Hypoallergenic Derivatives of Scy p 9 for Alleviating Specific Allergic Reactions in Mice.

Filamin C is an important allergen in Scylla paramamosain and designated as Scy p 9. Hypoallergenic derivatives are one of the tools for solving specific allergy problems. In this study, molecular modification techniques were used to delete the N-/C-terminal region (AA1∼10, AA839∼848), mutate the key amino acids (T270), and delete the linear B-cell epitopes of (L-AA187∼205, L-AA363∼377) of Scy p 9, thereby generating the derivative Scy p 9NCCL. Compared with Scy p 9, Scy p 9NCCL exhibited weaker immune binding activity and markedly attenuated its capacity to trigger basophil activation, indicating that Scy p 9NCCL represents a hypoallergenic derivative. In vivo, Scy p 9NCCL induced significantly lower levels of mouse-specific IgE, whereas the levels of Treg-cell differentiation were significantly higher. Scy p 9NCCL induced production of specific blocking antibodies and alleviated allergic reactions caused by Scy p 9. These results laid a foundation for alleviating seafood allergies.