Modulation of IL-4/IL-13 cytokine signaling in the context of allergic disease

CFTR negatively reprograms Th2 cell responses, and CFTR potentiation restrains allergic airway inflammation

Type 2 inflammatory diseases, including asthma, sinusitis, and allergic bronchopulmonary aspergillosis, are common in cystic fibrosis (CF). CD4+ Th2 cells promote these diseases through secretion of IL-4, IL-5, and IL-13. Whether the CF transmembrane conductance regulator (CFTR), the mutated protein in CF, has a direct effect on Th2 development is unknown. Using murine models of CFTR deficiency and human CD4+ T cells, we show that CD4+ T cells expressed Cftr transcript and CFTR protein following activation. Loss of T cell CFTR expression increased Th2 cytokine production compared with control cells. Mice with CFTR-deficient T cells developed increased allergic airway disease to Alternaria alternata extract compared with control mice. Culture of CFTR-deficient Th2 cells demonstrated increased IL-4Rα expression and increased sensitivity to IL-4 with greater induction of GATA3 and IL-13 compared with control Th2 cell cultures. The CFTR potentiator ivacaftor reduced allergic inflammation and type 2 cytokine secretion in bronchoalveolar lavage of humanized CFTR mice following Alternaria alternata extract challenge and decreased Th2 development in human T cell culture. These data support a direct role of CFTR in regulating T cell sensitivity to IL-4 and demonstrate a potential CFTR-specific therapeutic strategy for Th2 cell-mediated allergic disease.

Tracking inflammation status for improving patient prognosis: A review of current methods, unmet clinical needs and opportunities

Inflammation is the body's response to infection, trauma or injury and is activated in a coordinated fashion to ensure the restoration of tissue homeostasis and healthy physiology. This process requires communication between stromal cells resident to the tissue compartment and infiltrating immune cells which is dysregulated in disease. Clinical innovations in patient diagnosis and stratification include measures of inflammatory activation that support the assessment of patient prognosis and response to therapy. We propose that (i) the recent advances in fast, dynamic monitoring of inflammatory markers (e.g., cytokines) and (ii) data-dependent theoretical and computational modeling of inflammatory marker dynamics will enable the quantification of the inflammatory response, identification of optimal, disease-specific biomarkers and the design of personalized interventions to improve patient outcomes - multidisciplinary efforts in which biomedical engineers may potentially contribute. To illustrate these ideas, we describe the actions of cytokines, acute phase proteins and hormones in the inflammatory response and discuss their role in local wounds, COVID-19, cancer, autoimmune diseases, neurodegenerative diseases and aging, with a central focus on cardiac surgery. We also discuss the challenges and opportunities involved in tracking and modulating inflammation in clinical settings.

CD206+IL-4Rα+ Macrophages Are Drivers of Adverse Cardiac Remodeling in Ischemic Cardiomyopathy

BACKGROUND

The role of cardiac CD (cluster of differentiation) 206+ macrophages in chronic heart failure (HF) is unknown. We examined whether CD206+ macrophages expressing IL (interleukin)-4Rα are key drivers of adverse left ventricular (LV) remodeling in HF.

METHODS

Adult C57BL/6 mice underwent nonreperfused myocardial infarction to induce HF. Macrophages in murine and human hearts were profiled using flow cytometry and immunostaining. In vivo myeloid-specific IL-4Rα deletion and intramyocardial macrophage adoptive transfer defined the functional effects of M[IL-4] macrophages. Antisense oligonucleotides were used for in vivo IL-4Rα gene silencing in mice.

RESULTS

CD206+ macrophages steadily expanded in hearts after myocardial infarction, such that at 8 weeks after myocardial infarction, they comprised ≈85% of all macrophages. These macrophages were proliferative, predominantly CCR2- (C-C motif chemokine receptor) and MHC (major histocompatibility complex) IIhi, and correlated with LV dysfunction and fibrosis. Nearly half of CD206+ macrophages expressed IL-4Rα, and the majority of CD206+IL-4Rα+ macrophages coexpressed profibrotic FIZZ (found in inflammatory zone) 1. IL-4-polarized bone marrow-derived CD206+ macrophages also exhibited marked upregulation of FIZZ1 and induced FIZZ1-dependent myofibroblast differentiation of both cardiac mesenchymal stem cells and cardiac fibroblasts, in part related to DLL-4/Jagged1-Notch1 signaling in cardiac mesenchymal stem cells. Intramyocardial adoptive transfer of M[IL-4], but not M[IL-10], CD206+ macrophages to naïve mice induced progressive LV remodeling over 4 weeks, increasing fibrosis, cardiomyocyte hypertrophy, and apoptosis. Myeloid-specific IL-4Rα gene deletion in HF (initiated 4 weeks after myocardial infarction) in IL-4Rαf/fLysM-CreERT2 mice significantly reduced CD206+ macrophage proliferation and effectively depleted CD206+IL-4Rα+ cardiac macrophages. This was associated with abrogation of LV remodeling progression, reduction of cardiac fibrosis, and improved neovascularization. In vivo IL-4Rα gene silencing in mice with established HF effectively depleted cardiac CD206+IL-4Rα+ macrophages and reversed LV remodeling, improving fibrosis, neovascularization, and dysfunction, and suppressed both local and systemic inflammation. Last, alternatively activated CD206+ and CD163+ macrophages were significantly expanded in human failing hearts and correlated with fibrosis. The majority of CD163+ macrophages expressed IL-4Rα and FIZZ3, the human homolog of FIZZ1.

CONCLUSIONS

Cardiac CD206+IL-4Rα+ macrophages proliferate and expand in HF and are key mediators of pathological remodeling and fibrosis, in part through the secretion of FIZZ1. Inhibition of CD206+ macrophage IL-4Rα signaling alleviates LV remodeling in ischemic cardiomyopathy.

Immune therapies in coeliac disease and food allergies: Advances, challenges, and opportunities

Coeliac disease and food allergy management primarily relies on the strict avoidance of dietary antigens. This approach is challenging to maintain in real-world settings and in food allergy carries the risk of life-threatening anaphylaxis. Despite their distinct pathogenesis, both disorders are driven by maladaptive responses to dietary proteins, creating opportunities for shared treatment strategies. In food allergy, desensitisation therapies such as oral, sublingual, and epicutaneous immunotherapy are well-established, complemented by biologics like omalizumab and dupilumab. However, the induction of sustained tolerance remains challenging. In contrast, therapeutic advancements for coeliac disease are still in their early stages. Current efforts focus on gluten detoxification or modification, immune blockade or modulation, tolerogenic approaches, and barrier restoration. Emerging therapies, including JAK and BTK inhibitors and microbiome-targeted interventions, support further targeted treatment options for both conditions. Biomarkers tracking gluten-specific T cells have emerged as valuable tools for immunomonitoring and symptom assessment in coeliac disease, although standardisation of patient-reported outcome measures and gluten challenge protocols is still needed. Food allergy trials are reliant on double-blind placebo-controlled food challenges to measure allergen reactivity, but these are time-consuming, carry risks, and underscore the need for surrogate biomarkers. The successful development of immune-targeted therapies will require building an immune toolset to optimally assess systemic responses to antigens in both conditions. Clinically, this could lead to better outcomes for patients who might otherwise remain undiagnosed or untreated due to the absence of significant enteropathy or allergen-specific symptoms.

