Potential involvement of IL-17F in asthma

Asthma Phenotypes in the Era of Personalized Medicine

Asthma is a widespread disease affecting approximately 300-million people globally. This condition leads to significant morbidity, mortality, and economic strain worldwide. Recent clinical and laboratory research advancements have illuminated the immunological factors contributing to asthma. As of now, asthma is understood to be a heterogeneous disease. Personalized medicine involves categorizing asthma by its endotypes, linking observable characteristics to specific immunological mechanisms. Identifying these endotypic mechanisms is paramount in accurately profiling patients and tailoring therapeutic approaches using innovative biological agents targeting distinct immune pathways. This article presents a synopsis of the key immunological mechanisms implicated in the pathogenesis and manifestation of the disease's phenotypic traits and individualized treatments for severe asthma subtypes.

Analysis of ceRNA Regulatory Mechanism of Rape Pollen Allergy Based on Whole-Transcriptome Sequencing of Peripheral Blood Mononuclear Cells

Background

Rape pollen allergy is a common allergic reaction disorder that affects the health and life of patients seriously. The research on ceRNA regulatory network in rape pollen allergy is poor.

Methods

High throughput whole-transcriptome sequencing was conducted on rape pollen allergic samples and non-allergic samples. Differentially expressed microRNAs (DEmiRNAs), circRNAs (DEcircRNAs), long non-coding RNA (DElncRNAs), mRNA (DEmRNAs) were identified and a ceRNA regulatory network was constructed by Cytoscape. Functional enrichment analyses were performed on DEmRNAs in the ceRNA network. Then, the least absolute shrinkage and selection operator (LASSO) regression model was used to identify characteristic genes for rape pollen allergy. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic ability of characteristic genes.

Results

A total of 25 DEmiRNAs, 258 DEcircRNAs, 304 DElncRNAs, and 383 DEmRNAs in the allergic group compared with the non-allergic group were uncovered, respectively. A ceRNA network containing 21 miRNAs, 57 circRNAs, 28 lncRNAs, and 33 mRNAs was generated with 139 nodes and 160 edges. The signal transduction-related processes, immune-related processes, the ion, inorganic substance, and hormone regulation processes were associated with mRNAs in the ceRNA network. The results of pathway enrichment illustrated that mRNAs in the ceRNA were significantly linked to IL-17 signaling pathway, inflammatory mediator regulation of trp channels, GMP-PKG signaling pathway, signaling by GPCR, and GPCR downstream signaling pathway. Then, five characteristic genes (KCNQ3, CCR5, FOSB, CFAP43, and PRKG1) were defined by the LASSO algorithm. The AUC values of these genes indicated that these genes had a powerful discrimination ability in discriminating allergic samples from non-allergic samples.

Conclusion

Taken together, we revealed the ceRNA regulatory network in rape pollen allergy and excavated five characteristic genes (KCNQ3, CCR5, FOSB, CFAP43, and PRKG1) with the diagnostic value that may be a potential target in diagnosis and treatment.

Genetic Variants Associated with Bronchial Asthma Specific to the Population of the Russian Federation

Bronchial asthma (BA) is a disease that still lacks an exhaustive treatment protocol. In this regard, the global medical community pays special attention to the genetic prerequisites for the occurrence of this disease. Therefore, the search for the genetic polymorphisms underlying bronchial asthma has expanded considerably. As the present study progressed, a significant amount of scientific medical literature was analyzed and 167 genes reported to be associated with the development of bronchial asthma were identified. A group of participants (n = 7,303) who had voluntarily provided their biomaterial (venous blood) to be used in the research conducted by the Federal Medical Biological Agency of Russia was formed to subsequently perform a bioinformatic verification of known associations and search for new ones. This group of participants was divided into four cohorts, including two sex-distinct cohorts of individuals with a history of asthma and two sex-distinct cohorts of apparently healthy individuals. A search for polymorphisms was made in each cohort among the selected genes, and genetic variants were identified whose difference in occurrence in the different cohorts was statistically significant (significance level less than 0.0001). The study revealed 11 polymorphisms that affect the development of asthma: four genetic variants (rs869106717, rs1461555098, rs189649077, and rs1199362453), which are more common in men with bronchial asthma compared to apparently healthy men; five genetic variants (rs1923038536, rs181066119, rs143247175, rs140597386, and rs762042586), which are more common in women with bronchial asthma compared to apparently healthy women; and two genetic variants (rs1219244986 and rs2291651) that are rare in women with a history of asthma.

IL17F Expression as an Early Sign of Oxidative Stress-Induced Cytotoxicity/Apoptosis

Interleukin 17F (IL17F) has been found to be involved in various inflammatory pathologies and has recently become a target for therapeutic purposes. In contrast to IL17F secreted by immune cells, the focus of this study is to describe the triggers of IL17F release in non-immune cells with a particular focus on IL17F-induced fibrosis. IL17F induction was examined in human lung epithelial (BEAS-2B) and myeloid cell lines as well as in peripheral blood mononuclear cells after in vitro exposure to aqueous cigarette smoke extract (CSE), inorganic mercury, cadmium or the apoptosis inducer brefeldin A. Fibrosis was examined in vitro, evaluating the transition of human primary dermal fibroblasts to myofibroblasts. We observed that all stressors were able to induce IL17F gene expression regardless of cell type. Interestingly, its induction was associated with cytotoxic/apoptotic signs. Inhibiting oxidative stress by N-acetylcysteine abrogated CSE-induced cytotoxic and IL17F-inducing effects. The induction of IL17F was accompanied by IL17F protein expression. The transition of fibroblasts into myofibroblasts was not influenced by either recombinant IL17F or supernatants of CSE-exposed BEAS-2B. In addition to IL17F secretion by specialized or activated immune cells, we underscored the cell type-independent induction of IL17F by mechanisms of inhibitable oxidative stress-induced cytotoxicity. However, IL17F was not involved in dermal fibrosis under the conditions used in this study.

