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Eosinophilic esophagitis (EoE) can progress to fibrostenosis by unclear mechanisms. Herein, we investigated gene dysregulation in fibrostenotic EoE, its association with clinical parameters and specific pathways, and the functional consequences.Esophageal biopsies from subjects with EoE were collected across 11 Consortium of Eosinophilic Gastrointestinal Disease Researchers sites (n = 311) and 2 independent replication cohorts (n = 83). Inclusion criteria for fibrostenotic EoE were endoscopic rings, stricture, and/or a history of dilation. Endoscopic, histologic, and molecular features were assessed by the EoE Endoscopic Reference Score, EoE Histology Scoring System, EoE Diagnostic Panel, and RNA sequencing. Esophageal endothelial TSPAN12 expression and functional effects on barrier integrity and gene expression were analyzed in vitro.TSPAN12 was the gene most correlated with fibrostenosis (r = -0.40, P.001). TSPAN12 was lower in fibrostenotic EoE and correlated with EoE Endoscopic Reference Score, EoE Diagnostic Panel, and EoE Histology Scoring System (r = 0.34-0.47, P.001). Lower TSPAN12 associated with smaller esophageal diameter (r = 0.44, P = .03), increased lamina propria fibrosis (r = -0.41, P.001), and genes enriched in cell cycle-related pathways. Interleukin (IL)-13 reduced TSPAN12 expression in endothelial cells. Conversely, anti-IL-13 therapy increased TSPAN12 expression. TSPAN12 gene silencing increased endothelial cell permeability and dysregulated genes associated with extracellular matrix pathways. Endothelial cell-fibroblast crosstalk induced extracellular matrix changes relevant to esophageal remodeling.Patients with fibrostenotic EoE express decreased levels of endothelial TSPAN12. We propose that IL-13 decreases TSPAN12, likely contributing to the chronicity of EoE by promoting tissue remodeling through fibroblast-endothelial cell crosstalk.

BACKGROUND: Thymic stromal lymphopoietin (TSLP) is an epithelial-derived cytokine important in initiation of allergic inflammation. Single nucleotide polymorphisms (SNPs) in TSLP are associated with asthma, yet studies have shown inconsistent associations between circulating TSLP and asthma. Studies that integrate the combined effects of TSLP genotype, TSLP mRNA, circulating TSLP levels, and asthma outcome are lacking. OBJECTIVE: To recruit a novel cohort based on asthma-relevant TSLP SNPs and determine their impact on TSLP mRNA expression and TSLP circulating protein levels, and their individual and combined effects on asthma. METHODS: We developed an algorithm to prioritize TSLP SNPs and recruited 51 carriers and non-carriers based on TSLP genotypes. We quantified TSLP mRNA in nasal epithelial cells and circulating TSLP levels in plasma. We determined associations of defined TSLP risk genotypes and/or TSLP mRNA and protein levels with asthma. RESULTS: TSLP mRNA expression, but not circulating TSLP, was significantly increased in asthmatics compared to non-asthmatics (P=0.007; OR=1.44). Notably, 90% of children with the defined TSLP risk genotypes and high nasal TSLP mRNA expression (top tertile) had asthma compared to 40% of subjects without risk genotypes and with low TSLP expression (bottom tertile) (P=0.024). No association between circulating TSLP and asthma was observed. CONCLUSION: Collectively, these data suggest childhood asthma is modified by the combined effects of TSLP genotype and TSLP expression in the nasal epithelium. The increased asthma risk likely manifests when genetic variation enables eQTL in the TSLP locus to elevate TSLP. It is important to consider both biomarkers when factoring asthma risk. CLINICAL IMPLICATIONS: TSLP genotype and nasal mRNA expression may be useful biomarkers to aid asthma prediction and/or identify individuals who would benefit from therapy targeting this pathway.

Thymic stromal lymphopoietin (TSLP), positioned at the top of the inflammatory cascade, is a key regulator that enhances allergic inflammatory responses by activating T helper type 2 (Th2) cells, Group 2 innate lymphoid cells (ILC2), and myeloid dendritic cells (mDCs) via the TSLP receptor (TSLPR). We evaluated the inhibitory effects of ASP7266, a novel recombinant fully human IgG1 monoclonal antibody against TSLPR, on TSLP signaling and inflammation. The inhibitory effects of ASP7266 and the control antibody tezepelumab on TSLP and TSLPR interactions were investigated using a proliferation assay with TSLP stimulation and a chemokine production assay. The pharmacological effects of ASP7266 were investigated by examining differentiation of naive CD4+ T cells, ILC2 cytokine production, and ascaris extract-induced skin allergic reaction in cynomolgus monkeys. ASP7266 potently inhibited TSLP-induced cell proliferation and C-C motif chemokine ligand 17 (CCL17) production. Furthermore, ASP7266 inhibited TSLP-stimulated mDC-mediated naive CD4+ T cell differentiation, and IL-5 production by lineage-negative peripheral blood mononuclear cells (PBMCs), which can be considered ILC2, in vitro. In sensitized monkeys, ASP7266 completely suppressed ascaris extract-induced allergic skin reactions. Based on these results, ASP7266, a novel human therapeutic antibody against TSLPR, is a potential therapy for patients with allergic diseases. Significance Statement TSLP, positioned at the top of the inflammatory cascade, plays a key role in various allergic diseases, including asthma, chronic rhinosinusitis with nasal polyposis, and atopic dermatitis. Here we show that the anti-TSLPR antibody, ASP7266, exhibited excellent pharmacological activity in preclinical studies. Therefore, ASP7266 has the potential to be a promising treatment option for patients with allergic disorders.

Allergic disease is one of the most common chronic diseases, which can affect both children and adults, be often caused by allergen-induced unfavorable immune responses, and initiate various symptoms in different organs, including up-/low-airways and skin, such as asthma, atopic dermatitis, and rhinosinusitis. With increasing prevalence of allergic disease worldwide and their impact on the quality of life, new biological therapeutic approaches for these disorders become hot areas of intensive research. Multiple factors are involved and play important role in the pathogenesis of allergic disease, which can promote or trigger T helper 2 (Th2)-type immune responses, leading to production of the type 2 cytokines and immunoglobulin E (IgE)，the two critical events in the allergic diseases. Using monoclonal antibodies to target these molecules, therefore, might provide possible benefits for the patients suffered from these diseases. Apart of those having approved biologics for allergic diseases, some potential targets such as epithelial-derived alarmins thymic stromal lymphopoietin (TSLP) and interleukin 33 (IL-33) have been also described and proposed to develop monoclonal antibodies against either these cytokines, their receptors, or both. These new and potential targets have substantially enriched the therapeutic opportunities in the field of allergic diseases. The present review aims to briefly outline the role of monoclonal antibodies targeting the cytokines and immunoglobulin involved in the development of allergic diseases, and to discuss the clinical effects of these antibodies.

Eosinophilic inflammation is a feature of allergic asthma. Despite mounting evidence showing that chromatin filaments released from neutrophils mediate various diseases, the understanding of extracellular DNA from eosinophils is limited. Here we show that eosinophil extracellular traps (EETs) in bronchoalveolar lavage fluid are associated with the severity of asthma in patients. Functionally, we find that EETs augment goblet-cell hyperplasia, mucus production, infiltration of inflammatory cells and expressions of type 2 cytokines in experimental non-infection-related asthma using both pharmaceutical and genetic approaches. Multiple clinically relevant allergens trigger EET formation at least partially via thymic stromal lymphopoietin in vivo. Mechanically, EETs activate pulmonary neuroendocrine cells via the CCDC25-ILK-PKCα-CRTC1 pathway, which is potentiated by eosinophil peroxidase. Subsequently, the pulmonary neuroendocrine cells amplify allergic immune responses via neuropeptides and neurotransmitters. Therapeutically, inhibition of CCDC25 alleviates allergic inflammation. Together, our findings demonstrate a previously unknown role of EETs in integrating immunological and neurological cues to drive asthma progression.

The current study aimed to examine thymic stromal lymphopoietin receptor (TSLPR) genetic variation and breast cancer (BC) susceptibility in women in Saudi Arabia. Therefore, 127 blood samples from female patients diagnosed with BC and 116 blood samples from healthy female controls were studied using a genotyping assay to determine the association between three TSLPR single nucleotide polymorphisms (SNPs)-P196L, X201W, and A238V-and the risk of BC progression. In addition, gene expression was evaluated in 20 matching BC and normal tissues using immunohistochemistry. TSLPR protein levels were higher among BC patients than those with matching normal breast tissue. In addition, TSLPR SNP P196L was found to have a significant protective effect on BC progression (OR = 0.4427), although only the T allele for TSLPR P196L had this protective effect against BC progression in participants who were younger than 48 years old. In contrast, no association was found between the T allele and risk of BC in participants who were older than 48 years old, and the CT and TT genotypes were significantly associated with BC risk protection in the older group. The effects of the TT genotype and the T allele were closely associated with a decreased risk of BC in participants with estrogen receptors (ER+) and without them (ER-). Overall, the findings revealed a significant correlation between SNPs in the TSLPR genes and BC progression among women in Saudi Arabia.