Oral treatment with Rosa multiflora fructus extract modulates mast cells in canine atopic dermatitis

Introduction

Canine atopic dermatitis is a hereditary, often pruritic, and predominantly T-cell-driven inflammatory skin disease involving an interplay between skin barrier abnormalities and allergen sensitization. However, progress in developing therapeutics for companion animals remains slow, with few drugs advancing to Phase II clinical trials to investigate the underlying mechanisms in target animals. While Rosa multiflora fruit extract (RMFE) has been strongly implicated in the improvement of various inflammatory diseases, its effects on canine atopic dermatitis (cAD) and the putative underlying mechanisms remain unclear. In this study, we aimed to evaluate the efficacy of RMFE in the treatment of cAD and explore its underlying mechanisms.

Methods

In this study, RMFE was administered orally (repeatedly for 2 weeks) to ovalbumin (OVA)-induced atopic dermatitis-induced beagles. The effects of RMFE on cAD were assessed through clinical symptom observation and scoring using the canine atopic dermatitis extent and severity index. Additionally, histopathological analysis was performed (hematoxylin and eosin, Masson's trichrome, and toluidine blue). Cluster of differentiation 4-positive immunostaining was also performed, along with cytokine level and messenger ribonucleic acid level analyses of T-helper 2 (Th2) immune and inflammatory response markers in the modeled skin.

Results

RMFE improved the clinical manifestations of cAD, leading to histopathological modulation of inflammation and immune cells. It also altered Th2 effector cytokine levels. Furthermore, RMFE reduced allergic responses in the AD model dogs by reducing mast cell numbers, inhibiting their activation to release inflammatory mediators, and reducing immunoglobulin E (IgE) production.

Discussion

Our results suggest that RMFE can modulate mast cell activation and Th2-dominant immune responses in cAD, helping to reduce AD-induced inflammatory responses.

The supplementation of dietary black cumin (Nigella Sativa) seeds on performance, blood hematology, post-metabolic responses, antioxidant status, immunity, and inflammatory markers in pre-weaning calves

Pre-weaning feeding is critical for calf growth, laying the foundation for future productivity and health. Nigella sativa seeds (NS) are rich in bioactive compounds with numerous beneficial effects on health and various pharmacological properties. This study aimed to investigate the supplementation of NS powder on performance, post-metabolic attributes, immunity, antioxidant capacity, and inflammatory responses in pre-weaning Friesian calves. Twenty-four Friesian male calves at 4 days of age with a similar genetic line, weighing 33.67 ± 0.6 kg, were randomly allocated to three groups (8 animals per group). The study comprised three groups: a control group (NS0) receiving no supplementation, and two experimental groups received either 1% (NS1) or 3% (NS3) NS supplementation for 84 days. All levels of NS supplementation significantly improved the final body weight and body weight gain in a linear manner (P < 0.001), while the highest total dry matter intake was observed in NS1 group (quadratic; P < 0.001). White blood cells (quadratic, P = 0.026), lymphocytes (quadratic, P = 0.012), and monocytes (linear effect; P = 0.001) significantly decreased, whereas red blood cells (linear; P = 0.004), hematocrit (linear; P = 0.002), mean corpuscular volume (MCV, linear; P = 0.003), and mean corpuscular hemoglobin concentration (MCHC, quadratic, P = 0.007), platelets (linear; P < 0.001) increased in calves fed NS. Feeding calves diets supplemented with NS led to a significant linear decrease in plasma creatinine and liver enzymes (AST and ALT) compared to the control diet (P < 0.01). Calves fed 3% of NS in their diets had lower plasma cholesterol (linear; P < 0.001) and triglyceride levels (linear; P = 0.002) compared to calves in NS0 and NS1 groups. Polynomial analysis indicated a quadratic decrease in direct bilirubin (P = 0.006), and a quadratic increase in immunoglobulin G (IgG, P = 0.014) and M (IgM, P = 0.032) in the calves fed the NS diet. All NS-supplemented groups showed a significant increase in IL-10 (linear; P < 0.001), TAC (linear; P = 0.006), and CAT (linear; P < 0.001), and a significant decrease in IL-4 levels (linear; P < 0.001) of the plasma of pre-weaning calves. As expected, pre-weaning calves fed diets containing NS (1% or 3%) exhibited a quadratic decrease in plasma malondialdehyde (MDA, P < 0.001) levels compared to those fed diets without NS. Our findings suggest that incorporating up to 3% Nigella sativa into pre-weaning calf diets can enhance growth, bolster immune function, and mitigate oxidative stress, offering a promising strategy for improving health and sustainability on dairy farms.

Exploring the anti-anaphylaxis potential of natural products: A Review

Allergies are a common health issue affecting many people around the world, especially in developed countries. They occur when the immune system overreacts to substances that are usually harmless. Some common allergic conditions include asthma, sinus infections, skin rashes, food allergies, hay fever, severe allergic reactions, eczema, swelling, and reactions to medications or insect stings. The causes of these allergies are complex and often linked to genetics, which can lead to heightened immune responses known as atopy. Throughout history, plant extracts have been used for various purposes, including medicine and food. In addition, their bioactive compounds show a wide range of beneficial effects, such as reducing allergic reactions, fighting oxidative stress, mast cell stabilizers, and lowering inflammation, highlighting their potential for treating various health conditions. Flavonoids and phenolic compounds are commonly used in anaphylaxis for their potent anti-inflammatory action. This review aims to promote the use of natural products as potential treatments for anaphylaxis. In addition, the discovery of new drugs derived from natural sources holds significant promise for the management of anaphylaxis.