Discovery and Characterization of a Novel Series of Chloropyrimidines as Covalent Inhibitors of the Kinase MSK1

We describe the identification and characterization of a series of covalent inhibitors of the C-terminal kinase domain (CTKD) of MSK1. The initial hit was identified via a high-throughput screening and represents a rare example of a covalent inhibitor which acts via an S_NAr reaction of a 2,5-dichloropyrimidine with a cysteine residue (Cys440). The covalent mechanism of action was supported by in vitro biochemical experiments and was confirmed by mass spectrometry. Ultimately, the displacement of the 2-chloro moiety was confirmed by crystallization of an inhibitor with the CTKD. We also disclose the crystal structures of three compounds from this series bound to the CTKD of MSK1, in addition to the crystal structures of two unrelated RSK2 covalent inhibitors bound to the CTKD of MSK1.

Targeting the Interleukin-23/Interleukin-17 Inflammatory Pathway: Successes and Failures in the Treatment of Axial Spondyloarthritis

The IL-23/IL-17 pathway has been implicated in the etiopathogenesis of axial spondyloarthritis through studies of genetic polymorphisms associated with disease, an animal model with over-expression of IL-23 that resembles human disease, and observations that cytokines in this pathway can be found at the site of disease in both humans and animal models. However, the most direct evidence has emerged from clinical trials of agents targeting cytokines in this pathway. Monoclonal antibodies targeting IL-17A have been shown to ameliorate signs and symptoms, as well as MRI inflammation in the spine and sacroiliac joints, in patients with radiographic and non-radiographic axial spondyloarthritis. This was evident in patients refractory to non-steroidal anti-inflammatory agents as well as patients failing treatment with tumor necrosis factor inhibitor therapies. Treatment with a bispecific antibody targeting both IL-17A and IL-17F was also effective in a phase II study. Post-hoc analyses have even suggested a potential disease-modifying effect in reducing development of spinal ankylosis. However, benefits for extra-articular manifestations were limited to psoriasis and did not extend to colitis and uveitis. Conversely, trials of therapies targeting IL-23 did not demonstrate any significant impact on signs, symptoms, and MRI inflammation in axial spondyloarthritis. These developments coincide with recent observations that expression of these cytokines is evident in many different cell types with roles in innate as well as adaptive immunity. Moreover, evidence has emerged for the existence of both IL-23-dependent and IL-23-independent pathways regulating expression of IL-17, potentially associated with different roles in intestinal and axial skeletal inflammation.

Self-assembled chitosan nanoparticles for intranasal delivery of recombinant protein interleukin-17 receptor C (IL-17RC): preparation and evaluation in asthma mice

Asthma is mentioned as a chronic airway inflammatory disease, whose pathogenesis is complicated. The promotion of inflammation in asthma by IL-17A and IL-17F has been confirmed. In addition to covalent homodimers, both cytokines are also able to form heterodimers, further inducing downstream pathways via binding to the IL-17RA and IL-17RC receptor complex. In recent years, IL-17RA and its signal transduction pathway have been extensively researched. IL-17RC, however, remains relatively unexplored. In the present study, we self-assembled chitosan (CS) nanoparticles for intranasal delivery of recombinant protein IL-17RC (rIL-17RC) and preliminarily investigated its effect on a murine model of allergic asthma induced by ovalbumin (OVA). rIL-17RC was produced by the prokaryotic expression system and encapsulated into the CS nanoparticles via ionic cross-linking technique. The results showed that CS-RC nanoparticles via intranasal intervention significantly caused inhibition of mucus secretion and airway inflammatory cell infiltration, and reduced IL-4, IL-17, IL-17F levels in BALF. Hence, delivering receptor proteins such as IL-17RC, through CS nanoparticles as a carrier, could be an attractive therapeutic intervention for asthma.

Conditions Mimicking the Cancer Microenvironment Modulate the Functional Outcome of Human Chorionic Villus Mesenchymal Stem/Stromal Cells in vitro

Mesenchymal stem/stromal cells isolated from chorionic villi of human term placentae (CV-MSCs) possess unique biological characters. They exhibit self-renewal, directional migration, differentiation, and immunomodulatory effects on other cell lineages, by virtue of which they can be utilized as therapeutic carriers, for drug targeting, and therapy. Tumors display characteristic features of a damaged tissue microenvironment, which is saturated with conditions such as hypoxia, sustained inflammation, and increased oxidative stress. CV-MSCs function normally in a high oxidative stress environment induced by hydrogen peroxide (H₂O₂) and glucose and also protect endothelial cells from their damaging effects. For their therapeutic applications in a disease like cancer, it is necessary to ascertain the effects of tumor microenvironment on their functional outcome. In this study, we investigated the functional activities, of CV-MSCs in response to conditioned media (CM) obtained from the culture of breast cancer cell line MDA-231 (CM-MDA231). CV-MSCs were exposed to CM-MDA231 for different spatio-temporal conditions, and their biological functions as well as modulation in gene expression were evaluated. Effect of CM-MDA231 on factors responsible for changes in functional outcome were also investigated at the protein levels. CV-MSCs exhibited significant reduction in proliferation but increased adhesion and migration after CM-MDA231 treatment. Interestingly, there was no change in their invasion potential. CM-MDA231 treatment modulated expression of various genes involved in important cellular events including, integration, survival, message delivery and favorable outcome after transplantation. Analysis of pathways related to cell cycle regulation revealed significant changes in the expression of p53, and increased phosphorylation of Retinoblastoma (Rb) and Checkpoint Kinase 2 in CV-MSCs treated with CM-MDA231. To summarize, these data reveal that CV-MSCs retain the ability to survive, adhere, and migrate after sustained treatment with CM-MDA231, a medium that mimics the cancer microenvironment. These properties of CV-MSCs to withstand the inflammatory tumor like microenvironment prove that they may make useful candidate in a stem cell based therapy against cancer. However, further pre-clinical studies are needed to validate their therapeutic usage.

