeks, the mice were sensitized and challenged with ovalbumin (OVA). Treatment group were given rutin (37.5 or 75 mg/kg body weight) during OVA sensitization and challenge. Rutin treatment was found to significantly inhibit cellular infiltration in the airways and Th2 and Th17 cytokine levels as well. Flow cytometry revealed effectively raised CD4⁺CD25⁺Fox3⁺ Treg cells and supressed Th17 cell population on rutin treatment. Airway hyper-responsiveness observed following CS and OVA challenge were inhibited by rutin. NF-κB and iNOS, chief regulators of inflammatory responses robustly activated by CS and OVA were down-regulated by rutin. Rutin also inhibited the expression of matrix metalloproteinase 9, thereby aiding in prevention of airway remodelling in asthma thereby revealing to be a potent candidate in asthma therapy.

Invariant Natural Killer T Cell Subsets-More Than Just Developmental Intermediates

Invariant natural killer T (iNKT) cells are a CD1d-restricted T cell population that can respond to lipid antigenic stimulation within minutes by secreting a wide variety of cytokines. This broad functional scope has placed iNKT cells at the frontlines of many kinds of immune responses. Although the diverse functional capacities of iNKT cells have long been acknowledged, only recently have distinct iNKT cell subsets, each with a marked functional predisposition, been appreciated. Furthermore, the subsets can frequently occupy distinct niches in different tissues and sometimes establish long-term tissue residency where they can impact homeostasis and respond quickly when they sense perturbations. In this review, we discuss the developmental origins of the iNKT cell subsets, their localization patterns, and detail what is known about how different subsets specifically influence their surroundings in conditions of steady and diseased states.

Design and synthesis of novel 1,3,5-triphenyl pyrazolines as potential anti-inflammatory agents through allosteric inhibition of protein kinase Czeta (PKCζ)

Much light has been shed on the vital role of protein kinase Czeta (PKCζ) in NF-κB activation and the potential use of PKCζ inhibitors as anti-inflammatory agents. We previously reported a series of 1,3,5-trisubstituted pyrazolines as potent and selective allosteric inhibitors of PKCζ; in that series of compounds, the phenolic OH at the 5-phenyl was essential for binding to the PKCζ PIF pocket. In the present study, we surprisingly found that replacing it by a halogen and at the same time moving the OH to the 3-phenyl still resulted in active compounds. An extension of this class of compounds with a new focused library is presented herein, where the phenolic OH at the 5-phenyl, which was reported to be an irreplaceable feature for activity, was moved to the 3-phenyl and replaced by halogen. The new set of compounds maintained the same level of potency against PKCζ and selectivity against PKC isoforms, and showed reduced potency against the PIF pocket mutant PKCζ[Val297Leu]. Of note, the repositioning of the key functional groups resulted in a marked enhancement of cellular potency. One of the most potent new PKCζ inhibitors, 2h, was able to suppress NO production in RAW 264.7 macrophage cells with 8 times higher efficacy than the previous series, and inhibited the NF-κB transcriptional activity in U937 cells with a sub-micromolar IC50.

Initial Influenza Virus Replication Can Be Limited in Allergic Asthma Through Rapid Induction of Type III Interferons in Respiratory Epithelium

Although asthmatics has been considered to be highly susceptible to respiratory viral infection and most studies have focused on exacerbation of asthma by influenza A virus (IAV) infection, few experimental evidences exist to directly demonstrate that asthmatic mice are actually resistant to IAV infection. Here, we show that asthmatic mice are not highly susceptible to IAV in the early stage of infection and type III interferon (IFN) maintains antiviral immune response in the lung of IAV-infected asthmatic mouse resulting in inhibition of initial viral spread. C57BL/6 mice with allergic asthma were infected with IAV (WS/33: H1N1) and survival rate, body weight, viral titer, histopathological findings of lung and cytokine profiles including IFNs and Th2 cytokines were measured. Notably, asthmatic mice were significantly resistant to IAV and showed lower viral load until 7 days after infection. Furthermore, IAV-infected asthmatic mice exhibited decreased Th2-related inflammation in lung tissue until 7 days. These increased antiviral resistant mechanism and reduced Th2 inflammation were attributable to rapid induction of type III IFNs and blockade of type III IFNs in asthmatic lung led to aggravated IAV infection and to enhance the production of Th2 cytokines. Asthmatic mice showed bi-phasic responses against IAV-caused lung infection such as rapid production of type III IFNs and subsequent induction of type II IFNs. Actually, IAV-infected asthmatic mice become vulnerable to IAV infection after 7 days with noticeable morbidity and severe weight loss. However, intranasal administration of type III IFNs protects completely asthmatic mice from IAV-mediated immunopathology and lung infection until 14 days after infection. Taken together, our study indicates that the rapid induction of type III IFN might be distinctive immunological findings in the respiratory tract of IAV-infected asthmatic mice at the early stage of infection and crucial for suppression of initial viral spread in vivo asthma accompanying with restriction of Th2 cytokine productions.

