IL-4Rα signaling promotes barrier-altering oncostatin M and IL-6 production in aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is a severe disease involving dysregulated type 2 inflammation. However, the role other inflammatory pathways play in AERD is poorly understood.

OBJECTIVE

We sought to broadly define the inflammatory milieu of the upper respiratory tract in AERD and to determine the effects of IL-4Rα inhibition on mediators of nasal inflammation.

METHODS

Twenty-two AERD patients treated with dupilumab for 3 months were followed over 3 visits and compared to 10 healthy controls. Nasal fluid was assessed for 45 cytokines and chemokines using Olink Target 48. Blood neutrophils and cultured human mast cells, monocytes/macrophages, and nasal fibroblasts were assessed for response to IL-4/13 stimulation in vitro.

RESULTS

Of the nasal fluid cytokines measured, nearly one-third were higher in AERD patients compared to healthy controls, including IL-6 and the IL-6 family-related cytokine oncostatin M (OSM), both of which correlated with nasal albumin levels, a marker of epithelial barrier dysregulation. Dupilumab significantly decreased many nasal mediators, including OSM and IL-6. IL-4 stimulation induced OSM production from mast cells and macrophages, but not from neutrophils, and OSM and IL-13 stimulation induced IL-6 production from nasal fibroblasts.

CONCLUSION

In addition to type 2 inflammation, innate and IL-6-related cytokines are also elevated in the respiratory tract in AERD. Both OSM and IL-6 are locally produced in nasal polyps and likely promote pathology by negatively affecting epithelial barrier function. IL-4Rα blockade, though seemingly directed at type 2 inflammation, also decreases mediators of innate inflammation and epithelial dysregulation, which may contribute to dupilumab's therapeutic efficacy in AERD.

Global IL4Rα blockade exacerbates heart failure after an ischemic event in mice and humans

Ischemic heart failure continues to be a highly prevalent disease among westernized countries and there is great interest in understanding the mechanisms preventing or exacerbating disease progression. The literature suggests an important role for the activation of interleukin-13 or interleukin-4 signaling in improving ischemic heart failure outcomes after myocardial infarction in mice. Dupilumab, a neutralizing antibody that inhibits the shared IL13/IL4 receptor subunit IL4Rα, is widely used for conditions such as ectopic dermatitis in humans. If global depletion of IL4Rα influences ischemic heart failure, either in mice or in humans taking dupilumab, is unknown. Here, we investigated the pathophysiological effects of global IL4Rα genetic deletion in adult mice after surgically induced myocardial infarction (MI). We also determined heart failure risk in patients with ischemic heart disease and concomitant usage of dupilumab using the collaborative patient data network TriNetX. Global deletion of IL4Rα results in exacerbated cardiac dysfunction associated with reduced capillary size after myocardial infarction in mice. In agreement with our findings in mice, dupilumab treatment significantly increased the risk of heart failure development in patients with preexisting diagnosis of ischemic heart disease. Our results indicate that systemic IL4Rα signaling is protective against heart failure development in adult mice and human patients specifically following an ischemic event. Thus, the compelling evidence presented hereby advocates for the development of a randomized clinical trial specifically investigating heart failure development after myocardial ischemia in patients taking dupilumab for another underlying condition.NEW & NOTEWORTHY A body of literature suggests a protective role for IL4Rα signaling postmyocardial infarction in mice. Here, our observational study demonstrates that humans taking the IL4Rα neutralizing antibody, dupilumab, have increased incidence of heart failure following an ischemic event. Similarly, global IL4Rα deletion in mice exacerbates heart failure postinfarct. To our knowledge, this is the first study reporting an adverse association in humans of dupilumab use with heart failure following a cardiac ischemic event.

Evaluation of IL-4 and IL-13 Single Nucleotide Polymorphisms and Their Association With Childhood Asthma and Its Severity: A Hospital-Based Case-Control Study

BACKGROUND AND OBJECTIVES

Asthma is a common, chronic, atopic respiratory disease that is on the rise among children and adults worldwide. Various environmental, genetic, and biological interactions contribute to the surge in susceptibility to this disease. Interleukin (IL) genes, particularly IL-4 and IL-13, have been linked to asthma pathogenesis. The present study aims to investigate the genetic aberrations, specifically single nucleotide polymorphisms (SNPs) of IL-4 and IL-13, and their association with childhood asthma and its severity.

METHODS

An unmatched hospital-based case-control study was conducted in a tertiary care hospital in Assam, India. The sample size was calculated to be 120 (60 cases and 60 controls) using the Epi Info software version 7.2 (Centers for Disease Control and Prevention, Atlanta, GA, USA), assuming a confidence interval of 95%, a power of the study at 80%, a ratio of control to cases as 1, a proportion of controls with exposure at 22%, and a proportion of cases with exposure at 46%. A total of 53 clinically diagnosed cases of childhood asthma in the age range of three to 12 years and 39 healthy controls free from respiratory diseases and having no history of asthma and/or allergy of the same age group attending a tertiary care hospital were included in the study. Children who never had asthma or allergies and who did not suffer from any upper or lower respiratory infections for the previous four weeks were considered controls. Prior informed consent and ethical clearance were obtained. Very seriously ill cases and controls were excluded from the study. The genetic investigation used polymerase chain reaction (PCR), followed by restriction fragment length polymorphism (RFLP), to discover SNPs in the IL-4 and IL-13 genes. Sequencing analysis was done for the cases with +2044 G>A of the IL-13 gene in relation to the severity of the disease. The difference in the proportions of specific SNPs between cases and controls was analyzed using the χ2 test (a p-value of <0.05 was considered significant).

RESULTS

Both the rs2070874 and rs2243250 polymorphisms of IL-4 showed no statistically significant associations. The mutation of the IL-13 gene in 1111C>T was higher among cases than controls. Both genotypic and allelic distributions of the +2044G>A polymorphism of the IL-13 gene revealed a significant association (p<0.05) with the severity of the disease.

CONCLUSION

Genetic aberrations in SNPs of IL-4 and IL-13 are prevalent among the pediatric patients of the study region. The SNP +2044G>A of IL-13 is instrumental in disease manifestation and severity among the pediatric population of the study region.

German cockroach extract prevents IL-13-induced CCL26 expression in airway epithelial cells through IL-13 degradation

Inhaled aeroallergens can directly activate airway epithelial cells (AECs). Exposure to cockroach allergens is a strong risk factor for asthma. Cockroach allergens mediate some of their effects through their serine protease activity; protease activity is also a major contributor to allergenicity. The Th2 cytokine interleukin-13 (IL-13) induces upregulation of the eosinophil chemotactic factor CCL26. CCL26 induces eosinophil migration in allergic inflammation. In this work, we studied the effect of cockroach proteases on IL-13-induced effects. Immersed cultures of the human bronchial epithelial cell line BEAS-2B and air-liquid interface (ALI) cultures of primary normal human bronchial epithelial (NHBE) cells were stimulated with IL-13, Blattella Germanica cockroach extract (CE), or both. IL-13-induced genes were analyzed with qRT-PCR. IL-13 induced upregulation of CCL26, periostin, and IL-13Rα2 in bronchial epithelial cells which were decreased by CE. CE was heat-inactivated (HICE) or pre-incubated with protease inhibitors. HICE and CE preincubated with serine protease inhibitors did not prevent IL-13-induced CCL26 upregulation. CE-degraded IL-13 and specific cleavage sites were identified. CE also decreased IL-4-induced CCL26 upregulation and degraded IL-4. Other serine proteases such as bovine trypsin and house dust mite (HDM) serine proteases did not have the same effects on IL-13-induced CCL26. We conclude that CE serine proteases antagonize IL-13-induced effects in AECs, and this CE effect is mediated primarily through proteolytic cleavage of IL-13. IL-13 cleavage by cockroach serine proteases may modulate CCL26-mediated effects in allergic airway inflammation by interfering directly with the pro-inflammatory effects of IL-13 in vivo.

Role of IL-4 and IL-13 in Cutaneous T Cell Lymphoma

The interleukins IL-4 and IL-13 are increasingly recognized contributors to the pathogenesis of cutaneous T cell lymphomas (CTCLs), and their role in disease-associated pruritus is accepted. The prevailing Th2 profile in advanced CTCL underscores the significance of understanding IL-4/IL-13 expression dynamics from the early stages of disease, as a shift from Th1 to Th2 may explain CTCL progression. Targeted agents blocking key cytokines of type 2 immunity are established therapeutics in atopic disorders and have a promising therapeutic potential in CTCL, given their involvement in cutaneous symptoms and their contribution to the pathogenesis of disease. IL-4, IL-13, and IL-31 are implicated in pruritus, offering therapeutic targets with dupilumab, tralokinumab, lebrikizumab, and nemolizumab. This review analyzes current knowledge on the IL-4/IL-13 axis in mycosis fungoides and Sezary syndrome, the most common types of CTCL, examining existing literature on the pathogenetic implications with a focus on investigational treatments. Clinical trials and case reports are required to shed light on novel uses of medications in various diseases, and ongoing research into the role of IL-4/IL-13 axis blockers in CTCL therapy might not only improve the management of disease-related pruritus but also provide in-depth insights on the pathophysiologic mechanisms of CTCL.

