Dong Hai-Long, Li Zeng-Shan, Ye Jing, Qu Ping, Huang Ya-Yu, Wu Wen, Lu Shao-Ying, Chen Guang-Sheng, Sui Yan-Fang
Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China.
Cancer Biol Ther. 2004 Sep;3(9):891-8. doi: 10.4161/cbt.3.9.1081. Epub 2004 Sep 15.
Identification of the cytotoxic T lymphocytes (CTL) restricted epitopes of tumor antigens opens up possibilities of developing a new cancer vaccine. For the MAGE-n has been demonstrated closely associated with hepatocellular carcinoma (HCC) and HLA-A2.1 is found in over 50% of HCC patients in China, we aim at identifying MAGE-n-encoded peptide presented by HLA-A2.1.
A HLA-A2.1-restricted CTL epitope was identified by using an improved "reverse immunology" strategy: (a) computer-based epitope prediction from the amino acid sequence of MAGE-n antigen; (b) peptide-binding assay to determine the affinity of the predicted peptide with HLA-A2.1 molecule; (c) stimulation of primary T-cell response against the predicted peptides in vitro; and (d) testing of the induced CTLs toward HCC cells expressing MAGE-n antigen and HLA-A2.1.
Of the five tested peptides, effectors induced by a peptide of MAGE-n at residue position 159-167(QLVFGIEVV) lysed HCC cells expressing both MAGE-n and HLA-A2.1. Our results indicated that peptide QLVFGIEVV was a new HLA-A2.1-restricted CTL epitope capable of inducing MAGE-n specific CTLs in vitro.
Identification of the MAGE-n /HLA-A2.1 peptide QLVFGIEVV may facilitate peptide-based specific immunotherapy for HCC. The combination of epitope prediction, epitope reconstruction method and immunological methods can improve the efficiency and accuracy of CTL epitope studies.
肿瘤抗原细胞毒性T淋巴细胞（CTL）限制性表位的鉴定为开发新型癌症疫苗开辟了道路。鉴于MAGE-n已被证明与肝细胞癌（HCC）密切相关，且在中国超过50%的HCC患者中发现了HLA-A2.1，我们旨在鉴定由HLA-A2.1呈递的MAGE-n编码肽。
采用改进的“反向免疫学”策略鉴定HLA-A2.1限制性CTL表位：（a）基于计算机从MAGE-n抗原的氨基酸序列预测表位；（b）进行肽结合试验以确定预测肽与HLA-A2.1分子的亲和力；（c）在体外刺激针对预测肽的原发性T细胞反应；（d）检测诱导的CTL对表达MAGE-n抗原和HLA-A2.1的HCC细胞的作用。
在测试的5种肽中，由MAGE-n第159 - 167位残基的肽（QLVFGIEVV）诱导的效应细胞裂解了同时表达MAGE-n和HLA-A2.1的HCC细胞。我们的结果表明，肽QLVFGIEVV是一种新的HLA-A2.1限制性CTL表位，能够在体外诱导MAGE-n特异性CTL。
MAGE-n /HLA-A2.1肽QLVFGIEVV的鉴定可能有助于HCC的基于肽的特异性免疫治疗。表位预测、表位重建方法和免疫学方法的结合可以提高CTL表位研究的效率和准确性。
