Dust mite-derived Der f 3 activates a pro-inflammatory program in airway epithelial cells via PAR-1 and PAR-2

• Published in: Molecular immunology Vol. 109; pp. 1 - 11
• Main Authors: Li, Bizhou, Zou, Zehong, Meng, Fanmei, Raz, Eyal, Huang, Yuye, Tao, Ailin, Ai, Yuncan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2019
• Subjects: A549 Cells; Airway epithelial cell; allergens; Allergens - immunology; Allergens - pharmacology; Animals; Arthropod Proteins - immunology; Arthropod Proteins - pharmacology; calcium signaling; Calcium Signaling - drug effects; Calcium Signaling - genetics; Calcium Signaling - immunology; Cytokines - genetics; Cytokines - immunology; Der f 3; Dermatophagoides farinae; dust; dust mites; enzyme activity; enzyme-linked immunosorbent assay; epithelial cells; Epithelial Cells - immunology; Epithelial Cells - pathology; epithelium; Extracellular Signal-Regulated MAP Kinases - genetics; Extracellular Signal-Regulated MAP Kinases - immunology; Gene Expression Regulation - drug effects; Gene Expression Regulation - immunology; Gene Knockdown Techniques; gene silencing; genes; granulocyte-macrophage colony-stimulating factor; House dust mite (HDM); human cell lines; Humans; Inflammation; Inflammation - chemically induced; Inflammation - genetics; Inflammation - immunology; Inflammation - pathology; Inflammation Mediators - immunology; interleukin-6; interleukin-8; MAP Kinase Signaling System - drug effects; MAP Kinase Signaling System - genetics; MAP Kinase Signaling System - immunology; mitogen-activated protein kinase; NF-kappa B - genetics; NF-kappa B - immunology; pathogenesis; Protease; Protease-activated receptor (PAR); Pyroglyphidae - immunology; quantitative polymerase chain reaction; Receptor, PAR-1 - genetics; Receptor, PAR-1 - immunology; Receptor, PAR-2 - genetics; Receptor, PAR-2 - immunology; Respiratory Mucosa - immunology; reverse transcriptase polymerase chain reaction; sequence analysis; Serine Endopeptidases - immunology; Serine Endopeptidases - pharmacology; serine proteinases; small interfering RNA; Th17 Cells - immunology; Th17 Cells - pathology; Th2 Cells - immunology; Th2 Cells - pathology; transcription factor NF-kappa B; Airway epithelial cell; House dust mite (HDM); Inflammation; Protease-activated receptor (PAR); Protease; Der f 3
• ISSN: 0161-5890; 1872-9142; 1872-9142
• DOI: 10.1016/j.molimm.2019.02.018

•Der f 3 disrupts the airway epithelial barrier and induces a proinflammatory response in airway epithelial cells (AECs).•Der f 3 activates signaling pathways including NF-kB, MAP kinases, and calcium signaling in AECs via its protease activity.•Der f 3 activates the above signaling cascades via protease-activated receptors 1 and 2. Protease activity of allergens has been suggested to be involved in the pathogenesis of allergic diseases. The major allergen Der f 3 from Dermatophagoides farinae harbors serine protease activity, but its immunopathogenesis remains unclear. This study aims to explore the effect of Der f 3 on the airway epithelial barrier and on the molecular pathways by which Der f 3 induces inflammation. RNA-seq was performed to identify differentially expressed genes in bronchial airway epithelial cells (AEC) between native Der f 3 and heat-inactivated (H) Der f 3, coupled with real-time PCR (RT-PCR) and ELISA for validation. Unlike other protease allergens such as that induce Th2-promoting alarmins (IL-25, IL-33, TSLP) in AECs, Der f 3 induced pro-inflammatory cytokines and chemokines including IL-6, IL-8 and GM-CSF, which are known to promote Th17 response. These pro-inflammatory mediators were induced by Der f 3 via the MAPK and NF-κB pathways as well as the store-operated calcium signaling. Gene silencing with small interfering RNA in A549 and BEAS-2B cells indicated that activation of AECs by Der f 3 was mainly dependent on protease-activated receptor 2 (PAR-2), while PAR-1 was also required for the full activation of AECs. Double knock-down of PAR-1 and PAR-2 largely impaired Der f 3-inducecd IL-8 production and subsequent signaling pathways. Our data suggest that Der f 3 induces pro-inflammatory mediators in human epithelial cell lines via the PARs-MAPK-NF-κB axis. Our results provide a molecular mechanism by which Der f 3 may trigger the Th17-skewed allergic response toward house dust mites.