The pathogenicity of IL-33 on steroid-resistant eosinophilic inflammation via the activation of memory-type ST2+ CD4+ T cells

The lungs are the primary organs of the respiratory system in many animals and have unique epithelial barrier systems to protect the host from continuous invasion of various harmful particles, such as viruses and bacteria. IL-33, a member of the IL-1 family of cytokines, is released from epithelial cells in the mucosal organs and drives the type 2 immune response by activating a number of immune cells in cases of helminth infection. However, IL-33 derived from epithelial cells also causes various allergic diseases via the activation of ST2-positive immune cells, including memory-type (CD62L^low CD44^hi ) ST2⁺ CD4⁺ T cells in the lung. Recent studies have revealed that the type 2 inflammation induced by IL-33 is steroid resistant. Steroid resistance causes severe chronic inflammatory diseases, such as intractable asthma. In this review, we will discuss the impact of ST2⁺ CD4⁺ T cells on shaping the pathology of IL-33-induced eosinophilic inflammation. We will also highlight the mechanism underlying steroid resistance in eosinophilic pneumonia. A better understanding of the cellular and molecular mechanisms underlying steroid resistance is crucial for the development of new therapeutic strategies for intractable allergic diseases.

Plasmacytoid dendritic cells drive acute asthma exacerbations

BACKGROUND

Although acute exacerbations, mostly triggered by viruses, account for the majority of hospitalizations in asthmatic patients, there is still very little known about the pathophysiologic mechanisms involved. Plasmacytoid dendritic cells (pDCs), prominent cells of antiviral immunity, exhibit proinflammatory or tolerogenic functions depending on the context, yet their involvement in asthma exacerbations remains unexplored.

OBJECTIVES

We sought to investigate the role of pDCs in allergic airway inflammation and acute asthma exacerbations.

METHODS

Animal models of allergic airway disease (AAD) and virus-induced AAD exacerbations were used to dissect pDC function in vivo and unwind the potential mechanisms involved. Sputum from asthmatic patients with stable disease or acute exacerbations was further studied to determine the presence of pDCs and correlation with inflammation.

RESULTS

pDCs were key mediators of the immunoinflammatory cascade that drives asthma exacerbations. In animal models of AAD and rhinovirus-induced AAD exacerbations, pDCs were recruited to the lung during inflammation and migrated to the draining lymph nodes to boost T_H2-mediated effector responses. Accordingly, pDC depletion after allergen challenge or during rhinovirus infection abrogated exacerbation of inflammation and disease. Central to this process was IL-25, which was induced by allergen challenge or rhinovirus infection and conditioned pDCs for proinflammatory function. Consistently, in asthmatic patients pDC numbers were markedly increased during exacerbations and correlated with the severity of inflammation and the risk for asthma attacks.

CONCLUSIONS

Our studies uncover a previously unsuspected role of pDCs in asthma exacerbations with potential diagnostic and prognostic implications. They also propose the therapeutic targeting of pDCs and IL-25 for the treatment of acute asthma.

Inhibition of T Cell Alloreactivity by Bronchial Epithelium Is Impaired in Lung Transplant Recipients, Through Pathways Involving TGF-β, IL-10 and HLA-G

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) after lung transplantation (LTx) results from bronchial epithelial cell (BECs) damages, thought to be orchestrated by T cells primed by antigen-presenting cell presenting alloantigens. In this cell cross-talk, BECs are also suspected to play a pivotal immunosuppressive role in T cell alloreactivity. We studied the immunomodulating role of BECs in a human ex vivo model of allogeneic T cell response, both in healthy subjects and LTx recipients.

METHODS

BECs from 35 LTx recipients (n = 22 stable, n = 13 BOS) and healthy controls (n = 25) were cultured as primary cell cultures. Their inhibitory capacities through the involvement of tolerogenic molecules (HLA-G, TGF-β, and IL-10) were tested on a mixed lymphocyte reaction between antigen-presenting cells and recipient T cells.

