IL-33 promotes the induction of immunoglobulin production after inhalation of house dust mite extract in mice

Cytokines and their role as immunotherapeutics and vaccine Adjuvants: The emerging concepts

Cytokines are a protein family comprising interleukins, lymphokines, chemokines, monokines and interferons. They are significant constituents of the immune system, and they act in accordance with specific cytokine inhibiting compounds and receptors for the regulation of immune responses. Cytokine studies have resulted in the establishment of newer therapies which are being utilized for the treatment of several malignant diseases. The advancement of these therapies has occurred from two distinct strategies. The first strategy involves administrating the recombinant and purified cytokines, and the second strategy involves administrating the therapeutics which inhibits harmful effects of endogenous and overexpressed cytokines. Colony stimulating factors and interferons are two exemplary therapeutics of cytokines. An important effect of cytokine receptor antagonist is that they can serve as anti-inflammatory agents by altering the treatments of inflammation disorder, therefore inhibiting the effects of tumour necrosis factor. In this article, we have highlighted the research behind the establishment of cytokines as therapeutics and vaccine adjuvants, their role of immunotolerance, and their limitations.

Effect of curcumin on regulatory B cells in chronic colitis mice involving TLR/MyD88 signaling pathway

Curcumin (Cur) is a natural active phenolic compound extracted from the root of Curcuma Longa L. It has anti-inflammatory, anti-tumor and other pharmacological activities, and is commonly used to treat ulcerative colitis (UC). However, it is not clear whether curcumin regulates the function and differentiation of Breg cells to treat UC. In this study, mice with chronic colitis were induced by dextran sulfate sodium (DSS), and treated with curcumin for 12 days. Curcumin effectively improved the body weight, colonic weight, colonic length, decreased colonic weight index and pathological injury score under colonoscopy in mice with chronic colitis, and significantly inhibited the production of IL-1β, IL-6, IL-33, CCL-2, IFN-γ, TNF-α, and promoted the secretion of IL-4, IL-10, IL-13 and IgA. Importantly, curcumin markedly upregulated CD3^- CD19⁺ CD1d⁺ , CD3^- CD19⁺ CD25⁺ , CD3^- CD19⁺ Foxp3⁺ Breg cells level and significantly down-regulated CD3^- CD19⁺ PD-L1⁺ , CD3^- CD19⁺ tim-1⁺ , CD3^- CD19⁺ CD27⁺ Breg cells level. In addition, our results also showed that curcumin observably inhibited TLR2, TLR4, TLR5, MyD88, IRAK4, p-IRAK4, NF-κB P65, IRAK1, TRAF6, TAB1, TAB2, TAK1, MKK3, MKK6, p38MAPK, p-p38MAPK and CREB expression in TLR/MyD88 signaling pathway. These results suggest that curcumin can regulate the differentiation and function of Breg cell to alleviate DSS-induced colitis, which may be realized by inhibiting TLR/MyD88 pathway.

Role of IL-25, IL-33, and TSLP in triggering united airway diseases toward type 2 inflammation

Under the concept of "united airway diseases," the airway is a single organ wherein upper and lower airway diseases are commonly comorbid. The upper and lower airways are lined with respiratory epithelium that plays a vital role in immune surveillance and modulation as the first line of defense to various infective pathogens, allergens, and physical insults. Recently, there is a common hypothesis emphasizing epithelium-derived cytokines, namely IL-25, IL-33, and TSLP, as key regulatory factors that link in immune-pathogenic mechanisms of allergic rhinitis (AR), chronic rhinosinusitis (CRS), and asthma, mainly involving in type 2 inflammatory responses and linking innate and adaptive immunities. Herein, we review studies that elucidated the role of epithelium-derived triple cytokines in both upper and lower airways with the purpose of expediting better clinical treatments and managements of AR, CRS, asthma, and other associated allergic diseases via applications of the modulators of these cytokines.