IL17F rs763780 single nucleotide polymorphism is associated with asthma after bronchiolitis in infancy

AIM

Interleukin-17F (IL-17F) is involved with asthma. The aim of this study was to evaluate the association of IL17F polymorphisms with childhood asthma after bronchiolitis in infancy.

METHODS

We invited 166 children who were hospitalised for bronchiolitis at younger than 6 months of age to follow-up visits at 5-7 years and 11-13 years of ages. Asthma and allergy diagnoses, asthma-presumptive symptoms and use of inhaled corticosteroids (ICSs) were registered. Blood samples were available for IL17F rs763780 (T/C), rs11465553 (C/T) and rs7741835 (C/T) determinations in 165 cases.

RESULTS

The presence of IL17F rs11465553 and rs7741835 variations showed no significant associations with any asthma or allergy outcome at either 5-7 years or 11-13 years of ages. Instead, children with the variant IL17F rs763780 genotype had used more often ICSs between the follow-up visits from 5-7 to 11-13 years (adjusted OR 3.58) than those with the wild genotype. Children with the variant IL17F rs763780 genotype reported more often doctor-diagnosed atopic dermatitis (adjusted OR 2.71) at 11-13 years of age than those with the wild genotype.

CONCLUSION

This prospective long-term follow-up study provided preliminary evidence on the association of the IL17F rs763780 polymorphism with asthma at school age after bronchiolitis in infancy.

IL-33/ST2 axis promotes the inflammatory response of nasal mucosal epithelial cells through inducing the ERK1/2 pathway

Allergic rhinitis (AR) is a nasal mucosal inflammatory disease mediated by environmental allergens. At present, the relationship between the IL-33/ST2 axis, ERK1/2 pathway and AR progression needs further exploration. In our study, an AR model was constructed in vitro by treating HNEpC cells with Der p1. qRT-PCR was applied to assess the mRNA levels of IL-33, ST2, TNF-α, IL-6, and IL-8. Western blotting was used to measure the protein levels of IL-33, ST2, and the downstream proteins p-ERK1/2, ERK1/2, p-RSK, and RSK. IL-6, IL-8, IL-33, and TNF-α protein levels in cell supernatants were evaluated by ELISA. Flow cytometry was performed to check cell apoptosis of HNEpC in the presence or absence of Der p1. Our results indicate that the relative levels of IL-33, ST2, TNF-α, IL-6, and IL-8 were increased significantly in the AR model group. The above effects were notably reversed after transfection with shIL-33 or shST2. IL-33 stimulation further resulted in the increase in both ST2 and inflammation-associated cytokines, and these effects were restored after shST2 treatment. Also, the levels of inflammatory factors induced by IL-33 stimulation or ST2 overexpression were reversed after applying an ERK1/2 pathway blocker. In conclusion, IL-33/ST2 mediated inflammation of nasal mucosal epithelial cells by inducing the ERK1/2 pathway.

Asthma from immune pathogenesis to precision medicine

Asthma is characterized by multiple immunological mechanisms (endotypes) determining variable clinical presentations (phenotypes). The identification of endotypic mechanisms is crucial to better characterize patients and to identify tailored therapeutic approaches with novel biological agents targeting specific immunological pathways. This review focused on summarizing the major immunological mechanisms involved in the pathogenesis of asthma, as well as on discussing the emergence of phenotypic features of the disease. Novel biological agents and other drugs targeting specific endotypes are discussed, as their use represent a precision medicine approach to the disease that is nowadays mandatory particularly for treating more severe patients.

Relationship between various cytokines implicated in asthma

Asthma is a complex disorder involving immunologic, environmental, genetic and other factors. Today, asthma is the most common disease encountered in clinical medicine in both children and adults worldwide. Asthma is characterized by increased responsiveness of the tracheobronchial tree resulting in chronic swelling and inflammation of the airways recognized to be controlled by the T-helper 2 (Th2) lymphocytes, which secrete cytokines to increase the production of IgE by B cells. There are many cytokines implicated in the development of the chronic inflammatory processes that are often observed in asthma. Ultimately, these cytokines cause the release of mediators such as histamine and leukotrienes (LT), which in turn promote airway remodeling, bronchial hyperresponsiveness and bronchoconstriction. The CD4⁺ T-lymphocytes from the airways of asthmatics express a panel of cytokines that represent the Th2 cells. The knowledge derived from numerous experimental and clinical studies have allowed physicians and scientists to understand the normal functions of these cytokines and their roles in the pathogenesis of asthma. The main focus of this review is to accentuate the relationship between various cytokines implicated in human asthma. However, some key findings from animal models will be highlighted to support the discoveries from clinical studies.

