4种甲胎蛋白抗原表位肽段致敏树突状细胞诱导细胞毒性T淋巴细胞对肝癌细胞的杀伤效应比较

目的 通过体外杀伤试验,比较4种人肝癌特异性甲胎蛋白抗原表位肽段PLFQVEPVhAFP(137～145)],FMNKFIYEIhAFP(158～166)]、GLSPNLNRFLhAFP(325-334)]和GVAL,QTMKQhAFP(542～550)]修饰树突状细胞(DC)后诱导的细胞毒性T淋巴细胞(CTL)对人肝癌细胞的特异性杀伤效应. 方法 选取健康人外周血单个核细胞,体外诱导成熟DC;合成4种hAFP抗原表位肽段分别修饰和诱导DC,体外刺激CTL,通过流式细胞仪法和细胞毒性检测法检测该修饰后的DC所诱导的CTL在体外对肝癌细胞株SMMC-7721细胞的杀伤作用.组间比较应用t检验进行统计学分析. 结果 4种人肝癌特异性甲胎蛋白片段均能在体外修饰和诱导DC细胞的增殖和成熟;这些成熟DC在体外均能诱导特异性CTL,CTL对SMMC-7721细胞均可产生杀伤效应.其中FMNKFIYEIhAFP(158～166)]肽段诱导的CTL在效靶比分别为80:1、40:1及10:1时对肿瘤细胞的杀伤效应分别达到了78.1%±9.8%、43.9%±5.9%和28.2%±4.9%,比其他3种肽段的杀伤效应高(P<0.05). 结论 短肽段具有单独体外诱导特异CTL的作用,其诱导效果和杀伤效果均优于完整hAFP蛋白,其诱导的CTL有特异地杀伤SMM C-7721细胞的作用.

The killing effects of cytotoxic T lymphocytes stimulated by specific hAFP-derived peptides on hepatocellular cancer cells

Objective To compare the in vitro killing effects of cytotoxic T lymphocytes (CTLs) induced by dendritic cells(DCs) that modified with 4 different specific hAFP-derived peptides. Methods DCs derived from normal human peripheral monocytes were activated by GM-CSF and IL-4. MTT assay was applied to analyse the proliferation activities of the DCs. To induce the specific CTLs, DCs modified with four immunodominant epitopes from alpha fetoprotein (AFP) were cocultured with MNC derived CD8+ lymphocytes. The acquired specific CTLs were coclutured with SMMC-7721 cells at different dilutions, and the killing effects were detected by flow-cytometry and Non-Radiactive Cytotoxity kit. Results The CTLs stimulated by DCs modified with the four immunodominant epitopes from alpha fetoprotein (AFP) had spedific killing activities on the SMMC-7721 cells. And statistical differences of the killing effects existed between the hAFP (158-166) (FMNKFIYEI) group and the other three groups. Conclusion CTLs induced by the DCs modified with the four immunodominant peptides had significant killing effects on the hepatocellular cancer cells in vitro. The hAFP(158-166) (FMNKFIYEI) peptide had a relatively higher efficiency in inducing DCs and stimulating specific CTLs.