{"title":"House dust mite allergen directly activates ILC2 cells via the TLR4 signaling pathway in allergic airway diseases","authors":"","doi":"10.1016/j.cellimm.2024.104884","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Unlike T cells and B cells, the activation process of group 2 innate lymphoid cells (ILC2s) is mainly driven by epithelial cell derived cytokines rather than specific antigen recognition. Whether antigens have a direct role in activating ILC2s remains poorly understood.</div></div><div><h3>Methods</h3><div>Following stimulation, type 2 cytokine secretions and cell death were assessed in house dust mite (HDM)-stimulated ILC2s. To investigate the underlying mechanisms, RNA-sequencing (RNA-seq) was performed on HDM-stimulated ILC2s. The validation experiments were done through <em>in vitro</em> stimulation assays and an HDM-induced asthmatic murine model, using specific inhibitors targeting receptor and relevant proteins of signaling pathways.</div></div><div><h3>Results</h3><div>HDM stimulation increased the secretion of IL-5 and IL-13 cytokines from ILC2s, inhibited apoptosis of ILC2, and promoted the proliferation of ILC2s. As confirmed by RNA-seq, HDM stimulation upregulated genes in ILC2s, including those responsible for type 2 cytokines, ILC2s-specific transcriptional factors, and related receptors. Both toll-like receptor (TLR) 1 and TLR4 were constitutively expressed on ILC2s, however, only TLR4 was predominantly upregulated upon HDM stimulation. TAK242, a specific TLR4 inhibitor, significantly blocked the effect of HDM on ILC2s, in terms of type 2 cytokine secretions and cell death. Using specific inhibitors in pathways, we confirmed that HDM promoted ILC2s activation via TLR4-ERK, p38, and NF-κB signaling pathways.</div></div><div><h3>Conclusions</h3><div>Allergen HDM directly activates ILC2s through TLR4 mediated-ERK/p38/NF-κB signaling pathway. These findings provide new insights into how antigens propagate type 2 immune response via ILC2s, contributing to chronic inflammations in allergic airway diseases.</div></div>","PeriodicalId":9795,"journal":{"name":"Cellular immunology","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cellular immunology","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S000887492400087X","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Unlike T cells and B cells, the activation process of group 2 innate lymphoid cells (ILC2s) is mainly driven by epithelial cell derived cytokines rather than specific antigen recognition. Whether antigens have a direct role in activating ILC2s remains poorly understood.
Methods
Following stimulation, type 2 cytokine secretions and cell death were assessed in house dust mite (HDM)-stimulated ILC2s. To investigate the underlying mechanisms, RNA-sequencing (RNA-seq) was performed on HDM-stimulated ILC2s. The validation experiments were done through in vitro stimulation assays and an HDM-induced asthmatic murine model, using specific inhibitors targeting receptor and relevant proteins of signaling pathways.
Results
HDM stimulation increased the secretion of IL-5 and IL-13 cytokines from ILC2s, inhibited apoptosis of ILC2, and promoted the proliferation of ILC2s. As confirmed by RNA-seq, HDM stimulation upregulated genes in ILC2s, including those responsible for type 2 cytokines, ILC2s-specific transcriptional factors, and related receptors. Both toll-like receptor (TLR) 1 and TLR4 were constitutively expressed on ILC2s, however, only TLR4 was predominantly upregulated upon HDM stimulation. TAK242, a specific TLR4 inhibitor, significantly blocked the effect of HDM on ILC2s, in terms of type 2 cytokine secretions and cell death. Using specific inhibitors in pathways, we confirmed that HDM promoted ILC2s activation via TLR4-ERK, p38, and NF-κB signaling pathways.
Conclusions
Allergen HDM directly activates ILC2s through TLR4 mediated-ERK/p38/NF-κB signaling pathway. These findings provide new insights into how antigens propagate type 2 immune response via ILC2s, contributing to chronic inflammations in allergic airway diseases.
期刊介绍:
Cellular Immunology publishes original investigations concerned with the immunological activities of cells in experimental or clinical situations. The scope of the journal encompasses the broad area of in vitro and in vivo studies of cellular immune responses. Purely clinical descriptive studies are not considered.
Research Areas include:
• Antigen receptor sites
• Autoimmunity
• Delayed-type hypersensitivity or cellular immunity
• Immunologic deficiency states and their reconstitution
• Immunologic surveillance and tumor immunity
• Immunomodulation
• Immunotherapy
• Lymphokines and cytokines
• Nonantibody immunity
• Parasite immunology
• Resistance to intracellular microbial and viral infection
• Thymus and lymphocyte immunobiology
• Transplantation immunology
• Tumor immunity.