Recombinant allergen rBlo t 5 induces type 2 immune inflammation via Interleukin-10 and DDX58/IFIH1 Signaling pathways.

Blomia tropicalis is a clinically significant source of mite allergens, with Blo t 5 identified as a major component. This study aimed to produce recombinant Blo t 5 (rBlo t 5) and investigate its role in allergic immune responses. The rBlo t 5 protein (∼14 kDa) was successfully expressed in E. coli and purified with high purity. IgE-ELISA demonstrated specific IgE binding in 69% of serum samples from asthmatic children sensitized to B. tropicalis. Transcriptomic analysis of rBlo t 5-stimulated BEAS-2B bronchial epithelial cells revealed significant enrichment of genes associated with the interleukin-10 signaling and DDX58/IFIH1-mediated interferon-alpha/beta pathways. qPCR validation confirmed upregulation of key genes, including of CXCL1, CXCL2, CCL2, CCL5, IL1B, ICAM-1, RIG-I, IFIH1, IRF7, and ISG15. In a murine model of allergic airway inflammation, rBlo t 5 sensitization induced pronounced inflammatory cell infiltration, goblet cell hyperplasia, collagen deposition, and increased neutrophils in bronchoalveolar lavage fluid. Serum levels of allergen-specific IgE and IgG1 were elevated, accompanied by a Th2-skewed cytokine profile (increased IL-4 and IL-13, decreased IFN-γ and TGF-β). qPCR of lung tissues further confirmed upregulation of the same pathway-related genes.These findings indicate that rBlo t 5 elicits a type 2-polarized immune response initiated, in part, through the concurrent activation of the IL-10 and DDX58/IFIH1-interferon signaling axes in airway epithelium, providing new mechanistic insights into B. tropicalis-induced allergic inflammation.