Haiyu Hong,1– 3,* Kai Sen Tan,3– 6,* Yan Yan,3,7,8,* Fenghong Chen,2,* Hsiao Hui Ong,3,5 Yukei Oo,4 Jing Liu,3,5 Yew Kwang Ong,3,9 Mark Thong,3,9 Richard Sugrue,10 Vincent T Chow,4,5 De Yun Wang3,5 1Allergy Center, Department of Otolaryngology, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 2Otorhinolaryngology Hospital, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China; 3Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore; 4Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore; 5NUHS Infectious Diseases Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 6Biosafety level 3 Core Facility, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore; 7Guangdong Provincial Key Laboratory of Biomedical and Guangdong Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 8Central Laboratory, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People’s Republic of China; 9Department of Otolaryngology Head & Neck Surgery, National University Hospital, National University Health System, Singapore; 10School of Biological Sciences, Nanyang Technological University, Singapore*These authors contributed equally to this workCorrespondence: Vincent T ChowDepartment of Microbiology and Immunology, National University of Singapore, 5 Science Drive 2, Singapore, 117545, SingaporeEmail micctk@nus.edu.sgDe Yun WangDepartment of Otolaryngology, National University of Singapore, National University Health System, 1E Kent Ridge Road, Singapore, 119228, SingaporeEmail entwdy@nus.edu.sgBackground: Epithelial cytokines including IL-25, IL-33 and thymic stromal lymphopoietin (TLSP) are recently established as drivers of type 2 chronic inflammatory diseases such as chronic rhinosinusitis with nasal polyps (CRSwNP). Here, we further confirmed the increased expression of IL-25 in CRSwNP and investigated potential contributors of IL-25 in CRSwNP epithelium.Methods: Sixty CRSwNP, 25 CRSsNP and 15 healthy control tissues were examined for IL-25 expression and for the accompanying type 2 inflammatory cytokines. We then tested different respiratory virus infections on human nasal epithelial cells (hNECs) for their ability to trigger IL-25 expression. In addition, we subjected hNECs generated from CRSwNP tissues to pretreatment with recombinant interferon-alpha (IFN-α) prior to viral infection to evaluate IFN effects on IL-25 induction.Results: We confirmed that significantly enhanced levels of IL-25 were observed in CRSwNP tissues, and that IL-25 expression correlated with type 2 inflammatory cytokine expression. In vitro, we observed significantly elevated IL-25 in hNECs infected with influenza A virus as early as 24 hours post-infection (hpi), regardless of tissue origin, and IL-25 correlated positively with viral load. While other respiratory viruses exhibited increasing trends of IL-25, these were not significant at the time-points tested. IFN-α treatment of CRSwNP epithelium was found to exert bimodal effects, ie IFN-α treatment alone induced moderate IL-25 expression, whereas IFN-α pretreatment of hNECs before influenza infection significantly diminished IL-25 induction by active influenza virus infection.Conclusion: We have authenticated the observation of elevated IL-25 in CRSwNP, which is correlated with type 2 inflammatory cytokines. Notably, we identified influenza virus infection as a potential contributor of IL-25 in both control and CRSwNP epithelium during active infection. This IL-25 induction can be abated by IFN-α pretreatment which ameliorated active influenza infection.Trial Registration: Chictr.org.cn ChiCTR-BON-16010179, Registered 18 December 2016, http://www.chictr.org.cn/showproj.aspx?proj=17331. The authors agree on the sharing of deidentified participant data where it pertains to request directly related to the data in this article when contacted (Haiyu Hong; honghy@mail.sysu.edu.cn).Keywords: chronic rhinosinusitis with nasal polyps, interferon-alpha, interleukin 25, respiratory viruses, influenza virus, type 2 inflammation

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.

Numerous studies investigating the correlations between the severity of atopic dermatitis (AD) and various biomarkers have been reported over the past few decades. Recent studies have indicated that certain soluble mediators, including chemokines (such as thymus and activation-regulated chemokine/C-C motif chemokine ligand [CCL]17 and macrophage-derived chemokine/CCL22) and cytokines (such as thymic stromal lymphopoietin), could be good markers of inflammation in AD. This review focuses on circulating biomarkers of AD, including pediatric AD.

International audience; BACKGROUND: Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin, an epithelial-cell–derived cytokine implicated in the pathogenesis of asthma. The efficacy and safety of tezepelumab in patients with severe, uncontrolled asthma require further assessment.METHODS: We conducted a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. Patients (12 to 80 years of age) were randomly assigned to receive tezepelumab (210 mg) or placebo subcutaneously every 4 weeks for 52 weeks. The primary end point was the annualized rate of asthma exacerbations over a period of 52 weeks. This end point was also assessed in patients with baseline blood eosinophil counts of less than 300 cells per microliter. Secondary end points included the forced expiratory volume in 1 second (FEV1) and scores on the Asthma Control Questionnaire–6 (ACQ-6; range, 0 [no impairment] to 6 [maximum impairment]), Asthma Quality of Life Questionnaire (AQLQ; range, 1 [maximum impairment] to 7 [no impairment]), and Asthma Symptom Diary (ASD; range, 0 [no symptoms] to 4 [worst possible symptoms]).RESULTS: Overall, 1061 patients underwent randomization (529 were assigned to receive tezepelumab and 532 to receive placebo). The annualized rate of asthma exacerbations was 0.93 (95% confidence interval [CI], 0.80 to 1.07) with tezepelumab and 2.10 (95% CI, 1.84 to 2.39) with placebo (rate ratio, 0.44; 95% CI, 0.37 to 0.53; P

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases leading to pruritic skin lesions. A subset of AD patients exhibits a disseminated severe HSV infection called eczema herpeticum (EH) that can cause life-threatening complications. This review gives an overview of the clinical picture, and characteristics of the patients as well as the diagnosis and therapy of EH. A special focus lies on the pathophysiological hallmarks identified so far that predispose for EH. This aspect covers genetic aberrations, immunological changes, and environmental influences displaying a complex multifactorial situation, which is not completely understood. Type 2 skewing of virus-specific T cells in ADEH+ patients has been implicated in immune profile abnormalities, along with impaired functions of dendritic cells and natural killer cells. Furthermore, aberrations in interferon pathway-related genes such as IFNG and IFNGR1 have been identified to increase the risk of EH. IL-4, IL-25, and thymic stromal lymphopoietin (TSLP) are overexpressed in EH, whereas antimicrobial peptides like human β-defensins and LL-37 are reduced. Concerning the epidermal barrier, single nucleotide polymorphisms (SNPs) in skin barrier proteins such as filaggrin were identified in ADEH+ patients. A dysbalance of the skin microbiome also contributes to EH due to an increase of Staphylococcus aureus, which provides a supporting role to the viral infection via secreted toxins such as α-toxin. The risk of EH is reduced in AD patients treated with dupilumab. Further research is needed to identify and specifically target risk factors for EH in AD patients.

The aim of this study is to assess the level of Toll-like receptor level 2 (TLR-2) and thymic stromal lymphopoietin (TSLP) in the blood serum of children and to establish the relationship between these parameters and the severity of clinical manifestations of atopic dermatitis (AD) and the degree of microbial contamination of the gut. Research materials and methods: 68 children aged from 3 months to 6 years with an AD and 31 conditionally healthy children of the corresponding age were examined. Determination of the level of TLR-2 and TSLP in blood serum was carried out by enzyme immunoassay, and the composition of the intestinal microflora was assessed by MALDITOF mass spectrometry. Results: in children with AD, the median serum TLR-2 level was 2,88 [1,60; 4,91] ng/ml, TSLP – 6,01 [1,11; 9,5] pg/ml, which is statistically significantly higher than in conventionally healthy children (p

Background Roasted peanut is widely loved as a kind of food with rich taste. However, peanut allergy is one of the major threats to human health, which affects about 5% of children and 1.4-2% of adults in the world. Results To evaluate the sensitization mechanism of peanut allergen Ara h 3, Caco-2 cells as the model, which has the similar structure and function to differentiated small intestinal epithelial cells. Compared with Ara h 3-raw (purified from raw peanut) group, more significant results such as the inhibited Caco-2 cell viability and proliferation, the increased secretion of reactive oxygen species (ROS) and the decreased transepithelial electrical resistance were obtained in Ara h 3-roasted (purified from roasted peanut) group. Accordingly, oxidative stress and NF-κB signaling pathway were more imbalanced, which lead to the increased of thymic stromal lymphopoietin (TSLP), interleukin 6 (IL-6), IL-8 and monocyte chemotactic protein 1 (MCP-1). Then, the gene expression of tight junction proteins ZO-1, occludin and JAM-1 were reduced, which proved that the integrity of the Caco-2 monolayer barrier is severely damaged. Conclusion These finding identify the mechanisms of the allergenicity of roasted peanut allergy proteins are probably associated with intestinal uptake and cytokine dependent allergies. The aggravated allergic reaction might be caused by the increment of TSLP, IL-6, IL-8 and MCP-1 due to the activated NF-κB signaling pathway, and the enhanced transport of Ara h 3-roasted protein by Caco-2 monolayer. © 2021 Society of Chemical Industry.

