CD4 T-helper cells engineered to produce IL-10 prevent allergen-induced airway hyperreactivity and inflammation

IL-10 Differentially Promotes Mast Cell Responsiveness to IL-33, Resulting in Enhancement of Type 2 Inflammation and Suppression of Neutrophilia

Mast cells (MCs) play critical roles in the establishment of allergic diseases. We recently demonstrated an unexpected, proinflammatory role for IL-10 in regulating MC responses. IL-10 enhanced MC activation and promoted IgE-dependent responses during food allergy. However, whether these effects extend to IgE-independent stimuli is not clear. In this article, we demonstrate that IL-10 plays a critical role in driving IL-33-mediated MC responses. IL-10 stimulation enhanced MC expansion and degranulation, ST2 expression, IL-13 production, and phospho-relA upregulation in IL-33-treated cells while suppressing TNF-α. These effects were partly dependent on endogenous IL-10 and further amplified in MCs coactivated with both IL-33 and IgE/Ag. IL-10's divergent effects also extended in vivo. In a MC-dependent model of IL-33-induced neutrophilia, IL-10 treatment enhanced MC responsiveness, leading to suppression of neutrophils and decreased TNF-α. In contrast, during IL-33-induced type 2 inflammation, IL-10 priming exacerbated MC activity, resulting in MC recruitment to various tissues, enhanced ST2 expression, induction of hypothermia, recruitment of eosinophils, and increased MCPT-1 and IL-13 levels. Our data elucidate an important role for IL-10 as an augmenter of IL-33-mediated MC responses, with implications during both allergic diseases and other MC-dependent disorders. IL-10 induction is routinely used as a prognostic marker of disease improvement. Our data suggest instead that IL-10 can enhance ST2 responsiveness in IL-33-activated MCs, with the potential to both aggravate or suppress disease severity depending on the inflammatory context.

Evaluation of mucosal immune profile associated with Zileuton nanocrystal-formulated BCS-II drug upon oral administration in Sprague Dawley rats

Nanocrystal drug formulation involves several critical manufacturing procedures that result in complex structures to improve drug solubility, dissolution, bioavailability, and consequently the efficacy of poorly soluble Biopharmaceutics Classification System (BCS) II and IV drugs. Nanocrystal formulation of an already approved oral drug may need additional immunotoxic assessment due to changes in the physical properties of the active pharmaceutical ingredient (API). In this study, we selected Zileuton, an FDA-approved drug that belongs to BCS-II for nanocrystal formulation. To evaluate the efficacy and mucosal immune profile of the nanocrystal drug, 10-week-old rats were dosed using capsules containing either API alone or nanocrystal formulated Zileuton (NDZ), or with a physical mixture (PM) using flexible oral gavage syringes. Control groups consisted of untreated, or placebo treated animals. Test formulations were administrated to rats at a dose of 30 mg/kg body weight (bw) once a day for 15 days. The rats treated with NDZ or PM had approximately 4.0 times lower (7.5 mg/kg bw) API when compared to the micron sized API treated rats. At the end of treatment, mucosal (intestinal tissue) and circulating cytokines were measured. The immunological response revealed that NDZ decreased several proinflammatory cytokines in the ileal mucosa (Interleukin-18, Tumor necrosis Factor-α and RANTES [regulated upon activation, normal T cell expressed and secreted]). A similar pattern in the cytokine profile was also observed for the micron sized API and PM treated rats. The cytokine production revealed that there was a significant increase in the production of IL-1β and IL-10 in the females in all experimental groups. Additionally, NDZ showed an immunosuppressive effect on proinflammatory cytokines both locally and systemically, which was similar to the response in micron sized API treated rats. These findings indicate that NDZ significantly decreased several proinflammatory cytokines and it displays less immunotoxicity, probably due to the nanocrystal formulation. Thus, the nanocrystal formulation is more suitable for oral drug delivery, as it exhibited better efficacy, safety, and reduced toxicity.

Combination of Gut Microbial Features and the Proteomic Pattern Revealed Changes in Specific Intestinal Luminal Factors and Mechanisms of Their Regulation of Gluten Allergy

Recent research consensus has highlighted the role of intestinal luminal factors in the association between intestinal microenvironment homeostasis and food allergy. However, the association between intestinal immune homeostasis and food allergy-related proteomic features remains elusive. In this study, we aimed to investigate the changes in gluten allergy (GA)-defined phenotypes and endotypes and intestinal microenvironment factors in BALB/c mice and linked GA to colonic proteomic signatures. Combined with increased allergy and diarrhea scores, intense antibody responses and abnormalities in T-cell cytokine production were induced in mice. GA-associated disruption of intestinal microenvironment homeostasis was underlined by the increased colonic pH, decreased intestinal antioxidant capacity, impaired intestinal barrier function, and decreased production and imbalanced proportions of short-chain fatty acids. 16S rRNA amplicon sequencing showed that the gut microbiota dysbiosis in mice was characterized by significant enrichment of six bacterial taxonomic units, including Prevotellaceae, Escherichia Shigella, Alloprevotella, Escherichia coli, Bacteroides vulgatus, and Lachnospiraceae bacterium DW59, which was correlated with immune end points. Using a label-free proteomics quantitative approach, 24 differentially expressed proteins linking GA-induced gut dysbiosis were identified, with four of them enriched in the serine endopeptidase inhibitor activity pathway. The development of GA in mice was associated with changes in specific intestinal luminal factors and may be mediated by serine protease activity-associated metabolic routes.

Immunostimulatory effects of Nannochloropsis oculata supplementation on Barki rams growth performance, antioxidant assay, and immunological status

BACKGROUND

Natural feed supplements are gaining popularity in the animal production sector due to their safety and potential immunostimulatory properties, as well as the ban of some antibiotics and their negative residual effects. This study was carried out for 1 month to investigate the effect of Nannochloropsis oculata supplementation on growth performance and cell-mediated immunological status of rams assessed by leukogram assessment, lipid oxidation product malondialdehyde (MDA), total antioxidant capacity (TAC), interleukin assay after lymphocyte transformation test (LTT) including interleukin 6 (IL6), tumor necrosis factor-alpha (TNF-α), interleukin 12 (IL12), and gamma interferon (γ-IF), as well as Comet assay (% of DNA damage, tail length (px), % DNA in tail, tail moment and Olive tail moment).

METHODS

Eighteen Barki rams (26.21 ± 0.64 kg) were divided into 3 equal treatment groups (6 sheep/each), G1: animals served as the control group that was fed the basal diet only, while the other treated groups (G2 and G3 (Nan 1.5% and Nan 3%) were fed the basal diet supplemented with 1.5% and 3% N. oculata (dry matter basis), respectively.

RESULTS

The obtained results revealed that G3 showed a significant (P < 0.05) improvement in performance (body weight and body weight gain), the highest significant count (P < 0.05) in lymphocytes, and the lowest significant (P < 0.05) levels of neutrophils and neutrophils and lymphocytes ratio (N/L) ratio. Meanwhile, both levels of N. oculata significantly (P < 0.05) decreased MDA and increased TAC than control which seemed to be directly correlated with supplemented dose. There was a significant (P < 0.05) enhancement in the lymphocyte transformation assay produced significant (P < 0.05) high cytokines (IL6, γ-IF, IL12, and TNF-α) and the lowest significant (P <0.05) percent of DNA damage. The conducted principal component analysis estimated the inter-relationship between parameters and revealed that microalgae correlated strongly with cytokine assay and TAC, and negatively with Comet assay parameters; MDA, and neutrophils.

CONCLUSIONS

It can be noted that dietary addition of N. oculata 3% increased sheep's performance while also producing significant-high cytokines. It also enhanced sheep immunology by considerably enhancing lymphocyte transformation ability. The antioxidant activity of Nannochloropsis appears to influence these findings. It was proposed that the Barki rams' basal diet be supplemented with 3% N. oculata.

Sex Steroids Effects on Asthma: A Network Perspective of Immune and Airway Cells

A multitude of evidence has suggested the differential incidence, prevalence and severity of asthma between males and females. A compilation of recent literature recognized sex differences as a significant non-modifiable risk factor in asthma pathogenesis. Understanding the cellular and mechanistic basis of sex differences remains complex and the pivotal point of this ever elusive quest, which remains to be clarified in the current scenario. Sex steroids are an integral part of human development and evolution while also playing a critical role in the conditioning of the immune system and thereby influencing the function of peripheral organs. Classical perspectives suggest a pre-defined effect of sex steroids, generalizing estrogens popularly under the “estrogen paradox” due to conflicting reports associating estrogen with a pro- and anti-inflammatory role. On the other hand, androgens are classified as “anti-inflammatory,” serving a protective role in mitigating inflammation. Although considered mainstream and simplistic, this observation remains valid for numerous reasons, as elaborated in the current review. Women appear immune-favored with stronger and more responsive immune elements than men. However, the remarkable female predominance of diverse autoimmune and allergic diseases contradicts this observation suggesting that hormonal differences between the sexes might modulate the normal and dysfunctional regulation of the immune system. This review illustrates the potential relationship between key elements of the immune cell system and their interplay with sex steroids, relevant to structural cells in the pathophysiology of asthma and many other lung diseases. Here, we discuss established and emerging paradigms in the clarification of observed sex differences in asthma in the context of the immune system, which will deepen our understanding of asthma etiopathology.

