肝癌高表达抗原MAGEC2 CTL表位肽的鉴定  

Identification of cytotoxic T-lymphocyte epitopes from hepatocellular carcinoma antigen MAGEC2

作　　者：贺晓静 贺洁[2] HE Xiao-jing;HE Jie(Department of Medicine,Kaifeng University,Kaifeng 475000,China;College of Life Science,Henan University,Kaifeng 475000,China)

机构地区：[1]开封大学医学部 [2]河南大学生命科学院,河南开封475000

出　　处：《中国病理生理杂志》2018年第4期617-622,共6页Chinese Journal of Pathophysiology

基　　金：河南省教育厅自然科学研究计划项目(No.2011B210001);河南省高等学校重点科研项目(No.18B180019)

摘　　要：目的:观察肝癌高表达抗原MAGEC2的改造表位是否有HLA-A2限制性抗肿瘤能力。方法:通过Net CTL 1.2、SYFPEITHI和IEDB软件预测打分选取MAGEC2的HLA-A2限制性表位;替换MAGEC2抗原锚定位点氨基酸获得改造肽;结合力实验检测候选表位与T2细胞表面HLA-A2分子的结合能力,ELISPOT实验和胞内因子染色检测候选表位肽诱导细胞毒性T淋巴细胞(CTL)分泌干扰素γ(IFN-γ)的能力,体外细胞毒实验检测诱导CTL的能力。结果:P248、P248-1Y、P356、P356-1Y、P356-2L和P356-1Y2L具有较好的结合力,且P248-1Y和P356-1Y2L等改造肽与HLA-A2的结合力高于原肽。胞内因子染色和ELISPOT实验结果显示,表位肽P248、P248-1Y、P356和P356-1Y2L诱导的CTL具有分泌IFN-γ的能力,且P248-1Y和P356-1Y2L诱导特异性T细胞免疫分泌的IFN-γ略高于原肽(P<0.05)。细胞毒实验结果显示表位肽P248、P248-1Y、P356和P356-1Y2L对Hep G2细胞均有一定的杀伤作用,且P248-1Y和P356-1Y2L特异性CTLs对Hep G2细胞杀伤率高于原肽特异性CTLs(P<0.05)。结论:MAGEC2抗原改造表位P248-1Y和P356-1Y2L分别与天然表位P248和P356相比有更高的HLA-A2分子亲和力,保留了原有的免疫原性,并且改造肽抗肿瘤免疫效应强于天然表位。P248-1Y和P356-1Y2L是优秀的MAGEC2抗原的HLA-A2限制性CTL候选表位,可以成为新的抗肿瘤多肽免疫治疗疫苗的候选表位。AIM:To observe whether modified epitopes from hepatocellular carcinoma antigen MAGEC2 have HLA-A2-restricted antitumor ability.METHODS:HLA-A2 epitopes from MAGEC2 protein were predicted by NetCTL 1.2,SYFPEITHI and IEDB.The change of binding anchor motifs by replacing anchor residues created the modified peptides from MAGEC2.The binding affinity of the peptides to HLA-A*0201 molecule was evaluated by T2 cells binding assay.ELISPOT assay and intracellular cytokine staining were used to investigate the ability of the peptides inducing specific restricted cytotoxic T-lymphocytes(CTLs)to release interferon-γ(IFN-γ).The ability of the peptides to induce T-cell response was investigated by cytotoxicity assay in vitro.RESULTS:The candidate peptides P248,P248-1Y,P356,P356-1Y,P356-2L and P356-1Y2L showed moderate affinity toward HLA-A2 molecule.T2 binding assay showed that P248-1Y and P356-1Y2L showed significantly higher affinity for HLA-A2 than the native peptides.ELISPOT assay and intracellular cytokine staining showed P248,P248-1Y,P356 and P356-1Y2L were able to induce specific CTLs to release IFN-γ.ELISPOT assay showed that significantly higher levels of IFN-γrelease were induced by P248-1Y and P356-1Y2L than the native peptides.The CTLs induced by P248,P248-1Y,P356 and P356-1Y2L lysed HepG2 cells,and P248-1Y and P356-1Y2L peptide-specific CTLs showed higher cytotoxicity against HepG2 cells than the native peptide-specific CTLs(P<0.05).CONCLUSION:Compared with the native peptides,modified epitopes P248-1Y and P356-1Y2L have higher binding affinity with HLA-A2 and retain immunogenecity.In addition,the antitumor immunity effects of modified epitope P248-1Y and P356-1Y2L are stronger than the native peptides.The peptides P248-1Y and P356-1Y2L are excellent HLA-A2-restricted CTL epitopes from tumor antigen MAGEC2,which could serve as new candidates towards antitumor peptide vaccines.

关 键 词：MAGEC2 肿瘤疫苗 细胞毒性T淋巴细胞 肝癌 

分 类 号：R735.7[医药卫生—肿瘤] R392.32[医药卫生—临床医学]