Atopic dermatitis is a severe, chronic relapsing inflammatory disease of the skin with family clustering. It is characterized into acute phase, which is dominated by T helper 2-type immune responses, and chronic phase, which is dominated by T helper 1-type immune responses. Studies have shown that 3,3'-diindolylmethane not only has antitumor effects but also can relieve symptoms of inflammatory diseases by inhibiting the nuclear factor-κB signaling pathway and regulating T cell differentiation. To study the effect of 3,3'-diindolylmethane on atopic dermatitis and the underlying mechanism, a mouse model of acute atopic dermatitis was established using 2,4-dinitrofluorobenzene. After intraperitoneal injection of 3,3'-diindolylmethane, skin erythema and edema in mice were significantly alleviated. Furthermore, 3,3'-diindolylmethane reduced immune activation, probably by inhibiting the secretion of thymic stromal lymphopoietin by keratinocytes. 3,3'-Diindolylmethane also promoted the differentiation of regulatory T cells and inhibited the activation of T helper 2 and T helper 17 cells to reduce atopic dermatitis-related immune responses. However, it showed no significant effect on the differentiation of T helper 1 cells. These results indicate that 3,3'-diindolylmethane has a significant inhibitory effect on T helper 2 cells in the acute phase of atopic dermatitis. Our findings may provide not only more insights into the pathological mechanism of AD, but also a new candidate medicine for it.

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease of complex etiology. Despite its increasing prevalence, treatment for AD is still limited. Crude drugs, including herbal extracts or natural resources, are being used to treat AD symptoms, with minimum side effects. Cicadidae Periostracum (CP), derived from the slough of insects belonging to the family Cicadidae, is a commonly used crude drug in traditional Asian medicine to treat/control epilepsy, shock, and edema. However, the effect of CP on AD-like skin lesions is unknown. In this study, we examined the effect of a CP water extract on AD disease development in vivo, using a house dust mite-induced AD mouse model, and in vitro, using HaCaT keratinocytes and a 3D human skin equivalent system. Importantly, CP administration alleviated house dust mite-induced AD-like symptoms, suggested by the quantified dermatitis scores, animal scratching behaviors, skin moisture retention capacity, and skin lesion and ear thickness. Furthermore, histopathological analysis demonstrated that CP decreased intralesional mast cell infiltration. In addition, CP treatments decreased the systemic levels of immunoglobulin E, histamine, and thymic stromal lymphopoietin (TSLP) and the local mRNA expression of TSLP and several Th1/Th2 cytokines. Our data suggest that these effects were mediated by the inhibition of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation. In vivo and in vitro CP treatments resulted in the downregulation of inflammasome components, such as ASC and cleaved caspase-1, as well as related mediators such as IL-1β and reactive oxygen species. Collectively, our results suggest that CP is a potential therapeutic agent for AD, controlling inflammatory responses through the suppression of NLRP3 inflammasome activation.

Our aim was to detect type 2 innate lymphoid cells (ILC2s)-related cytokines of infants with bronchiolitis by using Elisa, Liquidchip technology and RT-PCR and investigated its correlation with bronchiolitis. We recruited 26 infants with bronchiolitis and 20 healthy infants as control from Xiangya Hospital. Compared to the control group, the serum levels of interleukin-5 (IL-5) [41.99 (21.11) vs 25.70 (19.64)], IL-9 [27.04 (37.51) vs 8.30 (0.54)], IL-13 [184.05 (132.81) vs 121.75 (176.13)], IL-33 [83.70 (46.69) vs 11.23 (55.31)] and thymic stromal lymphopoietin (TSLP) [31.42 (5.41) vs 28.76 (2.56)] were significantly increased in infants with bronchiolitis (P P > 0.05]. The mRNA expression of IL-17RB (9.83 ± 0.35 vs 9.19 ± 0.58), TSLP (16.98 ± 2.12 vs 15.07 ± 2.25), retinoid acid receptor related orphan receptor α (7.18 ± 0.71 vs 5.46 ± 1.09) and trans-acting T-cell-specific transcription factor 3 (4.86 ± 0.66 vs 4.19 ± 0.90) were significantly increased in infants with bronchiolitis versus the control group (P P > 0.05). Our findings suggested that ILC2s possibly play a specific role in immunopathology of bronchiolitis.

Jonathan Corren,1 Martin Karpefors,2 Åsa Hellqvist,3 Jane R Parnes,4 Gene Colice5 1Departments of Medicine and Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; 2Data Science and AI, AstraZeneca, Gothenburg, Sweden; 3Biometrics, Late-Stage Development, Respiratory and Immunology, AstraZeneca, Gothenburg, Sweden; 4Amgen, Thousand Oaks, CA, USA; 5Late-Stage Development, Respiratory and Immunology, AstraZeneca, Gaithersburg, MD, USACorrespondence: Jonathan CorrenDepartments of Medicine and Pediatrics, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave, Los Angeles, CA 90095, USATel +1-310-312-5050Email jcorren@ucla.eduIntroduction: Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin (TSLP), an epithelial cytokine implicated in airway inflammation in asthma, from binding to its heterodimeric receptor. In the PATHWAY phase 2b study, tezepelumab significantly reduced exacerbation rates compared with placebo in adults with severe, uncontrolled asthma, irrespective of baseline disease characteristics.Objective: To evaluate the effect of tezepelumab on asthma exacerbations on a seasonal basis.Methods: This was a post hoc analysis of the PATHWAY study (NCT02054130). Adults (N=550) with severe, uncontrolled asthma were randomized 1:1:1:1 to receive subcutaneous tezepelumab 70 mg every 4 weeks (Q4W), 210 mg Q4W or 280 mg every 2 weeks (Q2W), or placebo Q2W, for 52 weeks. The annualized asthma exacerbation rate (AAER), total number of days with an exacerbation, proportion of patients with at least one exacerbation or 0, 1 or ≥ 2 exacerbations, and proportion of patients experiencing an exacerbation per day were evaluated by season and over the year, by treatment in the overall study population and in subgroups according to baseline blood eosinophil count (≥ 300 cells/μL or < 300 cells/μL) or atopic asthma status (fluoro-enzyme immunoassay [FEIA]+ or FEIA−).Results: Seasonal variations in exacerbation rates were found, with peaks observed in fall and winter, and greater variations in patients with high blood eosinophil counts (≥ 300 cells/μL). Tezepelumab treatment consistently reduced exacerbation rates across all seasons compared with placebo. Furthermore, there was a trend, which was not significant, toward a reduction in the total number of days with exacerbations and in the proportion of patients with exacerbations during each season in patients treated with tezepelumab compared with those who received placebo, irrespective of blood eosinophil count or atopic asthma status.Conclusion: Tezepelumab reduced exacerbations across all seasons, irrespective of evaluated baseline disease characteristics. These data support the efficacy of tezepelumab in a broad population of patients with severe, uncontrolled asthma.Keywords: allergens, asthma, eosinophil, seasonal variation, tezepelumab, thymic stromal lymphopoietin

Asthma is a complex heterogeneous disease defined by chronic inflammation of the airways. Patients present with wheezing, chest tightness, cough and shortness of breath. Bronchial hyperresponsiveness and variable expiratory airflow limitation are hallmark features. About 3.6–6.1% of patients, despite receiving high-dose inhaled corticosteroids (ICS) and a second controller medication, report persistent symptoms referred to as severe asthma. Uncontrolled severe asthma is associated with increased mortality, morbidity, diminished quality of life and increased health expenditures. The development of modern biological therapy has revolutionized severe asthma treatment. By targeting specific chemokines, asthma control has drastically improved, resulting in better quality of life, less emergency department visits and inpatient admissions, and decreased chronic systemic corticosteroid utilization. Despite these advances, there remains a subset of asthma patients who remain symptomatic with poor quality of life and heavy utilization of the healthcare system. Recently attention has been given to pharmaceutical therapy directed at receptors and cytokines on the epithelial layer of the lung referred to as “alarmins”. Thymic stromal lymphopoietin (TSLP) is an interleukin-7-like receptor family found on the epithelial layer of the lung that releases a cytokine cascade inducing eosinophilic inflammation, mucus production and airflow obstruction in asthmatics. Tezepelumab is the first investigational monoclonal antibody that inhibits TSLP. Proof of concept study and phase IIb studies demonstrated reduced asthma exacerbations, improvement in quality of life, less decline in FEV1 and decrease in biochemical inflammatory markers in comparison to placebo. It is presently undergoing three phase III studies and an additional phase II study.