Emerging strategies for treating autoimmune disorders with genetically modified Treg cells

Gene editing of living cells is a cornerstone of present-day medical research that has enabled scientists to address fundamental biologic questions and identify novel strategies to treat diseases. The ability to manipulate adoptive cell therapy products has revolutionized cancer immunotherapy and promises similar results for the treatment of autoimmune diseases, inflammatory disorders, and transplant rejection. Clinical trials have recently deemed polyclonal regulatory T (Treg) cell therapy to be a safe therapeutic option, but questions remain regarding the efficacy of this approach. In this review, we discuss how gene editing technologies are being applied to transform the future of Treg cell therapy, focusing on the preclinical strategies that are currently being investigated to enhance the efficacy, function, and survival of human Treg cells. We explore approaches that may be used to generate immunoregulatory cells ex vivo, detail emerging strategies that are being used to modify these cells (such as using chimeric antigen receptors to confer antigen specificity), and outline concepts that have been explored to repurpose conventional T cells to target and destroy autoreactive and alloreactive lymphocytes. We also describe the key hurdles that currently hinder the clinical adoption of Treg cell therapy and propose potential future avenues of research for this field.

Sophora flavescens Alkaloids and Corticosteroid Synergistically Augment IL-10/IL-5 Ratio with Foxp3-Gene-Epigenetic Modification in Asthma PBMCs

Background

It has been demonstrated that ASHMI (antiasthma-simplified herbal medicine intervention) can improve airway function and reduce inflammation in human asthmatic patients with high safety and tolerability. In addition, ASHMI significantly suppresses Th2 cytokine production and increases Th1 cytokine production in treating asthma.

Objective

Allergic asthma is associated with dysregulation of cytokines. We focused on IL-5 and IL-10 as signature Th2 and Treg cytokines to characterize ASHMI immunomodulatory components.

Methods

The effects of ASHMI and individual herbal constituents on IL-5 and IL-10 production by PBMCs from asthmatic subjects were determined ex vivo. Sophora flavescens (SF)-F2, containing alkaloid compounds, effects on PBMC IL-10 and IL-5 production in the presence or absence of dexamethasone (Dex), and on DNA methylation levels at the foxp3 gene promoter were determined.

Results

The ratio of anti-CD3/CD28 stimulated IL-10/IL-5 production by PBMCs from asthmatic subjects was significantly reduced compared to healthy subjects. In PBMCs from asthmatic subjects, ASHMI significantly reduced IL-5 production and increased IL-10 secretion in a dose-dependent manner (p < 0.05–0.01). SF-F2 was most effective in increasing IL-10, whereas SF-F4 (flavonoid compounds) was most effective in suppressing IL-5 production. Dex-treated PBMCs from asthma subjects showed a trend of increasing ratio of IL-10/IL-5 while demonstrating reduced levels in both IL-5 and IL-10 (p < 0.05). Co-culture with Dex and SF-F2 significantly prevented Dex suppression of IL-10, while retained Dex-suppression of IL-5 production, and increased IL-10/IL-5 ratio by Dex. Co-culture with SF-F2 and Dex significantly reduced DNA methylation levels at the foxp3 gene promoter at CpG⁻¹²⁶.

Conclusion

The SF alkaloid-rich fraction may be responsible for ASHMI induction of IL-10 production by PBMCs and plays a synergistic effect with Dex for augmenting IL-10/IL-5 ratio.

An overview of possible pathogenesis mechanisms of Alternaria alternata in chronic rhinosinusitis and nasal polyposis

Chronic Rhinosinusitis (CRS) is a multifactorial disease, and different etiologies like metabolism and immunity disorders, bacterial superantigens, biofilms, and fungal allergens are known to develop this disease, especially the CRS with nasal polyps. Alternaria alternata (Alternaria) is one of the most prevalent airborne fungal species in the nasal discharge, which might have vigorous immunologic activities in nasal epithelial cells and play an essential role in the pathogenesis of CRS. Moreover, the interaction between this fungus and the innate and adaptive immune systems leads to the development of chronic inflammation. This inflammation may consequently instigate the CRS and nasal polyposis. The attenuation of surfactant protein synthesis or intracellular reserves and mucus hypersecretion could prevent the clearance of Alternaria from sinuses and may be correlated with colonization and re-infection of airborne fungi. Furthermore, higher expression of cathelicidin, thymic stromal lymphopoietin, toll-like receptors, and T helper 2-dominant immune responses can result in an IgE-mediated pathway activation and eosinophils degranulation. Moreover, higher local Alternaria-specific IgE was shown to be correlated with eosinophilic cationic proteins and might relate to nasal polyps. However, the role of genetic and environmental factors affecting CRS and nasal polyposis is not well studied. Likewise, further animal and clinical studies are required to better understand the role of Alternaria in CRS disease. The current article reviews the recent findings around the Alternaria-induced CRS and nasal polyposis.

IL-10 production by ILC2s requires Blimp-1 and cMaf, modulates cellular metabolism, and ameliorates airway hyperreactivity

BACKGROUND

Group 2 innate lymphoid cells (ILC2s) are the dominant innate lymphoid cell population in the lungs at steady state, and their release of type 2 cytokines is a central driver in responding eosinophil infiltration and increased airway hyperreactivity. Our laboratory has identified a unique subset of ILC2s in the lungs that actively produce IL-10 (ILC210s).

OBJECTIVE

Our aim was to characterize the effector functions of ILC210s in the development and pathology of allergic asthma.

METHODS

IL-4-stimulated ILC210s were isolated to evaluate cytokine secretion, transcription factor signaling, metabolic dependence, and effector functions in vitro. ILC210s were also adoptively transferred into Rag2-/-γc-/- mice, which were then challenged with IL-33 and assessed for airway hyperreactivity and lung inflammation.

RESULTS

We have determined that the transcription factors cMaf and Blimp-1 regulate IL-10 expression in ILC210s. Strikingly, our results demonstrate that ILC210s can utilize both autocrine and paracrine signaling to suppress proinflammatory ILC2 effector functions in vitro. Further, this subset dampens airway hyperreactivity and significantly reduces lung inflammation in vivo. Interestingly, ILC210s demonstrated a metabolic dependency on the glycolytic pathway for IL-10 production, shifting from the fatty acid oxidation pathway conventionally utilized for proinflammatory effector functions.

CONCLUSION

These findings provide an important and previously unrecognized role of ILC210s in diseases associated with ILC2s such as allergic lung inflammation and asthma. They also provide new insights into the metabolism dependency of proinflammatory and anti-inflammatory ILC2 phenotypes.

A T cell-myeloid IL-10 axis regulates pathogenic IFN-γ-dependent immunity in a mouse model of type 2-low asthma

BACKGROUND

Although originally defined as a type 2 (T2) immune-mediated condition, non-T2 cytokines, such as IFN-γ and IL-17A, have been implicated in asthma pathogenesis, particularly in patients with severe disease. IL-10 regulates TH cell phenotypes and can dampen T2 immunity to allergens, but its functions in controlling non-T2 cytokine responses in asthmatic patients are unclear.

OBJECTIVE

We sought to determine how IL-10 regulates the balance of TH cell responses to inhaled allergen.

METHODS

Allergic airway disease was induced in wild-type, IL-10 reporter, and conditional IL-10 or IL-10 receptor α (IL-10Rα) knockout mice by means of repeated intranasal administration of house dust mite (HDM). IL-10 and IFN-γ signaling were disrupted by using blocking antibodies.

RESULTS

Repeated HDM inhalation induced a mixed IL-13/IL-17A response and accumulation of IL-10-producing forkhead box P3-negative effector CD4+ T cells in the lungs. Ablation of T cell-derived IL-10 increased the IFN-γ and IL-17A response to HDM, reducing IL-13 levels and airway eosinophilia without affecting IgE levels or airway hyperresponsiveness. The increased IFN-γ response could be recapitulated by IL-10Rα deletion in CD11c+ myeloid cells or local IL-10Rα blockade. Disruption of the T cell-myeloid IL-10 axis resulted in increased pulmonary monocyte-derived dendritic cell numbers and increased IFN-γ-dependent expression of CXCR3 ligands by airway macrophages, which is suggestive of a feedforward loop of TH1 cell recruitment. Augmented IFN-γ responses in the HDM allergic airway disease model were accompanied by increased disruption of airway epithelium, which was reversed by therapeutic blockade of IFN-γ.

CONCLUSIONS

IL-10 from effector T cells signals to CD11c+ myeloid cells to suppress an atypical and pathogenic IFN-γ response to inhaled HDM.