Protease/antiprotease network in allergy: The role of Staphylococcus aureus protease-like proteins

Staphylococcus aureus is being recognized as a major cofactor in atopic diseases such as atopic dermatitis, chronic rhinosinusitis with nasal polyps, and asthma. The understanding of the relationship between S aureus virulence factors and the immune system is continuously improving. Although the precise mechanism of the host's immune response adaptation to the variable secretion profile of S aureus strains continues to be a matter of debate, an increasing number of studies have reported on central effects of S aureus secretome in allergy. In this review, we discuss how colonization of S aureus modulates the innate and adaptive immune response, thereby predisposing the organism to allergic sensitization and disrupting immune tolerance in the airways of patients with asthma and chronic rhinosinusitis with nasal polyps. Next, we provide a critical overview of novel concepts dealing with S aureus in the initiation and persistence of chronic rhinosinusitis with nasal polyps and asthma. The role of the S aureus serine protease-like proteins in the initiation of a type 2 response and the contribution of the IL-33/ST2 signaling axis in allergic responses induced by bacterial allergens are discussed.

Interleukin-33: Its Emerging Role in Allergic Diseases

Allergic diseases, which include asthma, allergic rhinitis (AR), chronic rhinosinusitis (CRS), atopic dermatitis (AD), food allergy (FA), allergic keratoconjunctivitis, seriously affect the quality of life of people all over the world. Recently, interleukin-33 (IL-33) has been found to play an important role in these refractory disorders, mainly by inducing T helper (Th) 2 immune responses. This article reviews the mobilization and biological function of IL-33 in allergic disorders, providing novel insights for addressing these hypersensitive conditions.

Downregulation of semaphorin 3E promotes hallmarks of experimental chronic allergic asthma

Guidance cues such as semaphorins are attractive novel therapeutic targets for allergic disorders. We have previously described an inhibitory effect of semaphorin 3E (Sema3E) on human airway smooth muscle cell function. We have further addressed a canonical role for Sema3E in acute model of allergic asthma in vivo. Considering the chronic nature of the disease, the potential implication of Sema3E to alleviate long-lasting deficits should be investigated. Expression of Sema3E in a chronic model of allergic asthma was assessed after exposure to house dust mite (HDM) as a clinically relevant allergen. Chronic features of allergic asthma including airway hyper-responsiveness (AHR), inflammation, and remodeling were studied in Sema3E-deficient mice. Additionally, the effect of exogenous Sema3E treatment was evaluated in prophylactic and therapeutic experimental models. We have demonstrated that expression of Sema3E is robustly suppressed in the airways upon chronic HDM exposure. Chronic allergic airway disease was significantly augmented in Sema3E-deficient mouse model which was associated with an increased AHR, remodeling, and Th2/Th17 inflammation. Intranasal Sema3E administration restored chronic deficits of allergic asthma in mice. Data from this study unveil a key regulatory role of Sema3E in chronic course of asthma via orchestration of impaired inflammatory and remodeling responses.

Efficacy research of salazosulfamide in ankylosing spondylitis and NAT1 gene polymorphism

The aim of this study was to explore the correlation of salazosulfamide efficacy on ankylosing spondylitis and N-acetyltransferase 1 (NAT1) gene polymorphism. Thirty-two patients with ankylosing spondylitis were recruited in the experimental group and 36 normal individuals were recruited to the control group. The experimental group received 8.0 mg of salazosulfamide (MTX) per week and the control group received isodose of normal saline. Twenty-six patients in the experimental group responded to the salazosulfamide treatment and 6 did not show response. Morning stiffness time of patients in the experimental group who responded to salazosulfamide was significantly lower than that of patients with no reaction to salazosulfamide, and similar to patients in the control group. The average tender joint count of patients in the experimental group that responded to salazosulfamide was lower than in patients with no response to treatment, and similar to patients in the control group. NAT1 gene sequencing determined that the patients sensitive to salazosulfamide treatment manifested as AA/AG at 263 locus, whereas patients not sensitive to salazosulfamide were GG. NAT1 expression was comparable between the different genotypes at the mRNA level. However, there was a significant difference of NAT1 protein between groups. Overall, salazosulfamide demonstrates curative activity for ankylosing spondylitis and we believe that NAT1 AA/GG genotype at 263 locus can promote salazosulfamide effectiveness on ankylosing spondylitis.