RESULTS

Control BECs inhibited T cell alloproliferation by a mean of 53 ± 7%. This inhibitory effect of BECs was significantly reduced in the stable LTx group (24 ± 8%, P = 0.009), but not in the BOS TxP group (53 ± 10%, P = 0.97). Neutralization of HLA-G, TGF-β, and IL-10 partially restored T cell alloproliferation, arguing for their involvement in the immunosuppressive effect of BECs. BECs culture supernatant from stable LTx patients with impaired BEC properties showed a skewed Th2-type secretion profile (high IL-4/IFN-γ ratio).

CONCLUSIONS

The inhibitory properties of BECs are dysregulated in stable LTx recipients, which could suggest their instrumental role in the initiation of BOS process and potential targeted therapies.

Safety and pharmacodynamics of intranasal GSK2245035, a TLR7 agonist for allergic rhinitis: A randomized trial

BACKGROUND

Toll-like receptor 7 (TLR7) stimulation in the airways may reduce responses to aeroallergens by induction of type 1 interferons (IFNs). GSK2245035 is a novel selective TLR7 agonist in pharmaceutical development.

OBJECTIVE

Assessment of safety, pharmacodynamics and nasal allergic reactivity following repeated weekly intranasal (i.n.) GSK2245035.

METHODS

This randomized, double-blind, placebo-controlled study (TL7116958) was conducted over two pollen seasons (2013-2014) and follow-up study (204509) conducted 1 year later. Participants with allergic rhinitis (n=42) were randomized to receive eight weekly doses of i.n. GSK2245035 (20 ng [2014 Cohort; n=14] or 80 ng [2013 Cohort; n=14]) or placebo (n=14). Adverse events (AEs) including cytokine release syndrome AEs (CytoRS-AEs) and nasal symptoms were assessed. Nasal and serum IFN-inducible protein 10 (IP-10) were measured after doses 1 and 8, then 1 (follow-up visit [FUV] 1) and 3 (FUV2) weeks after final dose. Nasal allergen challenges (NACs) and allergic biomarker assessment (nasal, serum) were conducted at baseline, FUV1, FUV2 and at a FUV 1 year after final dose (FUV3; 2014 Cohort only). A Bayesian framework enabled probability statements for mean effect sizes.

RESULTS

GSK2245035 induced CytoRS-AEs (most commonly headache, median duration <1 day) in 93% of participants at 80 ng, while AE incidence at 20 ng was similar to placebo. There was no evidence of nasal inflammation. Dose-related increases in nasal and serum IP-10 were observed 24 hours after doses 1 and 8 (>95% certainty). Both doses showed a trend in reducing total nasal symptom score 15 minutes post-NAC at FUV1 and FUV2, but there was no reduction evident at FUV3. Nasal levels of selected allergic biomarkers demonstrated trends for reductions at FUV1, FUV2 and FUV3.

CONCLUSIONS AND CLINICAL RELEVANCE

Weekly i.n. GSK2245035 20 ng was well tolerated and reduced allergic reactivity to nasal challenge for 3 weeks post-treatment.

Spectrum of T-lymphocyte activities regulating allergic lung inflammation

Despite advances in the treatment of asthma, optimization of symptom control remains an unmet need in many patients. These patients, labeled severe asthma, are responsible for a substantial fraction of the disease burden. In these patients, research is needed to define the cellular and molecular pathways contributing to disease which in large part are refractory to corticosteroid treatment. The causes of steroid-resistant asthma are multifactorial and result from complex interactions of genetics, environmental factors, and innate and adaptive immunity. Adaptive immunity, addressed here, integrates the activities of distinct T-cell subsets and by definition is dynamic and responsive to an ever-changing environment and the influences of epigenetic modifications. These T-cell subsets exhibit different susceptibilities to the actions of corticosteroids and, in some, corticosteroids enhance their functional activation. Moreover, these subsets are not fixed in lineage differentiation but can undergo transcriptional reprogramming in a bidirectional manner between protective and pathogenic effector states. Together, these factors contribute to asthma heterogeneity between patients but also in the same patient at different stages of their disease. Only by carefully defining mechanistic pathways, delineating their sensitivity to corticosteroids, and determining the balance between regulatory and effector pathways will precision medicine become a reality with selective and effective application of targeted therapies.

Fungal immunomodulatory protein-fve could modulate airway remodel through by affect IL17 cytokine

BACKGROUND

Asthma is one of the most common allergic diseases. Our previous studies have reported that FIP-fve in acute allergic mouse model can reduce inflammation, improve the balance of the Th1/Th2 system. However, the effects of reducing airway remodeling on FIP-fve is still unknown.