Il-10 producing T and B cells in allergy

The molecular and cellular mechanisms of allergen tolerance in humans have been intensively studied in the past few decades. The demonstration of epitope-specific T cell tolerance, particularly mediated by the immune suppressor functions of IL-10 led to a major conceptual change in this area more than 20 years ago. Currently, the known essential components of allergen tolerance include the induction of allergen-specific regulatory of T and B cells, the immune suppressive function of secreted factors, such as IL-10, IL-35, IL-1 receptor antagonist and TGF-β, immune suppressive functions of surface molecules such as CTLA-4 and PD-1, the production IgG4 isotype allergen-specific blocking antibodies, and decreased allergic inflammatory responses by mast cells, basophils, and eosinophils in inflamed tissues. In this review, we explain the importance of the role of IL-10 in allergen tolerance.

Generation of IgE-specific cytotoxic T lymphocytes as a novel immunotherapeutic approach for the treatment of allergic asthma

INTRODUCTION

Overproduction of immunoglobulin E (IgE) by a subset of B cells plays a key role in the pathogenesis of allergic asthma. Anti-IgE monoclonal antibodies have been successfully used to treat the disease, but long-term application is required.

METHODS

For this study, cytotoxic T lymphocytes (CTLs) against IgE-producing B cells were generated ex vivo by stimulating naive CD8 T cells with IgE-derived peptides presented by Drosophila-derived artificial antigen-presenting cells. Based on the treatment of allergic asthma in mice, the inhibitive effect of this CTL on IgE responses and airway inflammation was determined with the enzyme-linked immunosorbent assay and histochemical method.

RESULTS

The IgE-specific CTLs effectively lysed target cells in vitro, while the adoptively transferred CTLs specifically inhibited IgE responses and airway inflammation in an asthmatic mouse model. The effect of IgE-specific CTLs is MHC (major histocompatibility complex) Class I-restricted and requires the expression of perforin.

CONCLUSION

IgE-specific CTLs generated ex vivo may provide a novel treatment for allergic asthma and lead to a new therapy for other immunological disorders.

Preventive and therapeutic effects of Trichinella spiralis adult extracts on allergic inflammation in an experimental asthma mouse model

Background

Helminths immunomodulate the host immune system by secreting proteins to create an inhibitory environment as a strategy for survival in the host. As a bystander effect, this balances the host immune system to reduce hypersensitivity to allergens or autoantigens. Based on this, helminth therapy has been used to treat some allergic or autoimmune diseases. As a tissue-dwelling helminth, Trichinella spiralis infection has been identified to have strong immunomodulatory effects; the effective components in the worm have not yet been identified.

Methods

The soluble extracts of T. spiralis adult worms and muscle larvae were used to treat airway inflammation before and after an ovalbumin (OVA)-sensitization/challenge in an OVA-induced asthma mouse model. The therapeutic effects were observed by measuring the level of inflammation in the lungs.

Results

The soluble products derived from T. spiralis parasites, especially from adult worms, were able to ameliorate OVA-induced airway inflammatory responses which were associated with reduced eosinophil infiltration, OVA-specific IgE, Th2 cytokine IL-4, and increased IL-10 and TGF-β. The stimulation of the Treg response may contribute to the alleviated allergic inflammation.

Conclusions

Trichinella spiralis worm extracts stimulate regulatory cytokines that are associated with reduced allergic airway inflammation. The identification of effective components in the adult worm extracts will be a crucial approach for developing a novel therapeutic for allergic and autoimmune diseases.

Regulatory T cells and asthma

Asthma is a chronic disease of airway inflammation due to excessive T helper cell type 2 (Th2) response. Present treatment based on inhalation of synthetic glucocorticoids can only control Th2-driven chronic eosinophilic inflammation, but cannot change the immune tolerance of the body to external allergens. Regulatory T cells (Tregs) are the main negative regulatory cells of the immune response. Tregs play a great role in regulating allergic, autoimmune, graft-versus-host responses, and other immune responses. In this review, we will discuss the classification and biological characteristics, the established immunomodulatory mechanisms, and the characteristics of induced differentiation of Tregs. We will also discuss the progress of Tregs in the field of asthma. We believe that further studies on the regulatory mechanisms of Tregs will provide better treatments and control strategies for asthma.

Regulatory cytokine function in the respiratory tract

The respiratory tract is an important site of immune regulation; required to allow protective immunity against pathogens, while minimizing tissue damage and avoiding aberrant inflammatory responses to inhaled allergens. Several cell types work in concert to control pulmonary immune responses and maintain tolerance in the respiratory tract, including regulatory and effector T cells, airway and interstitial macrophages, dendritic cells and the airway epithelium. The cytokines transforming growth factor β, interleukin (IL-) 10, IL-27, and IL-35 are key coordinators of immune regulation in tissues such as the lung. Here, we discuss the role of these cytokines during respiratory infection and allergic airway disease, highlighting the critical importance of cellular source and immunological context for the effects of these cytokines in vivo.

Multispecies probiotics combination prevents ovalbumin-induced airway hyperreactivity in mice

BACKGROUND

Probiotics could be beneficial to health and some of them have shown to modulate immune responses.

AIM

The aim of this study is to investigate if the probiotic strains including Lactobacillus and Pediococcus strains are able to alleviate allergic reactions in an ovalbumin-induced airway allergy model.

METHODS

Lactobacillus multi-species preparation (LMP) was gavaged to BALB/c for total six weeks and BALB/c was challenged with ovalbumin in the last two weeks. A barometric whole-body plethysmography was used to assess enhanced pause (Penh) of airway hyperreactivity (AHR). Immunoglobulins (Ig) such as IgE, IgG1, IgG2a and cytokines such as IL-12, IFN-γ, IL-4, IL-5, TNF-α and IL-13 in bronchoalveolar lavage fluid were assayed using ELISA kits.

RESULTS

The results showed this LMP significantly reduced Th2 cytokines and enhanced Th1 cytokines production. OVA-specific IgE and IgG1 was lower in the probiotics-treated mice whereas IgG2a was increased. Most importantly, this murine model showed LMP supplementation significantly reduced AHR.

CONCLUSIONS

Overall, this Lactobacillus multi-species preparation seemed to suppress OVA-sensitized airway hyperreactivity, thus serving as a possible candidate for therapeutic uses for allergic airway symptoms.

Induction of Interleukin-10 Producing Dendritic Cells As a Tool to Suppress Allergen-Specific T Helper 2 Responses

Dendritic cells (DCs) are gatekeepers of the immune system that control induction and polarization of primary, antigen-specific immune responses. Depending on their maturation/activation status, the molecules expressed on their surface, and the cytokines produced DCs have been shown to either elicit immune responses through activation of effector T cells or induce tolerance through induction of either T cell anergy, regulatory T cells, or production of regulatory cytokines. Among the cytokines produced by tolerogenic DCs, interleukin 10 (IL-10) is a key regulatory cytokine limiting und ultimately terminating excessive T-cell responses to microbial pathogens to prevent chronic inflammation and tissue damage. Because of their important role in preventing autoimmune diseases, transplant rejection, allergic reactions, or in controlling chronic inflammation DCs have become an interesting tool to modulate antigen-specific immune responses. For the treatment of allergic inflammation, the aim is to downregulate allergen-specific T helper 2 (Th2) responses and the associated clinical symptoms [allergen-driven Th2 activation, Th2-driven immunoglobulin E (IgE) production, IgE-mediated mast cell and basophil activation, allergic inflammation]. Here, combining the presentation of allergens by DCs with a pro-tolerogenic, IL-10-producing phenotype is of special interest to modulate allergen-specific immune responses in the treatment of allergic diseases. This review discusses the reported strategies to induce DC-derived IL-10 secretion for the suppression of allergen-specific Th2-responses with a focus on IL-10 treatment, IL-10 transduction, and the usage of both whole bacteria and bacteria-derived components. Interestingly, while IL-10-producing DCs induced either by IL-10 treatment or IL-10 transduction are arrested in an immature/semi-mature state, treatment of DCs with live or killed bacteria as well as isolated bacterial components results in the induction of both anti-inflammatory IL-10 and pro-inflammatory, Th1-promoting IL-12 secretion often paralleled by an enhanced expression of co-stimulatory molecules on the stimulated DCs. By the secretion of DC-derived exosomes or CC-chemokine ligand 18, as well as the expression of inhibitory molecules like cytotoxic T lymphocyte-associated antigen 4, TNF receptor superfamily member 4, Ig-like transcript-22/cluster of differentiation 85, or programmed death-1, IL-10-producing DCs have been repeatedly shown to suppress antigen-specific Th2-responses. Therefore, DC-based vaccination approaches hold great potential to improve the treatment of allergic diseases.

Serum cytokine profiles as predictors of asthma control in adults from the EGEA study

BACKGROUND

To which extent serum cytokines may predict asthma control in adults remains understudied.

OBJECTIVES

We investigated cross-sectional and longitudinal associations between cytokine profiles and asthma outcomes.

