Treatment with onion bulb extract both prevents and reverses allergic inflammation in a murine model of asthma.

CONTEXT: Asthma presents a global health challenge. The main pharmacotherapy is synthetic chemicals and biological-based drugs that are costly, and have significant side effects. In contrast, use of natural products, such as onion (Allium cepa L., Amaryllidaceae) in the treatment of airway diseases has increased world-wide because of their perceived efficacy and little safety concerns. However, their pharmacological actions remain largely uncharacterized. OBJECTIVE: We investigated whether onion bulb extract (OBE) can (1) reverse established asthma phenotype (therapeutic treatment) and/or (2) prevent the development of the asthma phenotype, if given before the immunization process (preventative treatment). MATERIALS AND METHODS: Six groups of male Balb/c mice were established for the therapeutic (21 days) and five groups for the preventative (19 days) treatment protocols; including PBS and house dust mite (HDM)-challenged mice treated with vehicle or OBE (30, 60, and 100 mg/kg/i.p.). Airways inflammation was determined using cytology, histology, immunofluorescence, Western blot, and serum IgE. RESULTS: Therapeutic (60 mg/kg/i.p.) and preventative (100 mg/kg/i.p.) OBE treatment resulted in down-regulation of HDM-induced airway cellular influx, histopathological changes and the increase in expression of pro-inflammatory signaling pathway EGFR, ERK1/2, AKT, pro-inflammatory cytokines and serum IgE. DISCUSSION AND CONCLUSION: Our data show that OBE is an effective anti-inflammatory agent with both therapeutic and preventative anti-asthma effects. These findings imply that onion/OBE may be used as an adjunct therapeutic agent in established asthma and/or to prevent development of allergic asthma. However, further studies to identify the active constituents, and demonstrate proof-of-concept in humans are needed.

Early-life house dust mite aeroallergen exposure augments cigarette smoke-induced myeloid inflammation and emphysema in mice.

BACKGROUND: Longitudinal studies have identified childhood asthma as a risk factor for obstructive pulmonary disease (COPD) and asthma-COPD overlap (ACO) where persistent airflow limitation can develop more aggressively. However, a causal link between childhood asthma and COPD/ACO remains to be established. Our study aimed to model the natural history of childhood asthma and COPD and to investigate the cellular/molecular mechanisms that drive disease progression. METHODS: Allergic airways disease was established in three-week-old young C57BL/6 mice using house dust mite (HDM) extract. Mice were subsequently exposed to cigarette smoke (CS) and HDM for 8 weeks. Airspace enlargement (emphysema) was measured by the mean linear intercept method. Flow cytometry was utilised to phenotype lung immune cells. Bulk RNA-sequencing was performed on lung tissue. Volatile organic compounds (VOCs) in bronchoalveolar lavage-fluid were analysed to screen for disease-specific biomarkers. RESULTS: Chronic CS exposure induced emphysema that was significantly augmented by HDM challenge. Increased emphysematous changes were associated with more abundant immune cell lung infiltration consisting of neutrophils, interstitial macrophages, eosinophils and lymphocytes. Transcriptomic analyses identified a gene signature where disease-specific changes induced by HDM or CS alone were conserved in the HDM-CS group, and further revealed an enrichment of Mmp12, Il33 and Il13, and gene expression consistent with greater expansion of alternatively activated macrophages. VOC analysis also identified four compounds increased by CS exposure that were paradoxically reduced in the HDM-CS group. CONCLUSIONS: Early-life allergic airways disease worsened emphysematous lung pathology in CS-exposed mice and markedly alters the lung transcriptome.

Construction by artificial intelligence and immunovalidation of hypoallergenic mite allergen Der f 36 vaccine.

Background: The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives. Method: The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined. Results: The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36. Conclusion: This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.

MiR-4454 in Combined Allergic Rhinitis and Asthma Syndrome (CARAS): Clinical significance and mechanistic insights into airway inflammation.

