A Recombinant Der p 38 Mutant Protein as a Candidate for Allergen Immunotherapy in Mixed Granulocytic Asthma

Objectives: Asthma is a chronic allergic disorder often associated with sensitization to house dust mites (HDM).Der p 38, a key HDM allergen, elicits both eosinophilic and neutrophilic airway inflammation, thereby contributing to heterogeneous asthma endotypes.This study aimed to evaluate a recombinant Der p 38 mutant protein as a potential candidate for allergen immunotherapy (AIT).Methods: A recombinant Der p 38 mutant protein, D141Y, was generated using molecular biology techniques.Its immunological properties were assessed in vitro by biolayer interferometry, flow cytometry, and enzyme-linked immunosorbent assay.In vivo, the effects of D141Y were compared with those of wild-type (WT) Der p 38 in a murine model of mixed granulocytic asthma.Results: D141Y retained toll-like receptor 4-binding activity but did not affect neutrophil or eosinophil apoptosis.Moreover, D141Y exerted little to no effect on interleukin (IL)-6, IL-8, or monocyte chemoattractant protein-1 release from human lung epithelial BEAS-2B cells and attenuated the cytokine induction elicited by WT.In mice, D141Y induced significantly weaker airway inflammation and asthmatic responses compared to WT.Moreover, co-administration of WT with D141Y mitigated the mixed granulocytic features elicited by WT alone. Conclusion:The Der p 38 mutant protein D141Y exhibited reduced allergenic activity.These findings highlight the potential of Der p 38-based mutants as novel candidates for AIT across diverse asthma endotypes.