Diesel exhausts particles: Their role in increasing the incidence of asthma. Reviewing the evidence of a causal link

Exposure to air pollutants has been correlated with an increase in the severity of asthma and in the exacerbation of pre-existing asthma. However, whether or not environmental pollution can cause asthma remains a controversial issue. The present review analyzes the current scientific evidence of the possible causal link between diesel exhaust particles (DEP), the solid fraction of the complex mixture of diesel exhaust, and asthma. The mechanisms that influence the expression and development of asthma are complex. In children prolonged exposure to pollutants such as DEPs may increase asthma prevalence. In adults, this causal relation is less clear, probably because of the heterogeneity of the studies carried out. There is also evidence of physiological mechanisms by which DEPs can cause asthma. The most frequently described interactions between cellular responses and DEP are the induction of pulmonary oxidative stress and inflammation and the activation of receptors of the bronchial epithelium such as toll-like receptors or increases in Th2 and Th17 cytokines, which generally orchestrate the asthmatic response. Others support indirect mechanisms through epigenetic changes, pulmonary microbiome modifications, or the interaction of DEP with environmental antigens to enhance their activity. However, in spite of this evidence, more studies are needed to assess the harmful effects of pollution - not only in the short term in the form of increases in the rate of exacerbations, but in the medium and long term as well, as a possible trigger of the disease.

Assessment of IL-17F rs763780 gene polymorphism in immune thrombocytopenia

Interleukin-17F rs763780 (7488A/G) gene polymorphism obviously affecting the expression and activity of IL17F and may affect primary immune thrombocytopenia (PIT) susceptibility and its clinical features in Egyptian children and adults. 105 ITP patients divided into (63 pediatric and 42 adult patient) and 112 age and sex matched healthy controls were enrolled in this case control study. All patients were subjected to history taking; clinical examination, CBC, bone marrow aspiration and genotyping of IL17F rs763780 polymorphism by (PCR-RFLP) technique. Our results revealed significant decrease in the mutant heterozygous genotype AG and also in IL-17F mutant allele G frequency in ITP patient group and associated with increased risk for ITP compared with the control group (P = 0.04 and P = 0.005 respectively). Furthermore, the mutant allele G frequency was significantly decreased in childhood onset than adult onset ITP (OR = 0.31, P = 0.02) and also was significantly lower in chronic ITP when compared with newly diagnosed and persistent ITP (P = 0.005). Patients with the AA genotype showed severe thrombocytopenic state at diagnosis than those with the AG genotype (P = 0.04). We concluded from our results that interleukin-17F rs763780 (7488A/G) polymorphism is strongly correlated with susceptibility and severity of ITP.

Association between asthma control and Interleukin-17F expression levels in adult patients with atopic asthma

OBJECTIVES

To investigate the correlation between Interleukin 17 (IL-17F) and the level of asthma control.

METHODS

This is a cross-sectional study of 40 subjects who were diagnosed with atopic asthma. All participants were recruited from the Allergy and Immunology Clinic, Prof. R.D. Kandou General Hospital, Manado, Indonesia, between April 2015 and April 2016. Total serum IL-17F measured by using Enzyme-Linked Immunosorbent Assay methods; and mRNA IL-17F was obtained by using real-time reverse transcriptase polymerase chain reaction. Level of asthma control was quantified by using asthma control test (ACT) scoring system. The correlation between IL-17F, mRNA, and level of asthma control was analyzed by using Pearson's correlation coefficient (r).

RESULTS

There is a strong positive correlation between IL-17F serum level and Nathan's ACT-score (r=0.969) which is statistically significant (p less than 0.001). Analysis of the correlation between mRNA IL-17F serum level and Nathan's ACT-score revealed a strong positive correlation (r=0.963), which is statistically significant (p less than 0.001).

CONCLUSION

These findings suggest that IL-17F plays an important role in asthma control. However, the role played by IL-17F in asthma pathogenesis are still questions to be answered.

Transcription Elongation Factor P-TEFb Is Involved in IL-17F Signaling in Airway Smooth Muscle Cells

BACKGROUND

IL-17F is involved in the pathogenesis of several inflammatory diseases, including asthma and COPD. However, the effects of steroids on the function of IL-17F signaling mechanisms are largely unknown. One of the transcription elongation factors, positive transcription elongation factor b (P-TEFb) composed of cyclin T1 and cyclin-dependent kinase 9 (CDK9), is known as a novel checkpoint regulator of gene expression via bromodomain-containing protein 4 (Brd4).

METHODS

Human airway smooth muscle cells were stimulated with IL-17F and the expression of IL-8 was evaluated by real-time PCR and ELISA. Next, the phosphorylation of CDK9 was determined by Western blotting. The CDK9 inhibitor and short interfering RNAs (siRNAs) targeting Brd4, cyclin T1, and CDK9 were used to identify the effect on IL-17F-induced IL-8 expression. Finally, the effect of steroids and its signaling were evaluated.

RESULTS

IL-17F markedly induced the transcription of the IL-8 gene and the expression of the protein. Pretreatment of CDK9 inhibitor and transfection of siRNAs targeting CDK9 markedly abrogated IL-17F-induced IL-8 production. Transfection of siRNAs targeting Brd4 and cyclin T1 diminished IL-17F-induced phosphorylation of CDK9 and IL-8 production. Moreover, budesonide decreased CDK9 phosphorylation and markedly inhibited IL-17F-induced IL-8 production.

CONCLUSIONS

This is the first report that P-TEFb is involved in IL-17F-induced IL-8 expression and that steroids diminish it via the inhibition of CDK9 phosphorylation. IL-17F and P-TEFb might be novel therapeutic targets for airway inflammatory diseases.

The Study of IL-10 and IL-17A Genes Expression in Patients with Different Stages of Asthma: a Case-Control Study

BACKGROUND

Asthma is considered as a complex disorder in which genetics and environment play crucial role in its susceptibility. In addition to the huge financial costs that significantly reduce the quality of life of the patients and their families, it causes high prevalence of lung diseases. Finding contributing new genetic factors involved in early diagnosis or progression of asthma can provide novel approaches for treatment or managing of asthma. In the present study, the potential role of two key cytokines of IL-10 and IL-17A was investigated in asthma pathogenesis.