Abnormal expression of non-coding microRNA is associated with the development of combined allergic rhinitis and asthma syndrome (CARAS). However, the function of miR-4454 in CARAS is unknown. Our study aimed to reveal the clinical significance and related mechanism of miR-4454 in CARAS. Blood samples from 38 cases of CARAS and 43 cases of healthy subjects were collected to detect the expression of miR-4454. House dust mite (HDM) sensitization and challenge-induced bronchial epithelial cells to simulate the asthma state model in vitro, miR-4454 mimics and inhibitor transfection to detect the expression level of pro-inflammatory cytokines, cell survival rate and migration ability, flow cytometry and western blot (WB) Detection of cell cycle, apoptosis and inflammation-related protein levels. Compared with healthy controls, the expression of miR-4454 in the blood of CARAS patients was significantly up-regulated, and IL-6 and IL-8 were significantly up-regulated in the HDM treatment group, indicating that the model induction was successful. After overexpression of miR-4454, cell proliferation and migration in the HDM-treated group were significantly inhibited, and the levels of early apoptosis and inflammation-related proteins (IL-17, IL-17RD, TNF-α, GCSF and NF-κB) were increased High; after inhibiting miR-4454, cell proliferation and migration were significantly enhanced, and the levels of apoptosis and inflammation-related proteins were decreased. This study found that inhibiting the expression of miR-4454 can improve HDM-induced cell injury, which may be related to miR-4454 regulating the activation of IL-17/NF-кB inflammatory axis.

Novel monoclonal antibodies against house dust mite allergen Der p 21 and their application to analyze allergen extracts.

Background: Allergen extracts and recombinant allergens are used in allergy diagnostics and immunotherapy. Since allergen extracts from different manufacturers lack proper standardization regarding their composition, monoclonal antibodies (MAbs) against specific allergen components can be used for their identification and quantification in allergen extracts. This study aimed to generate MAbs against allergen Der p 21 of Dermatophagoides pteronyssinus for the analysis of allergen extracts. Methods: Recombinant Der p 21 was expressed in E. coli and purified using affinity chromatography. MAbs against Der p 21 were generated using hybridoma technology. House dust mite (HDM) allergen extracts were analyzed using the newly developed sandwich enzyme-linked immunosorbent assay, Western blotting and microarray immunoassay. Results: MAbs raised against recombinant Der p 21 were characterized in detail and proven to be reactive with natural Der p 21. Highly specific sandwich enzyme-linked immunosorbent assay for the quantification of Der p 21 was developed and optimized. The allergen was detected and its concentration was determined in only three of six analyzed HDM allergen extracts from different manufacturers. Conclusion: HDM analysis by MAb-based immunoassays shows their differences in allergen composition. The results demonstrate the importance of allergen-specific MAbs as a tool for the characterization of allergen extracts and the need for their appropriate standardization before their use for allergy diagnostics or immunotherapy.

Intermittent hypoxic pretreatment exacerbates house dust mite-induced asthma airway inflammation.

BACKGROUND: Asthma is widely recognized as an inflammatory disorder. In the context of this inflammatory microenvironment, the involvement of hypoxia and its impact on related pathways have drawn considerable attention. However, the exact role of hypoxia, a prevalent environmental factor, in the development and progression of asthma remains poorly understood. METHODS: Mice were treated with house dust mite (HDM) extracts for 23 days to induce asthma. Mice were divided into room air (RA) group and intermittent hypoxic (IH) group by exposing to different conditions and IH preconditioning (IHP) were underwent to the above groups before the hypoxic regimen. Airway inflammation in mice was evaluated by airway hyperresponsiveness, excessive mucus secretion, and recruitment of inflammatory cells. Immunohistochemistry was employed to quantify the expression levels of NF-κB. Subsequently, the dose of allergen was modified to investigate whether the impact of hypoxia on asthma is affected by different doses of allergens. RESULT: Compared to the RA and IH groups, HDM-treated mice in the IHP group exhibited aggravated inflammatory cell infiltration and airway hyperresponsiveness (p＜.05). Moreover, there was an increased release of inflammatory mediators and higher expression levels of NF-κB (p＜.05). Importantly, the impact ia on asthma was found to be influenced by high dose of allergen (p＜.05). CONCLUSION: IHP treatment potentially exacerbates HDM-induced airway inflammation in asthma, with the involvement of NF-κB, particularly under high-dose allergen stimulation.

Single-cell molecular signature of pathogenic T helper subsets in type 2-associated disorders in humans.

