title: Dectin-2 recognition of house dust mite triggers cysteinyl leukotriene generation by dendritic cells.
abstract: House dust mites are a significant source of airborne allergen worldwide, but there is little understanding of how they so potently generate allergic inflammation. We found that extracts from the house dust mites Dermatophagoides farinae (Df) and Dermatophagoides pteronyssinus and from the mold Aspergillus fumigatus stimulated a rapid and robust production of cysteinyl leukotrienes (cys-LTs), proinflammatory lipid mediators, from mouse bone marrow-derived dendritic cells (BMDCs). Con A affinity chromatography of the Df extract revealed that the relevant ligand is a glycan(s), suggesting stimulation via a dendritic cell (DC) lectin receptor. Cys-LT production in BMDCs from wild-type mice was inhibited by spleen tyrosine kinase (Syk) inhibitors and was abolished in BMDCs from FcRgamma-/- mice, implicating either Dectin-2 or DC immunoactivating receptor. Transfection of each receptor in bone marrow-derived mast cells revealed that only Dectin-2 mediates cys-LT production by Df, Dermatophagoides pteronyssinus, and Aspergillus fumigatus. Lentiviral knockdown of Dectin-2 in BMDCs attenuated Df extract-elicited cys-LT generation, thereby identifying Dectin-2 as the receptor. Lung CD11c+ cells, but not peritoneal or alveolar macrophages, also generated cys-LTs in response to Df. These findings place Dectin-2 among the C-type lectin receptors that activate arachidonic acid metabolism and identify the Dectin-2/FcRgamma/Syk/cys-LT axis as a novel mechanism by which three potent indoor allergens may activate innate immune cells to promote allergic inflammation.
authors.affiliation: Department of Medicine, Harvard Medical School, and Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: Nora A
authors.initials: NA
authors.lastname: Barrett
authors.forename: Akiko
authors.initials: A
authors.lastname: Maekawa
authors.forename: Opu M
authors.initials: OM
authors.lastname: Rahman
authors.forename: K Frank
authors.initials: KF
authors.lastname: Austen
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kanaoka
mesh_terms: D000485:Allergens / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology; D000946:Antigens, Fungal / Q000276:immunology / Q000378:metabolism; D001232:Aspergillus fumigatus / Q000276:immunology* / Q000378:metabolism; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D039521:CD11c Antigen / Q000096:biosynthesis; D002478:Cells, Cultured; D003545:Cysteine / Q000096:biosynthesis*; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology / Q000469:parasitology; D040001:Dermatophagoides farinae / Q000276:immunology* / Q000378:metabolism; D040002:Dermatophagoides pteronyssinus / Q000276:immunology* / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism* / Q000502:physiology; D015289:Leukotrienes / Q000096:biosynthesis*; D008168:Lung / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015398:Signal Transduction / Q000276:immunology
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D000946:Antigens, Fungal; D039521:CD11c Antigen; D037181:Lectins, C-Type; D015289:Leukotrienes; C112381:cysteinyl-leukotriene; C445340:dectin-2, mouse; D003545:Cysteine