A Case Report and Literature Review of the Role of Dupilumab in the Management of Lichen Planus: Cause or Treatment?

Lichen planus (LP) is a chronic inflammatory skin condition characterized by the six Ps (ie. purple, planar, polygonal, pruritic, plaques, and papules) often causing physical, emotional, and psychological stress for the person affected. Drug-induced LP has been described after the administration of drugs like antihypertensives, non-steroidal anti-inflammatory drugs (NSAIDs), and biologics like adalimumab and etanercept. Currently, there is a dearth of studies discussing the association between LP and dupilumab. Here, we present the case of a young adult female who developed LP 24 months after treatment with dupilumab for severe atopic dermatitis. We also conducted a review of the literature discussing the association between LP and dupilumab.

T helper 2 cells control monocyte to tissue-resident macrophage differentiation during nematode infection of the pleural cavity

The recent revolution in tissue-resident macrophage biology has resulted largely from murine studies performed in C57BL/6 mice. Here, using both C57BL/6 and BALB/c mice, we analyze immune cells in the pleural cavity. Unlike C57BL/6 mice, naive tissue-resident large-cavity macrophages (LCMs) of BALB/c mice failed to fully implement the tissue-residency program. Following infection with a pleural-dwelling nematode, these pre-existing differences were accentuated with LCM expansion occurring in C57BL/6, but not in BALB/c mice. While infection drove monocyte recruitment in both strains, only in C57BL/6 mice were monocytes able to efficiently integrate into the resident pool. Monocyte-to-macrophage conversion required both T cells and interleukin-4 receptor alpha (IL-4Rα) signaling. The transition to tissue residency altered macrophage function, and GATA6+ tissue-resident macrophages were required for host resistance to nematode infection. Therefore, during tissue nematode infection, T helper 2 (Th2) cells control the differentiation pathway of resident macrophages, which determines infection outcome.

Chronic interleukin-13 expression in mouse olfactory mucosa results in regional aneuronal epithelium

BACKGROUND

Olfactory dysfunction is highly associated with chronic rhinosinusitis with nasal polyps (CRSwNP), and the severity of loss has been linked with biomarkers of type 2 inflammation. The ability of dupilumab to rapidly improve the sense of smell prior to improvement in polyp size suggests a direct role of IL-4/IL-13 receptor signaling in the olfactory epithelium (OE).

METHODS

We created a transgenic mouse model in which IL-13 is inducibly expressed specifically within the OE. Gene expression analysis and immunohistology were utilized to characterize the effect of IL-13 on the structure of the OE.

RESULTS

After induction of olfactory IL-13 expression, there is a time-dependent loss of neurons from OE regions, accompanied by a modest inflammatory infiltrate. Horizontal basal cells undergo morphologic changes consistent with activation and demonstrate proliferation. Mucus production and increased expression of eotaxins is observed, with marked expression of Ym2 by sustentacular cells.

DISCUSSION

Chronic IL-13 exposure has several effects on the OE that are likely to affect function. The neuronal loss is in keeping with other models of allergic type 2 nasal inflammation. Future studies are needed to correlate cellular and molecular alterations in olfactory cell populations with findings in human CRSwNP, as well as to assess olfactory function in behavioral model systems.

Targeting Interleukin 13 for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin condition that has a significant impact on a patient's quality of life and requires ongoing management. Conventional topical and systemic therapies do not target specific components of AD pathogenesis and, therefore, have limited efficacy and may be associated with long-term toxicity. Thus, AD management is challenging, with a significant proportion of patients not achieving clear skin or a reduction in pruritus. There remains a large unmet need for effective therapeutic strategies with favorable safety profiles that can be used long-term in patients with refractory AD. The emergence of targeted biological and small molecule therapies has effectively broadened available treatment options for moderate-to-severe AD. Most recently, interleukin 13 (IL-13) inhibitors were shown to be efficacious and well-tolerated, with tralokinumab already approved for use in this patient population. It is important for dermatologists to be aware of the evidence behind this emerging class of biologic agents to guide treatment choices and improve outcomes in patients with AD. The main objective of this paper is to review the current literature regarding the efficacy and safety of current and emerging anti-IL-13 monoclonal antibodies, including tralokinumab, lebrikizumab, cendakimab, and eblasakimab, for the treatment of moderate-to-severe AD.

Cilia-Mediated Insulin/Akt and ST2/JNK Signaling Pathways Regulate the Recovery of Muscle Injury

Following injury, skeletal muscle regenerates but fatty tissue accumulation is seen in aged muscle or muscular dystrophies. Fibro/adipogenic progenitors (FAPs) are key players in these events; however, the effect of primary cilia on FAPs remains unclear. Here, it is reported that genetic ablation of trichoplein (TCHP), a ciliary regulator, induces ciliary elongation on FAPs after injury, which promotes muscle regeneration while inhibiting adipogenesis. The defective adipogenic differentiation of FAPs is attributed to dysfunction of cilia-dependent lipid raft dynamics, which is critical for insulin/Akt signaling. It is also found that interleukin (IL) 13 is substantially produced by intramuscular FAPs, which are upregulated by ciliary elongation and contribute to regeneration. Mechanistically, upon injury, long cilia excessively activate the IL33/ST2/JNK axis to enhance IL13 production, facilitating myoblast proliferation and M2 macrophage polarization. The results indicate that FAPs organize the regenerative responses to skeletal muscle injury via cilia-mediated insulin/Akt and ST2/JNK signaling pathways.

Treatment of bullous pemphigoid with dupilumab: Dupilumab exerts its effect by primarily suppressing T-helper 2 cytokines

We report a patient with bullous pemphigoid (BP) who was successfully treated with dupilumab monotherapy. To clarify the underlying mechanism of this effective treatment, we investigated the dynamics of a variety of cytokine-producing T cells before and after treatment in the circulation and in blister fluid using flow cytometry. The patient was a 72-year-old woman who had a pruritic eruption consisting of erythema and tense blisters on the whole body. The skin biopsy and direct immunofluorescence of the skin were typical for BP. The serum level of anti-BP180NC16a antibodies was 111 U/ml. Flow cytometric analyses revealed that the proportions of circulating interleukin (IL)-4-, IL-13-, and IL-31-producing CD4⁺ and CD8⁺ T cells were substantially higher in our BP patient than in healthy subjects. Moreover, IL-4- and IL-13-producing CD4⁺ and CD8⁺ T cells were much higher in the blister fluids than in the circulation, whereas IL-31-producing CD4⁺ and CD8⁺ T cells were only slightly higher in the blister fluids. The proportions of circulating interferon (IFN)-γ-producing CD4⁺ and CD8⁺ T cells in the circulation were slightly lower in the patient than in healthy subjects. There was no significant difference in the circulating IL-17-producing CD4⁺ and CD8⁺ T cells between the patient and healthy subjects, although IL-17-producing CD4⁺ and CD8⁺ T cells were slightly higher in the blister fluids. Treatment with dupilumab promptly improved the pruritus and skin lesions, and anti-BP180 antibodies became negative. After treatment with dupilumab, the proportions of circulating IL-4- and IL-13-producing CD4⁺ T cells mainly decreased and IL-17- and IL-31-producing CD4⁺ T cells slightly decreased. There were no significant differences in the proportions of circulating IFN-γ-producing CD4⁺ and CD8⁺ T cells between before and after treatment. These results suggest that T-helper (Th)2 cells are involved in the pathogenesis of BP, and dupilumab exerts its effect mainly by suppressing Th2 cytokines.

Butyrate and propionate restore interleukin 13-compromised esophageal epithelial barrier function

BACKGROUND

Eosinophilic esophagitis (EoE) is a food allergen driven disease that is accompanied by interleukin (IL) 13 overexpression and esophageal barrier dysfunction allowing transepithelial food allergen permeation. Nutraceuticals, such as short-chain fatty acids (SCFAs) that restore barrier function and increase immune fitness may be a promising tool in the management of EoE. Here, we investigated the effects of the SCFAs acetate, propionate, and butyrate on an IL-13-compromised human esophageal epithelial barrier, including the mechanisms involved.

METHODS

An air-liquid interface culture model of differentiated human EPC2-hTERT (EPC2) was used to study whether SCFAs could restore barrier function after IL-13-induced impairment. Esophageal epithelial barrier function was monitored by transepithelial electrical resistance (TEER) and FITC-dextran paracellular flux, and was further examined by qPCR and immunohistochemical analysis. G protein-coupled receptor (GPR) GPR41, GPR43, GPR109a, or histone deacetylase (HDAC) (ant)agonists were used to assess mechanisms of action of SCFAs.

RESULTS

IL-13 stimulation decreased TEER and increased FITC flux, which was counteracted by butyrate and propionate, but not acetate treatment. Barrier proteins FLG and DSG1 mRNA expression was upregulated following butyrate and propionate treatment, whereas expression of eosinophil chemoattractant CCL26 and protease CAPN14 was downregulated. Similarly, butyrate and propionate restored FLG and DSG1 protein expression. Similar effects were observed with an HDAC antagonist but not with GPR agonists.

CONCLUSION

Nutraceuticals butyrate and propionate restore the barrier function of esophageal epithelial cells after an inflammatory insult and may be of therapeutic benefit in the management of EoE.