Effect of PM2.5 exposure on susceptibility to allergic asthma in elderly rats treated with allergens

Fine particulate matter 2.5 (PM2.5) is a prevalent atmospheric pollutant that is closely associated with asthma. Elderly patients have a high incidence of asthma with a long course of illness. Our previous studies revealed that exposure to PM2.5 diminishes lung function and exacerbates lung damage in elderly rats. In the present study, we investigated whether PM2.5 exposure influences susceptibility to allergic asthma in elderly rats. Brown-Norway elderly rats were treated with ovalbumin (OVA) for different durations before and after PM2.5 exposure. The results from pulmonary function tests and histopathology indicated that early exposure to allergens prior to PM2.5 exposure increased susceptibility to airway hyperresponsiveness and led to severe lung injury in elderly asthmatic rats. Cytokine microarray analysis demonstrated that the majority of cytokines and chemokines were upregulated in OVA-treated rats before and after PM2.5 exposure. Cytological examination showed no change in eosinophil (EOS) counts, yet the amounts of neutrophils (NEU), white blood cells (WBC), lymphocytes (LYM), and monocytes (MON) in the lung lavage fluid of OVA-treated rats were significantly higher than those in control rats before and after PM2.5 exposure, suggesting that PM2.5 affects noneosinophilic asthma in elderly rats. ELISA results from the plasma and lung lavage fluid revealed that the levels of IgG1, IgE, IgG2a and IgG2b were significantly elevated in OVA-treated rats, whereas the level of IgG2b in the lung lavage fluid was significantly lower in rats treated with OVA prior to PM2.5 exposure compared to those treated afterward. A non-targeted metabolomic analysis of plasma identified 202 metabolites, among which 31 metabolites were differentially abundant. Ten metabolites and 11 metabolic pathways were uniquely detected in OVA-treated rats before PM2.5 exposure. Specifically, there were positive or negative correlations between the levels of Th2-associated cytokines (IL-4, IL-5, and IL-13) and six metabolites in the OVA-treated group before PM2.5 exposure, whereas the levels of IL-4 and IL-5 were negatively correlated with five metabolites in the OVA-treated group after PM2.5 exposure. Our findings suggest that PM2.5 exposure could influence the susceptibility of allergic asthma in response to allergens in elderly rats, potentially through changes in plasma metabolites.

The Etiology of IgE-Mediated Food Allergy: Potential Therapeutics and Challenges

Immunoglobulin E (IgE)-mediated food allergy has been dramatically increasing in incidence over the last few decades. The combinations of both genetic and environmental factors that affect the microbiome and immune system have demonstrated significant roles in its pathogenesis. The morbidity, and at times mortality, that occurs as the result of this specific, reproducible, but impaired immune response is due to the nature of the shift from a regulatory T (Treg) cellular response to a T helper 2 (Th2) cellular response. This imbalance caused by food allergens results in an interleukin (IL)-4 and IL-13 dominant environment that drives B cell activation and differentiation into IgE-producing plasma cells. The resulting symptoms can range from mild to more severe anaphylaxis, and even death. Current therapeutic strategies involve avoidance and broad symptom management upon accidental exposure; however, no definitive cure exists. This narrative review highlights how the elucidation of the pathogenesis of IgE-mediated food allergy resulted in the development of therapeutics that are more specific to these individual receptors and molecules which have been relatively successful in mitigating this potentially life-threatening allergic response. However, potential adverse effects and re-sensitization following the conclusion of treatment has urged the need for improved therapeutic methods. Therefore, given the understanding of their mechanism of action and the overlap with the mechanism of IgE-mediated food allergies, probiotics and small molecule natural compounds may provide novel therapeutic and preventative strategies. This is compelling, as they have demonstrated success in clinical trials and may provide hope to improve quality of life in allergy patients.

Cuproptosis genes in predicting the occurrence of allergic rhinitis and pharmacological treatment

BACKGROUND

While drug therapy and allergen immunotherapy are useful for alleviating symptoms of seasonal allergic rhinitis (AR), existing therapeutic options remain limited. Cuproptosis is a novel form of programmed cell death, and its role in allergic rhinitis has not yet been explored. Researching the interaction between cuproptosis and allergic rhinitis will likely pave the way for future treatment of this disease.

METHODS

A microarray dataset of AR patients and normal controls (GSE43523) were obtained from the Gene Expression Omnibus (GEO) database for differential gene analysis. Cuproptosis related genes were extracted from the differentially expressed genes (DEGs) to form the AR/cuprotosis-gene set and analyzed by the GO and KEGG databases. Intersection analysis further defined the AR signature genes (AR-sg). Consensus cluster analyses were used to define the AR/cuprotosis-genes into subsets. Finally, AR signature genes were used as targets for drug prediction and molecular docking to identify candidate drugs that may affect SAR.

RESULTS

Four AR signature genes (MRPS30, CLPX, MRPL13, and MRPL53) were selected by the MCC, EPC, BottleNeck, and Closeness algorithms. Correlation analysis of the AR signature genes and immune genes showed strong interactions; xCell analysis identified multiple immune cell types and supported these cells' importance in the AR pathogenesis. Finally, drug target analysis suggests that 1,5-isoquinolinediol and gefitinib have the potential to become future AR treatments.

CONCLUSION

Our study analyzed allergic rhinitis and cuproptosis related genes by the bioinformatics approach and predicted 1,5-isoquinolinediol and gefitinib as potentially useful drugs for treating AR patients in the future.

Childhood allergy and anxiety/depression in early adulthood: A longitudinal study in the ALSPAC birth cohort

BACKGROUND

Allergic disease and common mental disorders frequently co-occur. However, little is known about the longitudinal impact of childhood allergy on the subsequent risk of developing anxiety or depression, and the possible biological mechanisms for this.

METHODS

We performed longitudinal analyses of data from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. The baseline sample comprised n = 5256 children with allergy data available at age 7yrs. We used multivariable regression to test associations between childhood allergy at age 7yrs and: a) four inflammatory markers at age 9yrs; b) depression and anxiety measures between ages 10-24yrs. Allergy measures included biological markers (total serum immunoglobulin E (tIgE), number of positive skin prick tests (SPTs)), and presence of eczema, asthma and/or food allergy (mother reported). Inflammatory markers were interleukin-6 (IL-6), C-reactive protein (CRP), IL-4 and IL-13. We used structural equation modelling to test whether inflammatory markers mediated the association between tIgE and depression/anxiety.

RESULTS

tIgE and having ≥ 1 positive SPT at age 7 were associated with IL-6 levels at age 9 (adjusted β = 0.09; 95 % CI 0.06-0.13; p < 0.001 and adjusted β = 0.06; 95 % CI 0.03-0.09; p < 0.001 respectively), but not with CRP, IL-4 or IL13 levels. We found no strong evidence of an association between childhood allergy and subsequent depression/anxiety during adolescence and early adulthood. This finding was consistent across biological and mother-reported allergy measures.

CONCLUSIONS

Biological markers of childhood allergy are associated with IL-6, a key inflammatory cytokine. However, childhood allergy may not have a large long-term effect on subsequent depression/anxiety.