To unravel the heterogeneity and molecular signature of effector memory Th2 cells (Tem2), we analyzed 23 individuals' PBMCs of filaria-infected (Filaria+) and 24 healthy volunteers (Filaria-), with or without coincident house dust mite (HDM) allergic sensitization. Flow cytometry revealed 3 CD4+ Tem subsets - CCR4+CCR6+CRTH2- Tem17, CCR4+CCR6-CRTH2+ Tem2, and CCR6+CCR4+CRTH2+ Tem17.2 - markedly enriched in Filaria+ individuals. These subsets were sorted and analyzed by multiomic single-cell RNA immunoprofiling. SingleR-annotated Th2 cells from Tem2 and Tem17.2 cell subsets had features of pathogenic Th2 effector cells based on their transcriptional signatures, with downregulated CD27 and elevated expression levels of ITGA4, IL17RB, HPGDS, KLRB1, PTGDR2, IL9R, IL4, IL5, and IL13 genes. When the Filaria+ individuals were subdivided based on their allergic status, Tem2 cells in HDM+Filaria+ individuals showed an overall reduction in TCR diversity, suggesting the occurrence of antigen-driven clonal expansion. Moreover, HDM+Filaria+ individuals showed not only an expansion in the frequency of both Tem2 and Tem17.2 cell subsets, but also a change in their molecular program by overexpressing GATA3, IL17RB, CLRF2, and KLRB1, as well as increased antigen-induced IL-4, IL-5, and IL-13 production, suggesting that aeroallergens reshape the transcriptional and functional programming of Th2 cell subsets in human filarial infection toward a pathogenic immunophenotype.

The human MIF polymorphism CATT7 enhances pro-inflammatory macrophage polarization in a clinically relevant model of allergic airway inflammation.

High level expression of the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF) has been associated with severe asthma. The role of MIF and its functional promotor polymorphism in innate immune training is currently unknown. Using novel humanized CATT7 MIF mice, this study is the first to investigate the effect of MIF on bone marrow-derived macrophage (BMDM) memory after house dust mite (HDM) challenge. CATT7 BMDMs demonstrated a significant primed increase in M1 markers following HDM and LPS stimulation, compared to naive mice. This M1 signature was found to be MIF-dependent, as administration of a small molecule MIF inhibitor, SCD-19, blocked the induction of this pro-inflammatory M1-like phenotype in BMDMs from CATT7 mice challenged with HDM. Training naive BMDMs in vitro with HDM for 24 h followed by a rest period and subsequent stimulation with LPS led to significantly increased production of the pro-inflammatory cytokine TNFα in BMDMs from CATT7 mice but not WT mice. Addition of the pan methyltransferase inhibitor MTA before HDM training significantly abrogated this effect in BMDMs from CATT7 mice, suggesting that HDM-induced training is associated with epigenetic remodelling. These findings suggest that trained immunity induced by HDM is under genetic control, playing an important role in asthma patients with the high MIF genotypes (CATT6/7/8).

Dark under the Lamp: Neglected Biological Pollutants in the Environment Are Closely Linked to Lung Cancer.

Environmental pollutants are closely linked to lung cancer. The different types of environmental pollutants can be classified as chemical, physical, and biological. The roles of common chemical and physical pollutants such as PM2.5, smoking, radon, asbestos, and formaldehyde in lung cancer have been extensively studied. Notably, the worldwide COVID-19 pandemic raised awareness of the strong link between biological pollution and human health. Allergens such as house dust mites and pollen, as well as bacteria and viruses, are common biological pollutants. A few biological pollutants have been reported to promote lung cancer via inducing inflammatory cytokines secretion, such as IL-1ß, IL-6, and TGF-ß, as well as suppressing immunosurveillance by upregulating regulatory T (Treg) cells while dampening the function of CD8+ T cells and dendritic cells. However, the correlation between common biological hazards, such as SARS-CoV-2, human immunodeficiency viruses, Helicobacter pylori, and house dust mites, and lung cancer is not fully elucidated, and the underlying mechanisms are still unclear. Moreover, the majority of studies that have been performed in lung cancer and biological carcinogens were not based on the perspective of biological pollutants, which has challenged the systematicity and coherence in the field of biological pollutants in lung cancer. Here, in addition to reviewing the recent progress made in investigating the roles of allergens, viruses, and bacteria in lung cancer, we summarized the potential mechanisms underlying biological pollutants in lung cancer. Our narrative review can shed light on understanding the significance of biological pollutants in lung cancer, as well as inspire and broaden research ideas on lung cancer etiology.

[Angele experiment: innovative care paths for allergy sufferers]. / Expérimentation Angele : des parcours de soins innovants pour les patients allergiques.