Association of +1923C > T, -1112C > T and +2044A > G Polymorphisms in IL-13 Gene with Susceptibility to Pediatric Asthma: A Systematic Review and Meta-Analysis

BackgroundPrevious studies have provided conflicting evidence implicating the IL-13 polymorphism and pediatric asthma. Thus, we performed a meta-analysis to combine and analyze the available studies to provide more accurate conclusions. Methods: A comprehensive retrieval in PubMed, EMBASE, Web of Science, and CNKI was performed up to February 05, 2020. Results: A total of 39 case-control studies including 15 studies with 4,968 cases and 7,091 controls were on +1923 C > T, ten studies with 3,175 cases and 2,983 controls on -1112 C > T, and 14 studies with 4,476 cases and 5,121 controls on +2044 A > G were selected. Pooled data showed that the IL-13 + 1923 C > T, -1112 C > T and +2044 A > G polymorphisms were significantly associated with risk of pediatric asthma. The IL-13 + 1923 C > T (Asians and Africans), -1112 C > T (Caucasians) and +2044 A > G (Asians) polymorphisms were more frequently associated in these ethnic groups. Conclusions: Our pooled data indicated that IL-13 + 1923 C > T, -1112 C > T and +2044 A > G polymorphisms were correlated with risk of pediatric asthma.

Loss of Interleukin-13-Receptor-Alpha-1 Induces Apoptosis and Promotes EMT in Pancreatic Cancer

In search of new therapies for pancreatic cancer, cytokine pathways have attracted increasing interest in recent years. Cytokines play a vital role in the crosstalk between tumour cells and the tumour microenvironment. The related inflammatory cytokines IL-4 and IL-13 can regularly be detected at increased levels in the microenvironment of pancreatic cancer. They share a receptor heterodimer consisting of IL-4Rα and IL-13Rα1. While IL-4Rα induces a more oncogenic phenotype, the role of IL-13Rα1 was yet to be determined. ShRNA-based knockdown of IL-13Rα1 was performed in Capan-1 and MIA PaCa-2. We assessed cell growth and migratory capacities under the influence of IL-13Rα1. Pathway alterations were detected by immunoblot analysis. We now have demonstrated that the loss of IL-13Rα1 induces apoptosis in pancreatic cancer cells. This was associated with an epithelial-to-mesenchymal transition. Loss of IL-13Rα1 also abolished the effects of exogenous IL-4 and IL-13 stimulation. Interestingly, in wild type cells, cytokine stimulation caused a similar increase in migratory capacities as after IL-13Rα1 knockdown. Overall, our results indicate the vital role of IL-13Rα1 in the progression of pancreatic cancer. The differential expression of IL-4Rα and IL-13Rα1 has to be taken into account when considering a cytokine-targeted therapy in pancreatic cancer.

Biological agents targeting interleukin-13 for atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is pathogenically driven by type-2 inflammation. Interleukin-13 (IL-13) plays a central role in AD pathogenesis, as confirmed by the clinical efficacy of agents that selectively block IL-13, although their therapeutic value and place-in-therapy are incompletely defined.

AREAS COVERED

The aim of this review article is to describe preclinical and clinical data regarding selective IL-13 inhibitors investigated in AD. In particular, we discuss the clinical outcomes obtained with lebrikizumab and tralokinumab, which are in a more advanced phase of development.

EXPERT OPINION

Biological agents that neutralize IL-13 have demonstrated clinical benefits in treating AD with excellent safety profiles. Robust clinical evidence exists in support of tralokinumab, which underwent phase III trials, met the predefined primary endpoints, and is approaching the market. In contrast, clinical trial testing for lebrikizumab needs to be completed to fully assess its therapeutic potential.

PLAIN LANGUAGE SUMMARY

Atopic dermatitis (AD) is a chronic pathological inflammatory skin disease that results from type-2 inflammation. Selective interleukin-13 (IL-13) inhibitors have shown clinical efficacy against AD, suggesting that IL-13 plays a central in AD pathogenesis. However, the therapeutic value and place-in-therapy of IL-13 inhibitors are incompletely defined. The aim of this review article is to describe preclinical and clinical data for selective IL-13 inhibitors against AD, including lebrikizumab and tralokinumab, which are in a more advanced phase of development. The up-to-date overview of the strengths and limitations of different agents used to treat AD discussed in this article might be useful in driving treatment decision.

Entropy Analysis of Protein Sequences Reveals a Hierarchical Organization

BACKGROUND

Analyzing the local sequence content in proteins, earlier we found that amino acid residue frequencies differ on various distances between amino acid positions in the sequence, assuming the existence of structural units.

METHODS

We used informational entropy of protein sequences to find that the structural unit of proteins is a block of adjacent amino acid residues-"information unit". The ANIS (ANalysis of Informational Structure) method uses these information units for revealing hierarchically organized Elements of the Information Structure (ELIS) in amino acid sequences.

RESULTS

The developed mathematical apparatus gives stable results on the structural unit description even with a significant variation in the parameters. The optimal length of the information unit is five, and the number of allowed substitutions is one. Examples of the application of the method for the design of protein molecules, intermolecular interactions analysis, and the study of the mechanisms of functioning of protein molecular machines are given.

CONCLUSIONS

ANIS method makes it possible not only to analyze native proteins but also to design artificial polypeptide chains with a given spatial organization and, possibly, function.

Interleukin-4 and interleukin-13 induce different metabolic profiles in microglia and macrophages that relate with divergent outcomes after spinal cord injury

Background: Microglia and macrophages adopt a pro-inflammatory phenotype after spinal cord injury (SCI), what is thought to contribute to secondary tissue degeneration. We previously reported that this is due, in part, to the low levels of anti-inflammatory cytokines, such as IL-4. Since IL-13 and IL-4 share receptors and both cytokines drive microglia and macrophages towards an anti-inflammatory phenotype in vitro, here we studied whether administration of IL-13 and IL-4 after SCI leads to beneficial effects. Methods: We injected mice with recombinant IL-13 or IL-4 at 48 h after SCI and assessed their effects on microglia and macrophage phenotype and functional outcomes. We also performed RNA sequencing analysis of macrophages and microglia sorted from the injured spinal cords of mice treated with IL-13 or IL-4 and evaluated the metabolic state of these cells by using Seahorse technology. Results: We observed that IL-13 induced the expression of anti-inflammatory markers in microglia and macrophages after SCI but, in contrast to IL-4, it failed to mediate functional recovery. We found that these two cytokines induced different gene signatures in microglia and macrophages after SCI and that IL-4, in contrast to IL-13, shifted microglia and macrophage metabolism from glycolytic to oxidative phosphorylation. These findings were further confirmed by measuring the metabolic profile of these cells. Importantly, we also revealed that macrophages stimulated with IL-4 or IL-13 are not deleterious to neurons, but they become cytotoxic when oxidative metabolism is blocked. This suggests that the metabolic shift, from glycolysis to oxidative phosphorylation, is required to minimize the cytotoxic responses of microglia and macrophages. Conclusions: These results reveal that the metabolic fitness of microglia and macrophages after SCI contributes to secondary damage and that strategies aimed at boosting oxidative phosphorylation might be a novel approach to minimize the deleterious actions of microglia and macrophages in neurotrauma.

Diverse innate stimuli activate basophils through pathways involving Syk and IκB kinases

Mature basophils play critical inflammatory roles during helminthic, autoimmune, and allergic diseases through their secretion of histamine and the type 2 cytokines interleukin 4 (IL-4) and IL-13. Basophils are activated typically by allergen-mediated IgE cross-linking but also by endogenous "innate" factors. The aim of this study was to identify the innate stimuli (cytokines, chemokines, growth factors, hormones, neuropeptides, metabolites, and bacterial products) and signaling pathways inducing primary basophil activation. Basophils from naïve mice or helminth-infected mice were cultured with up to 96 distinct stimuli and their influence on basophil survival, activation, degranulation, and IL-4 or IL-13 expression were investigated. Activated basophils show a heterogeneous phenotype and segregate into distinct subsets expressing IL-4, IL-13, activation, or degranulation markers. We find that several innate stimuli including epithelial derived inflammatory cytokines (IL-33, IL-18, TSLP, and GM-CSF), growth factors (IL-3, IL-7, TGFβ, and VEGF), eicosanoids, metabolites, TLR ligands, and type I IFN exert significant direct effects on basophils. Basophil activation mediated by distinct upstream signaling pathways is always sensitive to Syk and IκB kinases-specific inhibitors but not necessarily to NFAT, STAT5, adenylate cyclase, or c-fos/AP-1 inhibitors. Thus, basophils are activated by very diverse mediators, but their activation seem controlled by a core checkpoint involving Syk and IκB kinases.