What is "eczema"?

Eczema is the most common category of inflammatory skin disorders as dermatologists see many patients with eczematous diseases in daily practice. It is characterized by the three major morphological features: multiple-pinpoint condition, polymorphism, and itch. To describe polymorphism, "eczema triangle" has been used in German/Japanese dermatology. The multiple pinpoints correspond to numerous tiny foci from which individual papules/vesicles arise. The polymorphism betrays composition of erythema, papule, seropapule, vesicle, pustule, scale, and crust, which are seen in acute eczema. Meanwhile, chronic eczema is represented by lichenification and hyperpigmentation, and possibly by hypopigmentation. In acute eczema, spongiosis is associated with overproduction of hyaluronic acid, secretion of self-protective galectin-7, and decreased expression of E-cadherin. In the upper dermis, Th1/Tc1 or Th2/Tc2, and additional Th17, Th22, and/or Tc22 infiltrate, depending on each eczematous disease. Innate lymphoid cells are also involved in the formation of eczema. In chronic eczema, periostin contributes to remodeling of inflammatory skin with dermal fibrosis, and epidermal melanogenesis and dermal pigment deposition result in hyperpigmentation. Finally, eczematous diseases are potentially associated with increased risk of comorbidities, including not only other allergic diseases but also coronary heart disease and mental problems such as depression. Although the original word for eczema is derived from old Greek "ekzein," eczema remains a major target of modern science and novel therapies.

Preventing NLRP3 inflammasome activation: Therapeutic atrategy and challenges in atopic dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin disorder characterized by its chronic, persistent, and recurrent nature. The pathophysiology of this condition is complex, involving various factors including cell-mediated immune responses, compromised skin barrier function, and alterations in hypersensitivity reactions. These components synergistically contribute to the perpetuation of the bothersome "itch-scratch-itch" cycle. Recent research has highlighted the significant role of the NLRP3 inflammasome in the development of AD and other inflammatory conditions. Current research indicates that the NLRP3 inflammasome plays a pivotal role in both the acute and chronic phases of AD by modulating the Th2/Th1 immune deviation. Moreover, the pharmacological suppression of NLRP3 has shown promising results in mitigating the pathological aspects of AD. This review outlines potential drug development strategies that target the NLRP3 inflammasome as a therapeutic approach for AD and the challenges faced in this endeavor.

An Integrative analysis of single-cell RNA-seq, transcriptome and Mendelian randomization for the Identification and validation of NAD+ Metabolism-Related biomarkers in ulcerative colitis

Ulcerative colitis (UC) is a chronic and refractory inflammatory disease of the colon and rectum. This study utilized bioinformatics methods to explore the potential of Nicotinamide adenine dinucleotide (NAD+) metabolism-related genes (NMRGs) as key genes in UC. Using the GSE87466 dataset, differentially expressed NMRGs were identified through differential expression analysis, weighted gene co-expression network analysis (WGCNA), and NMRG scoring. These NMRGs were used as exposure factors, with UC as the outcome, to identify causal candidate genes through Mendelian randomization (MR) analysis. Key genes were further validated as biomarkers using machine learning and expression validation in external datasets (GSE75214, GSE224758). A nomogram based on the expression levels of these biomarkers was constructed to predict UC risk, and the biomarkers' expression was validated through real-time quantitative polymerase chain reaction (RT-qPCR). Subsequently, signaling pathway analysis, enrichment analysis, immune infiltration analysis, and drug prediction were conducted to comprehensively understand the biological roles of the key genes in the human body. Single-cell (GSE116222) and spatial transcriptomic analyses (GSE189184) revealed the expression patterns of these key genes in specific cell types. NCF2, IL1B, S100A8, and SLC26A2 were identified as biomarkers, with NCF2 and IL1B serving as protective factors and S100A8 and SLC26A2 as risk factors for UC. The nomogram based on these biomarkers demonstrated strong predictive value. Functional analysis revealed significant IL1B, NCF2, and S100A8 enrichment in pathways such as IL-4 and IL-13 signaling, while SLC26A2 was strongly associated with respiratory electron transport. Significant differences in immune cells, such as macrophages and neutrophils, were also observed. Single-cell analysis showed high expression of NCF2, IL1B, and S100A8 in monocytes, while SLC26A2 was primarily expressed in epithelial cells, intestinal epithelial cells, and mast cells. Overall, these findings reveal the roles of NMRGs, providing valuable insights into the diagnosis and treatment of UC patients.

Genetically Predicted Immune Cell-Mediated Effect of Lipid Metabolism on Allergic Diseases: A Two-Step, Mediation Mendelian Randomization Study

INTRODUCTION

An increasing number of studies have demonstrated that dynamic changes in lipid species can affect allergic diseases; however, the causal relationship and mediating role of immune cells remain unclear.

METHODS

We conducted a bidirectional two-sample mendelian randomization (MR) analysis using genome-wide association study (GWAS) data on 179 lipid species (n = 7,174) and three types of allergic diseases including allergic rhinitis (AR) (n = 370,158), allergic asthma (n = 219,753), and allergic conjunctivitis (n = 377,277). The principal model used was the inverse variance-weighted approach, and a series of sensitivity analyses were conducted to ensure the robustness of the results. We used a two-step MR approach to assess whether the causal effect was mediated by immune cells (n = 3,757).

RESULTS

Sterol ester and sphingomyelin played pathogenic roles in allergic asthma, AR, and allergic conjunctivitis; however, the effective subtypes differed. Among them, CD45RA- CD4+ mature T cells and CCR2 on CD14+ CD16+ monocytes affected the promoting impact of sterol ester's metabolism on allergic asthma and AR with different mediating proportions, while the role of sphingomyelin may not involve the immune cells. Moreover, we observed that HLA-DR on CD33- HLA DR+ myeloid cells, CD11b on CD66b++ myeloid cells, and IgD+ CD38- B cells played the most mediating effect of phosphatidylethanolamine (O-18:2_20:4) in allergic asthma, phosphatidylinositol (16:0_18:1) in AR, and phosphatidylethanolamine (18:0_18:2) in allergic conjunctivitis.

CONCLUSION

This MR study provides evidence for specific lipid species associated with the risk of allergic diseases, especially sterol esters, and identifies the immune cells that mediate this causal relationship.