MATERIALS AND METHODS

Using real-time PCR technique, we analyzed the expression levels of target genes in two groups of mild and severe asthma patient in comparison with healthy individuals.

RESULTS

In comparison with control population, obtained data showed 4 and 7-fold down-regulation of IL-17A in the group of mild and severe asthma, respectively. Down-regulation of IL-17A showed a significant correlation with progression of asthma severity. While IL-10 showed up to 10-fold down-regulation in the group of severe asthma, its expression level was not correlated with severity of asthma.

CONCLUSION

Obtained data revealed that deregulation IL-10 and IL-17A have potential to play crucial role in pathogenesis and prognosis of asthma. Observed down-regulation of these cytokines in blood cells suggests their usefulness as a marker in diagnosis of asthmatic types in patients.

Dual IL-17A and IL-17F neutralisation by bimekizumab in psoriatic arthritis: evidence from preclinical experiments and a randomised placebo-controlled clinical trial that IL-17F contributes to human chronic tissue inflammation

OBJECTIVE

Interleukin (IL)-17A has emerged as pivotal in driving tissue pathology in immune-mediated inflammatory diseases. The role of IL-17F, sharing 50% sequence homology and overlapping biological function, remains less clear. We hypothesised that IL-17F, together with IL-17A, contributes to chronic tissue inflammation, and that dual neutralisation may lead to more profound suppression of inflammation than inhibition of IL-17A alone.

METHODS

Preclinical experiments assessed the role of IL-17A and IL-17F in tissue inflammation using disease-relevant human cells. A placebo-controlled proof-of-concept (PoC) clinical trial randomised patients with psoriatic arthritis (PsA) to bimekizumab (n=39) or placebo (n=14). Safety, pharmacokinetics and clinical efficacy of multiple doses (weeks 0, 3, 6 (240 mg/160 mg/160 mg; 80 mg/40 mg/40 mg; 160 mg/80 mg/80 mg and 560 mg/320 mg/320 mg)) of bimekizumab, a humanised monoclonal IgG1 antibody neutralising both IL-17A and IL-17F, were investigated.

RESULTS

IL-17F induced qualitatively similar inflammatory responses to IL-17A in skin and joint cells. Neutralisation of IL-17A and IL-17F with bimekizumab more effectively suppressed in vitro cytokine responses and neutrophil chemotaxis than inhibition of IL-17A or IL-17F alone. The PoC trial met both prespecified efficacy success criteria and showed rapid, profound responses in both joint and skin (pooled top three doses vs placebo at week 8: American College of Rheumatology 20% response criteria 80.0% vs 16.7% (posterior probability >99%); Psoriasis Area and Severity Index 100% response criteria 86.7% vs 0%), sustained to week 20, without unexpected safety signals.

CONCLUSIONS

These data support IL-17F as a key driver of human chronic tissue inflammation and the rationale for dual neutralisation of IL-17A and IL-17F in PsA and related conditions.

TRIAL REGISTRATION NUMBER

NCT02141763; Results.

Effects of diesel exhaust particle exposure on a murine model of asthma due to soybean

BACKGROUND

Exposure to soybean allergens has been linked to asthma outbreaks. Exposure to diesel exhaust particles (DEP) has been associated with an increase in the risk of asthma and asthma exacerbation; however, in both cases the underlying mechanisms remain poorly understood, as does the possible interaction between the two entities.

OBJECTIVE

To investigate how the combination of soybean allergens and DEP can affect the induction or exacerbation of asthma in a murine model.

METHODS

BALB/c mice received intranasal instillations of saline, 3 or 5 mg protein/ml soybean hull extract (SHE), or a combination of one of these three solutions with DEP. Airway hyperresponsiveness (AHR), pulmonary inflammation in bronchoalveolar lavage, total serum immunoglobulin E and histological studies were assessed.

RESULTS

A 5 mg protein/ml SHE solution was able by itself to enhance AHR (p = 0.0033), increase eosinophilic inflammation (p = 0.0003), increase levels of IL-4, IL-5, IL-13, IL-17A, IL-17F and CCL20, and reduce levels of IFN-γ. The combination of 5 mg protein/ml SHE with DEP also produced an increase in AHR and eosinophilic inflammation, but presented a slightly different cytokine profile with higher levels of Th17-related cytokines. However, while the 3 mg protein/ml SHE solution did not induce asthma, co-exposure with DEP resulted in a markedly enhanced AHR (p = 0.002) and eosinophilic inflammation (p = 0.004), with increased levels of IL-5, IL-17F and CCL20 and decreased levels of IFN-γ.

CONCLUSIONS & CLINICAL RELEVANCE

The combination of soybean allergens and DEP is capable of triggering an asthmatic response through a Th17-related mechanism when the soybean allergen concentration is too low to promote a response by itself. DEP monitoring may be a useful addition to allergen monitoring in order to prevent new asthma outbreaks.

Expression of mRNA IL-17F and sIL-17F in atopic asthma patients

Background

Asthma is a chronic inflammatory disorder of airway that involves many cells and elements. Chronic inflammation caused by increase Airway hyperresponsiveness that cause recurrent episodic symptoms of breathlessness, wheezing, chest tightness and coughing, especially at night or early morning. Interleukin 17F is a cytokine that plays an important role in the pathophysiology of asthma attacks. Some studies show a variety of IL-17F roles in the pathogenesis of airway inflammation due to an allergic reaction.

Results

The study was conducted at the Prof. Dr. R. D. Kandou Manado Hospital, Indonesia. Samples were taken continuously until the number of meant samples was achieved. Blood samples were collected from 40 atopic asthmatic patients. From statistical analysis based on the hypothesis, there was positive correlation between mRNA levels of IL-17F and IL-17F in atopic asthmatic patient (p = 0.000 and r = 0.988).

