Abstract
BACKGROUND: House dust mites (HDMs) produce major inhaled allergens that trigger allergic diseases worldwide. The identities of the full spectrum of HDM allergenic components are not yet known. We aimed to develop a new gelsolin interactome-analysis (GIA) method for discovering and identifying novel allergens. METHODS: Gelsolin-binding proteins (GBPs) in Dermatophagoides farinae extracts were analyzed with gelsolin-affinity resin and LC-MS/MS (liquid chromatography coupled to tandem mass spectrometry) analyses. Recombinant proteins generated from cDNAs encoding candidate allergens were expressed in a prokaryotic system. IgE binding was evaluated by ELISA (enzyme-linked immunosorbent assay), western blotting, and dot-blotting. RESULTS: A total of 14 GBPs were assayed, including 10 known allergens and 4 candidates. Three candidates bound recombinant gelsolin, and they were named Der f 42, Der f 43, and Der f 44 by the WHO/IUIS Allergen Nomenclature Sub-committee. IgE-binding assays showed that Der f 42, Der f 43, and Der f 44 had IgE-binding rates of 7.2% (9/125), 8.5% (12/143), and 6.7% (6/90), respectively. CONCLUSION: GIA revealed 3 novel HDM proteins in this study and represents a new strategy for discovering and studying allergens.