Hydrogen Gas Inhalation Alleviates Airway Inflammation and Oxidative Stress on Ovalbumin-Induced Asthmatic BALB/c Mouse Model

Airway inflammatory diseases, such as asthma, are a global public health concern owing to their chronic inflammatory effects on the respiratory mucosa. Molecular hydrogen (H2) has recently been recognized for its antioxidant and anti-inflammatory properties. In this study, we examined the therapeutic potential of H2 in airway inflammation using an ovalbumin (OVA)-induced BALB/c mouse model of allergic asthma. Female BALB/c mice were sensitized and challenged with OVA to induce airway inflammation, and 30 mice were randomly divided into five groups: NT (non-treatment), HTC (3% H2 treatment only), NC (negative control, OVA only), PC (positive control, OVA + intranasal 1 mg/mL salbutamol 50 μL), and HT (H2 treatment, OVA + inhaled 3% H2). Various inflammatory and oxidative stress (OS)-induced markers such as white blood cells (WBCs) and their differential counts, lung histology, cytokine levels such as interleukin (IL)-4, (IL)-5, (IL)-13, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), (IL)-10, reactive oxygen species (ROS), nitric oxide (NO), glutathione peroxidase (GPx), and catalase (CAT), and total immunoglobulin E (IgE) levels were investigated. Our results showed that inhaled H2 significantly reduced inflammatory cell infiltration, OS markers, and pro-inflammatory cytokine expression while upregulating antioxidant enzyme activity. Furthermore, H2 also significantly decreased serum IgE levels, a marker of allergic inflammation. Collectively, our findings suggest that H2 inhalation is a promising treatment option for airway inflammation, offering a novel approach with potential clinical applications.

Diterpenoid DGT alleviates atopic dermatitis-like responses in vitro and in vivo via targeting IL-4Rα

BACKGROUND

Atopic dermatitis is a common chronic inflammatory skin disease characterized by relapsing eczema and intense itch. DGT is a novel synthetic heterocyclic diterpenoid derived from plants. Its therapeutic potential and mechanism(s) of action are poorly understood.

OBJECTIVES

We investigated the potent therapeutic effect of DGT on atopic dermatitis, exploring the underlying mechanisms and determining whether DGT is a safe and well-tolerated topical treatment.

METHODS

We observed anti-inflammatory effects of DGT on tumor necrosis factor-α/interferon-γ-treated human keratinocytes, and anti-allergic effects on immunoglobulin E-sensitized bone marrow-derived mast cells. In vivo, DGT was topically applied to two experimental mouse models of atopic dermatitis: oxazolone-induced sensitization and topically applied calcipotriol. Then the therapeutic effects of DGT were evaluated physiologically and morphologically. Moreover, we performed nonclinical toxicology and safety pharmacology research, including general toxicity, pharmacokinetics, and safety pharmacology on the cardiovascular, respiratory, and central nervous systems.

RESULTS

In keratinocytes, DGT reduced the expression of inflammatory factors, promoting the expression of barrier functional proteins and tight junctions and maintaining the steady state of barrier function. DGT also inhibited the activation and degranulation of mast cells induced by immunoglobulin E. Moreover, we found that interleukin-4 receptor-α was the possible target of DGT. Meanwhile, DGT had therapeutic effects on oxazolone/calcipotriol-treated mice. Notably, our pharmacology results demonstrated that DGT was safe and nontoxic in our studies.

CONCLUSION

DGT's potent anti-inflammatory effects and good safety profile suggest that it is a potential candidate for the treatment of atopic dermatitis.

Daphnetin alleviates allergic airway inflammation by inhibiting T-cell activation and subsequent JAK/STAT6 signaling

Allergic asthma is a major health burden on society as a chronic respiratory disease characterized by inflammation and muscle tightening around the airways in response to inhaled allergens. Daphne kiusiana Miquel is a medicinal plant that can suppress allergic airway inflammation; however, its specific molecular mechanisms of action are unclear. In this study, we aimed to elucidate the mechanisms by which D. kiusiana inhibits allergic airway inflammation. We evaluated the anti-inflammatory effects of the ethyl acetate (EA) fraction of D. kiusiana and its major compound, daphnetin, on murine T lymphocyte EL4 cells stimulated with phorbol 12-myristate 13-acetate and ionomycin in vitro and on asthmatic mice stimulated with ovalbumin in vivo. The EA fraction and daphnetin inhibited T-helper type 2 (Th2) cytokine secretion, serum immunoglobulin E production, mucus secretion, and inflammatory cell recruitment in vivo. In vitro, daphnetin suppressed intracellular Ca2+ mobilization (a critical regulator of nuclear factor of activated T cells) and functions of the activator protein 1 transcription factor to reduce interleukin (IL)-4 and IL-13 expression. Daphnetin effectively suppressed the IL-4/-13-induced activation of Janus kinase (JAK)/signal transducer and activator of transcription 6 (STAT6) signaling in vitro and in vivo, thereby inhibiting the expression of GATA3 and PDEF, two STAT6-target genes responsible for producing Th2 cytokines and mucins. These findings indicate that daphnetin suppresses allergic airway inflammation by stabilizing intracellular Ca2+ levels and subsequently inactivating the JAK/STAT6/GATA3/PDEF pathway, suggesting that daphnetin is a promising alternative to existing asthma treatments.

Comparison of serum cytokines and chemokines levels and clinical significance in patients with pemphigus vulgaris-A retrospective study

In this study, we aimed to examine the relationship between the serum cytokine levels of patients with pemphigus vulgaris (PV) and the Pemphigus Disease Area Index (PDAI), along with the presence of anti-desmoglein (Dsg) 1 antibody, anti-Dsg3 antibody and co-infection among patients with pemphigus vulgaris. This retrospective study included 62 PV patients and 59 healthy individuals who attended the Second Affiliated Hospital of Kunming Medical University from November 2014 to November 2022. The serum concentrations of cytokines and chemokines were assessed using the Luminex 200 System (a high-throughput cytokine detection method). Additionally, anti-Dsg1 and anti-Dsg3 antibodies were determined through enzyme-linked immunosorbent assay, while disease severity was evaluated using the PDAI scoring system. The PV group exhibited elevated levels of Th1 cytokines (such as interleukin (IL)-1RA, IL-1β, IL-2, IL-12p70, GM-CSF, TNF-α, IL-18, IFN-γ), Th2 cytokines (IL-5, IL-10, IL-13) and Th17/Th22-related cytokines (IL-17A, IL-22) compared to the healthy control group (p < 0.05). Conversely, the levels of chemokines (macrophage inflammatory protein-1 alpha (MIP-1α), stromal cell-derived factor-1 alpha (SDF-1α), interferon-inducible protein-10 (IP-10), Regulated on Activation in Normal T-Cell Expressed And Secreted (RANTES), growth-regulated on-gene-alpha (GRO-α), MIP-1β) and Th2 (IL-31) were lower in the PV group compared to the healthy control group (p < 0.05). No significant differences were observed in other cytokines and chemokines (p > 0.05). Additionally, IL-7, IFN-γ, IL-18 and GRO-α showed positive correlations with PDAI, IL-6 correlated positively with anti-Dsg3 antibody levels, and IL-12p70, IL-18, and IFN-γ correlated positively with anti-Dsg1 antibody levels. Furthermore, IL-15 exhibited a positive association with skin infections. PV patients have elevated levels of various cytokines and chemokines, and there are different degrees of elevation in cytokines and chemokines associated with the activation of various T cell subsets. PDAI and the Dsg1 antibody levels are mainly related to the Th1-related cytokines.