OBJECTIVE

We hypothesized that orally administrated FIP-fve should be able to reduce airway remodeling in chronic allergic models.

METHODS

The chronic asthma animal model was established with 6-8 weeks female Balb/c mice. After intranasal challenges with OVA, the airway inflammation and AHR were determined by a BUXCO system. BALF was analyzed with Liu's stain and ELISA assay. Lung histopathologic changes and Collagen deposition were assayed with H&E, Masson's trichrome and IHC stain.

RESULTS

FIP-fve significantly decreased the number of infiltrating inflammatory cells and Th2 cytokines and increased Th1 cytokines in BALF and serum compared with the OVA sensitized mice. FIP-fve had a better effect than corticosteroid could reduce infiltrating cells in lung especially neutrophils and eosinophils. We also found that the oral FIP-fve group suppressed IL-17 and enhanced IL-22 in the serum and BALF. In addition, oral FIP-fve decreased MMP9 expression, collagen expression and airway remodeling in lung tissues.

CONCLUSION

FIP-fve had anti-inflammatory effects on OVA-induced airway inflammation and an effect to inhibited Th17 cells to reduced airway remodeling and collagen expression. Moreover, FIP-fve might be a potential alternative therapy for allergic airway diseases.

Downregulated regulatory T cell function is associated with increased peptic ulcer in Helicobacter pylori-infection

BACKGROUND

Helicobacter pylori (H. pylori) chronically colonizes gastric/duodenal mucosa and induces gastroduodenal disease such as gastritis and peptic ulcer and induces vigorous innate and specific immune responses; however, the infection is not removed, a state of chronic active gastritis persists for life if untreated. The objective of this study was to determine the number of regulatory T cells (Tregs) in gastric mucosa of patients with gastritis and peptic ulcer and determined the relationship between main virulence factor of H. pylori and Tregs.

METHODS AND MATERIALS

A total of 89 patients with gastritis, 63 patients with peptic ulcer and 40 healthy, H. pylori-negative subjects were enrolled in this study. Expression of CD4 and Foxp3 was determined by immunohistochemistry. Antrum biopsy was obtained for detection of H. pylori, bacterial virulence factors and histopathological assessments. TGF-β1, IL-10 and FOXP3 expressions were determined by real-time polymerase chain reaction (qPCR).

RESULTS

The numbers of CD4⁺ and Foxp3⁺ T cells as well as the expression of IL-10, TGF-β1, FOXP3, INF-γ and IL-17A in infected patients were significantly higher than the ones in uninfected patients. Also, the number of CD4⁺ T cells was independent on the vacuolating cytotoxin A (vacA) and outer inflammatory protein A (oipA), but it was positively correlated with cytotoxin-associated gene A (cagA). Instead, the number of Foxp3⁺ T cells was dependent on the vacA and oipA, but it was independent on cagA. The number of Foxp3⁺ T cells and the expression of IL-10, TGF-β1 and FOXP3 in infected patients with gastritis were significantly higher than the ones in infected patients with peptic ulcer. Moreover, the number of CD4⁺ T cells and the expression of IL-17A and INF-γ was the lowest in the gastritis patients, however, increased progressively in the peptic ulcer patients. Additionally, the numbers of CD4⁺ and Foxp3⁺ T cells as well as the expression of IL-10, TGF-β1, FOXP3 and INF-γ were positively correlated with the degree of H. pylori density and chronic inflammation.

CONCLUSION

Tregs are positively associated with vacA alleles and oipA status of H. pylori and histological grade but negatively associated with peptic ulcer disease.

Pathogenic Th cell subsets in chronic inflammatory diseases

CD4(+) T cells play central roles to appropriate protection against pathogens. While, they can also be pathogenic driving inflammatory diseases. Besides the classical model of differentiation of T helper 1 (Th1) and Th2 cells, various CD4(+) T cell subsets, including Th17, Th9, T follicular helper (Tfh) and T regulatory (Treg) cells, have been recognized recently. In this review, we will focus on how these various CD4(+) T cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. We will also discuss various unique subpopulations of T helper cells that have been identified. Recent advancement of the basic immunological research revealed that T helper cells are plastic than we imagined. So, we will focus on the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T helper cell subsets. These latest finding regarding T helper cell subsets has pushed us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the conventional Th1/Th2 balance. Toward this end, we put forward another model, "the pathogenic Th population disease induction model", as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases.

