肿瘤Ki-67抗原HLA-A2限制性细胞毒性T淋巴细胞表位的鉴定

目的 鉴定Ki-67抗原HLA-A2限制性细胞毒性T淋巴细胞(CTL)表位,为制备肿瘤疫苗提供依据.方法 根据BIMAS和SYFPEITHI数据库对人Ki-67抗原CTL表位综合评分结果,合成7条候选肽.通过T2-肽结合实验检测候选肽与HLA-A2分子亲和力;通过酶联免疫斑点法(ELISPOT)检测HLA-A2阳性CTL细胞分泌IFN-γ能力,评价候选肽免疫原性.结果 合成的候选肽及阳性对照肽HIV-1 pel 476-484纯度均超过95%.T2-肽结合实验结果显示280～288位置Ki-67氨基酸序列LQGETQLLV与HLA-A2分子结合力较强,其能够诱导特异性CTL活化.结论 LQGETQLLV(280～288)是Ki-67抗原的HLA-A2限制性CTL表位.

Identification of HLA-A2-restricted CTL epitopes encoded by Ki-67 antigen

Objective To identify the HLA-A2-restricted CTL epitopes encoded by antigen segment of Ki-67 for preparation of tumor vaccines. Methods Two epitope prediction databases ( BIMAS and SYFPEITHI) were used to predict the epitopes of Ki-67, and 7 peptides were synthesized as the candi-dates. The prediction was evaluated by peptide-binding test. ELISPOT was used to inspect the IFN-γ secre-ted by CTLs in order to reflect the immunogenicity of the peptides. Results The purities of synthetic pep-tides and positive control peptide were all above 95%. Peptide-binding test displayed that LQGETQLLV (280-288) of Ki-67 could bind with HLA-A2 molecule more strongly. ELISPOT assay displayed that LQGETQLLV could induce activation of specific CTLs. Conclusion LQGETQLLV (280-288) might be the HLA-A2-restricted CTL epitope of Ki-67 antigen.