Conclusions

According these data suggest that levels of mRNA IL-17F and IL17F might be useful parameters for the diagnosis of atopic asthma patient.

Th-17 regulatory cytokines IL-21, IL-23, and IL-6 enhance neutrophil production of IL-17 cytokines during asthma

BACKGROUND

In a subset of severe asthma patients, chronic airway inflammation is associated with infiltration of neutrophils, Th-17 cells and elevated expression of Th-17-derived cytokines (e.g., interleukin [IL]-17, IL-21, IL-22). Peripheral neutrophils from allergic asthmatics are known to express higher IL-17 cytokine levels than those from healthy subjects, but the regulatory mechanisms involved are not well understood. We hypothesize that Th-17 regulatory cytokines could modulate IL-17 expression in neutrophils.

METHODS

Peripheral blood neutrophils isolated from asthmatics were stimulated with IL-21, IL-23, and IL-6 cytokines and their ability to produce IL-17A and IL-17F was determined relative to healthy controls. Signal transducer and activator of transcription 3 (STAT3) phosphorylation levels were measured in stimulated neutrophil using flow cytometry. The requirement for STAT3 phosphorylation was determined by blocking its activation using a specific chemical inhibitor.

RESULTS

Stimulating asthmatic neutrophils with IL-21, 23, and 6 enhanced the production of IL-17A and IL-17F at significantly higher levels comparatively to healthy controls. Stimulating neutrophils with IL-21, IL-23, and IL-6 cytokines enhanced STAT3 phosphorylation, in all cases. Interestingly, inhibiting STAT3 phosphorylation using a specific chemical inhibitor dramatically blocked the ability of neutrophils to produce IL-17, demonstrating that STAT3 activation is the major factor mediating IL-17 gene expression.

CONCLUSIONS

These findings suggest that neutrophil infiltration in lungs of severe asthmatics may represent an important source of pro-inflammatory IL-17A and -F cytokines, a production enhanced by Th-17 regulatory cytokines, and thus providing a feedback mechanism that sustains inflammation. Our results suggest that STAT3 pathway could be a potential target for regulating neutrophilic inflammation during severe asthma.

IL-17A synergistically stimulates TNF-α-induced IL-8 production in human airway epithelial cells: A potential role in amplifying airway inflammation

BACKGROUND

Recent reports have suggested an involvement of neutrophilic inflammation driven by interleukin (IL)-17 from Th17 cells, especially in severe, refractory asthma. It remains unknown about the possible interactions of this cytokine and other proinflammatory cytokines to direct neutrophilic airway inflammation.

MATERIALS AND METHODS

We evaluated the effects of IL-17A, IL-17E, and IL-17F in combination with other stimuli such as tumor necrosis factor (TNF) -α on the production and expression of IL-8 in human bronchial epithelial cells. We also studied their effects on other cytokine production. The possible role of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways was evaluated by specific inhibitors. We examined the effects of anti-asthma drugs, such as steroids or salmeterol.

RESULTS

IL-17A alone induced only a minimal effect on IL-8 expression. IL-17A, but not IL-17E or IL-17F, in combination with TNF-α showed a synergistic effect on IL-8 expression. Similar findings were found when combination with IL-1β and IL-17A were used, but such was not the case with lipopolysaccharide (LPS). In addition, we further found such synergy on GM-CSF production. The synergy with TNF-α and IL-17A was significantly inhibited by MAPKs inhibitors. Corticosteroids such as fluticasone propionate and dexamethasone, but not salmeterol, partially suppressed the IL-17A and TNF-α-induced IL-8 production.

CONCLUSIONS

IL-17A in the combination with TNF-α or IL-1β showed a synergistic augmenting effect on IL-8 and GM-CSF production in human airway epithelial cells.

The IL-17A/IL-17RA axis in pulmonary defence and immunopathology

The interleukin (IL)-17A/IL-17 receptor A (IL-17RA) axis is emerging as a key player in host defence. Several studies have demonstrated that IL-17A-mediated responses play a critical role in both acute and chronic inflammation induced by infectious agents, environmental stimuli and genetic diseases in the airways. In this regard, it is becoming evident that IL-17A/IL-17RA signalling may have a protective and beneficial impact on health, but that it can also result in detrimental outcomes. On one hand, the IL-17A/IL-17RA axis can contribute to the elimination of noxious stimuli and to the resolution of acute inflammatory processes; on the other hand, it can exacerbate immunopathological responses, contributing to the development and progression of chronic respiratory illnesses. In addition, cellular and molecular signatures underlying IL-17A/IL-17RA signalling have been increasingly identified, although further studies are needed to clarify such complex responses. Here, we discuss the latest discoveries on the role of the IL-17A/IL-17RA axis in driving host pulmonary defence and immunopathology.

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

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

The parasitic worm-derived immunomodulator, ES-62 and its drug-like small molecule analogues exhibit therapeutic potential in a model of chronic asthma

Chronic asthma is associated with persistent lung inflammation and long-term remodelling of the airways that have proved refractory to conventional treatments such as steroids, despite their efficacy in controlling acute airway contraction and bronchial inflammation. As its recent dramatic increase in industrialised countries has not been mirrored in developing regions, it has been suggested that helminth infection may protect humans against developing asthma. Consistent with this, ES-62, an immunomodulator secreted by the parasitic worm Acanthocheilonema viteae, can prevent pathology associated with chronic asthma (cellular infiltration of the lungs, particularly neutrophils and mast cells, mucus hyper-production and airway thickening) in an experimental mouse model. Importantly, ES-62 can act even after airway remodelling has been established, arresting pathogenesis and ameliorating the inflammatory flares resulting from repeated exposure to allergen that are a debilitating feature of severe chronic asthma. Moreover, two chemical analogues of ES-62, 11a and 12b mimic its therapeutic actions in restoring levels of regulatory B cells and suppressing neutrophil and mast cell responses. These studies therefore provide a platform for developing ES-62-based drugs, with compounds 11a and 12b representing the first step in the development of a novel class of drugs to combat the hitherto intractable disorder of chronic asthma.