Background: There is a growing need for early biomarkers that may predict the development of atopic dermatitis (AD). As alterations in skin barrier may be a primary event in disease pathogenesis, epithelial cell (EC) cytokines expression patterns may be a potential biomarker in early life to target allergy preventive strategies towards “at-risk” infants. Objectives: The aim of this longitudinal investigation was to examine from birth over the course of infancy levels of the EC cytokines: thymic stromal lymphopoietin (TSLP), interleukin (IL)-33, IL-25, and IL-17 in infants at high-risk of AD due to maternal atopy. Method: We collected (n = 31) cord blood samples from atopic mothers and followed up their infants at 4–6 and 12 months of age for collection of peripheral venous blood samples and diagnosis of AD. TSLP concentration was measured by ELISA after acetone precipitation of the samples. IL-33, IL-25, and IL-17 levels were measured by Luminex. Results: Seven infants who developed AD had lower levels of IL-25 and IL-17 at birth compared to the 24 infants who did not develop AD by 12 months of age. Conclusions: Lower cord blood levels of IL-17 and IL-25, but not other EC cytokines, were associated with the onset of AD during infancy. Our results highlight that the in-utero period appears critical, and potential maternal influences on cord blood EC-derived cytokine concentrations requires further exploration.

Silica crystals (silica), which are a major mineral component of volcanic ash and desert dust, contribute to the pathogenesis of pulmonary disorders such as asthma and fibrosis. Although administration of silica or sand dust to rodents exacerbates development of ovalbumin-induced or house dust mite-induced asthma-like airway inflammation, the detailed mechanisms remain unclear. Here, using murine models, we found that silica can induce IL-33 expression in pulmonary epithelial cells. IL-33, but not IL-25 or TSLP, and type 2 cytokines such as IL-5 and IL-13 were critically involved in silica's exacerbation of OVA-induced airway eosinophilia in mice. Innate lymphoid cells (ILCs), but not T, B or NKT cells, were also involved in the setting. Moreover, a scavenger receptor that recognized silica was important for silica's exacerbating effect. These observations suggest that IL-33 induced in epithelial cells by silica activates ILCs to produce IL-5 and/or IL-13, contributing to silica's exacerbation of OVA-induced airway eosinophilia in mice. Our findings provide new insight into the underlying mechanisms of exacerbation of pulmonary disorders such as asthma following inhalation of silica-containing materials such as volcanic ash and desert dust.

Background: Atopic dermatitis (AD) is characterized by chronic, relapsing skin inflammation (eczema) with itchy sensation. Keratinocytes, which are located at the outermost part of our body, are supposed to play important roles at the early phase of type 2 inflammation including AD pathogenesis. Objective: The purpose of this study was to evaluate whether keratinocytes-derived reactive oxygen species (ROS) could be produced by the allergens or non-allergens, and the keratinocytes- derived ROS could modulate a set of biomarkers for type 2 inflammation of the skin. Methods: Normal human epidermal keratinocytes (NHEKs) were treated with an allergen of house dust mites (HDM) or a non-allergen of compound 48/80 (C48/80). Then, biomarkers for type 2 inflammation of the skin including those for neurogenic inflammation were checked by reverse transcriptase-polymerase chain reaction and western immunoblot experiments. Results: HDM or C48/80 was found to upregulate expression levels of our tested biomarkers, including type 2 T helper-driving pathway (KLK5, PAR2, and NFκB), epithelial-cell-derived cytokines (thymic stromal lymphopoietin, interleukin [IL]-25, IL-33), and neurogenic inflammation (NGF, CGRP). The HDMor C-48/80-induced expression levels of the biomarkers could be blocked by an antioxidant treatment with 5 mM N-acetyl- cysteine. In contrast, pro-oxidant treatment with 1 mM H2O2 could upregulate expression levels of the tested biomarkers in NHEKs. Conclusion: Our results reveal that keratinocytes- derived ROS, irrespective to their origins from allergens or non-allergens, have a potential to induce type 2 inflammation of AD skin. (Ann Dermatol 33(1) 26∼36, 2021)

Importance Surgery remains the gold standard in cholesteatoma treatment. However, the rate of recurrence is significant and the development of new nonsurgical treatment alternatives is warranted. One of the possible molecular pathways to target is the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Objective To investigate the JAK/STAT pathway in the middle ear mucosa in patients with acquired cholesteatoma compared with middle ear mucosa from healthy controls. Design Case-control study. Setting Linkoping University Hospital, Sweden, and Karolinska Institutet, Stockholm, Sweden. Sampling period: February 2011 to December 2016. Participants Middle ear mucosa from 26 patients with acquired cholesteatoma undergoing tympanoplasty and mastoidectomy, and 27 healthy controls undergoing translabyrinthine surgery for vestibular schwannoma or cochlear implantation was investigated. Main outcomes/measures The expression of Interleukin-7 receptor alpha, JAK1, JAK2, JAK3, STAT5A, STAT5B, and suppressor of cytokine signaling-1 (SOCS1) were quantified using quantitative polymerase chain reaction. In addition, expression level of cyclin D2, transforming growth factor beta 1, thymic stromal lymphopoietin, CD3, and CD19 was evaluated. Results In cholesteatoma-adjacent mucosa, SOCS1 was significantly upregulated (p= 0.0003) compared with healthy controls, whereas STAT5B was significantly downregulated (p = 0.0006). The expression of JAK1, JAK2, JAK3, and STAT5A did not differ significantly between groups. Conclusions and relevance To the best of our knowledge, this is the first article reporting dysregulation of the JAK/STAT pathway in cholesteatoma-adjacent mucosa. The main finding is that important players of the aforementioned pathway are significantly altered, namely SOCS1 is upregulated and STAT5B is downregulated compared with healthy controls.

In the past decade, research in the molecular and cellular underpinnings of basic and clinical immunology has significantly advanced our understanding of allergic disorders, allowing scientists and clinicians to diagnose and treat disorders such as asthma, allergic and nonallergic rhinitis, and food allergy. In this review, we discuss several significant recent developments in basic and clinical research as well as important future research directions in allergic inflammation. Certain key regulatory cytokines, genes, and molecules have recently been shown to play key roles in allergic disorders. For example,interleukin-33 (IL-33)plays an important role in refractory disorders such as asthma, allergic rhinitis, and food allergy, mainly by inducing T helper (Th) 2 immune responses. Further, the cytokine TSLP has been shown to be a key factor in maintaining immune homeostasis and regulating inflammatory responses at mucosal barriers and targeting TSLP-mediated signaling is considered an attractive therapeutic strategy. We discuss interleukin 4 receptor pathways, which recently has shown to play a critical role among the allergic inflammatory pathways that drive allergic disorders and pathogenesis. The alarmin IL-33 has found to play a major role in type-2 immune responses in allergic diseases and clinical trials with IL33 inhibitors are underway in food allergy. Further, the cytokine Thymic Stromal Lymphopoietin (TSLP)has recently been shown a factor in maintaining immune homeostasis and regulating type-2 inflammatory responses at mucosal barriers in allergic inflammation. Also, new immune and genetic studies found that IL-4R pathways play a critical role among the allergic inflammatory pathways that drive allergic disorders and pathogenesis. In addition, new findings establish an important T cell-intrinsic role of Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) proteolytic activity in the suppression of autoimmune responses. We have seen how mutations in the filaggrin gene are significant risk factor for allergic diseases such as atopic dermatitis, asthma, allergic rhinitis, food allergy (FA), and contact allergy and hand eczema. We are only beginning to understand the mechanisms by which the human microbiota may be regulating the immune system, and how sudden changes in the composition of the microbiota may have profound effects, linked with an increased risk of developing chronic inflammatory disorders, including allergies. New research has shown the important but complex role monocytes play in such disorders as food allergies. Finally, we discuss some of the new directions of research in this area, particularly the important use of biologicals in oral immunotherapy, advances in gene therapy, multi-food therapy, novel diagnostics in diagnosing allergic disorders, and the central role that OMICS plays in creating molecular signatures and biomarkers of allergic disorders such as food allergy. Such exciting new developments and advances has significantly moved forth our ability to understand the mechanisms underlying allergic diseases for improved patient care.

Allergic conjunctivitis is one the most common global diseases and affects many people worldwide. It has been reported that 15% to 20% of the total population in Japan suffers from allergic conjunctival disease. Although TH2 cytokines suchs as interleukin (IL)-4, IL-5, and IL-13 have long been known as causes of allergic conjunctivitis, new cytokines involved in allergic diseases have been identified since 2000. The discovery of type 2 immune response-initiating cytokines, such as IL-25, IL-33, and thymic stromal lymphopoietin, and type 2 innate lymphoid cells has suggested that allergic diseases can arise from not only T cells but also barrier function disruption. In this article, we summarize the results of experiments in mouse models of ragweed-induced experimental allergic conjunctivitis and papain-soaked contact lens-induced conjunctivitis.