Dose-dependent immunomodulating effects of endotoxin in allergic airway inflammation

How very high exposure levels to endotoxin in a farming environment provide protection against respiratory allergic symptoms and low-to-moderate levels of endotoxin in urban homes promote allergic response is unclear. Dose-specific bacterial endotoxin or LPS-induced tolerance mechanisms can affect lung inflammations, coupled with the Th2 immune responses. Here, we explored the effects of intranasal exposure of LPS at two different doses (based on occupational exposures during handling of agricultural wastes) in OVA-sensitized allergic wild type (WT) and TLR4-KO mice, particularly, with respect to Th2 cytokines and Tregs level. Low-dose LPS (100 ng) exposure prohibited airway tolerance and failed to generate T-cell-dependent protection against lung inflammations in allergic mice. Furthermore, low Tregs at the inflammatory site and induced Th2 cytokines, as well as IL-6 and IL-25, suggested that low-dose LPS might be associated with the suppression of tolerance mechanisms. In contrast, high-dose LPS (20 µg) favored the suppression of Th2 cytokines, IL-6 and IL-25, but failed to induce Th1 cytokines (e.g. IFN-γ). Our results suggest that low-dose LPS can enhance airway allergic inflammation through failing of antigen-dependent immune regulatory homeostasis. The exposure levels of LPS can determine the generation of inflammatory responses in airway allergy.

The Role of Lymphocytes in Radiotherapy-Induced Adverse Late Effects in the Lung

Radiation-induced pneumonitis and fibrosis are dose-limiting side effects of thoracic irradiation. Thoracic irradiation triggers acute and chronic environmental lung changes that are shaped by the damage response of resident cells, by the resulting reaction of the immune system, and by repair processes. Although considerable progress has been made during the last decade in defining involved effector cells and soluble mediators, the network of pathophysiological events and the cellular cross talk linking acute tissue damage to chronic inflammation and fibrosis still require further definition. Infiltration of cells from the innate and adaptive immune systems is a common response of normal tissues to ionizing radiation. Herein, lymphocytes represent a versatile and wide-ranged group of cells of the immune system that can react under specific conditions in various ways and participate in modulating the lung environment by adopting pro-inflammatory, anti-inflammatory, or even pro- or anti-fibrotic phenotypes. The present review provides an overview on published data about the role of lymphocytes in radiation-induced lung disease and related damage-associated pulmonary diseases with a focus on T lymphocytes and B lymphocytes. We also discuss the suspected dual role of specific lymphocyte subsets during the pneumonitic phase and fibrotic phase that is shaped by the environmental conditions as well as the interaction and the intercellular cross talk between cells from the innate and adaptive immune systems and (damaged) resident epithelial cells and stromal cells (e.g., endothelial cells, mesenchymal stem cells, and fibroblasts). Finally, we highlight potential therapeutic targets suited to counteract pathological lymphocyte responses to prevent or treat radiation-induced lung disease.

Th2 Cells in Health and Disease

Helper T (Th) cell subsets direct immune responses by producing signature cytokines. Th2 cells produce IL-4, IL-5, and IL-13, which are important in humoral immunity and protection from helminth infection and are central to the pathogenesis of many allergic inflammatory diseases. Molecular analysis of Th2 cell differentiation and maintenance of function has led to recent discoveries that have refined our understanding of Th2 cell biology. Epigenetic regulation of Gata3 expression by chromatin remodeling complexes such as Polycomb and Trithorax is crucial for maintaining Th2 cell identity. In the context of allergic diseases, memory-type pathogenic Th2 cells have been identified in both mice and humans. To better understand these disease-driving cell populations, we have developed a model called the pathogenic Th population disease induction model. The concept of defined subsets of pathogenic Th cells may spur new, effective strategies for treating intractable chronic inflammatory disorders.

Allergen-driven HLA-G expression and secretion in peripheral blood mononuclear cells from allergic rhinitis patients

BACKGROUND

It has been reported that soluble HLA-G serum levels are increased in patients with pollen-induced allergic rhinitis and decrease after immunotherapy. However, no functional study has been conducted so far. The aim of this study was to evaluate the membrane expression and secretion of HLA-G molecules in peripheral blood mononuclear cells from allergic rhinitis patients after in vitro incubation with the causal allergen.