Different Bla-g T cell antigens dominate responses in asthma versus rhinitis subjects

BACKGROUND AND OBJECTIVE

The allergenicity of several German cockroach (Bla-g) antigens at the level of IgE responses is well established. However, less is known about the specificity of CD4+ TH responses, and whether differences exist in associated magnitude or cytokine profiles as a function of disease severity.

METHODS

Proteomic and transcriptomic techniques were used to identify novel antigens recognized by allergen-specific T cells. To characterize different TH functionalities of allergen-specific T cells, ELISPOT assays with sets of overlapping peptides covering the sequences of known allergens and novel antigens were employed to measure release of IL-5, IFNγ, IL-10, IL-17 and IL-21.

RESULTS

Using these techniques, we characterized TH responses in a cohort of adult Bla-g-sensitized subjects, either with (n = 55) or without (n = 17) asthma, and nonsensitized controls (n = 20). T cell responses were detected for ten known Bla-g allergens and an additional ten novel Bla-g antigens, representing in total a 5-fold increase in the number of antigens demonstrated to be targeted by allergen-specific T cells. Responses of sensitized individuals regardless of asthma status were predominantly TH 2, but higher in patients with diagnosed asthma. In asthmatic subjects, Bla-g 5, 9 and 11 were immunodominant, while, in contrast, nonasthmatic-sensitized subjects responded mostly to Bla-g 5 and 4 and the novel antigen NBGA5.

CONCLUSIONS

Asthmatic and nonasthmatic cockroach-sensitized individuals exhibit similar TH 2-polarized responses. Compared with nonasthmatics, however, asthmatic individuals have responses of higher magnitude and different allergen specificity.

Decreased Frequency of IL-17F rs763780 Site Allele G is Associated With Genetic Susceptibility to Immune Thrombocytopenia in a Chinese Population

Interleukin 17F (IL-17F) is an inflammatory cytokine that plays an important role in autoimmune disease by inducing the expression of multiple chemokines, cytokines, and adhesion molecules. In vitro functional analysis revealed that IL-17F rs763780 polymorphism is associated with IL-17 expression and activity. Thus, considering the abnormal percentage of T helper 17 cells in patients with primary immune thrombocytopenia (ITP), we speculated there was a possible association between the IL-17F rs763780 polymorphisms and genetic susceptibility to ITP in a Chinese Han population. A total of 165 patients with ITP and 149 healthy controls were included in this study, and IL-17F rs763780 polymorphisms were analyzed by a polymerase chain reaction–restriction fragment length polymorphism system. The results showed that the frequency of the IL-17F rs763780 G allele in total patients with ITP or patients with chronic ITP was significantly lower than in normal controls (total ITP 3.6% vs controls 7.7%, P = .026; chronic ITP 3.5% vs controls 7.7%, P = .031). However, no significant difference in genotype frequencies was found among total patients with ITP, patients with chronic ITP, and normal controls. We further analyzed the association of IL-17F polymorphisms with clinical parameters of patients with ITP, and no association revealed between gene distribution and first onset age, clinical therapy response to glucocorticoids, or disease course. What’s more, an evident discrepancy with allelic frequencies was observed between female patients with ITP and gender-matched controls. In conclusion, IL-17F rs763780 polymorphisms may be associated with the development of ITP in a Chinese Han population.

The paradigm of cytokine networks in allergic airway inflammation

PURPOSE OF REVIEW

Cytokines are immunomodulatory proteins important in cell signaling. Complex interactions of innate and adaptive immune cells, as well as structural cells and their cytokines, play crucial roles in regulating allergic airway inflammation. Here, we summarize current knowledge about the potential roles of known and newly identified helper T cells and epithelial cell-derived cytokines [interleukin (IL)-9, IL-17, IL-22, IL-25, and IL-33] in allergic rhinitis and asthma.

RECENT FINDINGS

Although T-helper (Th)2 cells were considered to be the main orchestrators of allergic airway inflammation, recent studies have revealed the potential interaction of other helper T cells and their cytokines in this process. Th17 cells may have a role in allergic rhinitis and asthma, and chronic rhinosinusitis with nasal polyps. An IL-9-producing subset called Th9 cells, Th22 cells which primarily secrete IL-22, IL-13, tumor necrosis factor-α, Th25 cells via producing IL-25 and epithelial cell-derived thymic stromal lymphopoietin, IL-33, IL-31, and IL-25 are believed to be important for the initiation of allergic reactions and inducing airway inflammation.

SUMMARY

A new paradigm of an interplay of cytokines is important in allergic rhinitis and asthma in orchestrating the allergic inflammatory response. Potential therapeutic applications emerging from the roles of these cytokines are promising, but need further research.