Pruritus is one of the leading symptoms of dermatitis herpetiformis (DH), however, studies on the pathogenesis of pruritus are scarce. Currently, skin mast cells (MCs) have been indicated to play a role in pruritus in autoimmune bullous disease. To study the role of mast cells and related mediators involved in the pathogenesis of pruritus in DH. The number of MCs and expression of histamine and thymic stromal lymphopoietin (TSLP) was investigated in lesions of 29 DH cases and 15 healthy skin donors by immunohistochemistry. Fourteen patients were assessed for severity of pruritus based on the Numeric Rating Scale and Pruritus Grading System. The levels of histamine and TSLP in the serum of 18 DH patients and 15 healthy controls were also investigated. A significant increase in the number of MCs and degranulation was observed in DH lesions, which positively correlated with intensity of pruritus. In addition, skin TSLP but not histamine was shown to correlate with intensity of pruritus. No significant difference in expression of serum TSLP or histamine was observed between DH patients and healthy controls. These results suggest that skin MCs and TSLP might be involved in the pathogenesis of pruritus in DH which should be further clarified in future studies.

Immunomodulatory drugs (IMiDs), lenalidomide and pomalidomide, are widely used treatments for multiple myeloma; however, they occasionally lead to episodes of itchy skin and rashes. Here, we analyzed the effects of IMiDs on human myeloid dendritic cells (mDCs) as major regulators of Th1 or Th2 responses and the role they play in allergy. We found that lenalidomide and pomalidomide used at clinical concentrations did not affect the survival or CD86 and OX40-ligand expression of blood mDCs in response to lipopolysaccharide (LPS) and thymic stromal lymphopoietin (TSLP) stimulation. Both lenalidomide and pomalidomide dose-dependently inhibited interleukin-12 (IL-12) and TNF production and STAT4 expression, and enhanced IL-10 production in response to LPS. When stimulated with TSLP, both IMiDs significantly enhanced CCL17 production and STAT6 and IRF4 expression and promoted memory Th2-cell responses. In 46 myeloma patients, serum CCL17 levels at the onset of lenalidomide-associated rash were significantly higher than those without rashes during lenalidomide treatment and those before treatment. Furthermore, serum CCL17 levels in patients who achieved a very good partial response (VGPR) were significantly higher compared with a less than VGPR during lenalidomide treatment. The median time to next treatment was significantly longer in lenalidomide-treated patients with rashes than those without. Collectively, IMiDs suppressed the Th1-inducing capacity of DCs, instead promoting a Th2 response. Thus, the lenalidomide-associated rashes might be a result of an allergic response driven by Th2-axis activation. Our findings suggest clinical efficacy and rashes as a side effect of IMiDs are inextricably linked through immunostimulation.

Thymic stromal lymphopoietin (TSLP) is a key cytokine that initiates and promotes allergic inflammation both in humans and mice. It is well known that TSLP is important in initial step of inflammation by stimulating dendritic cells to promote Th2 differentiation of naive T cells. However, TSLP is abundantly produced in the late phase of inflammation, as well; therefore, we focused on the function of TSLP in chronic Th2-type inflammation. By establishing a novel (to our knowledge) chronic allergic skin inflammation mouse model with repetitive challenges of hapten after sensitization, we demonstrated that CD4 T cell–specific deletion of TSLP receptor (TSLPR) resulted in near-complete ablation of ear swelling and infiltration of CD4 T cells and eosinophils, but after second challenge. Of note, TSLPR deletion on CD4 T cells did not affect acute inflammation. As expected, transfer of Ag-sensitized wild-type CD4T cells, but not of TSLPR-deficient CD4T cells, increased skin inflammation in the model upon challenge. Furthermore, production of IL-4 from TSLPR-deficient CD4T cells in inflamed ear lesions was markedly diminished, demonstrating that TSLP-dependent IL-4 production from CD4T cells was critical for the exacerbation of skin inflammation. Similar results were obtained in Th2-type allergic skin inflammation model using MC903. Collectively, these results indicate that TSLP acts directly on CD4 T cells to elicit pathogenesis of Th2 cells, thereby having a critical role in exacerbation of skin inflammation in the chronic phase.

Background One of the hallmarks of bullous pemphigoid (BP) is moderate to severe chronic itch. Managing this is difficult because little is known about the mechanisms of itch in BP. Objective We sought to elucidate the pathophysiologic mechanisms of itch in BP. Methods The expression of itch mediators in lesions of 24 patients with BP and 6 healthy individuals were examined through immunofluorescence staining. Furthermore, the expression of itch mediators and itch severity was correlated. Results Itch severity was correlated with eosinophils, substance P, neurokinin 1R, interleukin (IL) 31 receptor A, oncostatin M receptor-β, IL-13, periostin, and basophils. There was also a trend between itch severity and IL-31 expression. Most of the cells expressing IL-31 or neurokinin 1R were identified as eosinophils. Intraepidermal nerve fiber density was decreased. Other itch mediators, including mast cells, IL-4, thymic stromal lymphopoietin, transient receptor potential vanilloid 1 and ankyrin 1, and protease activated receptor 2 were not significantly correlated with itch severity. Limitations The relatively small sample size, the examination of protein expression exclusively through immunofluorescent analysis, and lack of functional assays in patients are the limitations. Conclusions Multiple factors are involved in BP-associated itch, including eosinophils, substance P, neurokinin 1R, IL-31, IL-31 receptor A, oncostatin M receptor-β, IL-13, periostin, and basophils. They could be useful therapeutic targets.

Oesophageal cancer is the 6th most common cause of cancer related death worldwide. The current standard of care for oesophageal adenocarcinoma (OAC) focuses on neoadjuvant therapy with chemoradiation or chemotherapy, however the 5-year survival rates remain at

Background Atopic dermatitis (AD) is associated with chronic skin inflammatory reactions. p-coumaric acid (pCA) is an active ingredient of Panax ginseng Meyer (Araliaceae). Methods Here, we estimated an anti-AD effect of pCA on activated mast cells, activated splenocytes, and a mouse model of AD. Cytokines levels were measured by ELISA and protein activation was analyzed by Western blotting. 2,4-dinitrofluorobenzene (DNFB) was used to induce AD-like skin lesions. Results The treatment with pCA suppressed the productions and mRNA expressions of thymic stromal lymphopoietin (TSLP), TNF-ɑ, IL-6, and IL-1β in HMC-1 cells. pCA downregulated the expressions of RIP2 and caspase-1, phosphorylated-(p)p38/pJNK/pERK, and pIKKβ/pIkBɑ/NF-κB in HMC-1 cells. pCA also decreased the productions of TSLP, TNF-ɑ, IL-6, IL-4, and IFN-γ in the supernatant of stimulated splenic cells. Comparing to DNFB-sensitized control group, pCA-treated group alleviated pathological changes of AD-like lesions. pCA decreased the proteins and mRNA expressions levels of TSLP, IL-6, and IL-4 in the skin lesions. Caspase-1 activation was also downregulated by pCA treatment in the AD-like lesions. The serum levels of histamine, IgE, TSLP, TNF-ɑ, IL-6, and IL-4 were suppressed following treatment with pCA. Conclusion This study suggests that pCA has the potential to improve AD by suppressing TSLP as well as inflammatory cytokines via blocking of caspase-1/NF-κB signal cascade.

Atopic dermatitis (AD) is generally considered a T helper type 2-dominated disease. Pediatric AD is usually less severe than adult AD, but it may present as moderate to severe lesions that are inadequately managed by current modalities including emollients/moisturizers, topical corticosteroids (TCSs), topical calcineurin inhibitors (TCIs), and even systemic immunosuppressants (such as cyclosporine, azathioprine, methotrexate, and mycophenolate mofetil). In addition, systemic immunosuppressants are often not recommended for childhood AD by the current guidelines due to their toxicities. Therefore, there is still an unmet need for a safe and effective long-term therapy for pediatric AD patients whose disease is inadequately controlled or who are intolerant to current treatments. The emerging therapeutics for AD focuses on intervening in the inflammatory pathway by targeting specific cytokines/chemokines or their receptors. Monoclonal antibodies against immunoglobulin E (IgE), interleukin (IL)-4 receptor subunit α, IL-5, IL-13, IL-31 receptor subunit α, IL-33, and thymic stromal lymphopoietin (TSLP) have been evaluated clinically for AD. Encouraging results have been reported for many of the biologics, of which the most exciting is dupilumab. Other emerging systemic therapies include small molecules such as baricitinib, abrocitinib, upadacitinib, and tradipitant. Several novel topical agents are under clinical investigation for the treatment of AD, including topical phosphodiesterase 4 (PDE4) inhibitors, Janus kinase (JAK) inhibitors, aryl hydrocarbon receptor (AhR) modulating agents, and transient receptor potential vanilloid subfamily member 1 (TRPV1) antagonists. Accompanied by thorough characterization of different phenotype and endotype subsets, the application of precision medicine could provide new prospects for the optimal treatment of AD.