The Angele project (for Allergies complexes: prise en charge globale, diététique et environnementale) is an article 51 experiment in shared care pathways in allergology. These care paths, dedicated to patients with allergies to house dust mites and/or food, involve collaboration between doctors and paramedics. The aim of this initiative is to optimize patient care by structuring their care pathways. This article presents these pathways and the preliminary results of the experiment.

Up-regulation of HSP90α in HDM-induced asthma causes pyroptosis of airway epithelial cells by activating the cGAS-STING-ER stress pathway.

Heat Shock protein 90 α (HSP90α), an main subtype of chaperone protein HSP90, involves important biological functions such as DNA damage repair, protein modification, innate immunity. However, the potential role of HSP90α in asthma occurrence and development is still unclear. This study aimed to elucidate the underlying mechanism of HSP90α in asthma by focusing on the cGAS-STING-Endoplasmic Reticulum stress pathway in inflammatory airway epithelial cell death (i.e., pyroptosis; inflammatory cell death). To accomplish that, we modeled allergen exposure in C57/6BL mice and bronchial epithelial cells with house dust mite. Protein technologies and immunofluorescence utilized to study the expression of HSP90α, activation of cGAS-STING pathway and pyroptosis. The effect of inhibitors on HDM-exposed mice detected by histological techniques and examination of bronchoalveolar lavage fluid. Results showed that HSP90α promotes asthma inflammation via pyroptosis and activation of the cGAS-STING-ER stress pathway. Treatment with the HSP90 inhibitor tanespimycin (17-AAG) significantly relieved airway inflammation and abrogated the effect of HSP90α on pyroptosis and cGAS-STING-ER stress in vitro and in vivo models of HDM. Further data indicated that up-regulation of HSP90α stabilized STING through interaction, which increased localization of STING on the ER. Activation of STING triggered ER stress and leaded to pyroptosis-related airway inflammation. The finding showed the potential role of pyroptosis caused by dysregulation of HSP90α on airway epithelial cells in allergic inflammation, suggested that targeting HSP90α in airway epithelial cells might prove to be a potential additional treatment strategy for asthma.

House dust mite SCIT reduces asthma risk and significantly improves long-term rhinitis and asthma control-A RWE study.

BACKGROUND: The German Therapy Allergen Ordinance (TAO) triggered an ongoing upheaval in the market for house dust mite (HDM) allergen immunotherapy (AIT) products. Three HDM subcutaneous AIT (SCIT) products hold approval in Germany and therefore will be available after the scheduled completion of the TAO procedure in 2026. In general, data from clinical trials on the long-term effectiveness of HDM AIT are rare. We evaluated real-world data (RWD) in a retrospective, observational cohort study based on a longitudinal claims database including 60% of all German statutory healthcare prescriptions to show the long-term effectiveness of one of these products in daily life. Aim of this analysis was to provide a per product analysis on effectiveness of mite AIT as it is demanded by international guidelines on AIT. METHODS: Subjects between 5 and 70 years receiving their first (index) prescription of SCIT with a native HDM product (SCIT group) between 2009 and 2013 were included. The exactly 3:1 matched control group received prescriptions for only symptomatic AR medication (non-AIT group); the evaluation period for up to 6 years of follow-up ended in February 2017. Study endpoints were the progression of allergic rhinitis (AR) and asthma, asthma occurrence and time to the onset of asthma after at least 2 treatment years. RESULTS: In total, 892 subjects (608 adults and 284 children/adolescents) were included in the SCIT group and 2676 subjects (1824 adults and 852 children/adolescents) in the non-AIT group. During the follow-up period after at least 2 years of SCIT, the number of prescriptions in the SCIT group was reduced by 62.8% (p < .0001) for AR medication and by 42.4% for asthma medication (p = .0003). New-onset asthma risk was significantly reduced in the SCIT vs non-AIT group by 27.0% (p = .0212). The asthma-preventive effect of SCIT occurred 15 months after start of the treatment. In the SCIT group, the time to onset of asthma was prolonged compared to the non-AIT group (p = .0010). CONCLUSION: In this first product based RWD analysis on SCIT with a native HDM product, patients aged 5 to 70 years benefited from AIT in the long term in terms of reduced progression of AR and asthma after at least 2 years of treatment. The effects seemed to last for up to 6 years after treatment termination. A significantly reduced risk of asthma onset was observed, starting after 15 months of treatment.