Tick-Borne Encephalitis Specific Lymphocyte Response after Allogeneic Hematopoietic Stem Cell Transplantation Predicts Humoral Immunity after Vaccination

The aim of this prospective study was to assess lymphocyte proliferative and cytokine response prior to and following tick-borne encephalitis (TBE) immunization among patients after allogeneic hematopoietic stem cell transplantation (HSCT). Seventeen adult patients 11–13 months after HSCT and eight unvaccinated healthy adults received up to three TBE vaccinations. Following in vitro stimulation with TBE-antigen, lymphocyte proliferation and cytokine secretion (IL-2, IL-10, IL-13, TNF-alpha, IFN-gamma, GM-CSF) were analyzed by thymidine incorporation assay and the Luminex system. Ten patients (59%) showed significant baseline TBE-specific lymphocyte proliferation (stimulation index (SI) > 3) prior to vaccination, but none of the unvaccinated controls (p = 0.002). All patients with a TBE-specific antibody response after two vaccinations (at least 2-fold increase of neutralization test titers) exhibited a strong TBE-specific lymphocyte proliferative response at baseline (SI > 10). Patients with sibling donors had a significantly stronger baseline TBE-specific lymphocyte proliferative and IL-13 cytokine response than patients with unrelated donors (p < 0.05). In conclusion, a relevant proportion of patients showed TBE-specific lymphocyte proliferative and cytokine responses prior to vaccination after HSCT, which predicted the humoral response to the vaccine. Patients with vaccinated sibling donors were more likely to elicit a cellular immune response than patients with unrelated donors of unknown vaccination status.

Searching for Noninvasive Predictors of the Diagnosis and Monitoring of Eosinophilic Esophagitis-The Importance of Biomarkers of the Inflammatory Reaction Involving Eosinophils

Background: Invasive and costly endoscopic diagnosis is obligatory for the diagnosis and monitoring of eosinophilic esophagitis (EoE). This study aims to evaluate the usefulness of serum biomarkers involved in eosinophil-mediated inflammation in the management of EoE. Methods: A prospective cohort study was conducted in 58 patients with dysphagia. Each participant completed a health questionnaire, underwent esophagogastroduodenoscopy with esophageal biopsy for histopathological examination and assessment of total, inflammatory and fibrostenotic Eosinophilic Esophagitis Reference Score (EREFS). Serum levels of interleukin 5 (IL-5), interleukin 13 (IL-13), transforming growth factor β1 (TGF-β1), major basic protein (MBP), and eotaxin 3 were determined by enzyme immunoassays. Total of 16 patients meeting the histological criteria for EoE were treated with proton pump inhibitors for 8 weeks, and then the same diagnostics was performed again. Results: Statistically significantly higher concentrations of MBP and TGF-β1 were demonstrated in the group of patients with EoE, while MBP and eotaxin 3 correlated with the peak eosinophil count (PEC). Baseline MBP levels and eotaxin 3 after treatment significantly positively correlated with EREFS. There was a negative correlation between IL-13 and fibrostenotic EREFS. Additionally, after treatment, a negative correlation TGF-β1 was noted with the inflammatory EREFS and a positive correlation with the fibrostenotic EREFS. Conclusions: The potential role of MBP in predicting the diagnosis of EoE, eotaxin 3 in predicting the advancement and correlation of IL-13 and TGF-β1 in differentiating the inflammatory and fibrotic course of the disease may facilitate the management and individualization of EoE therapy.

ANGPTL3 Variants Associate with Lower Levels of Irisin and C-Peptide in a Cohort of Arab Individuals

ANGPTL3 is an important regulator of lipid metabolism. Its inhibition in people with hypercholesteremia reduces plasma lipid levels dramatically. Genome-wide association studies have associated ANGPTL3 variants with lipid traits. Irisin, an exercise-modulated protein, has been associated with lipid metabolism. Intracellular accumulation of lipids impairs insulin action and contributes to metabolic disorders. In this study, we evaluate the impact of ANGPTL3 variants on levels of irisin and markers associated with lipid metabolism and insulin resistance. ANGPTL3 rs1748197 and rs12130333 variants were genotyped in a cohort of 278 Arab individuals from Kuwait. Levels of irisin and other metabolic markers were measured by ELISA. Significance of association signals was assessed using Bonferroni-corrected p-values and empirical p-values. The study variants were significantly associated with low levels of c-peptide and irisin. Levels of c-peptide and irisin were mediated by interaction between carrier genotypes (GA + AA) at rs1748197 and measures of IL13 and TG, respectively. While levels of c-peptide and IL13 were directly correlated in individuals with the reference genotype, they were inversely correlated in individuals with the carrier genotype. Irisin correlated positively with TG and was strong in individuals with carrier genotypes. These observations illustrate ANGPTL3 as a potential link connecting lipid metabolism, insulin resistance and cardioprotection.

Defective STING expression potentiates IL-13 signaling in epithelial cells in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Stimulator of interferon genes (STING) activation favors effective innate immune responses against viral infections. Its role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains unknown.

OBJECTIVE

Our aim was to explore the expression, regulation, and function of STING in CRSwNP.

METHODS

STING expression in sinonasal mucosal samples was analyzed by means of quantitative RT-PCR, immunohistochemistry, flow cytometry, and Western blotting. Regulation and function of STING expression were explored by using cultured primary human nasal epithelial cells (HNECs) and cells of the line BEAS-2B in vitro.

RESULTS

STING expression was reduced in eosinophilic nasal polyps compared with that in noneosinophilic nasal polyps and control tissues. STING was predominantly expressed by epithelial cells in nasal tissue and was downregulated by IL-4 and IL-13 in a signal transducer and activator of transcription 6 (STAT6)-dependent manner. HNECs derived from eosinophilic polyps displayed compromised STING-dependent type I interferon production but heightened IL-13-induced STAT6 activation and CCL26 production as compared with HNECs from noneosinophilic polyps and control tissues, which were rescued by exogenous STING overexpression. Knocking down or overexpressing STING decreased or enhanced expression of suppressor of cytokine signaling 1 (SOCS1) in BEAS-2B cells, respectively, independent of the canonic STING pathway elements TBK1 and IRF3. Knocking down SOCS1 abolished the inhibitory effect of STING on IL-13 signaling in BEAS-2B cells. STING expression was positively correlated with SOCS1 expression but negatively correlated with CCL26 expression in nasal epithelial cells from patients with CRSwNP.

CONCLUSIONS

Reduced STING expression caused by the type 2 milieu not only impairs STING-dependent type I interferon production but also amplifies IL-13 signaling by decreasing SOCS1 expression in nasal epithelial cells in eosinophilic CRSwNP.

Tralokinumab does not impact vaccine-induced immune responses: Results from a 30-week, randomized, placebo-controlled trial in adults with moderate-to-severe atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Interleukin (IL) 13 is a type 2 cytokine that is key to the inflammation underlying AD. Tralokinumab is a first-in-class, fully human, monoclonal antibody that specifically binds with high affinity to IL-13, neutralizing it in AD. Immunomodulatory treatments may impair vaccine-induced immune responses.

OBJECTIVE

Assess the immune responses to standard vaccines in adults with moderate-to-severe AD who are undergoing treatment with tralokinumab.

METHODS

ECZema TRAlokinumab Trial No. 5 (ECZTRA 5; NCT03562377) was a phase 2, double-blind, randomized, placebo-controlled trial taking place over 30 weeks. Eligible adults were randomized 1:1, with 107 patients receiving tralokinumab 300 mg and 108 patients receiving a placebo every 2 weeks for 16 weeks. All patients received Tdap (tetanus/diphtheria/pertussis) and meningococcal vaccines at week 12. The primary end points were positive antitetanus and antimeningococcal responses between weeks 12 and 16 (noninferiority margin, -25%; responder, >3-fold increase in IgG).

RESULTS

The noninferiority of tralokinumab versus placebo for immune response to Tdap (91.9% vs 96.1%) and meningococcal (86.0% vs 84.2%) vaccines was demonstrated at week 16. During treatment, the rates of adverse events were lower for tralokinumab than for the placebo, with most events being mild or moderate.

LIMITATIONS

Responses to other vaccines (including influenza) were not examined.

CONCLUSIONS

Treatment with tralokinumab 300 mg every 2 weeks did not affect immune responses to Tdap and meningococcal vaccines. Treatment was well tolerated when administered concomitantly with the vaccines and demonstrated a safety profile comparable to phase 3 trials.

Impact of zinc oxide nanoparticles and thymoquinone in Ehrlich ascites carcinoma induced in mice

BACKGROUND

The field of nanotechnology offers great opportunities for cancer therapy.

OBJECTIVE

This study aimed to compare the therapeutic impact of Zn oxide nanoparticles (ZnO NPs) and thymoquinone (TQ) alone or as cotherapy in Ehrlich ascites carcinoma (EAC) induced in mice.

MATERIALS AND METHODS

This study was performed on 75 female albino mice divided into Group I: EAC-bearing control group, Group II: EAC treated with TQ, Group III: EAC treated with low-dose ZnO NPs, Group IV: EAC treated with high-dose ZnO NPs, Group V: EAC treated with TQ and low-dose ZnO NPs. All groups were subjected to measurement of cell viability, ascites fluid volume, Bcl2 protein expression by Western blot analysis, cyclooxygenase 2 (COX2) gene expression by a real-time polymerase chain reaction, enzyme-linked immunosorbent assay levels of Beclin 1, interferon γ (INFγ), interleukin 13 (IL-13), and estimation of Zn concentrations in EAC cells and liver homogenate to evaluate its toxicity.