Thymic stromal lymphopoietin (TSLP), an epithelial cytokine (alarmin), is a central regulator of the immune response to inhaled environmental insults such as allergens, viruses and pollutants, initiating a cascade of downstream inflammation. There is compelling evidence that TSLP plays a major role in the pathology of asthma, and therapies that aim to block its activity are in development.We review studies conducted in humans and human cells, largely published in PubMed January 2010-October 2019, that investigated the innate and adaptive immune mechanisms of TSLP in asthma relevant to type 2-driven (eosinophilic/allergic) inflammation and non-type 2-driven (non-eosinophilic/non-allergic) inflammation, and the role of TSLP as a mediator between immune cells and structural cells in the airway. Clinical data from studies evaluating TSLP blockade are also discussed.The position of TSLP at the top of the inflammatory cascade makes it a promising therapeutic target in asthma. Systemic anti-TSLP monoclonal antibody therapy with tezepelumab has yielded positive results in clinical trials to date, reducing exacerbations and biomarkers of inflammation in patients across the spectrum of inflammatory endotypes. Inhaled anti-TSLP is an alternative route currently under evaluation. The long-term safety and efficacy of TSLP blockade need to be evaluated.

Interleukin (IL)‑18, a pro‑inflammatory cytokine, plays an important role in a number of skin diseases. The aim of the present study was to investigate the role of IL‑18 in the development of atopic dermatitis (AD). For this purpose, mice were divided into 4 groups (n=5/group) as follows: i) The wild‑type (WT) controls; ii) IL18 knockout (KO) controls; iii) MC903‑treated WT mice; and iv) MC903‑treated KO mice. MC903 (4 nmol in ethanol) was topically applied daily for 15 consecutive days to the exposed skins of mice. AD‑like symptoms and severity were evaluated by the scoring of AD (SCORAD). Serum immunoglobulin E (IgE) and thymic stromal lymphopoietin (TSLP) levels were determined with the use of an enzyme‑linked immunosorbent assay. Immunohistochemistry was used to assess the expression of IL‑1β, signal transducer and activator of transcription (STAT)3 and filaggrin (FLG) in the skin lesions. RT‑qPCR was performed to assess the mRNA levels of IL‑1β, IL‑4, IL‑9, STAT3, corticotropin‑releasing hormone receptor (CRHR)1, CRHR2, TSLP and caspase‑1 in the skin lesions. It was demonstrated that IL‑18 may function as a pleiotropic pro‑inflammatory cytokine in the development of AD‑like lesions. IL‑18 KO reduced aggravated AD‑like lesions induced by MC903, in part by upregulating Th2 cytokines. IL‑18 promoted the expression of FLG in the epidermis and CRHR2 in AD‑like lesions, but downregulated the serum levels of IgE. On the whole, the findings of the present study demonstrate that IL‑18 deficiency alleviates AD‑induced lesions in mice.

Background Atopic dermatitis (AD) is an inflammatory pruritic chronic dermatosis involving the alarmin thymic stromal lymphopoietin (TSLP), which is directly implicated in AD pruritus. Aims To evaluate the efficacy of Tambourissa trichophylla leaf extract (TTLE) titrated in polyphenols and 18β-glycyrrhetinic acid (GA) in vitro and in vivo for AD pruritus. Patients/methods Initially, in vitro assessment of TSLP production in keratinocytes was undertaken. In normal human keratinocytes in vitro, TSLP was induced by polyinosinic:polycytidylic acid (Poly:IC), tumor necrosis factor (TNF)-α, and interleukin (IL)-4 and then quantified by ELISA in supernatants. Some cells were pretreated with TTLE and/or GA. Thereafter, an in vivo clinical study was performed including 48 infants and children with mild to severe AD flare-ups, some of which were treated with topical corticosteroids. A topical spray containing TTLE and GA was applied. After 21 days of topical spray application, pruritus, sleeplessness, the SCORing Atopic Dermatitis (SCORAD) index, the Infant's Dermatitis Quality of Life index (IDQOL), and the Dermatitis Family Impact Questionnaire (DFIQ) were assessed. Results Thymic stromal lymphopoietin secretion was inhibited significantly in an AD environment by TTLE and GA by up to 57.2% and 73.3%, respectively. The use of the topical spray induced a significant reduction in pruritus and sleeplessness scores, as well as the SCORAD, IDQOL, and DFIQ indexes in the total group. Similar results were observed in patient subgroups with or without topical corticosteroid treatment. Conclusions A topical spray containing TTLE and GA, which inhibit TSLP secretion, efficiently decreases AD pruritus and improves the quality of life of AD patients.

Purpose of review Although several reviews concerning diagnosis and treatment of eosinophilic esophagitis (EoE) have been presented, there are few in regard to eosinophilic gastroenteritis (EGE). Fortunately, findings related to epidemiology, as well as diagnosis and treatment of this disease have recently been increasing. Recent findings The rates of incidence of both EoE and EGE have been reported to be increasing. For accurate diagnosis, plasma concentrations of thymic stromal lymphopoietin and IL-33 may be useful as biomarkers, though consensus has not been reached, while increased eosinophil infiltration in gastrointestinal tissue remains a critical factor. Topical glucocorticoid administration, an elimination diet, and molecular target therapy with neutralizing antibodies are potentially effective therapies that have recently been evaluated. Summary As seen with other allergic diseases, EGE seems to be increasing. Several research projects regarding diagnosis and treatment of the disease are currently in progress.

This study aimed to figure out the underlying mechanism of miR-142-5p in the non-alcoholic steatohepatitis (NASH). Bioinformatics, luciferase assay and Western blot were performed. The NASH mouse model was established through feeding a high fat diet (HFD). Relative expressions of miR-142-5p, thymic stromal lymphopoietin (TSLP), inflammatory factors were detected by qRT-PCR. The injury level of liver was assessed via measurement of serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST). H&E staining and Masson’s trichrome staining examine the liver fatty degeneration and fibrosis. MiR-142-5p and TSLP were differentially expressed and JAK-STAT signaling pathway was activated in the NASH group. Luciferase assay identified that TSLP was the downstream target of miR-142-5p. Through overexpression of miR-142-5p, ALT and AST in serum were inhibited, pro-inflammatory factors, liver fatty degeneration and fibrosis in liver tissues were decreased, while anti-inflammatory factors were increased. Overexpression of TSLP and JAK-STAT signaling pathway activation could reverse the effects of miR-142-5p on NASH. Taken together, overexpression of miR-142-5p could attenuate NASH progression via inhibiting TSLP and JAK-STAT pathway. MiR-142-5p might be a novel latent target for NASH therapy.

Objective: To investigate the differential expression of the thymic stromal lymphopoietin isoforms, short and long, and discern their biological implications under eosinophilic gastroenteritis. Methods: The expression of thymic stromal lymphopoietin and its two isoforms in tissues was assessed by quantitative RT-PCR in healthy controls (n = 24) and patients with eosinophilic gastroenteritis (n = 17). Results: Thymic stromal lymphopoietin mRNA was significantly reduced in eosinophilic gastroenteritis when compared with healthy controls (p < 0.0001). A significantly lower amount of short thymic stromal lymphopoietin mRNA was observed in eosinophilic gastroenteritis when compared with controls (p < 0.05), while a significantly higher amount of long thymic stromal lymphopoietin mRNA was observed in eosinophilic gastroenteritis when compared with controls (p < 0.05). Peak eosinophilic count is significantly positively correlated with the expression of long thymic stromal lymphopoietin mRNA in the gastrointestinal mucosal of patients with eosinophilic gastroenteritis (r s = 0.623, p < 0.005), while peak eosinophilic count is significantly negatively correlated with the expression of short thymic stromal lymphopoietin mRNA in the gastrointestinal mucosal of patients with eosinophilic gastroenteritis (r s = −0.4474, p < 0.05). Conclusions: Abnormal mucosal thymic stromal lymphopoietin expression may contribute to gastrointestinal mucosa damage in eosinophilic gastroenteritis. Resumo Objetivo: Investigar a expressão diferencial das isoformas da linfopoietina estromal tímica, curta e longa, e discernir suas implicações biológicas na gastroenterite eosinofílica. Métodos: Avaliamos a expressão das isoformas da linfopoietina estromal tímica e suas duas isoformas através da técnica RT-PCR quantitativa em tecidos de controles saudáveis (n = 24) e pacientes com gastroenterite eosinofílica (n = 17). Resultados: Demonstramos que o RNAm das isoformas da linfopoietina estromal tímica estava significativamente reduzido na gastroenterite eosinofílica em comparação com os controles saudáveis (p < 0,0001). Também descobrimos uma quantidade significativamente menor de RNAm das isoformas da linfopoietina estromal tímica curta na gastroenterite eosinofílica em comparação com os controles (p < 0,05) e uma quantidade significativamente maior de RNAm das isoformas da linfopoietina estromal tímica longa na gastroenterite eosinofílica em comparação com os controles (p < 0,05). O pico da contagem eosinofílica está correlacionado positiva e significativamente com a expressão do RNAm das isoformas da linfopoietina estromal tímica longa na mucosa gastrointestinal de pacientes com gastroenterite eosinofílica (rs = 0,623, p < 0,005), enquanto o pico de contagem eosinofílica está negativa e significativamente correlacionado com a expressão do RNAm das isoformas da linfopoietina estromal tímica curta na mucosa gastrointestinal de pacientes com gastroenterite eosinofílica (rs = -0,4474, p < 0,05). Conclusões: A expressão anormal das isoformas da linfopoietina estromal tímica na mucosa pode contribuir para o dano da mucosa gastrointestinal na gastroenterite eosinofílica.