Innate Immune Responses to Fungal Allergens

PURPOSE OF REVIEW

In this review, we describe innate immunity to fungi and the ability of pattern recognition receptors (PRRs) to recognize fungal-associated molecular patterns (FAMPs) and danger-associated molecular patterns (DAMPs).

RECENT FINDINGS

Protective responses against fungal antigens can be divided into two parts: innate immunity and adaptive immunity. Detection of foreign substance by the innate immune system is mediated by a variety of genetically encoded receptors known as pattern recognition receptors (PRRs). These PRRs bind to PAMPs (pathogen-associated molecular patterns) and more specifically to fungal-associated molecular patterns or FAMPs on target microorganisms. They also bind to DAMPs (damage-associated molecular patterns) which are substances released due to tissue and cell damage. PRRs can be divided into several families including Toll-like receptors (TLRs), nucleotide-oligomerization domain (NOD)-like receptors (NLRs), and C-type lectin receptors. Fungal PRRs can respond to internal and external components found in fungi. In addition, a number of fungal products, including some fungal allergens, seem to mimic or represent DAMPs. Collectively, activation of these fungal PRRs alerts the innate immune system to the presence of fungal exposure and can promote both innate and adaptive immune responses.

Oxidative Stress: Promoter of Allergic Sensitization to Protease Allergens?

Allergies arise from aberrant T helper type 2 responses to allergens. Several respiratory allergens possess proteolytic activity, which has been recognized to act as an adjuvant for the development of a Th2 response. Allergen source-derived proteases can activate the protease-activated receptor-2, have specific effects on immune cells by cleaving cell membrane-bound regulatory molecules, and can disrupt tight junctions. The protease activity can induce a non-allergen-specific inflammatory response in the airways, which will set the stage for an allergen-specific Th2 response. In this review, we will discuss the evidence for the induction of oxidative stress as an underlying mechanism in Th2 sensitization to proteolytic allergens. We will discuss recent data linking the proteolytic activity of an allergen to its potential to induce oxidative stress and how this can facilitate allergic sensitization. Based on experimental data, we propose that a less proficient anti-oxidant response to allergen-induced oxidative stress contributes to the susceptibility to allergic sensitization. Besides the effect of oxidative stress on the immune response, we will also discuss how oxidative stress can increase the immunogenicity of an allergen by chemical modification.

Potential Therapeutic Aspects of Alarmin Cytokine Interleukin 33 or Its Inhibitors in Various Diseases

PURPOSE

The purpose of this review was to examine the comprehensively accumulated data regarding potential therapeutic aspects of exogenous administration of interleukin 33 (IL-33) or its antagonists in allergic, cancerous, infectious, and inflammatory diseases.

METHODS

A selected review was undertaken of publications that examined the protective and exacerbating effects of IL-33 or its inhibitors in different diseases. Mechanisms of action are summarized to examine the putative role of IL-33 in various diseases.

FINDINGS

IL-33 promoted antibacterial, antiviral, anti-inflammatory, and vaccine adjuvant functions. However, in TH2-biased respiratory, allergic, parasitic, and inflammatory conditions, IL-33 exhibited disease-sensitizing effects. The alarmin cytokine IL-33 induced protective effects in diseases via recruitment of regulatory T cells; antiviral CD8(+) cells, natural killer cells, γδ T cells, and nuocytes; antibacterial and antifungal neutrophils or macrophages; vaccine-associated B/T cells; and inhibition of nuclear factor-κB-mediated gene transcription. In contrast, IL-33 exacerbated the disease process by increasing TH2 cytokines, IgE and eosinophilic immune responses, and inhibition of leukocyte recruitment in various diseases.

