To characterize the functional epitope distribution of the Artemisia vulgaris allergen Art v 4 and to investigate its potential cross-reactive epitopes with the peach allergen Pru p 4.

Immunoinformatics approaches were used to predict B-cell and T-cell epitopes of Art v 4, followed by spatial localization analysis based on its three-dimensional structure. Potential shared cross-reactive epitopes between Art v 4 and Pru p 4 were screened by sequence alignment. Candidate peptides were synthesized, and their inhibitory effects on the binding of patients’ serum IgE to the natural allergen were evaluated by inhibitory Dot-Blot assay.

Multiple potential linear B-cell epitopes were identified in Art v 4, among which the 13-20 aa and 108-116 aa regions showed high overlap across different prediction algorithms. Among the predicted dominant CD4^＋ T-cell epitopes, the 101-115 aa region showed a high tendency for MHC II binding. Art v 4 and Pru p 4 exhibited high sequence homology in multiple regions, and some dominant T-cell epitopes were highly conserved. The 31-45 aa and 101-115 aa peptides significantly inhibited the binding of patients’ serum IgE to the natural allergen.

Art v 4 contains multiple candidate epitopes, and the regions 31-45 aa and 101-115 aa may represent cross-reactive epitope regions worthy of further investigation.