METHODS

Serum interleukin (IL)-1Ra, IL-5, IL-7, IL-8, IL-10, IL-13 and TNF-α levels were determined in 283 adults with current asthma from the 2nd survey of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA2). Participants were followed-up seven years later. Asthma symptom control was assessed according to GINA 2015 guidelines. Cytokine profiles were identified by principal component (PC) analyses, and expressed as above/below the median.

RESULTS

The first two PCs captured 82.5% of the variability. While all seven cytokines scored high on PC1, only IL-1Ra and IL-10 scored high on PC2. At EGEA2, neither PC1 nor PC2 were related to exacerbations, asthma attacks, asthma symptom control, lung function, or allergic diseases. High level of PC1 (above the median) was associated with higher blood neutrophil counts (P = 0.02), while high level of PC2 was associated with lower IgE levels (P = 0.04). High level of PC2 at EGEA2 was associated with lower bronchial hyperresponsiveness (adjusted(a) OR[95%CI] = 0.46[0.23; 0.91]) and with subsequent lower risk of worsening asthma control and attacks (aOR[95%CI] = 0.24[0.09; 0.60]; 0.31[0.11; 0.85] respectively).

CONCLUSIONS

Serum cytokine profiles with high levels of IL-1Ra and IL-10 were associated with lower subsequent risks of worsening asthma control and attacks in adults. This study adds new findings for the role of serum cytokine profiles to help identifying adults with subsequent risk of asthma burden that could be targeted for specific therapies.

Schistosoma mansoni antigens alter activation markers and cytokine profile in lymphocytes of patients with asthma

Asthma is a chronic disease characterized by airway inflammation, obstruction and hyperresponsiveness. Severe asthma affects a small proportion of subjects but results in most of the morbidity, costs and mortality associated with the disease. Studies have suggested that Schistosoma mansoni infection reduces the severity of asthma and prevent atopy.

OBJECTIVE

We evaluated the ability of S. mansoni antigens, Sm29 and Sm29TSP-2 to modulate lymphocyte activation status in response to the allergen of the mite Dermatophagoides pteronyssinus (Der p1) in cell cultures of individuals with asthma.

METHODS

Thirty four patients were enrolled in this study: seventeen patients with severe asthma (SA group), seventeen patients with mild asthma (MA group) and six controls with no asthma. Peripheral blood mononuclear cells (PBMC) were obtained and stimulated with Sm29 and Sm29TSP-2 in the presence or absence of Der p1. The expression of surface markers and cytokines on lymphocytes was evaluated by flow cytometry and the levels of IL-10 in the culture supernatant were determined by ELISA.

RESULTS

The addition of Sm29 and Sm29TSP-2 antigens to PBMC cultures from both groups of subjects with asthma stimulated with Der p1 reduced the frequency of CD4⁺CD25^low cells whereas and increased frequency of CD4⁺CD25^high population was observed compared to unstimulated cultures. Moreover, cultures stimulated with Sm29TSP-2 showed a reduction in the frequency of T cells expressing CD69, IFN-γ, TNF and TGF-β in the MA group and an increase in the frequency of CD4⁺TSLPR⁺ T cells in the SA group. The addition of Sm29 to the cultures reduced the frequency of CD4⁺CD69⁺ and CD4⁺IL-5⁺ T cells in all asthmatic groups, and reduced the frequency of CD4⁺ T cells expressing IL-13 in the MA group. The cultures stimulated with Sm29 and Sm29TSP-2 showed an increase in the level of IL-10 in the supernatants.

CONCLUSION

These results suggest that the addition of Sm29 and Sm29TSP-2 to the cells cultures from subjects with asthma reduced cell activation markers and altered the cytokine production pattern in a way that can potentialy control the inflammatory response associated with asthma.

IL-10 Enhances IgE-Mediated Mast Cell Responses and Is Essential for the Development of Experimental Food Allergy in IL-10-Deficient Mice

IL-10 is a key pleiotropic cytokine that can both promote and curb Th2-dependent allergic responses. In this study, we demonstrate a novel role for IL-10 in promoting mast cell expansion and the development of IgE-mediated food allergy. Oral OVA challenge in sensitized BALB/c mice resulted in a robust intestinal mast cell response accompanied by allergic diarrhea, mast cell activation, and a predominance of Th2 cytokines, including enhanced IL-10 expression. In contrast, the development of intestinal anaphylaxis, including diarrhea, mast cell activation, and Th2 cytokine production, was significantly attenuated in IL-10(-/-) mice compared with wild-type (WT) controls. IL-10 also directly promoted the expansion, survival, and activation of mast cells; increased FcεRI expression on mast cells; and enhanced the production of mast cell cytokines. IL-10(-/-) mast cells had reduced functional capacity, which could be restored by exogenous IL-10. Similarly, attenuated passive anaphylaxis in IL-10(-/-) mice could be restored by IL-10 administration. The adoptive transfer of WT mast cells restored allergic symptoms in IL-10(-/-) mice, suggesting that the attenuated phenotype observed in these animals is due to a deficiency in IL-10-responding mast cells. Lastly, transfer of WT CD4 T cells also restored allergic diarrhea and intestinal mast cell numbers in IL-10(-/-) mice, suggesting that the regulation of IL-10-mediated intestinal mast cell expansion is T cell dependent. Our observations demonstrate a critical role for IL-10 in driving mucosal mast cell expansion and activation, suggesting that, in its absence, mast cell function is impaired, leading to attenuated food allergy symptoms.

IL-10-producing lung interstitial macrophages prevent neutrophilic asthma

Inflammatory responses contribute to host defense against harmful organisms and allergens, whereas a failure of immune tolerance can cause chronic inflammation including asthma. The lung has several innate myeloid cell subsets. Among these subsets, there are two types of macrophages: alveolar macrophages (AMs) and interstitial macrophages (IMs). However, compared with AMs, the role of IMs in lung homeostasis remains poorly understood. In this study, we characterized AMs and IMs in healthy and inflammatory conditions. Pulmonary IMs constitutively produce the anti-inflammatory cytokine IL-10 through activation of the TLR4/MyD88 pathway in a microbiota-independent manner. In addition to IMs, Foxp3⁺ T_reg cells show persistent IL-10 expression in the lung, with IL-10-producing IMs more prevalent than Foxp3⁺ T_reg cells. IMs, but not Foxp3⁺ T_reg cells, increased IL-10 production in house dust mite (HDM)-challenged mice, a model of human asthma. HDM-challenged Il10 ^-/- mice exhibited severe lung pathology characterized by neutrophilia compared with that of wild-type mice. In addition, transplantation of wild-type IMs reduced neutrophilic inflammation, goblet cell mucus production and decreased expression of lung IL-13 and T_h17-related neutrophil-activating cytokines such as IL-17, GM-CSF, and TNF-α. Together these results demonstrate that IL-10-producing IMs negatively regulate T_h2- and T_h17-mediated inflammatory responses, helping prevent neutrophilic asthma.

Avidity of human T cell receptor engineered CD4(+) T cells drives T-helper differentiation fate

The role of the T cell receptor (TCR) in antigen recognition and activation of T lymphocytes is well established. However, how the TCR affects T-helper differentiation/skewing is less well understood, particularly for human CD4(+) (CD4) T cell subsets. Here we investigate the role of TCR specific antigen avidity in differentiation and maintenance of human Th1, Th2 and Th17 subsets. Two human TCRs, both specific for the same peptide antigen but with different avidities, were cloned and expressed in human CD4 T cells. These TCR engineered cells were then stimulated with specific antigen in unskewed and T-helper skewed conditions. We show that TCR avidity can control the percentage of IL-4 and IFN-γ co-expression in unskewed TCR engineered cells, that effector function can be maintained in a TCR avidity-dependent manner in skewed TCR engineered cells, and that increased TCR avidity can accelerate Th1 skewing of TCR engineered cells.

Lung CD200 Receptor Activation Abrogates Airway Hyperresponsiveness in Experimental Asthma

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

Oral fungal immunomodulatory protein-Flammulina velutipes has influence on pulmonary inflammatory process and potential treatment for allergic airway disease: A mouse model

BACKGROUND/PURPOSE

House dust mite (HDM) is well known as one of the major indoor allergens that trigger allergic inflammation, especially asthma, and accounts for 85% of all cases. So far, asthma has been thought of as a condition of imbalance between T helper (Th)1 and Th2. Fungal immunomodulatory protein-Flammulina velutipes (FIP-fve) has been seemingly demonstrated to modulate the response to Th1 cytokine production. The aim of this study was to investigate if the oral administration of FIP-fve can inhibit HDM-induced asthma inflammation in the mouse model.

METHODS

We divided the mice (female BALB/c, 4-6 weeks) into four groups: the prevention group, which consisted of mice sensitized by HDM (intraperitoneally on Day 1, Day 7, and Day 14, and intranasally on Day 14, Day 17, Day 21, Day 24, and Day 27) fed with FIP-fve from Day 1 to Day 14; the treatment group, which comprised mice that received treatment from Day 14 to Day 28; the positive control (PC, sensitized by HDM fed without FIP-fve) group; and the negative control group (NC, nonsensitized). Airway hyperresponsiveness induced by methacholine challenge was determined using whole-body barometric plethysmography. In addition, cytokines were analyzed from bronchoalveolar lavage fluid and serum. Histopathological studies and Liu's staining method in mice lungs were also performed.