Anti-Allergic and Anti-Inflammatory Signaling Mechanisms of Natural Compounds/Extracts in In Vitro System of RBL-2H3 Cell: A Systematic Review

Various extracts are tested for anti-allergic or anti-inflammatory properties on in vitro models. RBL-2H3 cells are widely used in allergic or immunological studies. FCεRI and its downstream signaling cascades, such as MAPK, NF-κB, and JAK/STAT signaling pathways, are important allergic or inflammatory signaling mechanisms in mast and basophil cells. This systematic review aims to study common signaling pathways of the anti-allergic or anti-inflammatory compounds on RBL-2H3 cells. We selected the relevant research articles published after 2015 from the PubMed, Scopus, Science Direct and Web of Science databases. The risk of bias of the studies was assessed based on the modified CONSORT checklist for in vitro studies. The cell lines, treatments, assay, primary findings, and signaling pathways on RBL-2H3 cells were extracted to synthesize the results. Thirty-eight articles were included, and FCεRI and its downstream pathways, such as Lyn, Sky, PLCγ, and MAPK, were commonly studied. Moreover, the JAK/STAT pathway was a potential signaling mechanism in RBL-2H3 cells. However, the findings based on RBL-2H3 cells needed to be tested along with human mast cells to confirm its relevance to human health. In conclusion, a single plant extract may act as an anti-inflammatory reagent in RBL-2H3 cells via multiple signaling pathways besides the MAPK signaling pathway.

Computational insights into rational design and virtual screening of pyrazolopyrimidine derivatives targeting Janus kinase 3 (JAK3)

The Janus kinase 3 (JAK3) family, particularly JAK3, is pivotal in initiating autoimmune diseases such as rheumatoid arthritis. Recent advancements have focused on developing antirheumatic drugs targeting JAK3, leading to the discovery of novel pyrazolopyrimidine-based compounds as potential inhibitors. This research employed covalent docking, ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) analysis, molecular dynamics modeling, and MM/GBSA (Molecular Mechanics Generalized Born Surface Area) binding free energy techniques to screen 41 in silico-designed pyrazolopyrimidine derivatives. Initially, 3D structures of the JAK3 enzyme were generated using SWISS-MODEL, followed by virtual screening and covalent docking via AutoDock4 (AD4). The selection process involved the AMES test, binding affinity assessment, and ADMET analysis, narrowing down the candidates to 27 compounds that passed the toxicity test. Further covalent docking identified compounds 21 and 41 as the most promising due to their high affinity and favourable ADMET profiles. Subsequent development led to the creation of nine potent molecules, with derivatives 43 and 46 showing exceptional affinity upon evaluation through molecular dynamics simulation and MM/GBSA calculations over 300 nanoseconds, comparable to tofacitinib, an approved RA drug. However, compounds L21 and L46 demonstrated stable performance, suggesting their effectiveness in treating rheumatoid arthritis and other autoimmune conditions associated with JAK3 inhibition.

Global influence of dupilumab on Quality of Life in a severe asthma patient with T2 multimorbidities: a case report on atopic dermatitis, chronic rhinosinusitis with nasal polyposis, and eosinophilic esophagitis

INTRODUCTION

Interleukin (IL)-4 and IL-13 are considered key drivers of type 2 inflammatory diseases. Dupilumab is a fully human monoclonal antibody that blocks the shared receptor component for IL-4 and IL-13, thus inhibiting signaling of both cytokines.

CASE STUDY

We report a case of a patient with uncontrolled severe asthma and other T2 inflammatory diseases (atopic dermatitis, chronic rhinosinusitis with nasal polyposis and eosinophilic esophagitis) treated with dupilumab.

RESULTS

After one year of treatment, dupilumab improved asthma control together with lung function parameters and airway inflammation. Additionally, a positive impact on quality of life (QoL), evaluated by validated questionnaires, across all the diseases was observed.

CONCLUSION

In this case report, a positive and objectively measurable of global improvement on QoL across all four T2 comorbidities was observed after treatment with dupilumab, demonstrating the important role of IL-4 and IL-13 and the existence of a unifying pathological mechanism in T2 diseases.

Pathogenic roles of follicular helper T cells in IgG4-related disease and implications for potential therapy

IgG4-related disease (IgG4-RD) is a recently described autoimmune disorder characterized by elevated serum IgG4 levels and tissue infiltration of IgG4+ plasma cells in multiple organ systems. Recent advancements have significantly enhanced our understanding of the pathological mechanism underlying this immune-mediated disease. T cell immunity plays a crucial role in the pathogenesis of IgG4-RD, and follicular helper T cells (Tfh) are particularly important in germinal center (GC) formation, plasmablast differentiation, and IgG4 class-switching. Apart from serum IgG4 concentrations, the expansion of circulating Tfh2 cells and plasmablasts may also serve as novel biomarkers for disease diagnosis and activity monitoring in IgG4-RD. Further exploration into the pathogenic roles of Tfh in IgG4-RD could potentially lead to identifying new therapeutic targets that offer more effective alternatives for treating this condition. In this review, we will focus on the current knowledge regarding the pathogenic roles Tfh cells play in IgG4-RD and outline potential therapeutic targets for future clinical intervention.

The Possible Roles of IL-4/IL-13 in the Development of Eosinophil-Predominant Severe Asthma

Bronchial asthma is characterized by airway inflammation, airway hyperresponsiveness, and reversible airway obstruction. Eosinophils contribute to the pathogenesis of airway disease mainly by releasing eosinophil-specific granules, lipid mediators, superoxide anions, and their DNA. Type-2 cytokines such as interleukin (IL)-4 and IL-13 also play roles in the development of bronchial asthma. Among these cytokines, IL-4 is involved in T-cell differentiation, B-cell activation, B-cell differentiation into plasma cells, and the production of immunoglobulin E. Although IL-13 has similar effects to IL-4, IL-13 mainly affects structural cells, such as epithelial cells, smooth muscle cells, and fibroblasts. IL-13 induces the differentiation of goblet cells that produce mucus and induces the airway remodeling, including smooth muscle hypertrophy. IL-4 and IL-13 do not directly activate the effector functions of eosinophils; however, they can induce eosinophilic airway inflammation by upregulating the expression of vascular cell adhesion molecule-1 (for adhesion) and CC chemokine receptor 3 ligands (for migration). Dupilumab, a human anti-IL-4 receptor α monoclonal antibody that inhibits IL-4 and IL-13 signaling, decreases asthma exacerbations and mucus plugs and increases lung function in moderate to severe asthma. In addition, dupilumab is effective for chronic rhinosinusitis with nasal polyps and for atopic dermatitis, and IL-4/IL-13 blocking is expected to suppress allergen sensitization, including transcutaneous sensitization and atopic march.