RESULTS

Cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy, resulting in reducing tumor cell viability and ascites fluid volume together with downregulation of Bcl2 protein expression. This cotherapy increases Beclin 1 and INFγ and decreases IL-13. ZnO NPs upregulate COX2 expression, whereas TQ downregulates its expression. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NPs liver toxicity.

CONCLUSION

The cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NP liver toxicity.

Tumor Targeted Delivery of an Anti-Cancer Therapeutic: An In Vitro and In Vivo Evaluation

The limited effectiveness of current therapeutics against malignant brain gliomas has led to an urgent need for development of new formulations against these tumors. Chelator Dp44mT (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone) presents a promising candidate to defeat gliomas due to its exceptional anti-tumor activity and its unique ability to overcome multidrug resistance. The goal of this study is to develop a targeted nano-carrier for Dp44mT delivery to glioma tumors and to assess its therapeutic efficacy in vitro and in vivo. Dp44mT is loaded into poly(ethylene glycol) (PEG)ylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) decorated with glioma-targeting ligand Interlukin 13 (IL13). IL13-conjugation enhanced the NP uptake by glioma cells and also improved their transport across an in vitro blood-brain-barrier (BBB) model. This targeted formulation showed an outstanding toxicity towards glioma cell lines and patient-derived stem cells in vitro, with IC₅₀ values less than 125 nM, and caused no significant death in healthy brain microvascular endothelial cells. In vivo, when tested on a xenograft mouse model, IL13-conjugated Dp44mT-NPs reduced the glioma tumor growth by ≈62% while their untargeted counterparts reduced the tumor growth by only ≈16%. Notably, this formulation does not cause any significant weight loss or kidney/liver toxicity in mice, demonstrating its great therapeutic potential.

Protective effects of ascorbic acid and calcitriol combination on airway remodelling in ovalbumin-induced chronic asthma

Context: Airway remodelling is one of the most refractory problems in asthma. According to the critical roles of oxidative stress and inflammation in airway remodelling, it is supposed that ascorbic acid and calcitriol have beneficial effects. However, a combination of antioxidants may be more effective for asthma therapy.Objective: This study investigated the protective effects of ascorbic acid in combination with calcitriol on airway remodelling in ovalbumin (OVA)-induced chronic asthma.Materials and methods: BALB/c mice were assigned into seven groups: (1) Control; (2) Asthma; (3) Ineffective C (orally 39 mg/kg ascorbic acid); (4) Ineffective D (intraperitoneally 1.5 μg/kg calcitriol); (5) Effective C (orally 130 mg/kg ascorbic acid); (6) Effective D (intraperitoneally 5 μg/kg calcitriol); (7) Combination (orally 39 mg/kg ascorbic acid + intraperitoneally 1.5 μg/kg calcitriol). All animals were sensitized and challenged with OVA except in the control group (normal saline). In all treatment groups, mice were administrated vitamins 30 min before each challenge (three times per week for 8 consecutive weeks).Results: In comparison with the asthma group, co-administration of ineffective doses of ascorbic acid and calcitriol led to the decreased levels of IL-13 (50.5 ± 1.85 vs. 42.13 ± 0.37 pg/mL, p = 0.02) and IgE (58.74 ± 0.43 vs. 45.78 ± 2.05 ng/mL, p = 0.003) as well as the reduction of goblet hyperplasia and subepithelial fibrosis (5 vs. 1 score, p = 0.001 and 5 vs. 2 score, p = 0.001, respectively).Discussion and conclusions: Combination of ascorbic acid with calcitriol in ineffective doses improves airway remodelling due to additive effects possibly through reduction of oxidative stress and inflammation. This study provides a scientific basis for further research and clinical applications of ascorbic acid and calcitriol and can be generalized to the broader pharmacological studies.

The first synthesis and immunomodulatory properties of p-hydroxyphenyl caffeate derived from Wedelia trilobata

Herein, we report a concise and efficient method for the synthesis of p-hydroxyphenyl caffeate, a novel natural caffeic acid ester derivative isolated from Wedelia trilobata. The key feature of this synthesis is the Verley-Doebner modification of the Knoevenagel condensation of the p-hydroxyphenyl malonate intermediate. The synthesized p-hydroxyphenyl caffeate enhanced interleukin 2 production by murine lymph node T cells, and suppressed interleukin 13 production by murine epidermal T cells. This implies that p-hydroxyphenyl caffeate might be a novel immunomodulatory drug candidate, specifically targeting T helper 2 cell type responses in skin diseases such as atopic dermatitis and vitiligo. [Formula: see text].

Murine induced pluripotent stem cell-derived neuroimmune cell culture models emphasize opposite immune-effector functions of interleukin 13-primed microglia and macrophages in terms of neuroimmune toxicity

Cellular models of induced pluripotent stem cell (iPSC)-derived microglia and macrophages are an emerging toolbox to investigate neuroinflammation in vitro. We previously demonstrated that murine iPSC-microglia and iPSC-macrophages display phenotypical activation properties highly comparable to microglia and macrophages in vivo. Here we extended the characterization of iPSC-microglia and iPSC-macrophages with the analysis of their transcriptome profile. Next, these cellular models were employed to evaluate neuroimmune toxicity in vitro and to investigate the immune-modulatory properties of interleukin 13 (IL13), a cytokine known for its ability to protect against neuroinflammation-induced pathology by modulating microglia and macrophage activation. iPSC-microglia and iPSC-macrophages, in co-culture with astrocyte-committed neural stem cells (NSC), were (pre)treated with IL13 and stimulated with lipopolysaccharide (LPS) and interferon γ (IFNγ), to assess how IL13 modulates their inflammatory response. Additionally, the use of luciferase-expressing NSC (Luc-NSC) allowed real-time monitoring of immune-mediated neurotoxicity. Despite the known anti-inflammatory properties of IL13, iPSC-microglia primed with IL13 before LPS + IFNγ stimulation significantly increased NO secretion. This was associated with a marked reduction of the luminescence signal produced by Luc-NSC. Interestingly, we observed that IL13 signaling has a divergent functional outcome in microglia as compared to macrophages, as for the latter no major alterations in NO release and Luc-NSC viability were observed upon IL13 (pre)treatment. Finally, the striking IL13-induced upregulation of NO secretion by microglia under pro-inflammatory conditions was confirmed in vivo, where intracerebral delivery of IL13 increased inducible nitric oxide synthase mRNA expression. Concluding, we applied iPSC-derived neuroimmune cell culture models to identify distinct neuroimmune (toxicity) responses of microglia and macrophages to IL13-based immune modulation.

The Intriguing Role of Interleukin 13 in the Pathophysiology of Asthma

Approximately 5–10% of asthmatic patients worldwide suffer from severe asthma. Experimental and clinical studies have demonstrated that IL-13 is an important cytokine in chronic airways inflammation. IL-13 is involved in Th2 inflammation and has been identified as a possible therapeutic target in the treatment of asthma. Two different human monoclonal antibodies (mAbs) anti-IL-13 (tralokinumab and lebrikizumab) block binding and signaling of IL-13 to its receptors, IL-13Rα1 and IL-13Rα2. Several randomized, double-blind, placebo-controlled multicenter studies have evaluated the safety and efficacy of tralokinumab and lebrikizumab in the treatment of adult patients with severe asthma, but all have failed to meet their primary endpoints. No serious adverse events related to the treatment with these anti-IL-13 mAbs have been reported in these studies. These negative clinical results contrast with positive findings from blocking IL-13 signaling in experimental models of asthma, raising doubts about the transferrable value of some models. Interestingly, dupilumab, a mAb which blocks both IL-4 and IL-13 signaling reduces exacerbation rates and improves lung function in severe asthmatics. These results suggest that IL-4 and IL-13 share some, but not all functional activities in airway inflammation. Tralokinumab might show efficacy in a highly selected cohort of asthmatics characterized by overexpression of IL-13.

SCF promotes the production of IL-13 via the MEK-ERK-CREB signaling pathway in mast cells

Mast cells serve a key role in the occurrence and development of allergy. As an important growth factor of mast cells, stem cell factor (SCF) has an effect on the apoptosis, chemotaxis, adhesion, degranulation and other biological characteristics of mast cells. However, there are few studies regarding the effect of SCF signal on the production of cytokines from mast cells, particularly Th2 type cytokines. In the present study, the expression and secretion of IL-13 in P815 cells stimulated by SCF were detected by fluorescence quantitative PCR and ELISA, and western blotting and EMSA were used to detect ERK phosphorylation and activation of CREB in stimulated P815 cells. The results demonstrated that the production of IL-13 was significantly increased in P815 cells stimulated by SCF (1–100 ng/ml; P<0.01). There was an obvious phosphorylation of ERK and CREB activation in P815 cells stimulated by SCF (50 ng/ml). Compared with the SCF single stimulation group, the production of IL-13 was significantly reduced in P815 cells stimulated with U0126 (ERK-MEK/pathway inhibitor) or H-89 (CREB inhibitor) combined with SCF stimulation group (P<0.01). However, JSI-124 (JAK/STAT3 pathway inhibitor), Wortmannin (PI3K/Akt pathway inhibitor) and PDTC (NF-κB inhibitor) had no effect on the role of SCF promoting the P815 cells producing IL-13. Therefore, SCF signaling promotes mast cell P815 to produce IL-13, and this effect is associated with the MEK-ERK-CREB signaling pathway.