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

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

Association between IL-17F rs763780 polymorphism and susceptibility of asthma: a meta-analysis

Published data on the association between interleukin-17F (IL-17F) rs763780 polymorphism and asthma susceptibility are inconclusive. To derive a more precise estimation of this association, a meta-analysis was performed. A literature search was conducted in PubMed, Web of Science, Elsevier, Wanfang, and China National Knowledge Infrastructure (CNKI) databases to identify eligible studies. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to calculate the strength of association. Sensitivity analysis was performed to evaluate the influence of individual studies on the overall effect estimates and funnel plots were inspected for indication of publication bias. Seven studies with a total of 4200 subjects were finally identified. Overall, we found no significant association between IL-17F rs763780 polymorphism and asthma susceptibility (G vs. A: OR = 1.08, 95% CI = 0.81-1.44, P = 0.62; GA vs. AA: OR = 1.11, 95% CI = 0.84-1.47, P = 0.47; GG + GA vs. AA: OR = 1.07, 95% CI = 0.79-1.44, P = 0.65). After categorizing studies into different subgroups on the basis of ethnicity and age, there remained no significant association (all P > 0.05). Sensitivity analysis demonstrated the stability of our results and publication bias was not evident. The present meta-analysis, combining all currently available data, suggests that IL-17F rs763780 polymorphism is not associated with the susceptibility of asthma.

Microbiome and Asthma: What Have Experimental Models Already Taught Us?

Asthma is a chronic inflammatory disease that imposes a substantial burden on patients, their families, and the community. Although many aspects of the pathogenesis of classical allergic asthma are well known by the scientific community, other points are not yet understood. Experimental asthma models, particularly murine models, have been used for over 100 years in order to better understand the immunopathology of asthma. It has been shown that human microbiome is an important component in the development of the immune system. Furthermore, the occurrence of many inflammatory diseases is influenced by the presence of microbes. Again, experimental models of asthma have helped researchers to understand the relationship between the microbiome and respiratory inflammation. In this review, we discuss the evolution of murine models of asthma and approach the major studies involving the microbiome and asthma.

Involvement of the IL-23/IL-17 axis and the Th17/Treg balance in the pathogenesis and control of autoimmune arthritis

The T helper (Th) cell subsets are characterized by the type of cytokines produced and the master transcription factor expressed. Th1 cells participate in cell-mediated immunity, whereas Th2 cells promote humoral immunity. Furthermore, the two subsets can control each other. Thereby, Th1-Th2 balance offered a key paradigm in understanding the induction and regulation of immune pathology in autoimmune and other diseases. However, over the past decade, Th17 cells producing interleukin-17 (IL-17) have emerged as the major pathogenic T cell subset in many pathological conditions that were previously attributed to Th1 cells. In addition, the role of CD4+CD25+T regulatory cells (Treg) in controlling the activity of Th17 and other T cell subsets has increasingly been realized. Thereby, examination of the Th17/Treg balance in the course of autoimmune diseases has significantly advanced our understanding of the pathogenesis of these disorders. The differentiation of Th17 and Treg cells from naïve T cells is inter-related and controlled in part by the cytokine milieu. For example, transforming growth factor β (TGFβ) is required for Treg induction, whereas the same cytokine in the presence of IL-6 (or IL-1) promotes the differentiation of Th17. Furthermore, IL-23 plays a role in the maintenance of Th17. Accordingly, novel therapeutic approaches are being developed to target IL-23/IL-17 as well as to modulate the Th17/Treg balance in favor of immune regulation to control autoimmunity.

Recombinant HMGB1 A box protein inhibits Th17 responses in mice with neutrophilic asthma by suppressing dendritic cell-mediated Th17 polarization

High mobility group box chromosomal protein 1 (HMGB1) is a critical pro-inflammatory cytokine involved in diverse inflammatory diseases and has important immunomodulatory effects on allergic asthma. Our recent studies demonstrate that HMGB1) ^ReloadFigure=Yes1 expression increases in the lung tissue and associates with interleukin-17(+) (IL-17) helper T cell (Th17) responses in a murine model of neutrophilic asthma. In this study, to examine the immunomodulatory mechanisms of HMGB1, we evaluated the effects of recombinant HMGB1 A box (an antagonist of HMGB1) administration on allergic airway inflammation and lung antigen-presenting cell (APC) function in a murine model of neutrophilic asthma. In OVA-challenged mice, rHMGB1 A box attenuated HMGB1 expression, airway neutrophilic inflammation and hyper-responsiveness. In addition, the administration of rHMGB1 A box decreased the number of Th17 cells and IL-23(+) CD11c(+) APCs in lung cells. In vivo, rHMGB1 A box revealed an inhibitory effect of rHMGB1-activated dendritic cells (DCs) to produce IL-23 and induce a Th17 response. Finally, we showed that adoptive transfer of rHMGB1-activated DCs was sufficient to restore the characteristics of neutrophilic asthma in a DCs-driven model of asthma, whereas the transfer of rHMGB1 A box plus rHMGB1-activated DCs significantly reduced these inflammation phenotypes. These data demonstrate that rHMGB1 A box may have therapeutic effects on controlling Th17 polarization and airway inflammation in neutrophilic asthma by blocking the HMGB1 pathway on DCs.

Th17-associated cytokines as a therapeutic target for steroid-insensitive asthma

Steroid-insensitive asthma is an infrequent but problematic airway disease that presents with persistent symptoms, airflow limitation, or recurrent exacerbations even when treated with steroid-based therapies. Because of unsatisfactory results obtained from currently available therapies for steroid-insensitive asthma, a better understanding of its pathogenesis and the development of new targeted molecular therapies are warranted. Recent studies indicated that levels of interleukin (IL)-17 are increased and both eosinophils and neutrophils infiltrate the airways of severe asthmatics. IL-17 is a proinflammatory cytokine mainly secreted from helper T (Th) 17 cells and is important for the induction of neutrophil recruitment and migration at sites of inflammation. This review focuses on the pathogenetic role of Th17 cells and their associated cytokines in steroid-insensitive asthma and discusses the prospects of novel therapeutic options targeting the Th17 signaling pathway.