METHODS AND RESULTS

Twenty-two allergic rhinitis patients and ten healthy subjects were enrolled. Membrane HLA-G expression was determined by flow cytometry and soluble HLA-G in culture supernatant was determined by immunoenzymatic assay. HLA-G expression was detected in CD4+ (T-helper-2) cells and monocytes after in vitro stimulation with the causal allergen but not with non specific stimuli and non causal allergens. Accordingly, the release of soluble HLA-G in culture supernatant occurred only after the stimulation with the causal allergen. Collectively, these results were confirmed by Western blot analysis.

CONCLUSIONS

The present study provides the first in vitro evidence that in allergic patients HLA-G expression and secretion is specifically induced by the causal allergen. These data may add new insights into the pathogenetic mechanisms underlying allergic inflammation and allergen specific immunotherapy.

The role of autophagy in allergic inflammation: a new target for severe asthma

Autophagy has been investigated for its involvement in inflammatory diseases, but its role in asthma has been little studied. This study aimed to explore the possible role of autophagy and its therapeutic potential in severe allergic asthma. BALB/c mice were sensitized with ovalbumin (OVA) on days 0 and 14, followed by primary OVA challenge on days 28–30. The mice received a secondary 1 or 2% OVA challenge on days 44–46. After the final OVA challenge, the mice were assessed for airway responsiveness (AHR), cell composition and cytokine levels in bronchoalveolar lavage fluid (BALF). LC3 expression in lung tissue was measured by western blot and immunofluorescence staining. Autophagosomes were detected by electron microscopy. 3-Methyladenine (3-MA) treatment and Atg5 knockdown were applied to investigate the potential role of autophagy in allergic asthma mice. AHR, inflammation in BALF and LC3 expression in lung tissue were significantly increased in the 2% OVA-challenged mice compared with the 1% OVA-challenged mice (P<0.05). In addition, eosinophils showed prominent formation of autophagosomes and increased LC3 expression compared with other inflammatory cells in BALF and lung tissue. After autophagy was inhibited by 3-MA and Atg5 shRNA treatment, AHR, eosinophilia, interleukin (IL)-5 levels in BALF and histological inflammatory findings were much improved. Finally, treatment with an anti-IL-5 antibody considerably reduced LC3 II expression in lung homogenates. Our findings suggest that autophagy is closely correlated with the severity of asthma through eosinophilic inflammation, and its modulation may provide novel therapeutic approaches for severe allergic asthma.

Immunoregulatory Role of HLA-G in Allergic Diseases

Allergic diseases are sustained by a T-helper 2 polarization leading to interleukin-4 secretion, IgE-dependent inflammation, and mast cell and eosinophil activation. HLA-G molecules, both in membrane-bound and in soluble forms, play a central role in modulation of immune responses. Elevated levels of soluble HLA-G (sHLA-G) molecules are detected in serum of patients with allergic rhinitis to seasonal and perennial allergens and correlate with allergen-specific IgE levels, clinical severity, drug consumption, and response to allergen-specific immunotherapy. sHLA-G molecules are also found in airway epithelium of patients with allergic asthma and high levels of sHLA-G molecules are detectable in plasma and bronchoalveolar lavage of asthmatic patients correlating with allergen-specific IgE levels. Finally, HLA-G molecules are expressed by T cells, monocytes-macrophages, and Langerhans cells infiltrating the dermis of atopic dermatitis patients. Collectively, although at present it is difficult to completely define the role of HLA-G molecules in allergic diseases, it may be suggested that they are expressed and secreted by immune cells during the allergic reaction in an attempt to suppress allergic inflammation.

Inhibition of inflammatory reactions in 2,4-Dinitrochlorobenzene induced Nc/Nga atopic dermatitis mice by non-thermal plasma

Non-thermal plasma (NTP) has recently been introduced and reported as a novel tool with a range of medicinal and biological roles. Although many studies using NTP have been performed, none has investigated the direct relationship between NTP and immune responses yet. Especially, the effects of NTP on atopic dermatitis (AD) were not been explored. Here, NTP was tested whether it controls immune reactions of AD. NTP treatment was administered to pro-inflammatory cytokine-stimulated keratinocytes and DNCB (2,4-Dinitrochlorobenzene)-induced atopic dermatitis mice, then the immune reactions of cells and skin tissues were monitored. Cells treated with NTP showed decreased expression levels of CCL11, CCL13, and CCL17 along with down-regulation of NF-κB activity. Repeated administration of NTP to AD-induced mice reduced the numbers of mast cells and eosinophils, IgE, CCL17, IFNγ levels, and inhibited NF-κB activity in the skin lesion. Furthermore, combined treatment with NTP and 1% hydrocortisone cream significantly decreased the immune responses of AD than that with either of these two treatments individually. Overall, this study revealed that NTP significantly inhibits several immune reactions of AD by regulating NF-κB activity. Therefore, NTP could be useful to suppress the exaggerated immune reactions in severe skin inflammatory diseases such as AD.