RESULTS

The results showed that both pre- and posttreated FIP-fve groups had significantly reduced airway hyperresponsiveness compared with the PC group after methacholine challenge. In addition, a significantly decreased level of HDM-specific immunoglobulin E in serum and decreased production of Th2 cytokines in bronchoalveolar lavage fluid and serum were observed in these two FIP-fve fed groups. Moreover, more decreased amounts of infiltrating inflammatory cells were present in the lungs of FIP-fve fed groups than those of the PC group.

CONCLUSION

Oral FIP-fve had an anti-inflammatory effect on the acute phase of the airway inflammatory process induced by HDM in the mouse model and might have a potentially therapeutic role for allergic airway diseases.

A novel pentapeptide originated from calf thymus named TIPP shows an inhibitory effect on lung allergic inflammation

Thymic immunosuppressive pentapeptide (TIPP) is a novel pentapeptide originally obtained from calf thymic immunosuppressive extract. In this study we aimed to investigate the anti-inflammatory effect and mechanisms of TIPP in vivo with an ovalbumin-induced mouse allergic asthma model. We investigated the effects of TIPP on the infiltration of inflammation cells, immune cell subtypes, Th2 cytokines in BALF and IgE in serum, mRNA levels of IL-4, IL-10, TNF-α and eotaxin-1, expression of MCP-1, VCAM-1 and COX-2, and activation of MAP kinases and NF-κB. Our results showed that TIPP significantly inhibited the increase in Th2 cytokines and OVA-specific IgE production, mRNA levels of IL-4, TNF-α and eotaxin-1 and the expression of MCP-1, VCAM-1 and COX-2 in lung tissues, as well effectively resisting the balance changes of cells in BALF. In addition, it was found that the administration of TIPP attenuated the activation of MAP kinases and NF-κB in the lung tissues of the allergic mice. Our data suggest that TIPP effectively suppresses the allergic and inflammatory responses in allergic mice via blocking MAP kinases/NF-κB signalling pathway. The investigation indicated that TIPP may become an anti-allergic and anti-inflammatory drug.

Association of serum cytokines levels, interleukin 10 -1082G/A and interferon-γ +874T/A polymorphisms with atopic asthma children from Saudi Arabia

The aim of this study was to clarify the role of IL-4, IL-10, IL-13 and interferon (IFN) -γ levels in atopic asthma patients by studying the relation between their serum levels and severity of the disease. The effect of IL-10 -1082G/A and IFN-γ +874T/A SNPs was also studied. The study included 200 atopic children with asthma and 50 age- and gender matched healthy children as controls. The levels of both IL-4 and IL-13 were significantly (p<0.001) higher, while IFN-γ was significantly (p<0.001) lower in patients compared to that of the controls. There was a significant effect of gene polymorphisms of IL-10 (p<0.05) and IFN-γ (p<0.001) in occurrence of atopic asthma and increased IgE level. Polymorphism of IFN-γ gene had an effect on the serum level of IFN-γ. In conclusion, IFN-γ gene polymorphism at position +874 and IL-10 gene polymorphism at position -1082A/G are genetic determinants which contribute to susceptibility to atopic asthma in children from Saudi Arabia.

Astragaloside IV attenuates allergic inflammation by regulation Th1/Th2 cytokine and enhancement CD4(+)CD25(+)Foxp3 T cells in ovalbumin-induced asthma

Astragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair and regeneration of injured organ and tissues. We tested the anti-asthmatic effects of AST IV and the possible mechanisms. BALB/c mice that were sensitized and challenged to ovalbumin (OVA) were treated with AST IV (40mg/kg and 20mg/kg) 1h before they were challenged with OVA. Our study demonstrated that AST IV inhibited OVA-induced increases in eosinophil count; interleukin (IL)-4 level were recovered in bronchoalveolar lavage fluid increased IFN-γ and IL-10 levels in bronchoalveolar lavage fluid. Histological studies demonstrated that AST IV substantially inhibited OVA-induced eosinophilia in lung tissue. Flow cytometry studies demonstrated that AST IV substantially increased CD4(+)CD25(+)Foxp3 T cells (Treg). Furthermore quantitative real-time (qPCR) studies demonstrated that AST IV substantially enhanced Foxp3 mRNA expression in lung tissue. These findings suggest that AST IV may effectively ameliorate the progression of airway inflammation and could be used as a therapy for patients with allergic inflammation.

Tolerogenic dendritic cells derived from donors with natural rubber latex allergy modulate allergen-specific T-cell responses and IgE production

Natural rubber latex (NRL; Hevea brasiliensis) allergy is an IgE-mediated reaction to latex proteins. When latex glove exposure is the main sensitizing agent, Hev b 5 is one of the major allergens. Dendritic cells (DC), the main antigen presenting cells, modulated with pharmacological agents can restore tolerance in several experimental models, including allergy. In the current study, we aimed to generate DC with tolerogenic properties from NRL-allergic patients and evaluate their ability to modulate allergen-specific T and B cell responses. Here we show that dexamethasone-treated DC (dxDC) differentiated into a subset of DC, characterized by low expression of MHC class II, CD40, CD80, CD86 and CD83 molecules. Compared with LPS-matured DC, dxDC secreted lower IL-12 and higher IL-10 after CD40L activation, and induced lower alloantigenic T cell proliferation. We also show that dxDC pulsed with the dominant Hev b 5 T-cell epitope peptide, Hev b 5_46–65^, inhibited both proliferation of Hev b 5-specific T-cell lines and the production of Hev b 5-specific IgE. Additionally, dxDC induced a subpopulation of IL-10-producing regulatory T cells that suppressed proliferation of Hev b 5-primed T cells. In conclusion, dxDC generated from NRL-allergic patients can modulate allergen-specific T-cell responses and IgE production, supporting their potential use in allergen-specific immunotherapy.

Modulation of distinct asthmatic phenotypes in mice by dose-dependent inhalation of microbial products

BACKGROUND

Humans with asthma display considerable heterogeneity with regard to T helper (Th) 2-associated eosinophilic and Th17-associated neutrophilic inflammation, but the impact of the environment on these different forms of asthma is poorly understood.

OBJECTIVE

We studied the nature and longevity of asthma-like responses triggered by inhalation of allergen together with environmentally relevant doses of inhaled lipopolysaccharide (LPS).

METHODS

Ovalbumin (OVA) was instilled into the airways of mice together with a wide range of LPS doses. Following a single OVA challenge, or multiple challenges, animals were assessed for pulmonary cytokine production, airway inflammation, and airway hyperresponsiveness (AHR).

RESULTS

Mice instilled with OVA together with very low doses (≤10⁻³ μg) of LPS displayed modest amounts of Th2 cytokines, with associated airway eosinophilia and AHR after a single challenge, and these responses were sustained after multiple OVA challenges. When the higher but still environmentally relevant dose of 10⁻¹ μg LPS was used, mice initially displayed similar Th2 responses, as well as Th17-associated neutrophilia. After multiple OVA challenges, however, the 10⁻¹ μg LPS animals also accumulated large numbers of allergen-specific T regulatory (Treg) cells with high levels of inducible co-stimulatory molecule (ICOS). As a result, asthma-like features in these mice were shorter-lived than in mice sensitized using lower doses of LPS.

CONCLUSIONS

The nature and longevity of Th2, Th17, and Treg immune responses to inhaled allergen are dependent on the quantity of LPS inhaled at the time of allergic sensitization. These findings might account in part for the heterogeneity of inflammatory infiltrates seen in lungs of asthmatics.

Interleukin-10 promoter gene polymorphisms and susceptibility to asthma: a meta-analysis

Objective

The aim of this study was to explore whether the interleukin (IL)-10 polymorphisms and their haplotypes contribute to asthma susceptibility.

Methods

MEDLINE, EMBASE and the COCHRANE library databases were utilized to identify available articles. A meta-analysis was conducted on IL-10 -1082 G/A, -819 C/T, -592 C/A polymorphisms, and their haplotypes and asthma.

Results

Eleven studies involving 2,215 asthma patients and 2,170 controls were considered in the meta-analysis. The meta-analysis revealed no association between asthma and the IL-10 -1082 G allele [Odds ratio (OR) = 0.87, 95% Confidence interval (CI) = 0.68–1.12, p = 0.28]. However, meta-analysis of the five studies in Hardy-Weinburg equilibrium produced the relationship between the IL-10 -1082 G allele and asthma (OR = 0.71, 95% CI = 0.60–0.83, p<0.0001). Stratification by ethnicity indicated an association between the IL-10 -1082 G allele and asthma in East Asians (OR = 0.74, 95% CI = 0.57–0.96, p = 0.02), but not in West Asians. Furthermore, stratification by age indicated an association between the IL-10 -1082 G allele and asthma in adults and mixed groups (OR = 0.77, 95% CI = 0.62–0.96, p = 0.02; OR = 0.67, 95% CI = 0.49–0.92, p = 0.01). No association was found between asthma and IL-10 -819 C/T and IL-10 -592 C/A polymorphisms and their haplotypes.