Understanding the immune landscape in atopic dermatitis: The era of biologics and emerging therapeutic approaches

Atopic dermatitis (AD) is a chronic, systemic, inflammatory disease that affects the skin and is characterized by persistent itch and marked redness. AD is associated with an increased risk of skin infections and a reduced quality of life. Most AD treatment options to date were not designed to selectively target disease-causing pathways that have been established for this indication. Topical therapies have limited efficacy in moderate-to-severe disease, and systemic agents such as corticosteroids and immunosuppressants present with tolerability issues. Advances in the understanding of AD pathobiology have made possible a new generation of more disease-specific AD therapies. AD is characterized by the inappropriate activation of type 2 T helper (Th2) cells and type 2 innate lymphoid (ILC2) cells, with a predominant increase in type 2 cytokines in the skin, including interleukin (IL)-13 and IL-4. Both cytokines are implicated in tissue inflammation and epidermal barrier dysfunction, and monoclonal antibodies targeting each of these interleukins or their receptors are in clinical development in AD. In March 2017, dupilumab, a human anti-IL-4Rα antibody, became the first biologic to receive approval in the United States for the treatment of moderate-to-severe AD. The anti-IL-13 monoclonal antibodies lebrikizumab and tralokinumab, which bind different IL-13 epitopes with potentially different effects, are currently in advanced-stage trials. Here, we briefly review the underlying pathobiology of AD, the scientific basis for current AD targets, and summarize current clinical studies of these agents, including new research to develop both predictive and response biomarkers to further advance AD therapy in the era of precision medicine.

IL-13 Impairs Tight Junctions in Airway Epithelia

Interleukin-13 (IL-13) drives symptoms in asthma with high levels of T-helper type 2 cells (T_h2-cells). Since tight junctions (TJ) constitute the epithelial diffusion barrier, we investigated the effect of IL-13 on TJ in human tracheal epithelial cells. We observed that IL-13 increases paracellular permeability, changes claudin expression pattern and induces intracellular aggregation of the TJ proteins zonlua occludens protein 1, as well as claudins. Furthermore, IL-13 treatment increases expression of ubiquitin conjugating E2 enzyme UBE2Z. Co-localization and proximity ligation assays further showed that ubiquitin and the proteasomal marker PSMA5 co-localize with TJ proteins in IL-13 treated cells, showing that TJ proteins are ubiquitinated following IL-13 exposure. UBE2Z upregulation occurs within the first day after IL-13 exposure. Proteasomal aggregation of ubiquitinated TJ proteins starts three days after IL-13 exposure and transepithelial electrical resistance (TEER) decrease follows the time course of TJ-protein aggregation. Inhibition of JAK/STAT signaling abolishes IL-13 induced effects. Our data suggest that that IL-13 induces ubiquitination and proteasomal aggregation of TJ proteins via JAK/STAT dependent expression of UBE2Z, resulting in opening of TJs. This may contribute to barrier disturbances in pulmonary epithelia and lung damage of patients with inflammatory lung diseases.

Transcriptomic Analysis Links Eosinophilic Esophagitis and Atopic Dermatitis

Background: Eosinophilic esophagitis (EoE) is commonly associated with concomitant atopic diseases including atopic dermatitis (AD) and allergic airway (AA) diseases including asthma. Despite this link and the shared pathologic features across these three disorders, detailed analyses of the unifying molecular pathways are lacking. Objectives: We sought to investigate the mRNA expression profile overlap between EoE, AA, and AD and to identify the involvement of interleukin 13 (IL-13) in modulating gene expression. Methods: Whole-genome mRNA expression analyses were performed on tissue specimens (biopsies or nasal brushes) from patients with EoE, AD, and AA, and IL-13-stimulated primary human epithelial cells from the esophagus, the skin, and the airways. Results: By human disease expression profiles, EoE evidenced a significantly higher overlap (p = 0.0006) with AD (181 transcripts; 10%) than with AA (124 transcripts, 7%). Only 18 genes were found to be commonly dysregulated among the three diseases; these included filaggrin, histamine receptor H1, claudin 1, cathepsin C, plasminogen activator urokinase receptor, and suppressor of cytokine signaling 3. Ontogenetic analysis revealed a common immune/inflammatory response among the three diseases and a different epithelial response (epidermal cell differentiation) between EoE and AA. The overlap between the IL-13-stimulated epithelial cell transcriptome and the respective disease transcriptome was 22, 9, and 5% in EoE, AD, and AA, respectively, indicating a greater involvement of the IL-13 pathway in EoE than AA (p = 0.0007) or AD (p = 0.02). Conclusion: EoE, AD, and AA share a common set of disease-specific transcripts, highlighting common molecular etiology. Their comparative analysis indicates relatively closer relationships between EoE and AD, particularly centered around IL-13-driven pathways. Therefore, these findings provide an increased rationale for shared therapeutic strategies.

Rapid Evolution of Primate Type 2 Immune Response Factors Linked to Asthma Susceptibility

Host immunity pathways evolve rapidly in response to antagonism by pathogens. Microbial infections can also trigger excessive inflammation that contributes to diverse autoimmune disorders including asthma, lupus, diabetes, and arthritis. Definitive links between immune system evolution and human autoimmune disease remain unclear. Here we provide evidence that several components of the type 2 immune response pathway have been subject to recurrent positive selection in the primate lineage. Notably, substitutions in the central immune regulator IL13 correspond to a polymorphism linked to asthma susceptibility in humans. We also find evidence of accelerated amino acid substitutions as well as gene gain and loss events among eosinophil granule proteins, which act as toxic antimicrobial effectors that promote asthma pathology by damaging airway tissues. These results support the hypothesis that evolutionary conflicts with pathogens promote tradeoffs for increasingly robust immune responses during animal evolution. Our findings are also consistent with the view that natural selection has contributed to the spread of autoimmune disease alleles in humans.

Cigarette smoke differentially affects IL-13-induced gene expression in human airway epithelial cells

Allergic airways inflammation in asthma is characterized by an airway epithelial gene signature composed of POSTN, CLCA1, and SERPINB2 This Th2 gene signature is proposed as a tool to classify patients with asthma into Th2-high and Th2-low phenotypes. However, many asthmatics smoke and the effects of cigarette smoke exposure on the epithelial Th2 gene signature are largely unknown. Therefore, we investigated the combined effect of IL-13 and whole cigarette smoke (CS) on the Th2 gene signature and the mucin-related genes MUC5AC and SPDEF in air-liquid interface differentiated human bronchial (ALI-PBEC) and tracheal epithelial cells (ALI-PTEC). Cultures were exposed to IL-13 for 14 days followed by 5 days of IL-13 with CS exposure. Alternatively, cultures were exposed once daily to CS for 14 days, followed by 5 days CS with IL-13. POSTN, SERPINB2, and CLCA1 expression were measured 24 h after the last exposure to CS and IL-13. In both models POSTN, SERPINB2, and CLCA1 expression were increased by IL-13. CS markedly affected the IL-13-induced Th2 gene signature as indicated by a reduced POSTN, CLCA1, and MUC5AC expression in both models. In contrast, IL-13-induced SERPINB2 expression remained unaffected by CS, whereas SPDEF expression was additively increased. Importantly, cessation of CS exposure failed to restore IL-13-induced POSTN and CLCA1 expression. We show for the first time that CS differentially affects the IL-13-induced gene signature for Th2-high asthma. These findings provide novel insights into the interaction between Th2 inflammation and cigarette smoke that is important for asthma pathogenesis and biomarker-guided therapy in asthma.

Micro RNA-155 plays a critical role in the initiation of food allergen-related inflammation in the intestine

The pathogenesis of food allergy (FA) is to be further investigated. Regulatory B cells (B10 cell) play a critical in the maintenance of the homeostasis in the intestine. Deregulation of B10 cell is associated with immune inflammation. Micro RNA (miR) 155 is involved in affecting immune cell function. This study tests a hypothesis that miR-155 affects the B10 cell function to facilitate the initiation of FA. In this study, BALB/c mice were sensitized to ovalbumin (OVA) to induce FA-like inflammation in the intestine. B cells were isolated from the intestine by magnetic cell sorting. The expression of miR-155 and IL-10 in B cells was assessed by real time RT-PCR. The results showed that mice sensitized to OVA showed FA-like inflammation and lower frequency of B10 cell in the intestine. B cells isolated from the intestine of FA mice showed higher levels of miR-155 and lower levels of IL-10. Although all the three T helper (Th)2 cytokines, including interleukin (IL)-4, IL-5 and IL-13, were higher in the serum, only IL-13 was positively correlated with the levels of miR-155 in the intestinal B cells. Exposure to IL-13 in the culture markedly increased the expression of miR-155 and suppressed the expression of IL-10 in B cells. Blocking miR-155 abolished the IL-13-induced IL-10 suppression in B cells and inhibited FA response in mice. In conclusion, miR-155 plays a critical role in the initiation of FA in mice. Blocking miR-155 has therapeutic potential in the treatment of FA.