CD4+ T-cell subsets in inflammatory diseases: beyond the Th1/Th2 paradigm

CD4(+)T cells are crucial for directing appropriate immune responses during host defense and for the pathogenesis of inflammatory diseases. In addition to the classical biphasic model of differentiation of T-helper 1 (Th1) and Th2 cells, unexpected increases in the numbers of CD4(+)T-cell subsets, including Th17, Th9, T follicular-helper (Tfh) and T-regulatory (Treg) cells, have been recognized. In the present review, we focus on how these various T-helper cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. In particular, we focus on multiple sclerosis, psoriasis and asthma as typical model diseases in which multiple T-helper cell subsets have recently been suggested to play a role. We will also discuss various unique sub-populations of T-helper cells that have been identified. First, we will introduce the heterogeneous T-helper cell subsets, which are classified by their simultaneous expression of multiple key transcription factors. We will also introduce different kinds of memory-type Th2 cells, which are involved in the pathogenesis of chronic type-2 immune-related diseases. Finally, we will discuss the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T-helper cell subsets. The latest progress in the study of T-helper cell subsets has forced us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the Th1/Th2 balance. To this end, we propose another model--the pathogenic T-helper population disease-induction model--as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases.

High mobility group box 1: a novel mediator of Th2-type response-induced airway inflammation of acute allergic asthma

BACKGROUND

High mobility group box 1 (HMGB1) is an inflammatory mediator involved into the advanced stage of systemic inflammatory response syndrome (SIRS), and is over-expressed in bacterial sepsis and hemorrhagic shock. Recently, it has been found that the HMGB1 was abnormally expressed in induced sputum and plasma of asthmatic patients. However, the precise role of HMGB1 in the acute allergic asthma is unclear. Therefore, we aim to investigate the role HMGB1 in regulating airway inflammation of acute allergic asthma and its possible mechanism in this study.

METHODS

Forty-eight BALB/c female mice were randomly divided into four groups: control group (Control), asthma group (Asthma), HMGB1 group (HMGB1) and anti-HMGB1 (HMGB1 monoclonal antibody of mice) group (Anti-HMGB1). Acute allergic asthma mice models were established by ovalbumin (OVA)-challenge. Then, we measured the levels of HMGB1 in bronchoalveolar lavage fluid (BALF) and lung tissue of mice. Finally, after exogenous HMGB1 and/or anti-HMGB1 administration, pulmonary function test, histological analysis, Western blot, cytological analysis and ELISA assay were performed to explore the effect of HMGB1 in acute allergic asthma.

RESULTS

The levels of HMGB1 in BALF and lung tissue and the expression of HMGB1 protein in the lung tissue of asthma group were significantly higher than those in control group, respectively (P<0.01). Moreover, the HMGB1 group was showed an increased mucus secretion and infiltration of eosinophils and neutrophils in the airway of asthma mice, and a decrease of pulmonary function, compared to control group (P<0.01, respectively). Meanwhile, exogenous HMGB1 could increase the levels of IL-4, IL-5, IL-6, IL-8 and IL-17, whereas could reduce the IFN-γ in the BALF and lung tissue (P<0.05, respectively). Exogenous HMGB1 could enhance GATA3 expression of Th2 cells and attenuate the T-bet expression of Th1 cells (P<0.05, respectively), which could be abrogated after inhibiting HMGB1.

CONCLUSIONS

HMGB1 could aggravate eosinophilic inflammation in the airway of acute allergic asthma through inducing a dominance of Th2-type response and promoting the neutrophilic inflammation.

Control of regulatory T cells and airway tolerance by lung macrophages and dendritic cells

Airway tolerance, a state of immunological surveillance, suppresses the development of lung inflammatory disorders that are driven by various pathological effector cells of the immune system. Tolerance in the lung to inhaled antigens is primarily mediated by regulatory T cells (Treg cells) that can inhibit effector T cells via a myriad of mechanisms. Accumulating evidence suggests that regulatory antigen-presenting cells are critical for generating Treg cells and/or maintaining the suppressive environment in the lung. This review focuses on the control of airway tolerance by Treg cells and the role of regulatory lung tissue and alveolar macrophages, and lung and lymph node dendritic cells, in contributing to airway tolerance that is associated with suppression of allergic asthmatic disease.