Causal relationship between inflammatory cytokines and autoimmune thyroid disease: a bidirectional two-sample Mendelian randomization analysis

Background

Autoimmune thyroid disease (AITD) ranks among the most prevalent thyroid diseases, with inflammatory cytokines playing a decisive role in its pathophysiological process. However, the causal relationship between the inflammatory cytokines and AITD remains elusive.

Methods

A two-sample Mendelian randomization (MR) analysis was performed to elucidate the causal connection between AITD and 41 inflammatory cytokines. Genetic variations associated with inflammatory cytokines were sourced from the FinnGen biobank, whereas a comprehensive meta-analysis of genome-wide association studies (GWASs) yielded data on Graves' disease (GD) and Hashimoto thyroiditis. Regarding the MR analysis, the inverse variance-weighted, MR-Egger, and weighted median methods were utilized. Additionally, sensitivity analysis was conducted using MR-Egger regression, MR-pleiotropy residual sum, and outliers.

Results

Seven causal associations were identified between inflammatory cytokines and AITD. High levels of tumor necrosis factor-β and low levels of stem cell growth factor-β were indicative of a higher risk of GD. In contrast, high levels of interleukin-12p70 (IL-12p70), IL-13, and interferon-γ and low levels of monocyte chemotactic protein-1 (MCP-1) and TNF-α suggested a higher risk of HD. Moreover, 14 causal associations were detected between AITD and inflammatory cytokines. GD increases the levels of macrophage inflammatory protein-1β, MCP-1, monokine induced by interferon-γ (MIG), interferon γ-induced protein 10 (IP-10), stromal cell-derived factor-1α, platelet-derived growth factor BB, β-nerve growth factor, IL-2ra, IL-4, and IL-17 in blood, whereas HD increases the levels of MIG, IL-2ra, IP-10, and IL-16 levels.

Conclusion

Our bidirectional MR analysis revealed a causal relationship between inflammatory cytokines and AITD. These findings offer valuable insights into the pathophysiological mechanisms underlying AITD.

The role of hormones in ILC2-driven allergic airway inflammation

Group 2 innate lymphoid cells (ILC2s) are a type of innate immune cells that produce a large amount of IL-5 and IL-13 and two cytokines that are crucial for various processes such as allergic airway inflammation, tissue repair and tissue homeostasis. It is known that damaged epithelial-derived alarmins, such as IL-33, IL-25 and thymic stromal lymphopoietin (TSLP), are the predominant ILC2 activators that mediate the production of type 2 cytokines. In recent years, abundant studies have found that many factors can regulate ILC2 development and function. Hormones synthesized by the body's endocrine glands or cells play an important role in immune response. Notably, ILC2s express hormone receptors and their proliferation and function can be modulated by multiple hormones during allergic airway inflammation. Here, we summarize the effects of multiple hormones on ILC2-driven allergic airway inflammation and discuss the underlying mechanisms and potential therapeutic significance.

Human germline gain-of-function in STAT6: from severe allergic disease to lymphoma and beyond

Signal transducer and activator of transcription (STAT)-6 is a transcription factor central to pro-allergic immune responses, although the function of human STAT6 at the whole-organism level has long remained unknown. Germline heterozygous gain-of-function (GOF) rare variants in STAT6 have been recently recognized to cause a broad and severe clinical phenotype of early-onset, multi-system allergic disease. Here, we provide an overview of the clinical presentation of STAT6-GOF disease, discussing how dysregulation of the STAT6 pathway causes severe allergic disease, and identifying possible targeted treatment approaches. Finally, we explore the mechanistic overlap between STAT6-GOF disease and other monogenic atopic disorders, and how this group of inborn errors of immunity (IEIs) powerfully inform our fundamental understanding of common human allergic disease.

IL-13 neutralization attenuates carotid artery intimal hyperplasia and increases endothelial cell migration via modulating the JAK-1/STAT-3 signaling pathway

The aim of this study was to investigate how the concentration of interleukin-13 (IL-13) affects the regulation of endothelial cell migration after injury. The incubation of recombinant human interleukin-13 (rhIL-13) strongly increased the content of reactive oxygen species (ROS) in HUVECs via the JAK-1/STAT-3/NOX-4 signaling pathway. Antagonizing the high intracellular ROS that was induced by rhIL-13 promoted the migration of HUVECs. Furthermore, IL-13 neutralization not only inhibited intimal hyperplasia, but also promoted the migration of endothelial cells (ECs) after injury. The results suggest that IL-13 inhibition is a potential means of stimulating endothelial cells recovery after injury. Therefore, the attenuation of IL-13 activation may have therapeutic value for vascular disease.

Liubao tea extract ameliorates ovalbumin-induced allergic asthma by regulating gut microbiota in mice

Asthma, a chronic airway inflammatory disease, has a complicated pathogenesis and limited therapeutic treatment. Evidence shows that the intestinal microbiota exhibits crucial functional interaction with asthma syndrome. Liubao tea (LBT), a type of postfermented tea in China, positively modulates gut microbiota. However, the potential benefits of LBT extract (LBTE) for allergic asthma are still not understood. Herein, the anti-inflammatory effects of LBTE and its modulation of the gut microbiota of asthmatic mice induced by ovalbumin were explored. The results demonstrate that LBTE significantly inhibited airway hyper-responsiveness and restrained the proliferation of proinflammatory cytokines and inflammatory cells associated with allergic asthma. Additionally, LBTE suppressed inflammatory infiltration, mucus secretion, and excessive goblet cell production by downregulating the gene expression of inflammatory indicators. Interestingly, fecal microbiota transplantation results further implied that the modulation of LBTE on gut microbiota played an essential role in alleviating airway inflammatory symptoms of allergic asthma.

Severe allergic dysregulation due to a gain of function mutation in the transcription factor STAT6

BACKGROUND

Inborn errors of immunity have been implicated in causing immune dysregulation, including allergic diseases. STAT6 is a key regulator of allergic responses.

OBJECTIVES

This study sought to characterize a novel gain-of-function STAT6 mutation identified in a child with severe allergic manifestations.