The two sides of the coin: Similarities and differences in the pathomechanisms of fistulas and stricture formations in irritable bowel disease

Fistulas and fibrosis or strictures represent frequent complications in irritable bowel disease (IBD) patients. To date, treatment options for fistulas are limited and surgery is often required. Similarly, no preventive treatment for fibrosis and stricture formation has been established. Frequently, stricture formation and fibrosis precede fistula formation, indicating that both processes may be connected or interrelated. Knowledge about the pathology of both processes is limited. A crucial role for the epithelial-to-mesenchymal transition (EMT) in fistula development has been demonstrated. Of note, EMT also plays a major role in the pathogenesis of fibrosis in many organs, and most likely also plays that role in the intestine. In addition, aberrant matrix remodeling, as well as soluble factors such as tumor necrosis factor (TNF), interleukin 13 (IL-13) and tumor growth factor beta (TGFβ) were involved, both in the onset of the fistula and fibrosis formation. Both fistulas and fibrosis may occur due to deregulated wound healing mechanisms from chronic and severe intestinal inflammation; however, further research is required to obtain a better understanding of the complex pathophysiology of fistula and intestinal fibrosis formation, to allow the development of new and more effective preventive treatment options for those important disease complications.

Enhanced protection from fibrosis and inflammation in the combined absence of IL-13 and IFN-γ

Persistent or dysregulated IL-13 responses are key drivers of fibrosis in multiple organ systems, and this identifies this cytokine as an important therapeutic target. Nevertheless, the mechanisms by which IL-13 blockade leads to the amelioration of fibrosis remain unclear. Because IFN-γ exhibits potent anti-fibrotic activity, and IL-4Rα signalling antagonizes IFN-γ effector function, compensatory increases in IFN-γ activity following IL-13/IL-4Rα blockade might contribute to the reduction in fibrosis. To investigate the role of IFN-γ, we developed novel IL-13(-/-) /IFN-γ(-/-) double cytokine-deficient mice and examined disease progression in models of type 2-driven fibrosis. As predicted, we showed that fibrosis in the lung and liver are both highly dependent on IL-13. We also observed increased IFN-γ production and inflammatory activity in the tissues of IL-13-deficient mice. Surprisingly, however, an even greater reduction in fibrosis was observed in IL-13/IFN-γ double deficient mice, most notably in the livers of mice chronically infected with Schistosoma mansoni. The increased protection was associated with marked decreases in Tgfb1, Mmp12, and Timp1 mRNA expression in the tissues; reduced inflammation; and decreased expression of important pro-inflammatory mediators such as TNF-α. Experiments conducted with neutralizing monoclonal antibodies to IL-13 and IFN-γ validated the findings with the genetically deficient mice. Together, these studies demonstrate that the reduction in fibrosis observed when IL-13 signalling is suppressed is not dependent on increased IFN-γ activity. Instead, by reducing compensatory increases in type 1-associated inflammation, therapeutic strategies that block IFN-γ and IL-13 activity simultaneously can confer greater protection from progressive fibrosis than IL-13 blockade alone. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Coexistence of 2282del4 FLG gene mutation and IL-18 -137G/C gene polymorphism enhances the risk of atopic dermatitis

Introduction

Atopic dermatitis (AD) pathogenesis appears in the context of the correlation between cornified envelope proteins and immunological factors.

Aim

To estimate the association between FLG R501X and 2282del4 gene mutations, –137 G/C IL-18 and –1112 C/T IL-13 gene polymorphisms and their influence on AD course and the risk in the Polish population.

Material and methods

One hundred and fifty-two AD patients and 123 healthy volunteers were included into the study. Amplification refractory mutation system – polymerase chain reaction method was used.

Results

2282del4 FLG mutation, predominant (p = 0.04) in Polish AD patients, enhanced the risk of AD (OR = 2.35; p = 0.01) and was associated with itch (p = 0.023). GG genotype of IL-18 was prevailing in AD (p < 0.0001), associated with elevated IgE levels (p = 0.00074) and pruritus (p < 0.0001). GG genotype and G-allele in –137 position of IL-18 increased AD risk (OR = 5.4; p = 0.0001, respectively, OR = 5.3; p = 0.000029). –1112 C/T polymorphism of IL-13 was associated with elevated IgE levels (p = 0.00049), pruritus (p = 0.0005), SCORAD score (p = 0.02), concomitant asthma (p = 0.0087) and AD risk (OR = 2.02; p = 0.012). Coexistence of 2282del4 or R501X FLG gene mutation with GG genotype of IL-18 was associated with a 6-fold higher risk of AD (OR = 5.8; p = 0.00013), contrary to combined occurrence of FLG mutations with T-allele in –1112 position of IL-13 gene (OR = 0.12; p = 0.1).

Conclusions

2282del4 FLG mutation similarly to GG genotype and G-allele in –137 position of IL-18 gene enhance the risk of AD in the Polish population. Coexistence of FLG mutations with GG genotype of IL-18 may be helpful to estimate chances of AD development.

The TLR4-associated phospholipase D1 activation is crucial for Der f 2-induced IL-13 production

BACKGROUND

House dust mites (HDMs) are the most important source of indoor aeroallergens that contribute to the rising incidence of allergic diseases such as allergic asthma. The major HDM, Der f 2, induces inflammatory cytokine expression. Little is known about the signaling pathway involved.

OBJECTIVE

We wanted to define the Der f 2 signaling pathway from its receptor to the transcription factor responsible for IL-13 expression and production.

METHODS

Human bronchial epithelial cells were stimulated with Der f 2. The release and gene expression of IL-13 were measured by means of ELISA and RT-PCR, respectively. In the airway inflammation mouse model, airway responses were assessed using ELISA, histology, BAL fluid, and methacholine responsiveness.

RESULTS

Here, we show that Der f 2 binds to TLR4 and induces IL-13 expression and production. In the airway inflammation mouse model, Der f 2-induced IL-13 production significantly decreased with treatment of TAK-242, a novel TLR4 inhibitor. Activation of TLR4 by Der f 2 requires the recruitment and activation of Syk, which leads to phosphorylation of PLCγ and membrane translocation of PKCα. p38 MAPK is then activated by PKCα and stimulates PLD1 activity by phosphorylating the Thr147 residue of PLD1. PLD1 activation enhanced binding of ROCK1 to ATF-2 and leads to increased expression of IL-13.

CONCLUSION

Our data extend the knowledge for a variety of possible roles of PLD1 in allergic disorders including asthma pathogenesis and suggest possible candidacy of PLD1 as a molecular target for novel therapeutic approaches.

Role of epidermal γδ T-cell-derived interleukin 13 in the skin-whitening effect of Ginsenoside F1

Ginsenoside F1 (GF1) is a metabolite of ginsenoside Rg1. Although GF1 has several benefits for skin physiology, the effect of GF1 on skin pigmentation has not been reported. We found that a cream containing 0.1% GF1 showed a significant whitening effect on artificially tanned human skin after 8 weeks of application. However, GF1 did not inhibit mRNA expression of tyrosinase or dopachrome tautomerase (DCT) in normal human epidermal melanocytes (NHEMs) or cocultured NHEMs/normal human epidermal keratinocytes. Interestingly, GF1 enhanced production of interleukin 13 (IL-13) from human epidermal γδ T cells. IL-13 significantly reduced the mRNA expression and protein amount of both tyrosinase and DCT and reduced melanin synthesis activities in NHEMs, resulting in visible brightening of NHEM pellet. These results suggest that enhancement of IL-13 production by GF1 from epidermal γδ T cells might play a role in the skin-whitening effect of GF1 via the suppression of tyrosinase and DCT.

Thrombospondin-1 (TSP1)-producing B cells restore antigen (Ag)-specific immune tolerance in an allergic environment

Restoration of the antigen (Ag)-specific immune tolerance in an allergic environment is refractory. B cells are involved in immune regulation. Whether B cells facilitate the generation of Ag-specific immune tolerance in an allergic environment requires further investigation. This paper aims to elucidate the mechanism by which B cells restore the Ag-specific immune tolerance in an allergic environment. In this study, a B cell-deficient mouse model was created by injecting an anti-CD20 antibody. The frequency of tolerogenic dendritic cell (TolDC) was assessed by flow cytometry. The levels of cytokines were determined by enzyme-linked immunosorbent assay. The expression of thrombospondin-1 (TSP1) was assessed by quantitative real-time RT-PCR, Western blotting, and methylation-specific PCR. The results showed that B cells were required in the generation of the TGF-β-producing TolDCs in mice. B cell-derived TSP1 converted the latent TGF-β to the active TGF-β in DCs, which generated TGF-β-producing TolDCs. Exposure to IL-13 inhibited the expression of TSP1 in B cells by enhancing the TSP1 gene DNA methylation. Treating food allergy mice with Ag-specific immunotherapy and IL-13 antagonists restored the generation of TolDCs and enhanced the effect of specific immunotherapy. In conclusion, B cells play a critical role in the restoration of specific immune tolerance in an allergic environment. Blocking IL-13 in an allergic environment facilitated the generation of TolDCs and enhanced the therapeutic effect of immunotherapy.