Mast cell activation disrupts interactions between endothelial cells and pericytes during early life allergic asthma.

Allergic asthma generally starts during early life and is linked to substantial tissue remodeling and lung dysfunction. Although angiogenesis is a feature of the disrupted airway, the impact of allergic asthma on the pulmonary microcirculation during early life is unknown. Here, using quantitative imaging in precision-cut lung slices (PCLSs), we report that exposure of neonatal mice to house dust mite (HDM) extract disrupts endothelial cell/pericyte interactions in adventitial areas. Central to the blood vessel structure, the loss of pericyte coverage was driven by mast cell (MC) proteases, such as tryptase, that can induce pericyte retraction and loss of the critical adhesion molecule N-cadherin. Furthermore, spatial transcriptomics of pediatric asthmatic endobronchial biopsies suggests intense vascular stress and remodeling linked with increased expression of MC activation pathways in regions enriched in blood vessels. These data provide previously unappreciated insights into the pathophysiology of allergic asthma with potential long-term vascular defects.

COBRAPed cohort: Do sensitization patterns differentiate children with severe asthma from those with a milder disease?

BACKGROUND: It is unclear whether sensitization patterns differentiate children with severe recurrent wheeze (SRW)/severe asthma (SA) from those with non-severe recurrent wheeze (NSRW)/non-severe asthma (NSA). Our objective was to determine whether sensitization patterns can discriminate between children from the French COBRAPed cohort with NSRW/NSA and those with SRW/SA. METHODS: IgE to 112 components (c-sIgE) (ImmunoCAP® ISAC) were analyzed in 125 preschools (3-6 years) and 170 school-age children (7-12 years). Supervised analyses and clustering methods were applied to identify patterns of sensitization among children with positive c-sIgE. RESULTS: We observed c-sIgE sensitization in 51% of preschool and 75% of school-age children. Sensitization to house dust mite (HDM) components was more frequent among NSRW than SRW (53% vs. 24%, p < .01). Sensitization to non-specific lipid transfer protein (nsLTP) components was more frequent among SA than NSA (16% vs. 4%, p < .01) and associated with an FEV1/FVC < -1.64 z-score. Among sensitized children, seven clusters with varying patterns were identified. The two broader clusters identified in each age group were characterized by "few sensitizations, mainly to HDM." One cluster (n = 4) with "multiple sensitizations, mainly to grass pollen, HDM, PR-10, and nsLTP" was associated with SA in school-age children. CONCLUSIONS: Although children with wheeze/asthma display frequent occurrences and high levels of sensitization, sensitization patterns did not provide strong signals to discriminate children with severe disease from those with milder disease. These results suggest that the severity of wheeze/asthma may depend on both IgE- and non-IgE-mediated mechanisms.

Dectin-1 aggravates neutrophil inflammation through caspase-11/4-mediated macrophage pyroptosis in asthma.

BACKGROUND: The pattern recognition receptor Dectin-1 was initially discovered to play a pivotal role in mediating pulmonary antifungal immunity and promoting neutrophil-driven inflammation. Recent studies have revealed that Dectin-1 is overexpressed in asthma, but the specific mechanism remains elusive. Additionally, Dectin-1 has been implicated in promoting pyroptosis, a hallmark of severe asthma airway inflammation. Nevertheless, the involvement of the non-classical pyroptosis signal caspase-11/4 and its upstream regulatory mechanisms in asthma has not been completely explored. METHODS: House dust mite (HDM)-induced mice was treated with Dectin-1 agonist Curdlan, Dectin-1 inhibitor Laminarin, and caspase-11 inhibitor wedelolactone separately. Subsequently, inflammatory cells in bronchoalveolar lavage fluid (BALF) were analyzed. Western blotting was performed to measure the protein expression of caspase-11 and gasdermin D (GSDMD). Cell pyroptosis and the expression of chemokine were detected in vitro. The correlation between Dectin-1 expression, pyroptosis factors and neutrophils in the induced sputum of asthma patients was analyzed. RESULTS: Curdlan appeared to exacerbate neutrophil airway inflammation in asthmatic mice, whereas wedelolactone effectively alleviated airway inflammation aggravated by Curdlan. Moreover, Curdlan enhanced the release of caspase-11 activation fragments and N-terminal fragments of gasdermin D (GSDMD-N) stimulated by HDM both in vivo or in vitro. In mouse alveolar macrophages (MH-S cells), Curdlan/HDM stimulation resulted in vacuolar degeneration and elevated lactate dehydrogenase (LDH) release. In addition, there was an upregulation of neutrophil chemokines CXCL1, CXCL3, CXCL5 and their receptor CXCR2, which was suppressed by wedelolactone. In asthma patients, a positive correlation was observed between the expression of Dectin-1 on macrophages and caspase-4 (the human homology of caspase-11), and the proportion of neutrophils in induced sputum. CONCLUSION: Dectin-1 activation in asthma induced caspase-11/4 mediated macrophage pyroptosis, which subsequently stimulated the secretion of chemokines, leading to the exacerbation of airway neutrophil inflammation.