The main factors involved in the pathogenesis of atopic dermatitis (AD) are skin barrier abnormality, allergy/immunology, and pruritus. Considering how oxidative stress influences these factors, antioxidant agents may be effective candidates in the treatment of AD. To evaluate the effect of Caffeoyl–Pro–His amide (CA-PH), an antioxidant agent, on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like phenotypes in BALB/c mice. Topical sensitization and challenge by DNCB were performed on the dorsal skin of BALB/c mice to induce AD-like cutaneous lesions, phenotypes, and immunologic response. CA-PH was applied topically for 2 weeks to assess its effects on DNCB-induced AD-like phenotypes. As a result, CA-PH relieved DNCB-induced AD-like phenotypes quantified by dermatitis severity score, scratching duration, and trans-epidermal water loss. Histopathological analysis showed that CA-PH decreased epidermal thickening, the number of mast cells, and eosinophil infiltration in dermis. Immunohistochemical staining revealed that CA-PH recovered skin barrier-related proteins: filaggrin, involucrin, and loricrin. As for the immunologic aspects, CA-PH treatment lowered mRNA or protein levels of interleukin (IL)-4, IL-6, IL-17a, IL-1b, IL-31, and IL-33 levels and thymic stromal lymphopoietin (TSLP) levels in cutaneous tissue, reducing the DNCB-induced serum IgE level elevation. In conclusion, topical CA-PH may be a therapeutic option for the treatment of AD.

The skin plays a critical role in maintenance of water homeostasis. Dysfunction of the skin barrier causes not only delayed wound healing and hypertrophic scarring, but it also contributes to the development of various skin diseases. Dermatitis is a chronic inflammatory skin disorder that has several different subtypes. Skin of contact dermatitis and atopic dermatitis (AD) show epidermal barrier dysfunction. Nax is a sodium channel that regulates inflammatory gene expression in response to perturbation of barrier function of the skin. We found that in vivo knockdown of Nax using RNAi reduced hyperkeratosis and keratinocyte hyperproliferation in rabbit ear dermatitic skin. Increased infiltration of inflammatory cells (mast cells, eosinophils, T cells, and macrophages), a characteristic of dermatitis, was reduced by Nax knockdown. Upregulation of PAR-2 and thymic stromal lymphopoietin (TSLP), which induce Th2-mediated allergic responses, was inhibited by Nax knockdown. In addition, expression of COX-2, IL-1β, IL-8, and S100A9, which are downstream genes of Nax and are involved in dermatitis pathogenesis, were also decreased by Nax knockdown. Our data show that knockdown of Nax relieved dermatitis symptoms in vivo and indicate that Nax is a novel therapeutic target for dermatitis, which currently has limited therapeutic options. Dermatitis is a chronic inflammatory skin disorder. Nax is a sodium channel that regulates inflammatory gene expression when the barrier function of the skin is disrupted. Knockdown of Nax relieves dermatitis symptoms in rabbit dermatitic skin. Nax is a novel therapeutic target for dermatitis, which currently has limited treatment options.

Idiopathic pulmonary fibrosis is a relentless fibrotic disease with largely unknown etiologies. Currently, the crosstalk between alveolar epithelial cells and lung-resident mesenchymal cells (especially [myo]fibroblasts) is considered to be the central pathogenesis to initiate and propagate the fibrotic process. Unfortunately, the master switch hidden in the profibrotic milieu that mediates pathogenic epithelial-mesenchymal interactions is still not well elucidated. Thus, the definite treatment target that can block and cure idiopathic pulmonary fibrosis is now lacking. Based on the previous studies, we proposed the notion that epithelium-derived triple type 2 cytokines, i.e. interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) are important pro-fibrotic mediators in idiopathic pulmonary fibrosis via two possible mechanisms: (1) paracrine pathway: directly acting on (myo)fibroblast. There may exist a structural and functional axis of (IL-25/IL-33/TSLP)+alveolar epithelial cells-(IL-25R/IL-33R/TSLPR)+(myo)fibroblasts in fibroblastic foci of idiopathic pulmonary fibrosis patients. The crosstalk between alveolar epithelium and the adjacent mesenchymal compartment is well established by the binding of IL-25/IL-33/TSLP expressed on alveolar epithelial cells with their corresponding receptors (i.e. IL-17BR/sT2L/TSLPR) expressed on (myo)fibroblasts; (2) autocrine pathway: directly acting on alveolar epithelial cells. Alveolar epithelial cells may act as both cellular sources and targets of IL-25/IL-33/TSLP. Autocrine IL-25/IL-33/TSLP causes salient injury and phenotypic changes of alveolar epithelial cells. Thus, epithelium-derived IL-25/IL-33/TSLP may be the novel promising treatment target for the cure of idiopathic pulmonary fibrosis.Impact statementWe suggest a novel modality in terms of IL-25/IL-33/TSLP’s pro-fibrotic role in IPF. First, IL-25/IL-33/TSLP fully activates (myo)fibroblasts in fibroblastic foci (FF) in a paracrine-dependent manner. (IL-25/IL-33/TSLP)+alveolar epithelial cells-(IL-25R/IL-33R/TSLPR)+(myo)fibroblasts axis may contribute greatly to the abnormal epithelial-mesenchymal crosstalk and lung fibrosis. Second, IL-25/IL-33/TSLP causes significant injury and phenotypic changes of alveolar epithelial cells in an autocrine-dependent manner. By acting directly on the two most important cells in the fibrotic process, i.e. alveolar epithelial cells and (myo)fibroblasts, we support the notion that biological therapies targeting IL-25/IL-33/TSLP will shed new light on the cure of IPF patients.

Atopic dermatitis (AD) is a chronic inflammatory skin disease and sometimes is a tough challenge for physicians. We previously reported that in Th2 environment, the production and secretion of thymic stromal lymphopoietin (TSLP) from human keratinocytes was inhibited by recombinant heat shock protein 70 (rHSP70). The present study assessed the therapeutic effectiveness of rHSP70 in a mouse model of AD. An experimental model of AD was reproduced by systemic sensitization and local epicutaneous challenge with ovalbumin (OVA). Treatment of rHSP70 was performed by subcutaneous administration. The levels of OVA‐specific IgE, as well as cytokines, were detected by ELISA. Skin samples from patch areas were also taken for histologic examination. Injection of rHSP70 improved the histologic picture by reducing the thickness of epidermis and allergic inflammation. Skin sonography revealed rHSP70 ameliorated skin remodeling. rHSP70 also significantly decreased the protein expression of TSLP of skin from patch areas. Furthermore, in ex vivo studies also showed group of rHSP70 treatment decreased IL‐13, RANTES, MIP‐1β and increased IFN‐γ secreted from splenocytes stimulated with OVA. The rHSP70 intervention in the mouse model of AD reduced the skin expression of TSLP and attenuated the clinical appearance of OVA‐induced AD mice. The effect was achieved by suppressed Th2 immune response in injected skin tissue and enhanced systemic Th1 immune response. These results suggest that rHSP70 have potential as a promising protein for the treatment of AD.

Exposure to chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) has been associated with allergic contact dermatitis and occupational asthma. Despite this association however, no study has investigated the effects of CMIT/MIT exposure on the development of atopic dermatitis (AD). This study was conducted to investigate the influence of epicutaneous exposure to CMIT/MIT on AD in a mouse model and the underlying biological mechanisms. BALB/C mice were exposed to CMIT/MIT for 3 weeks and AD was developed using ovalbumin (OVA) epidermal sensitization. CMIT/MIT epicutaneous exposure in normal mice significantly enhanced AD-like phenotypes (e.g., transepidermal water loss, clinical score, total serum immunoglobulin E level and infiltration of inflammatory cells). In addition, CMIT/MIT exposure significantly augmented the mRNA expression level of T helper (Th) 2-related cytokines (thymic stromal lymphopoietin, interleukin (IL)-6 and IL-13), Th2 chemokine (chemokine (C-C motif) ligand 17) and the population of CD4+IL-4+ cells in the skin. Moreover, mice exposed to CMIT/MIT in the OVA challenge had greater AD-like phenotypes, higher IL-4 and IL-17A skin mRNA expression levels, and a larger population of CD4+IL-4+- and IL-17A+-producing cells in the skin-draining lymph nodes. Our current findings in a mouse model thus suggest that CMIT/MIT exposure may cause AD symptoms through the dysregulation of Th2/Th17-related immune responses.

