Antigenic epitopes and cross-reactivity analysis of tropomyosin from Oratosquilla oratorio†

Abstract

Tropomyosin (TM) has been determined as the major allergen in Oratosquilla oratoria. However, little information is available about its antigenic epitopes and cross-reactivity. In this study, recombinant TM was obtained through genetic engineering and its IgG-/IgE-binding activity was similar to native TM. Subsequently, four T-cell epitopes were identified by using bioinformatics technology combined with CD4⁺ T-cell proliferation assay, and seven B-cell epitopes were identified by bioinformatics technology combined with serological assay. Moreover, dot blot analysis showed that TM had cross-reactivity among O. oratoria and other shellfish by using IgE polycolonal antibody from sera of shrimp-sensitive individuals or O. oratoria TM-immunized mice. Interestingly, three T-cell epitopes (AA_4–24, AA_194–212, and AA_221–243) and four B-cell epitopes (AA_85–100, AA_121–138, AA_209–233, and AA_242–259) of TM in O. oratoria were conserved between O. oratoria and other shellfish, which may be the main reason for the cross-reactivity between them. In summary, these findings could serve for the diagnosis and prevention of shrimp allergy.