House dust mite allergens induce Ca2+ signalling and alarmin responses in asthma airway epithelial cells.

Type 2 inflammation in asthma develops with exposure to stimuli to include inhaled allergens from house dust mites (HDM). Features include mucus hypersecretion and the formation of pro-secretory ion transport characterised by elevated basal Cl- current. Studies using human sinonasal epithelial cells treated with HDM extract report a higher protease activated receptor-2 (PAR-2) agonist-induced calcium mobilisation that may be related to airway sensitisation by allergen-associated proteases. Herein, this study aimed to investigate the effect of HDM on Ca2+ signalling and inflammatory responses in asthmatic airway epithelial cells. Primary bronchial epithelial cells (hPBECs) from asthma donors cultured at air-liquid interface were used to assess electrophysiological, Ca2+ signalling and inflammatory responses. Differences were observed regarding Ca2+ signalling in response to PAR-2 agonist 2-Furoyl-LIGRLO-amide (2-FLI), and equivalent short-circuit current (Ieq) in response to trypsin and 2-FLI, in ALI-asthma and healthy hPBECs. HDM treatment led to increased levels of intracellular cations (Ca2+, Na+) and significantly reduced the 2-FLI-induced change of Ieq in asthma cells. Apical HDM-induced Ca2+ mobilisation was found to mainly involve the activation of PAR-2 and PAR-4-associated store-operated Ca2+ influx and TRPV1. In contrast, PAR-2, PAR-4 antagonists and TRPV1 antagonist only showed slight impact on basolateral HDM-induced Ca2+ mobilisation. HDM trypsin-like serine proteases were the main components leading to non-amiloride sensitive Ieq and also increased interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) from asthma hPBECs. These studies add further insight into the complex mechanisms associated with HDM-induced alterations in cell signalling and their relevance to pathological changes within asthma.

Food-specific IgG4-guided diet elimination improves allergy symptoms in children.

Allergic diseases in children are major public health concerns due to their widespread and rising prevalence. Food-specific immunoglobulin G4(FS-IgG4) has been detected in patients with allergic diseases, but its clinical significance is still debated. In the present study, 407 children with allergic diseases were recruited and categorized into three groups according to the different systems involved: the respiratory system group, the skin system group, and a multiple system group, with the collection of clinical symptoms and serum antibodies, including total immunoglobulin E (IgE), house dust mite (HDM) IgE, food-specific IgE (FS-IgE), and FS-IgG4. Part of these patients were followed up with the intervention of FS-IgG4-guided diet elimination with or without add-on probiotics supplement. The analysis at baseline revealed distinct serum levels of different antibodies. The positive rate of FS-IgG4 in all groups was more than 80%, and the proportion of total IgE and FS-IgG4 both positive in the multi-system group was the highest (p=0.039). Egg and milk were the foods with the highest positive rate of FS-IgG4 in all groups. After diet elimination for more than 3 months, serum FS-IgG4 in children significantly decreased (P<0.05) along with the improvement of clinical symptoms, regardless of the add-on of probiotics. However, the intervention did not impact the serum levels of total IgE, FS-IgE, and HDM IgE. There was no further decrease of serum FS-IgG4 level in children followed up for more than 1 year, which may be related to noncompliance with diet elimination. Multivariate regression analysis revealed that the decline of serum FS-IgG4 was an independent predictable factor for the improvement of clinical symptoms (adjusted OR:1.412,95%CI 1.017-1.96, p=0.039). The add-on of probiotics showed less efficiency in reducing the FS-IgG4 level in more patients with relief of clinical symptoms. Our results confirmed the correlation between FS-IgG4 and allergic diseases, and the decreased FS-IgG4 could be a useful predictor for the improvement of allergic symptoms. FS-IgG4-guided diet elimination is an efficient treatment for allergic diseases. Our study adds solid data to the clinical significance of FS-IgG4 in allergic diseases.