METHODS

Whole-exome and targeted gene sequencing, lymphocyte characterization, and molecular and functional analyses of mutated STAT6 were performed.

RESULTS

This study reports a child with a missense mutation in the DNA binding domain of STAT6 (c.1114G>A, p.E372K) who presented with severe atopic dermatitis, eosinophilia, and elevated IgE. Naive lymphocytes from the affected patient displayed increased TH2- and suppressed TH1- and TH17-cell responses. The mutation augmented both basal and cytokine-induced STAT6 phosphorylation without affecting dephosphorylation kinetics. Treatment with the Janus kinase 1/2 inhibitor ruxolitinib reversed STAT6 hyperresponsiveness to IL-4, normalized TH1 and TH17 cells, suppressed the eosinophilia, and improved the patient's atopic dermatitis.

CONCLUSIONS

This study identified a novel inborn error of immunity due to a STAT6 gain-of-function mutation that gave rise to severe allergic dysregulation. Janus kinase inhibitor therapy could represent an effective targeted treatment for this disorder.

Cytokines and intestinal epithelial permeability: A systematic review

BACKGROUND

The intestinal mucosa is composed of a well-organized epithelium, acting as a physical barrier to harmful luminal contents, while simultaneously ensuring absorption of physiological nutrients and solutes. Increased intestinal permeability has been described in various chronic diseases, leading to abnormal activation of subepithelial immune cells and overproduction of inflammatory mediators. This review aimed to summarize and evaluate the effects of cytokines on intestinal permeability.

METHODS

A systematic review of the literature was performed in the Medline, Cochrane and Embase databases, up to 01/04/2022, to identify published studies assessing the direct effect of cytokines on intestinal permeability. We collected data on the study design, the method of assessment of intestinal permeability, the type of intervention and the subsequent effect on gut permeability.

RESULTS

A total of 120 publications were included, describing a total of 89 in vitro and 44 in vivo studies. TNFα, IFNγ or IL-1β were the most frequently studied cytokines, inducing an increase in intestinal permeability through a myosin light-chain-mediated mechanism. In situations associated with intestinal barrier disruption, such as inflammatory bowel diseases, in vivo studies showed that anti-TNFα treatment decreased intestinal permeability while achieving clinical recovery. In contrast to TNFα, IL-10 decreased permeability in conditions associated with intestinal hyperpermeability. For some cytokines (e.g. IL-17, IL-23), results are conflicting, with both an increase and a decrease in gut permeability reported, depending on the study model, methodology, or the studied conditions (e.g. burn injury, colitis, ischemia, sepsis).

CONCLUSION

This systematic review provides evidence that intestinal permeability can be directly influenced by cytokines in numerous conditions. The immune environment probably plays an important role, given the variability of their effect, according to different conditions. A better understanding of these mechanisms could open new therapeutic perspectives for disorders associated with gut barrier dysfunction.

Biologic therapies for chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a disorder characterized by a complicated chronic inflammatory response that is resistant to corticosteroid therapy. As a result, there is a critical need for effective anti-inflammatory medications to treat people with COPD. Using monoclonal antibodies (mAbs) to inhibit cytokines and chemokines or their receptors could be a potential approach to treating the inflammatory component of COPD.

AREAS COVERED

The therapeutic potential that some of these mAbs might have in COPD is reviewed.

EXPERT OPINION

No mAb directed against cytokines or chemokines has shown any therapeutic impact in COPD patients, apart from mAbs targeting the IL-5 pathway that appear to have statistically significant, albeit weak, effect in patients with eosinophilic COPD. This may reflect the complexity of COPD, in which no single cytokine or chemokine has a dominant role. Because the umbrella term COPD encompasses several endotypes with diverse underlying processes, mAbs targeting specific cytokines or chemokines should most likely be evaluated in limited and focused populations.

CD4 T-Cell Subsets and the Pathophysiology of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an umbrella term for the chronic immune-mediated idiopathic inflammation of the gastrointestinal tract, manifesting as Crohn's disease (CD) or ulcerative colitis (UC). IBD is characterized by exacerbated innate and adaptive immunity in the gut in association with microbiota dysbiosis and the disruption of the intestinal barrier, resulting in increased bacterial exposure. In response to signals from microorganisms and damaged tissue, innate immune cells produce inflammatory cytokines and factors that stimulate T and B cells of the adaptive immune system, and a prominent characteristic of IBD patients is the accumulation of inflammatory T-cells and their proinflammatory-associated cytokines in intestinal tissue. Upon antigen recognition and activation, CD4 T-cells differentiate towards a range of distinct phenotypes: T helper(h)1, Th2, Th9, Th17, Th22, T follicular helper (Tfh), and several types of T-regulatory cells (Treg). T-cells are generated according to and adapt to microenvironmental conditions and participate in a complex network of interactions among other immune cells that modulate the further progression of IBD. This review examines the role of the CD4 T-cells most relevant to IBD, highlighting how these cells adapt to the environment and interact with other cell populations to promote or inhibit the development of IBD.

Keratinocytes activated by IL-4/IL-13 express IL-2Rγ with consequences on epidermal barrier function

Atopic dermatitis (AD) is a Th2-type inflammatory disease characterized by an alteration of epidermal barrier following the release of IL-4 and IL-13. These cytokines activate type II IL-4Rα/IL-13Rα1 receptors in the keratinocyte. Whilst IL-2Rγ, that forms type I receptor for IL-4, is only expressed in haematopoietic cells, recent studies suggest its induction in keratinocytes, which questions about its role. We studied expression of IL-2Rγ in keratinocytes and its role in alteration of keratinocyte function and epidermal barrier. IL-2Rγ expression in keratinocytes was studied using both reconstructed human epidermis (RHE) exposed to IL-4/IL-13 and AD skin. IL-2Rγ induction by type II receptor has been analyzed using JAK inhibitors and RHE knockout (KO) for IL13RA1. IL-2Rγ function was investigated in RHE KO for IL2RG. In RHE, IL-4/IL-13 induce expression of IL-2Rγ at the mRNA and protein levels. Its mRNA expression is also visualized in keratinocytes of lesional AD skin. IL-2Rγ expression is low in RHE treated with JAK inhibitors and absent in RHE KO for IL13RA1. Exposure to IL-4/IL-13 alters epidermal barrier, but this alteration is absent in RHE KO for IL2RG. A more important induction of IL-13Rα2 is reported in RHE KO for IL2RG than in not edited RHE. These results demonstrate IL-2Rγ induction in keratinocytes through activation of type II receptor. IL-2Rγ is involved in the alteration of the epidermal barrier and in the regulation of IL-13Rα2 expression. Observation of IL-2Rγ expression by keratinocytes inside AD lesional skin suggests a role for this receptor subunit in the disease.