The present invention provides a nucleic acid that is expected to be useful for the treatment of crustacean allergy. The present invention provides a nucleic acid comprising a nucleotide sequence encoding a message peptide, a nucleotide sequence encoding an intracellular stable region of LAMP, and an allergen region including Lit v 1, Lit v 4 and Lit v 3 The base sequence, the base sequence encoding the transmembrane region, and the base sequence encoding the endosome / lysosomal target region of LAMP, and the base sequence encoding the chimeric protein.本發明提供一種期待對甲殼類過敏治療有用之核酸。本發明提供一種核酸，其係依序包含編碼訊息肽之鹼基序列、編碼LAMP之胞器內穩定區之鹼基序列、編碼包含Lit v 1、Lit v 4及Lit v 3之過敏原區之鹼基序列、編碼跨膜區之鹼基序列、以及編碼LAMP之內體/溶酶體靶區之鹼基序列者，且包含編碼嵌合體蛋白之鹼基序列。