Conclusion

The IL-10 -1082 G/A polymorphism confers susceptibility to asthma in East Asians and in adults. However, the IL-10 -819 C/T, -592 C/A polymorphisms and their haplotypes are not associated with asthma.

Interleukin-10 promoter polymorphisms and asthma risk: a meta-analysis

Several studies assessed the associations of interleukin-10 (IL-10) polymorphisms with asthma in different populations. However, the results were inconclusive. The aim of the present study was to further assess the associations by the method of meta-analysis. Pubmed, EMBASE, Wanfang Database, China National Knowledge Infrastructure (CNKI) and Weipu Database were searched. Data were extracted independently by two authors. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Seventeen potentially eligible articles were identified (4478 cases and 4803 controls). Significant associations between -1082A/G and -592A/C polymorphisms and asthma were observed. However, there was no significant association between -819T/C polymorphism and asthma risk. In addition, there were significant associations of the IL-10 haplotypes with asthma. In summary, this meta-analysis suggested that IL-10 promoter polymorphisms were associated with asthma risk.

The decreased CD4+CD25+ FoxP3+ T cells in nonstimulated allergic rhinitis patients sensitized to house dust mites

OBJECTIVE

Regulatory (CD4(+)CD25(+)) T cells have been shown to play an important role in the development of allergic diseases. This study aims to investigate CD4(+)CD25(+) T cells, Forkhead box P3 (FoxP3(+) cells), and T-helper 1/T-helper 2 (Th1/Th2) cytokines in newly diagnosed allergic rhinitis (AR) patients.

METHODS

Altogether, 10 subjects with AR and 12 age-matched nonallergic healthy subjects were included in this study. CD4(+)CD25(+) T cells, FoxP3(+) T cells in peripheral blood mononuclear cells (PBMCs) were evaluated by flow cytometry, and the Th1/Th2 cytokine levels were determined by cytometric bead array immunoassay in both PBMC supernatants and nasal lavage fluids.

RESULTS

The percentage of CD4(+)CD25(+) T cells were significantly higher, whereas the percentage of FoxP3(+) cells were lower in AR patients compared with healthy subjects. In PBMC culture supernatants, interleukin-10 (IL-10) levels were significantly lower (p = .012), whereas IL-4, IL-5, and tumor necrosis factor-α (TNF-α) levels in nasal lavage fluids were higher in AR patients compared with healthy subjects (p = .026, p = .015, p = .03, respectively).

CONCLUSIONS

Our findings indicate that decrease in CD4(+)CD25(+)FoxP3(+) T cell fraction and diminished levels of IL-10 are noteworthy without allergen stimulation in house dust mite AR patients.

Uteroglobulin-related protein 1 and severity of respiratory syncytial virus infection in children admitted to hospital

There are several reports suggesting that genetic factors contribute to the severity of infection with the respiratory syncytial virus (RSV). Infants hospitalized with lower respiratory tract infection (LRTI) due to RSV are at a significantly increased risk for both recurrent wheezing and childhood asthma. Uteroglobin-related protein 1 (UGRP1) is a secretory protein expressed in the airways, and speculated to have anti-inflammatory activity. The presence of the -112G/A polymorphism in the UGRP1 promoter was found to have a significant correlation with asthma phenotype. Also plasma UGRP1 levels were shown to be associated both with this polymorphism and the severity of asthma. The study population consisted of 62 previously healthy infants, ≤12 months of age, who were hospitalized with RSV LRTI, and a control group of 99 healthy adults. Genotyping was performed by restriction fragment length polymorphism. UGRP1 serum levels were determined using ELISA. There were no significant differences in the overall distribution of UGRP1 -112G/A polymorphism genotypes or alleles between the hospitalized infants and healthy adults. A comparison of serum UGRP1 concentration measured at the time of admission and discharge between patients with and without the -112A allele revealed that there was no relation between the presence of the -112A allele and serum UGRP1 in hospitalized infants with RSV infection. Furthermore, there was no relationship between severity of RSV infection and genotype or serum UGRP1 concentration. These results suggest that UGRP1 does not have a major role in the development of severe RSV infection.

Thymic stromal lymphopoietin: a promising therapeutic target for allergic diseases

Thymic stromal lymphopoietin (TSLP), an interleukin 7-like cytokine, can trigger dendritic cell (DC)-mediated T-helper type 2 (Th2) inflammatory responses. Recent evidence demonstrates that cytokines TSLP and OX40 (CD134)/OX40 ligand seem to be important players in the maintenance of Th2 memory pool in the pathogenesis of asthma. Accumulating data reveal that the pathogenic T cells involved in asthma are likely to be inflammatory Th2 cells. TSLP is involved in the development of asthma through crosstalk with nuclear factor NF-ĸB. Progression of skin fibrosis in atopic dermatitis occurs via TSLP/TSLP receptor. TSLP-mediated dermal inflammation aggravates experimental allergic asthma. Also, TSLP polymorphisms are associated with susceptibility to asthma, atopic dermatitis, and eczema herpeticum. These findings suggest a master switch of TSLP in the initiation of allergic and adaptive inflammation through innate pathways at the epithelial cell-DC interface. The TSLP pathway is therefore a promising target for immunotherapy of allergic diseases.

Enforced IL-10 expression confers type 1 regulatory T cell (Tr1) phenotype and function to human CD4(+) T cells

Type 1 regulatory T (Tr1) cells are an inducible subset of CD4(+) Tr cells characterized by high levels of interleukin (IL)-10 production and regulatory properties. Several protocols to generate human Tr1 cells have been developed in vitro. However, the resulting population includes a significant fraction of contaminating non-Tr1 cells, representing a major bottleneck for clinical application of Tr1 cell therapy. We generated an homogeneous IL-10-producing Tr1 cell population by transducing human CD4(+) T cells with a bidirectional lentiviral vector (LV) encoding for human IL-10 and the marker gene, green fluorescent protein (GFP), which are independently coexpressed. The resulting GFP(+) LV-IL-10-transduced human CD4(+) T (CD4(LV-IL-10)) cells expressed, upon T-cell receptor (TCR) activation, high levels of IL-10 and concomitant low levels of IL-4, and markers associated with IL-10. Moreover, CD4(LV-IL-10) T cells displayed typical Tr1 features: the anergic phenotype, the IL-10, and transforming growth factor (TGF)-β dependent suppression of allogeneic T-cell responses, and the ability to suppress in a cell-to-cell contact independent manner in vitro. CD4(LV-IL-10) T cells were able to control xeno graft-versus-host disease (GvHD), demonstrating their suppressive function in vivo. These results show that constitutive over-expression of IL-10 in human CD4(+) T cells leads to a stable cell population that recapitulates the phenotype and function of Tr1 cells.

Cellular and molecular mechanisms of TSLP function in human allergic disorders--TSLP programs the "Th2 code" in dendritic cells

Thymic stromal lymphopoietin (TSLP) has been recently implicated as a key molecule for initiating allergic inflammation at the epithelial cell-dendritic cell (DC) interface. In humans, aberrant TSLP expression is observed in allergic tissues, such as lesional skins of atopic dermatitis, lungs of asthmatics, nasal mucosa of atopic rhinitis and nasal polyps, and ocular surface of allergic keratoconjunctivitis. TSLP is produced predominantly by damaged epithelial cells and stimulates myeloid DCs (mDCs). TSLP-activated mDCs can promote the differentiation of naïve CD4(+) T cells into a Th2 phenotype and the expansion of CD4(+) Th2 memory cells in a unique manner dependent on OX40L, one of the tumor necrosis factor superfamily members with Th2-promoting function, and lack of production of IL-12. From a genetic point of view, multiple genome-wide association studies have repeatedly identified the TSLP gene as one of the loci associated with susceptibility to allergic diseases. Thus, TSLP is a rational therapeutic target for the treatment of allergic disorders. Elucidating the mechanisms that regulate TSLP expression and the effects of TSLP on orchestrating the immune response toward a Th2 phenotype is essential for developing anti-TSLP therapy.

IL-35 production by inducible costimulator (ICOS)-positive regulatory T cells reverses established IL-17-dependent allergic airways disease

BACKGROUND

Recent evidence suggests that IL-17 contributes to airway hyperresponsiveness (AHR); however, the mechanisms that suppress the production of this cytokine remain poorly defined.

OBJECTIVE

We sought to identify the regulatory cells and molecules that suppress IL-17-dependent allergic airways disease.

METHODS

Mice were sensitized by means of airway instillations of ovalbumin together with low levels of LPS. Leukocyte recruitment to the lung and AHR were assessed after daily challenges with aerosolized ovalbumin. Flow cytometry, quantitative PCR, and gene-targeted mice were used to identify naturally arising subsets of regulatory T (Treg) cells and their cytokines required for the suppression of established allergic airway disease.