Single-cell analysis reveals alterations in cellular composition and cell-cell communication associated with airway inflammation and remodeling in asthma.

BACKGROUND: Asthma is a heterogeneous disease characterized by airway inflammation and remodeling, whose pathogenetic complexity was associated with abnormal responses of various cell types in the lung. The specific interactions between immune and stromal cells, crucial for asthma pathogenesis, remain unclear. This study aims to determine the key cell types and their pathological mechanisms in asthma through single-cell RNA sequencing (scRNA-seq). METHODS: A 16-week mouse model of house dust mite (HDM) induced asthma (n = 3) and controls (n = 3) were profiled with scRNA-seq. The cellular composition and gene expression profiles were assessed by bioinformatic analyses, including cell enrichment analysis, trajectory analysis, and Gene Set Enrichment Analysis. Cell-cell communication analysis was employed to investigate the ligand-receptor interactions. RESULTS: The asthma model results in airway inflammation coupled with airway remodeling and hyperresponsiveness. Single-cell analysis revealed notable changes in cell compositions and heterogeneities associated with airway inflammation and remodeling. GdT17 cells were identified to be a primary cellular source of IL-17, related to inflammatory exacerbation, while a subpopulation of alveolar macrophages exhibited numerous significantly up-regulated genes involved in multiple pathways related to neutrophil activities in asthma. A distinct fibroblast subpopulation, marked by elevated expression levels of numerous contractile genes and their regulators, was observed in increased airway smooth muscle layer by immunofluorescence analysis. Asthmatic stromal-immune cell communication significantly strengthened, particularly involving GdT17 cells, and macrophages interacting with fibroblasts. CXCL12/CXCR4 signaling was remarkedly up-regulated in asthma, predominantly bridging the interaction between fibroblasts and immune cell populations. Fibroblasts and macrophages could jointly interact with various immune cell subpopulations via the CCL8/CCR2 signaling. In particular, fibroblast-macrophage cell circuits played a crucial role in the development of airway inflammation and remodeling through IL1B paracrine signaling. CONCLUSIONS: Our study established a mouse model of asthma that recapitulated key pathological features of asthma. ScRNA-seq analysis revealed the cellular landscape, highlighting key pathological cell populations associated with asthma pathogenesis. Cell-cell communication analysis identified the crucial ligand-receptor interactions contributing to airway inflammation and remodeling. Our findings emphasized the significance of cell-cell communication in bridging the possible causality between airway inflammation and remodeling, providing valuable hints for therapeutic strategies for asthma.

Anti-CD20 treatment attenuates Th2 cell responses: implications for the role of lung follicular mature B cells in the asthmatic mice.

BACKGROUND: B cells were believed to act as antigen-presenting cells (APCs) to promote T helper type 2 (Th2) cell responses. However, the role of lung B cells and its subpopulations in Th2 cell responses in asthma remains unclear. OBJECTIVE: We leveraged an anti-CD20 monoclonal antibody (mAb) treatment that has been shown to selectively deplete B cells in mice and investigated whether this treatment modulates Th2 cell responses and this modulation is related to lung follicular mature (FM) B cells in a murine model of asthma. METHODS AND RESULTS: We used a house dust mite (HDM)-induced asthma mouse model and found that anti-CD20 mAb treatment attenuates Th2 cell responses. Meanwhile, anti-CD20 mAb treatment did dramatically reduce the number of B cells, especially FM B cells in the lungs, but did not impact the frequency of other immune cell types, including lung T cells, dendritic cells, natural killer cells, and regulatory T cells in wild-type mice. Moreover, we found that the suppressive effect of anti-CD20 mAb treatment on Th2 cell responses could be reversed upon adoptive transfer of lung FM B cells, but not lung CD19+ B cells without FM B cells in asthmatic mice. CONCLUSIONS: These findings reveal that anti-CD20 mAb treatment alleviates Th2 cell responses, possibly by depleting lung FM B cells in a Th2-driven asthma model. This implies a potential therapeutic approach for asthma treatment through the targeting of lung FM B cells.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress.

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.