The antibody-mediated targeted delivery of interleukin-13 to syngeneic murine tumors mediates a potent anticancer activity

We describe the expression and in vivo characterization of an antibody-cytokine fusion protein, based on murine Interleukin-13 (IL13) and the monoclonal antibody F8, specific to the alternatively spliced extra domain A of fibronectin, a marker of neo-angiogenesis. The IL13 moiety was fused at the C-terminal extremity of the F8 antibody in diabody format. The resulting F8-IL13 immunocytokine retained the full binding properties of the parental antibody and cytokine bioactivity. The fusion protein could be expressed in mammalian cells, purified to homogeneity and showed a preferential accumulation at the tumor site. When used as single agent at doses of 200 μg, F8-IL13 exhibited a strong inhibition of tumor growth rate in two models of cancer (F9 teratocarcinoma and Wehi-164), promoting an infiltration of various types of leukocytes into the neoplastic mass. This anticancer activity could be potentiated by combination with an immunocytokine based on the F8 antibody and murine IL12, leading to complete and long-lasting tumor eradications. Mice cured from Wehi-164 sarcomas acquired a durable protective antitumor immunity, and selective depletion of immune cells revealed that the antitumor activity was mainly mediated by cluster of differentiation 4-positive T cells. This study indicates that IL13 can be efficiently delivered to the tumor neo-vasculature and that it mediates a potent anticancer activity in the two models of cancer investigated in this study. The observed mechanism of action for F8-IL13 was surprising, since immunocytokines based on other payloads (e.g., IL2, IL4, IL12 and TNF) eradicate cancer by the combined contribution of natural killer cells and cluster of differentiation 8-positive T cells.

Association of IL-13 single nucleotide polymorphisms in Iranian patients to multiple sclerosis

MS is an autoimmune disease and interleukin 13 (IL-13) has been proposed to be an important neuroprotective mediator in MS. Because of plausible effect of single nucleotide polymorphisms (SNPs) in expression level or biological activity of any cytokine, we sought to investigate association of IL-13 SNPs, C-1112T, A-1512C and G+2044A, with risk to MS. Sixty-eight RRMS patients and 110 healthy controls were involved in this study. After extraction of genomic DNA, frequency of genotypes and alleles were determined by PCR-RFLP and data were analyzed statistically. Results showed significant higher frequency of CC, CC, and AA genotypes and C, C, and A alleles of -1112CT, -1512AC and +2044GA SNPs respectively, in patients group. There was significant association between -1112C allele with onset age of MS. No significant association was seen between any of genotypes or alleles with expanded disability status scale (EDSS) of patients. Our findings showed significant association between three studied SNPs of IL-13 with susceptibility to MS in Iranian patients. More studies should be done on other IL-13 SNPs, and also polymorphisms of IL-13 receptor and other cytokines to determine the exact role of SNPs in protecting or predisposing of individuals for MS.

Serum immunoglobulin E and interleukin-13 levels in children with idiopathic nephrotic syndrome

Serum IgE and IL-13 levels were estimated in 40 idiopathic nephrotic syndrome and 16 controls. There were 15 first episode nephrotic syndrome (FENS), 15 infrequent relapsing nephrotic syndrome (IRNS) and 10 patients belonged to frequent relapsing nephrotic syndrome (FRNS). Serum IgE and IL-13 levels were significantly increased in active nephrotic syndrome and its sub-groups as compared to controls and remission (p < 0.001). IgE levels did not differ significantly among different subgroups, while Il-13 was significantly higher in FRNS in comparison with FENS (p = 0.041). Both IgE and IL-13 levels were comparable in nephrotic patients with and without bronchial asthma. Serum IL-13 had significant positive correlation with IgE (r = 0.605, p < 0.001). Thus, raised levels of IgE and IL-13 are found in nephrotic syndrome and could have a role in the pathogenesis of disease.

Regulation of STATs by polycystin-1 and their role in polycystic kidney disease

Autosomal-dominant polycystic kidney disease (ADPKD) is a common genetic disease caused by mutations in the gene coding for polycystin-1 (PC1). PC1 can regulate STAT transcription factors by a novel, dual mechanism. STAT3 and STAT6 are aberrantly activated in renal cysts. Genetic and pharmacological approaches to inhibit STAT3 or STAT6 have led to promising results in ADPKD mouse models. Here, we review current findings that lead to a model of PC1 as a key regulator of STAT signaling in renal tubule cells. We discuss how PC1 may orchestrate appropriate epithelial responses to renal injury, and how this system may lead to aberrant STAT activation in ADPKD thereby causing inappropriate activation of tissue repair programs that culminate in renal cyst growth and fibrosis.

TGF beta and IL13 in Schistosomiasis mansoni associated pulmonary arterial hypertension; a descriptive study with comparative groups

BACKGROUND

It is suggested that interleukin (IL)-13 and transforming growth factor (TGF)-beta play a role in the pulmonary vascular changes found in animal models of schistosomiasis. The aim of this study was to assess and compare the serum levels of total TGF-beta and IL-13 of patients with schistosomiasis with pulmonary arterial hypertension (PAH) and patients with schistosomiasis without PAH.

METHODS

34 patients from the schistosomiasis outpatient clinic of the Hospital das Clinicas, Recife, Pernambuco, Brazil, without PAH assessed by echocardiography and 34 patients from the Reference Centre of Pulmonary Hypertension of Pronto Socorro Cardiológico de Pernambuco, Recife, Brazil with PAH, confirmed by right heart catheterization, were enrolled on the study. Both groups presented with schistosomal periportal fibrosis after abdominal ultrasound. Serum levels of TGF-beta1 and IL-13 were determined by ELISA. Student t test to independent samples, Mann-Whitney test to nonparametric variables, Pearson correlation test for correlation analyses and Fisher Chi-squared test to compare categorical analyses were used.

RESULTS

The median value of TGF-beta1 was significantly higher in patients with PAH (22496.9 pg/ml, interquartile range [IR] 15936.7 - 32087.8) than in patients without PAH (13629.9 pg/ml, IR: 10192.2- 22193.8) (p = 0.006). There was no difference in the median value of IL-13 in the group with Sch-PAH compared to patients without Sch-PAH (p > 0.05).

CONCLUSION

Our results suggest that TGF-beta possibly plays a role in the pathogenesis of schistosomiasis-associated PAH.

Interleukin-4 and interleukin-13 compromise the sinonasal epithelial barrier and perturb intercellular junction protein expression

BACKGROUND

Altered expression of epithelial intercellular junction proteins has been observed in sinonasal biopsies from nasal polyps and epithelial layers cultured from nasal polyp patients. These alterations comprise a "leaky" epithelial barrier phenotype. We hypothesize that T helper 2 (Th2) cytokines interleukin (IL)-4 and IL-13 modulate epithelial junction proteins, thereby contributing to the leaky epithelial barrier.

METHODS

Differentiated primary sinonasal epithelial layers cultured at the air-liquid interface were exposed to IL-4, IL-13, and controls for 24 hours at 37°C. Epithelial resistance measurements were taken every 4 hours during cytokine exposure. Western blot and immunofluorescence staining/confocal microscopy were used to assess changes in a panel of tight and adherens junction proteins. Western blot densitometry was quantified with image analysis.

RESULTS

IL-4 and IL-13 exposure resulted in a mean decrease in transepithelial resistance at 24 hours to 51.6% (n = 6) and 68.6% (n = 8) of baseline, respectively. Tight junction protein junctional adhesion molecule-A (JAM-A) expression decreased 42.2% with IL-4 exposure (n = 9) and 37.5% with IL-13 exposure (n = 9). Adherens junction protein E-cadherin expression decreased 35.3% with IL-4 exposure (n = 9) and 32.9% with IL-13 exposure (n = 9). Tight junction protein claudin-2 showed more variability but had a trend toward higher expression with Th2 cytokine exposure. There were no appreciable changes in claudin-1, occludin, or zonula occludens-1 (ZO-1) with IL-4 or IL-13 exposure.

CONCLUSION

Sinonasal epithelial exposure to Th2 cytokines IL-4 and IL-13 results in alterations in intercellular junction proteins, reflecting increased epithelial permeability. Such changes may explain some of the phenotypic manifestations of Th2-mediated sinonasal disease, such as edema, nasal discharge, and environmental reactivity.

T helper cytokines in dry eye disease

Dry eye is an inflammatory disease that results from activation of innate inflammatory pathways in resident ocular surface cells, as well as cytokines produced by recruited T helper (Th) cells. Cytokines produced by the infiltrating Th cells alter the normal cytokine balance on the ocular surface and cause ocular surface epithelial pathology. Changes in levels of Th cytokines on the ocular surface have been measured in dry eye and the biological effects of these cytokines have been documented in experimental culture and mouse model systems. The Th2 cytokine IL-13 has a homeostatic role in promoting goblet cell differentiation. In contrast, The Th1 cytokine IFN-γ antagonizes IL-13 and promotes apoptosis and squamous metaplasia of the ocular surface epithelia. The Th17 cytokine, IL-17 promotes corneal epithelial barrier disruption. The ocular surface epithelium expresses receptors to all of these Th cytokines. Therapies that maintain normal IL-13 signaling, or suppress IFN-γ and IL-17 have potential for treating the ocular surface disease of dry eye.