RESULTS

Allergic sensitization through the airway primed both effector and regulatory responses. Effector responses were initially dominant and led to airway inflammation and IL-17-dependent AHR. However, after multiple daily allergen challenges, IL-17 production and AHR decreased, even though pulmonary levels of T(H)17 cells remained high. This loss of AHR was reversible and required the expansion of a Treg cell subset expressing both forkhead box protein 3 and inducible costimulator. These Treg cells also expressed the regulatory cytokines IL-10, TGF-β, and IL-35. Whereas IL-10 and TGF-β were dispensable for suppression of AHR, IL-35 was required.

CONCLUSION

IL-35 production by inducible costimulator-positive Treg cells can suppress IL-17 production and thereby reverse established, IL-17-dependent AHR in mice. Targeting this pathway might therefore be of therapeutic value for treating allergic asthma in human subjects.

Alteration of immune responses by N-acetylglucosaminyltransferase V during allergic airway inflammation

BACKGROUND

β-1,6-N-acetylglucosaminyltransferase V (Mgat5 or GlcNac-TV), which is involved in the glycosylation of proteins, is known to be important for down-regulation of TCR-mediated T-cell activation and negatively regulates induction of contact dermatitis and experimental autoimmune encephalomyelitis. However, the role of Mgat5 in the induction of allergic airway inflammation remains unclear.

METHODS

To elucidate the role of Mgat5 in the pathogenesis of allergic airway inflammation, ovalbumin (OVA)-induced airway inflammation was induced in Mgat5-deficient mice. The OVA-specific lymphocyte proliferation and cytokine production levels, OVA-specific IgG1, IgG2a and IgE levels in the serum, and the number of leukocytes and cytokine levels in the bronchoalveolar lavage (BAL) fluid were compared between wild-type and Mgat5-deficient mice.

RESULTS

OVA-specific lymphocyte proliferation and production of IFN-γ and IL-10, but not IL-4, were increased in Mgat5-deficient mice, suggesting that Th2-type immune responses are seemed to be suppressed by increased IFN-γ and IL-10 production in these mice. However, Th2-type responses such as OVA-specific IgG1, but not IgE, and IL-5 levels in BAL fluids were increased in Mgat5-deficient mice. Meanwhile, the number of eosinophils was normal, but the numbers of neutrophils, macrophages and lymphocytes were reduced, in these mutant mice during OVA-induced airway inflammation.

CONCLUSIONS

Mgat5-dependent glycosylation of proteins can modulate acquired immune responses, but it is not essential for the development of OVA-induced eosinophilic airway inflammation.

Oral tolerance induction does not resolve gastrointestinal inflammation in a mouse model of food allergy

SCOPE

Oral immunotherapy (OIT) involving continuous oral administration of allergenic foods has gained attention as a therapy for food allergies. To study the influence of oral administration of allergenic foods on gastrointestinal symptoms including inflammation, we established a mouse model of food-induced intestinal allergy.

METHODS AND RESULTS

BALB/c mice were fed an egg white (EW) diet containing ovalbumin (OVA, a major EW allergen) after intraperitoneal sensitisation with OVA and Alum. The mice on the EW diet for one wk presented gastrointestinal symptoms (i.e. weight loss and soft stools) and inflammation in the small intestines (i.e. duodenum, jejunum and ileum). Further continuous EW diet resolved the weight loss but not the soft stools. Splenic CD4(+) T-cells of EW diet-fed mice on the continuous diet showed less proliferation and cytokine production compared with those of control mice, suggesting tolerance induction by the diet. The continuous EW diet reduced levels of OVA-specific IgE antibodies, but significantly aggravated the inflammation in the jejunum.

CONCLUSION

Our mouse model would be useful to investigate inflammatory and regulatory mechanisms in food-induced intestinal allergies. Our results suggest potential gastrointestinal inflammation in patients undergoing OIT as continuous administration of allergenic foods, even though the therapy may induce clinical tolerance.

Can exhaled inflammatory markers predict a steroid response in wheezing preschool children?

BACKGROUND

The efficacy of inhaled corticosteroids (ICS) varies among wheezing preschool children. Currently, it is not possible to predict which fraction of wheezing children will benefit from an ICS treatment.

OBJECTIVE

We explored whether fractional exhaled nitric oxide (FeNO) and inflammatory markers in exhaled breath condensate (EBC) can predict an ICS response in preschool wheezers.

METHODS

An 8-week ICS study (registered at Clinicaltrial.gov: NCT 00422747; 200 μg; beclomethasone extra-fine daily) was performed in 93 wheezing children (age range 2.0-4.4 years). At baseline, FeNO was determined off-line. EBC was collected using a closed glass-condenser. The acidity of EBC was determined and other EBC markers [interleukin (IL)-1α, IL-2, IL-4, IL-5, IL-10, soluble intercellular adhesion molecule, interferon-γ, eotaxin] were measured using a multiplex immunoassay. The change in airway resistance (Rint) and symptom score following ICS treatment was related to atopy (positive Phadiatop Infant test), FeNO and EBC markers.

RESULTS

Airway resistance and symptoms mildly improved after ICS treatment [median (IQR): 1.4 (1.2-1.7) to 1.3 (1.1-1.5) kPa s/L, symptom score: 26 (23-28) to 28 (24-29), P < 0.01, respectively]. Only IL-10 and atopy had limited predictive value regarding a change in symptoms [β (SE) =-0.13 (0.07), P = 0.08, β (SE) = 2.05 (1.17), P = 0.08, respectively].

CONCLUSIONS AND CLINICAL RELEVANCE

We did not find convincing evidence that FeNO and EBC markers could predict an ICS response in preschool wheezers. Recommendations for future studies on this topic are given.

Association between genes encoding components of the IL-10/IL-0 receptor pathway and asthma in children

BACKGROUND

Asthma is a chronic inflammation of the airways associated with recurrent symptoms that range from mild to debilitating. Interleukin-10 (IL-10) is a cytokine that displays pleiotropic effects in asthma and allergy.

OBJECTIVE

To determine whether polymorphisms of IL-10/IL-10R pathway contribute to asthma susceptibility in Egyptian children.

METHODS

The IL-10 (-1082G/A), IL-10R1 (G330R), and signal transducer and activator of transcription 3 (STAT3) rs2293452 single-nucleotide polymorphism (SNP) were genotyped in 110 atopic children with asthma, 110 non-atopic children with asthma, and 110 healthy children. Serum IL-10 and immunoglobulin E (IgE) levels were determined by enzyme-linked immunosorbent assay.

RESULTS

A significant association was observed between the IL-10 polymorphism and asthma in both atopic (P = .03) and non-atopic asthma groups (P = .04). The genotype frequencies of IL-10R1 polymorphisms did not differ between all groups. We identified a significant association between STAT3 polymorphism and asthma susceptibility in atopic asthma (P < .001), whereas no such association was observed in the non-atopic asthma group (P = .9). No evidence of gene interactions was found.

CONCLUSION

Polymorphisms of IL-10 and STAT3 may be useful as a new DNA-based diagnostic biomarker for identifying high-risk children susceptible to asthma.

CD4+CD25-mTGFbeta+ T cells induced by nasal application of ovalbumin transfer tolerance in a therapeutic model of asthma

BACKGROUND

Intranasal administration of high amount of allergen was shown to induce tolerance and to reverse the allergic phenotype. However, mechanisms of tolerance induction via the mucosal route are still unclear.

OBJECTIVES

To characterize the therapeutic effects of intranasal application of ovalbumin (OVA) in a mouse model of bronchial inflammation as well as the cellular and molecular mechanisms leading to protection upon re-exposure to allergen.

METHODS

After induction of bronchial inflammation, mice were treated intranasally with OVA and re-exposed to OVA aerosols 10 days later. Bronchoalveolar lavage fluid (BALF), T cell proliferation and cytokine secretion were examined. The respective role of CD4(+)CD25(+) and CD4(+)CD25(-) T cells in the induction of tolerance was analysed.

RESULTS

Intranasal treatment with OVA drastically reduced inflammatory cell recruitment into BALF and bronchial hyperresponsiveness upon re-exposure to allergen. Both OVA- specific-proliferation of T cells, T(h)1 and T(h)2 cytokine production from lung and bronchial lymph nodes were inhibited. Transfer of CD4(+)CD25(-) T cells, which strongly expressed membrane-bound transforming growth factor β (mTGFβ), from tolerized mice protected asthmatic recipient mice from subsequent aerosol challenges. The presence of CD4(+)CD25(+)(Foxp3(+)) T cells during the process of tolerization was indispensable to CD4(+)CD25(-) T cells to acquire regulatory properties. Whereas the presence of IL-10 appeared dispensable in this model, the suppression of CD4(+)CD25(-)mTGFβ(+) T cells in transfer experiments significantly impaired the down-regulation of airways inflammation.

CONCLUSION

Nasal application of OVA in established asthma led to the induction of CD4(+)CD25(-)mTGFβ(+) T cells with regulatory properties, able to confer protection upon allergen re-exposure.