IMPLICATIONS

The protective or exacerbated aspects of use of IL-33 or its inhibitors are dependent on the type of infection or inflammatory condition, duration of disease (acute or chronic), organ involved, cytokine microenvironment, dose or kinetics of IL-33, and genetic predisposition. The alarmin cytokine IL-33 acts at cellular, molecular, and transcriptional levels to mediate pluripotent functions in various diseases and has potential therapeutic value to mitigate the disease process.

Indoor Pollutant Hexabromocyclododecane Has a Modest Immunomodulatory Effect on House Dust Mite Induced Allergic Asthma in Mice

Hexabromocyclododecane (HBCD) has been recognized as an indoor pollutant. HBCD is added as a flame retardant to many consumer products and leaches from the products into house dust. HBCD might be potentially hazardous to the airways because of inhalation of house dust. Sensitization to house dust mite (HDM) is a risk factor for the development of allergic asthma. In this study, we examined whether HBCD can affect the immune response to HDM allergens. Bone-marrow-derived dendritic cells (BMDCs) were exposed simultaneously to HBCD and HDM in vitro. HBCD enhanced oxidative stress in HDM-pulsed BMDCs, which was accompanied by a higher production of Interleukin (IL)-6 and -10. Adoptive transfer of HDM/HBCD-exposed BMDCs into naı̈ve mice resulted in enhanced levels of IL-17A after inhalational challenge with HDM. Direct mucosal exposure to HBCD during HDM inhalation enhanced IL-4 or IL-17A production, depending on the HDM extract used, but did not aggravate the eosinophilic airway inflammation or airway hyper-reactivity. Our results indicate that exposure to HBCD can have a mild immune-modulating effect by enhancing the inflammatory cytokine production in response to inhaled HDM in mice.

Innate and Adaptive Immune Response to Fungal Products and Allergens

Exposure to fungi and their products is practically ubiquitous, yet most of this is of little consequence to most healthy individuals. This is because there are a number of elaborate mechanisms to deal with these exposures. Most of these mechanisms are designed to recognize and neutralize such exposures. However, in understanding these mechanisms it has become clear that many of them overlap with our ability to respond to disruptions in tissue function caused by trauma or deterioration. These responses involve the innate and adaptive immune systems usually through the activation of nuclear factor kappa B and the production of cytokines that are considered inflammatory accompanied by other factors that can moderate these reactivities. Depending on different genetic backgrounds and the extent of activation of these mechanisms, various pathologies with resulting symptoms can ensue. Complicating this is the fact that these mechanisms can bias toward type 2 innate and adaptive immune responses. Thus, to understand what we refer to as allergens from fungal sources, we must first understand how they influence these innate mechanisms. In doing so it has become clear that many of the proteins that are described as fungal allergens are essentially homologues of our own proteins that signal or cause tissue disruptions.

Antiallergic effects of anti-interleukin-33 are associated with suppression of immunoglobulin light chain and inducible nitric oxide synthase

OBJECTIVE

We aimed to find novel genes that are significantly induced in allergic mice and that are significantly downregulated with anti-interleukin (IL) 33 treatment.

METHODS

Thirty-six mice were allocated into each of group A (intraperitoneal [i.p.]) sensitized and intranasally challenged to saline solution), group B (sensitized and challenged to ovalbumin), group C (sensitized and challenged with ovalbumin, and null treatment with i.p. saline solution), and group D (sensitized and challenged with ovalbumin, and treatment with anti-IL-33 i.p. injection). We counted the number of nose-scratching in 10 minutes, serum ovalbumin-specific immunoglobulin E (IgE), and titers of cytokines (IL-1, IL-4, IL-5, IL-10, IL-13) in bronchoalveolar lavage fluid. By using one whole lung from each mouse, we performed microarray analysis and real-time polymerase chain reaction.

