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Updated: May 7, 2026
Identification and Characterization of Immunogenic RNA Species in HDM Allergens that Modulate Eosinophilic Lung Inflammation
Published on: May 30, 2020
Protease-activated receptor-2 deficient mice have reduced house dust mite-evoked allergic lung inflammation
J Daan de Boer1, Cornelis Van't Veer2, Ingrid Stroo3
1Academic Medical Center, University of Amsterdam, Center of Infection and Immunity Amsterdam & Center for Experimental and Molecular Medicine, Amsterdam, the Netherlands j.d.deboer@amc.uva.nl.
Abstract:
Protease-activated receptor-2 (PAR2) is abundantly expressed in the pulmonary compartment. House dust mite (HDM) is a common cause of allergic asthma and contains multiple PAR2 agonistic proteases. The aim of this study was to determine the role of PAR2 in HDM-induced allergic lung inflammation. For this, the extent of allergic lung inflammation was studied in wild type (Wt) and PAR2 knockout (KO) mice after repeated airway exposure to HDM. HDM exposure of Wt mice resulted in a profound influx of eosinophils in bronchoalveolar lavage fluid (BALF) and accumulation of eosinophils in lung tissue, which both were strongly reduced in PAR2 KO mice. PAR2 KO mice demonstrated attenuated lung pathology and protein leak in the bronchoalveolar space, accompanied by lower BALF levels of the anaphylatoxins C3a and C5a. This study reveals, for the first time, an important role for PAR2 in allergic lung inflammation induced by the clinically relevant allergens contained in HDM.
Insights
Protease-activated receptor-2 (PAR2) plays a key role in house dust mite-induced allergic lung inflammation. Blocking PAR2 significantly reduced eosinophil influx and lung pathology in asthma models.
Area of Science:
- Immunology
- Pulmonology
- Allergy Research
Background:
- Protease-activated receptor-2 (PAR2) is highly expressed in lung tissue.
- House dust mite (HDM) allergens contain proteases that activate PAR2.
- Allergic asthma is a significant respiratory condition often triggered by HDM.
Purpose of the Study:
- To investigate the role of PAR2 in the development of allergic lung inflammation caused by HDM.
- To compare the effects of HDM exposure on wild-type (Wt) and PAR2 knockout (KO) mice.
Main Methods:
- Repeated airway exposure to HDM in Wt and PAR2 KO mice.
- Analysis of eosinophil influx in bronchoalveolar lavage fluid (BALF) and lung tissue.
- Assessment of lung pathology, protein leak, and anaphylatoxin levels (C3a, C5a) in BALF.
Main Results:
- HDM exposure caused significant eosinophil influx and lung inflammation in Wt mice.
- PAR2 KO mice showed markedly reduced eosinophil infiltration and attenuated lung pathology.
- PAR2 deficiency led to decreased protein leak and lower levels of C3a and C5a in BALF.
Conclusions:
- PAR2 plays a critical role in mediating HDM-induced allergic lung inflammation.
- Targeting PAR2 may offer a therapeutic strategy for managing HDM-allergic asthma.
- This study provides novel insights into the mechanisms of allergic airway disease.
