PROBLEM TO BE SOLVED: To provide a vaccine for treating or preventing HHV-6B using a U54-specific cytotoxic T cell epitope peptide, a passive immunotherapeutic agent for U54, and a method for quantification of cytotoxic T cells specific to U54.SOLUTION: According to the present invention, there are provided a peptide has the property of inducing a U54-specific HLA-A24 restrictive cytotoxic T cell (CTL) of human herpesvirus 6B (HHV-6B)； a nucleic acid encoding the peptide； an expression vector containing the nucleic acid； and an antigen-presenting cell in which the peptide is presented on HHV-A24. There is also presented a vaccine composition for treating or preventing HHV-6B, the composition comprising the nucleic acid, the expression vector, or the antigen-presenting cell as an active ingredient.SELECTED DRAWING: None【課題】Ｕ５４特異的な細胞傷害性Ｔ細胞エピトープペプチドを用いたＨＨＶ－６Ｂを治療又は予防するワクチン、Ｕ５４に対する受動免疫療法剤、およびＵ５４に特異的な細胞傷害性Ｔ細胞の定量方法の提供。【解決手段】ヒトヘルペスウイルス６Ｂ（ＨＨＶ－６Ｂ）のＵ５４特異的ＨＬＡ－Ａ２４拘束性細胞傷害性Ｔ細胞（ＣＴＬ）を誘導する性質を有する、ペプチド。ペプチドをコードする核酸。核酸を含む発現ベクター。ペプチドをＨＬＡ－Ａ２４に提示した抗原提示細胞。核酸、発現ベクター、又は抗原提示細胞を有効成分として含む、ＨＨＶ－６Ｂを治療、又は予防するためのワクチン組成物。【選択図】なし