RESULTS

group D showed a significantly reduced nose-scratching events and lower serum ovalbumin-specific IgE compared with groups B and C. All the cytokines in the bronchoalveolar lavage fluid were significantly decreased after anti-IL-33 treatment. Microarray analysis revealed that group B (immunoglobulin free light chain [IgFLC], 89.1 times; nitric oxide synthase [NOS] 2, 11.5 times) and group C (IgFLC, 141.6 times; NOS2, 11.7 times) had significantly increased expression of IgFLC and NOS2 genes compared with group A. After anti-IL-33 treatment, group D showed significantly decreased expression of both IgFLC (49.3 times) and NOS2 (6.5 times). In real-time polymerase chain reaction, groups B and C had significantly increased expression of these genes (IgFLC, 10.4 times and 29 times, respectively; NOS2, 3.8 times and 4.5 times, respectively). After treatment, group D showed significantly decreased expression of IgFLC (5.0 times) and NOS2 (2.5 times).

CONCLUSION

The antiallergic effect of anti-IL-33 can be explained by suppression of IgFLC and NOS2 in a murine model of allergic rhinitis.

Interaction of thymic stromal lymphopoietin, IL-33, and their receptors in epithelial cells in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Thymic stromal lymphopoietin (TSLP), IL-25, and IL-33 system contribute to the initiation and development of Th2 responses. This study aimed to explore the involvement of TSLP, IL-25, IL-33, and their receptors in type 2 T-helper (Th) responses in chronic rhinosinusitis with nasal polyps (CRSwNPs) and their cross-regulation in human nasal epithelial cells (HNECs).

METHODS

Immunohistochemistry, quantitative RT-PCR, ELISA, Bio-Plex assay, and flow cytometry were used to detect the expression of TSLP/common γ-like TSLP receptor (TSLPR)/IL-7 receptor α (IL-7Rα), IL-25/IL-17B receptor (IL-17RB), and IL-33/membrane-bound ST2 (ST2L)/soluble ST2 (sST2) in sinonasal mucosa and HNECs. HNECs cultured at an air-liquid interface were used to explore the expression in regulation of these cytokine systems.

RESULTS

Compared with controls and noneosinophilic CRSwNP, the expression of TSLP/TSLPR/IL-7Rα and ST2L/sST2 was significantly increased in eosinophilic CRSwNP, predominantly in epithelial cells. In contrast, the expression of IL-33 and IL-25/IL-17RB was enhanced in epithelial cells in both eosinophilic and noneosinophilic CRSwNP compared to controls. The expression of TSLP, TSLPR, and ST2L was positively correlated with symptom and computer tomography scan scores in eosinophilic CRSwNP and with Th2 cytokine expression in sinonasal mucosa. The expression of ST2L was correlated with TSLP and its receptor expression. TSLP could induce ST2L expression that promoted IL-33-induced TSLP expression in HNECs. In addition, TSLP/TSLPR/IL-7Rα and ST2L could be induced by Th2 cytokines, while IL-25/IL-17RB and IL-33 could be upregulated by Th1/Th17 cytokines, in HNECs.

CONCLUSIONS

The positive feedback loop between TSLP, IL-33 and their receptors, and Th2 cytokines may facilitate Th2-skewed inflammation in eosinophilic CRSwNP.

Airway epithelium interactions with aeroallergens: role of secreted cytokines and chemokines in innate immunity

Airway epithelial cells are the first line of defense against the constituents of the inhaled air, which include allergens, pathogens, pollutants, and toxic compounds. The epithelium not only prevents the penetration of these foreign substances into the interstitium, but also senses their presence and informs the organism’s immune system of the impending assault. The epithelium accomplishes the latter through the release of inflammatory cytokines and chemokines that recruit and activate innate immune cells at the site of assault. These epithelial responses aim to eliminate the inhaled foreign substances and minimize their detrimental effects to the organism. Quite frequently, however, the innate immune responses of the epithelium to inhaled substances lead to chronic and high level release of pro-inflammatory mediators that may mediate the lung pathology seen in asthma. The interactions of airway epithelial cells with allergens will be discussed with particular focus on interactions-mediated epithelial release of cytokines and chemokines and their role in the immune response. As pollutants are other major constituents of inhaled air, we will also discuss how pollutants may alter the responses of airway epithelial cells to allergens.