Aluminum precipitates have long been used as adjuvants for human vaccines, but there is a clear need for safer and more effective adjuvants. Here we report in a mouse model that the psoriasis drug Oxarol ointment is a highly effective vaccine adjuvant. By applying Oxarol ointment onto skin, humoral responses and germinal center (GC) reactions were augmented, and the treated mice were protected from death caused by influenza virus infection. Keratinocyte-specific vitamin D3 receptor (Vdr) gene expression was required for these responses through induction of the thymic stromal lymphopoietin (Tslp) gene. Experiments involving administration of recombinant TSLP or, conversely, anti-TSLP antibody demonstrated that TSLP plays a key role in the GC reactions. Furthermore, cell-type-specific Tslpr gene deletion or diphtheria toxin-mediated deletion of specific cell types revealed that CD11c+ cells excluding Langerhans cells were responsible for the Oxarol-mediated GC reactions. These results indicate that active vitamin D3 is able to enhance the humoral response via Tslp induction in the skin and serves as a new vaccine adjuvant.

Intrauterine growth restriction (IUGR) and low birth weight are risk factors for childhood asthma. Atopic march describes the progression from early dermatitis to asthma during life. Since inflammatory signaling is linked to increased airway resistance and lung remodeling in rats after IUGR, we queried if these findings are related to skin inflammatory response. Firstly, we induced IUGR in Wistar rats by isocaloric protein restriction during gestation. IUGR rats showed lower body weight at postnatal day 1 (P1), catch-up growth at P21, and similar body weight like controls at P90. At P1 and P90, mRNA of inflammatory as well as fibrotic markers and number of skin immune cells (macrophages) were increased after IUGR. Skin thymic stromal lymphopoietin (TSLP) mRNA at P1 and serum TSLP at P1 and P21 were elevated in IUGR. Moreover, IUGR impaired transepidermal water loss at P21 and P90. IUGR induced higher. Secondly, the increase of TEWL after Oxazolone treatment as a model of atopic dermatitis (AD) was greater in IUGR than in Co. Our data demonstrate an early inflammatory skin response, which is linked to persistent macrophage infiltration in the skin and impaired epidermal barrier function after IUGR. These findings coupled with elevated TSLP could underlie atopic diseases in rats after IUGR. KEY MESSAGES: • The present study shows that IUGR increases macrophage infiltration and induces an inflammatory and fibrotic gene expression pattern in the skin of newborn rats. • Early postnatal inflammatory response in the skin after IUGR is followed by impaired epidermal barrier function later in life. • IUGR aggravates transepidermal water loss in an experimental atopic dermatitis model, possibly through elevated TSLP in skin and serum. • Early anti-inflammatory treatment and targeting TSLP signaling could offer novel avenues for early prevention of atopic disorders and late asthma in high-risk infants.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation with accumulation of activated group 2 innate lymphoid cells (ILC2s) and elevation of thymic stromal lymphopoietin (TSLP). A member of the TNF superfamily (TNFSF), TNFSF15, is known to induce the production of type 2 cytokines in ILC2s. Although ILC2s have been implicated in CRSwNP, the presence and role of TNFSFs in ILC2-mediated type 2 inflammation in CRSwNP has not been elucidated. Here, we investigate the involvement of TNFSFs in ILC2-mediated type 2 inflammation in CRSwNP. We found that receptor activator of NF-κB (RANK) ligand (RANK-L (TNFSF11)) was significantly elevated in nasal polyps (NPs), and that the receptor of RANK-L, RANK, was expressed on ILC2s in human peripheral blood and NPs. An agonistic antibody against RANK induced production of type 2 cytokines in human ILC2s, and TSLP significantly enhanced this reaction. The membrane-bound RANK-L was detected mainly on CD45 + immune cells, including TH2 cells in NPs. The co-culture of NP-derived ILC2s and TH2 cells significantly enhanced production of type 2 cytokines, and anti-RANK-L monoclonal antibody suppressed this enhancement. In conclusion, RANK-L, together with TSLP, may play an inductive role in the ILC2-mediated type 2 inflammation in CRSwNP.

Aim: Common indoor pollutants, as fine particulate matter (PM2.5), can damage people's health and cause skin allergies. However, it remains unknown which common pollutants can lead to allergy, such as, in children atopic dermatitis, and what is the key molecule. This study aimed to investigate the thymic stromal lymphopoietin (TSLP) produced from keratinocytes after environmental pollutant stimulation. Methods: PAM212 cells were treated by several pollutants, including PM2.5, formaldehyde, m-xylene, and 1,2,4-trimethylbenzene, and tried to analyze their relationships. The mRNA expression level of TSLP was determined by qPCR. The protein level of TSLP was detected by ELISA analysis. Results: The mRNA expression of TSLP was significantly up-regulated when PAM212 cells were stimulated by PM2.5 at 25 μg/ml for 12 h. Meanwhile, the protein level of TSLP in culture supernatant was increased. However, TSLP protein production was not detected in culture supernatant treated with formaldehyde, m-xylene, and 1, 2, 4-trimethylbenzene. Conclusion: PM2.5 promotes the expression of TSLP and may aggravate allergic response using this pathway.

Atopic dermatitis (AD) is a common chronic skin disease with multiple pathogenic factors including skin barrier dysfunction, immune abnormalities, and pruritus. This review summarizes components involved in these pathogenic factors. (1) Skin barrier dysfunction in AD could be due to the down-regulation of epidermal barrier components such as filaggrin, acylceramides, cornified envelope precursors, and claudin-1. (2) T helper type 2 (Th2) cell-derived cytokines, such as interleukin (IL)-4 and IL-13, and keratinocyte-derived cytokines, such as thymic stromal lymphopoietin (TSLP) and IL-33, contribute to Th2-mediated skin inflammation in AD. (3) IL-31, TSLP, IL-4, and IL-13 are able to directly activate primary sensory neurons to induce pruritus in AD, and increased susceptibility to itch (so-called alloknesis) is partly due to epidermal hyperinnervation. Importantly, the three key factors (skin barrier dysfunction, immune abnormalities, and pruritis) interact with each other, creating a positive feedback loop that leads to the induction and maintenance of AD. Therefore, a better understanding of not only each pathogenic factor but also their interactions is important to elucidate the complex pathophysiological mechanisms of AD, which will then lead to the development of new therapeutic strategies and drugs for the treatment of this common skin disease.

Objective: To evaluate the effect of different extracts of Diospyros lotus leaves in atopic dermatitis Methods: Diospyros lotus leaves were extracted in ethanol and treated with or without hydrochloric acid or α-rhamnosidase to obtain three different extracts-ethanol, acid-hydrolyzed, and enzyme-hydrolyzed leaf extracts of date plum. The myricitrin content in all samples was measured using HPLC analysis. In vitro antioxidant and anti-inflammatory activities of the extracts were determined by measuring DPPH radical scavenging activities and nitric oxide production in RAW264.7 cells, respectively. Seven- week-old male hairless mice were used to evaluate the anti-atopic dermatitis effects of three extracts in vivo. Splenocytes and mast cells were used to further determine the anti-atopic dermatitis effects of the major compound in the ethanol leaf extract. Results: Enzyme-hydrolyzed leaf extract showed significant in vitro antioxidant and anti-inflammatory activities, and attenuated atopic dermatitis-like skin symptoms and clinical signs more significantly than ethanol and acid-hydrolyzed leaf extracts in 1-fluoro-2,4- dinitrobenzene and house dust mite antigen-treated hairless mice. Enzyme-hydrolyzed leaf extract also suppressed the serum level of immunoglobulin E, interleukin (IL)-4, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, thymic stromal lymphopoietin, and thymus and activation-regulated chemokine in mice with atopic dermatitis. Furthermore, histological analysis revealed that enzyme- hydrolyzed leaf extract suppressed the increased epidermal thickness, dermal infiltration of inflammatory cells, and infiltration and degranulation of mast cells more markedly than the other two extracts in atopic dermatitis-like skin lesions. In addition, this extract effectively inhibited the production of IFN-γ, IL-4,and thymus and activation-regulated chemokine compared with the other two extracts in concanavalin A-stimulated splenocytes. Myricitrin, a major compound of enzyme-hydrolyzed leaf extract, suppressed atopic dermatitis biomarkers in stimulated mouse splenocytes and HMC-1 human mast cells. Conclusions: These results suggest that enzyme-hydrolyzed leaf extract might be a potential candidate to treat atopic dermatitis.