Inhibition of Epithelial CC-Family Chemokine Synthesis by the Synthetic Chalcone DMPF-1 via Disruption of NF-κB Nuclear Translocation and Suppression of Experimental Asthma in Mice

Asthma is associated with increased pulmonary inflammation and airway hyperresponsiveness. The interaction between airway epithelium and inflammatory mediators plays a key role in the pathogenesis of asthma. In vitro studies evaluated the inhibitory effects of 3-(2,5-dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one (DMPF-1), a synthetic chalcone analogue, upon inflammation in the A549 lung epithelial cell line. DMPF-1 selectively inhibited TNF-α-stimulated CC chemokine secretion (RANTES, eotaxin-1, and MCP-1) without any effect upon CXC chemokine (GRO-α and IL-8) secretion. Western blot analysis further demonstrated that the inhibitory activity resulted from disruption of p65NF-κB nuclear translocation without any effects on the mitogen-activated protein kinase (MAPK) pathway. Treatment of ovalbumin-sensitized and ovalbumin-challenged BALB/c mice with DMPF-1 (0.2–100 mg/kg) demonstrated significant reduction in the secretion and gene expression of CC chemokines (RANTES, eotaxin-1, and MCP-1) and Th2 cytokines (IL-4, IL-5, and IL-13). Furthermore, DMPF-1 treatment inhibited eosinophilia, goblet cell hyperplasia, peripheral blood total IgE, and airway hyperresponsiveness in ovalbumin-sensitized and ovalbumin-challenged mice. In conclusion, these findings demonstrate the potential of DMPF-1, a nonsteroidal compound, as an antiasthmatic agent for further pharmacological evaluation.

Serum-soluble HLA-G is associated with specific IgE in patients with allergic rhinitis and asthma

Allergic rhinitis (AR) and allergic asthma (AA) are characterized by T helper (Th)2-polarized immune response. Soluble human leukocyte antigen G (sHLA-G) molecule plays an immunomodulatory activity. Previously, it has been reported that children with AR or AA had higher sHLA-G levels in comparison with normal subjects. Thus, the present study aimed at confirming these data in adults and investigating whether there was a relationship between serum sHLA-G levels and serum IgE levels, in patients with AR or AA. One hundred twenty symptomatic patients, suffering from respiratory symptoms, were enrolled: 45 non-allergic and 75 allergic. A group of 44 healthy subjects was considered as control. Serum sHLA-G levels and serum allergen-specific IgE were determined by immunoenzymatic methods. Allergic patients had significantly higher levels of sHLA-G molecules than non-allergic patients and normal controls (p<0.0001). There was no difference between AR and AA. sHLA-G moderately related with allergen-specific IgE both in AR (r=0.468) and AA patients (r=0.479). The present study confirms that serum sHLA-G molecules are significantly increased in allergic disease and demonstrates that sHLA-G levels are related with allergen-specific IgE levels.

Long-Term Exposure to House Dust Mite Leads to the Suppression of Allergic Airway Disease Despite Persistent Lung Inflammation

BACKGROUND

Allergic asthma is a major cause of worldwide morbidity and results from inadequate immune regulation in response to innocuous, environmental antigens. The need exists to understand the mechanisms that promote nonreactivity to human-relevant allergens such as house dust mite (HDM) in order to develop curative therapies for asthma. The aim of our study was to compare the effects of short-, intermediate- and long-term HDM administration in a murine asthma model and determine the ability of long-term HDM exposure to suppress allergic inflammation.

METHODS

C57BL/6 mice were intranasally instilled with HDM for short-term (2 weeks), intermediate-term (5 weeks) and long-term (11 weeks) periods to induce allergic airway disease (AAD). The severity of AAD was compared across all stages of the model via both immunological and pulmonary parameters.

RESULTS

Short- and intermediate-term HDM exposure stimulated the development of AAD that included eosinophilia in the bronchoalveolar lavage fluid (BALF), pronounced airway hyperreactivity (AHR) and evidence of lung inflammation. Long-term HDM exposure promoted the suppression of AAD, with a loss of BALF eosinophilia and AHR despite persistent mononuclear inflammation in the lungs. Suppression of AAD with long-term HDM exposure was associated with an increase in both Foxp3+ regulatory T cells and IL-10-positive alveolar macrophages at the site of inflammation.

CONCLUSIONS

This model recapitulates the key features of human asthma and may facilitate investigation into the mechanisms that promote immunological tolerance against clinically relevant aeroallergens.