人端粒酶逆转录酶表位多抗原肽疫苗的体外抗肿瘤免疫效应研究

In vitro antitumor immune activity of human telomerase reverse transcriptase epitope multiple antigen peptide vaccine

目的检测基于人端粒酶逆转录酶(human telomerase reverse transcriptase,hTERT)细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)表位R540的多抗原肽(multiple antigen peptide,MAP)的体外抗肿瘤活性。方法将HLA-A2限制性hTERT CTL表位的多抗原肽负载正常人外周血来源(peripheral blood mononuclear cell,PBMC)的树突细胞,并将负载多肽的树突细胞刺激淋巴细胞产生hTERT特异性的CTL细胞,采用51Cr释放实验检测所诱导的CTL细胞体外抗肿瘤杀伤效应。结果 hTERT特异性CTL表位的多抗原肽所诱导的CTL细胞对hTERT及HLA-A2表达均阳性的肿瘤细胞杀伤作用较之其单肽疫苗杀伤活性明显增强,在最大效靶比(E/T)80∶1时,高出率均大于25%。而对HLA-A2阴性的HepG2肝癌细胞及hTERT阴性的U2OS骨肉瘤细胞不具有杀伤效应,同时其对自体淋巴细胞和树突细胞也不具有杀伤效应。结论 HLA-A2限制性hTERT CTL表位多抗原肽相较于其单肽能在体外诱导更强的抗肿瘤免疫效应。

Objective To detect the antitumor activity of multiple antigen peptide（MAP） vaccine of human telomerase reverse transcriptase（hTERT） based on cytotoxic T lymphocytes（CTL） epitope R540 in vitro.Methods Dendritic cells（DC） from human peripheral blood mononuclear cells（PBMC） pulsed with HLA-A2-restricted hTERT MAP were used to stimulate lymphocytes to produce hTERT-specific CTL.In vitro antitumor activity of hTERT MAP vaccine against tumor cells was detected by 51Cr release assay.Results The in vitro antitumor activity of hTERT MAP vaccine was significantly stronger than its linear peptide vaccine against tumor cells with a positive expression of hTERT and HLA-A2 and at the maximum effector/target（E/T） ratio（80∶1）,the lysis rate was over 25%.The hTERT MAP vaccine had no killing effect on hTERT or HLA-A2 negative tumor cells and on autologous lymphocytes or DC.Conclusion The antitumor activity of hTERT MAP vaccine is stronger than its linear peptide vaccine against tumor cells in vitro.