A defect of CD4+CD25+ regulatory T cells in inducing interleukin-10 production from CD4+ T cells under CD46 costimulation in asthma patients

BACKGROUND

The suppressive cytokine interleukin-10 (IL-10) plays a central role in disease control and clinical therapies of asthma. CD46 was recently identified as costimulatory molecule in inducing IL-10-producing regulatory T cells type 1 (Tr1) from CD4(+) T cells. Alterations in CD46 costimulation pathway were shown to be associated with multiple sclerosis and hemodialysis. In this study, the authors investigated alterations in CD46 costimulatory pathway in asthma.

METHODS

CD4(+)CD25(+) regulatory T cells (Tregs) and CD4(+)CD25(-) T cells were isolated from peripheral blood mononuclear cells (PBMCs) of asthma patients (n = 13) and healthy subjects (n = 17). Both subsets of CD4(+) T cells were cultured alone or cocultured at a ratio of 1:10 under stimulation with CD3/CD28 or CD3/CD46, and the production of IL-10 in the supernatants was assessed by enzyme-linked immunosorbent assay (ELISA), the proliferation rates of the cells were determined with thymidine incorporation assay.

RESULTS

Levels of IL-10 in the supernatants were higher in undivided CD4(+) T cells and 1:10 cocultured CD4(+)CD25(+) Tregs/CD4(+)CD25(-) T cells than in CD4(+)CD25(+) Tregs or CD4(+)CD25(-) T cells alone, either under CD46 or under CD28 costimulation, both in healthy controls (n = 9) and in asthma patients (n = 7). Under anti-CD3/CD46 stimulation, IL-10 production in undivided CD4(+) T cells and cocultured T cells from asthma patients was lower than that in healthy controls. When treated with glucocorticoids, IL-10 production in undivided CD4(+) T cells and 1:10 cocultured CD4(+) T cells was not different between asthma patients (n = 6) and healthy controls (n = 8). The proliferation rates and the surface expression of CD46 were not different in T cells from both groups.

CONCLUSIONS

This study identified a new functional defect of CD4(+)CD25(+) Tregs in inducing IL-10 production from CD4(+)CD25(-) T cells under CD46 costimulation in asthma patients, which may be involved in the pathogenesis of allergic asthma.

Diosgenin, a plant-derived sapogenin, enhances regulatory T-cell immunity in the intestine of mice with food allergy

It was hypothesized that the suppressive effect of diosgenin (1) on the intestinal T helper (Th)2 responses is associated with an enhancement of the regulatory T-cell immunity. Ovalbumin (OVA)-sensitized BALB/c mice were gavaged daily with 1 and received repeatedly oral OVA challenges to induce intestinal allergic responses. The expression of Th2- and Treg-related cytokines and transcription factors was examined by immunohistochemical staining and RT-PCR. Administration of 1 markedly attenuated the intestinal expression of interleukin (IL)-4 and GATA3. In addition, administration of 1 reversed the diminished density of intestinal Foxp3(+) cells induced by OVA oral challenges and enhanced the expression of IL-10 by Foxp3(+) cells markedly. These results suggest that the suppressive effect of 1 on allergen-induced intestinal Th2 responses is closely associated with an up-regulation of the regulatory T-cell immunity in the inflammatory site.

Epitope-specific T-cell responses and allergic phenotypes: implications for T-cell peptide therapy

In the 1990s, elucidation of the primary amino acid sequence of several major allergens using molecular cloning techniques opened the door to T-cell epitope mapping studies. Such analyses underscored the complexity of the allergen-specific T-cell repertoire and the challenges to using allergen-derived peptides to identify epitope-specific differences associated with allergic and nonallergic responses. This review highlights important factors that may influence the nature of epitope-specific T-cell responses observed in vitro. These include the properties of the allergen, genetics of the host and selection of patients with defined allergic phenotypes based on serum antibody profiles and skin test reactivity. By taking these factors into account, T-cell epitope-specific differences associated with distinct allergic phenotypes can be identified. Observations at the T-cell epitope level undermine the Th1/Th2 paradigm as a model for the development of allergic versus nonallergic responses. Instead, they support the mounting data that point to a network of interactions between T helper cells and regulatory T cells, which controls the allergic response. The ability of peptides that localize to polypeptide chain 2 of the major cat allergen, Fel d 1, to preferentially induce interleukin-10 and interferon-gamma is discussed. Mechanisms whereby specific allergen-derived peptides may modify the T-cell repertoire and influence the immune outcome are also outlined. Further investigation of allergen-derived T-cell epitopes is warranted in order to optimize the design of peptide vaccines for the treatment of allergic disease.

Importance of cytokines in murine allergic airway disease and human asthma

Asthma is a common, disabling inflammatory respiratory disease that has increased in frequency and severity in developed nations. We review studies of murine allergic airway disease (MAAD) and human asthma that evaluate the importance of Th2 cytokines, Th2 response-promoting cytokines, IL-17, and proinflammatory and anti-inflammatory cytokines in MAAD and human asthma. We discuss murine studies that directly stimulate airways with specific cytokines or delete, inactivate, neutralize, or block specific cytokines or their receptors, as well as controversial issues including the roles of IL-5, IL-17, and IL-13Ralpha2 in MAAD and IL-4Ralpha expression by specific cell types. Studies of human asthmatic cytokine gene and protein expression, linkage of cytokine polymorphisms to asthma, cytokine responses to allergen stimulation, and clinical responses to cytokine antagonists are discussed as well. Results of these analyses establish the importance of specific cytokines in MAAD and human asthma and have therapeutic implications.

Synergistic therapeutic effects of combined adenovirus-mediated interleukin-10 and interleukin-12 gene therapy on airway inflammation in asthmatic mice

BACKGROUND

Asthma is a chronic disease characterized by airway inflammation caused by the dysregulated production of cytokines secreted by allergen-specific type 2 T helper (Th2) cells. Although the Th1-promoting cytokine, interleukin (IL)-12, is capable of inhibiting Th2-driven allergen-induced airway changes in mice, IL-12 also aggravates the Th1-driven inflammatory pulmonary pathology. Further, IL-10 was found to exert both anti-inflammatory and immunoregulatory activities. To avoid the side-effects of IL-12, we hypothesized that the low-dose expression of IL-10 with concomitant IL-12 administration in the airway may represent a more effective therapy for allergic airway diseases. Thus, the present study explored the immunomodulatory and therapeutic effects of IL-10 combined with IL-12 in airway inflammation in allergic asthma.

METHODS

Adenovirus-expressing murine IL-10 (Ad-IL-10) and IL-12 (Ad-IL-12) were co-administrated in an established murine model of ovalbumin (OVA)-induced asthma.

RESULTS

We found that a single combined treatment of low doses of Ad-IL-10 and Ad-IL-12 efficiently inhibited the development of airway hyper-responsiveness compared to Ad-IL-10 or Ad-IL-12 treatment alone. Moreover, both Ad-IL-10 and Ad-IL-12 treatment reduced pulmonary infiltration of eosinophils and neutrophils. In addition, histological studies showed that combined treatment was able to reduce tumor necrosis factor-alpha-mediated airway inflammation induced by IL-12 treatment. Suppression of IL-4, IL-5, Keratinocyte-derived chemokine (KC) and eotaxin in bronchoalveolar lavage fluid was also noted in OVA-immunized mice with combined Ad-IL-10 and Ad-IL-12 treatment.

CONCLUSIONS

Taken together, the results obtained in the present study indicate that co-administration of IL-12 and IL-10 may have therapeutic potential for the immunomodulatory treatment of allergic asthma.

Nuclear factor kappa B induction in airway epithelium increases lung inflammation in allergen-challenged mice

Nuclear factor kappa B (NF-kappa B) is a critical transcription factor for the production of many inflammatory cytokines. It is activated in the airway epithelium of human asthmatics and in mice after allergic stimulation. To examine the role of NF-kappa B activation in allergic inflammation, the authors generated transgenic mouse lines that allowed for the inducible stimulation of NF-kappa B in airway epithelial cells. After allergic sensitization with ovalbumin and alum, mice were challenged daily with ovalbumin aerosols and NF-kappa B was activated in airway epithelium by administration of doxycycline. Enhancement of airway epithelial NF-kappa B expression alone did not lead to increased airway responsiveness to methacholine. However, induction of epithelial NF-kappa B during allergic inflammation caused airway hyperresponsiveness, increased airway neutrophilic and lymphocytic inflammation and goblet cell hyperplasia. Accompanying the exaggerated inflammation was an increase in the cytokines granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-15, and KC. Interestingly, the counter regulatory interleukin, IL-10, was suppressed by NF-kappa B activation. The epithelial NF-kappa B dependent modulation of these cytokines provides a plausible explanation for the increased inflammation seen with overexpression of NF-kappa B. Modulation of airway epithelial NF-kappa B activation enhances the airway hyperresponsiveness and mucus secretion found in the mouse lung during allergic inflammation. NF-kappa B represents a potential target for pharmacologic intervention in human asthma.