肿瘤增殖细胞核抗原的人白细胞抗原-A2限制性细胞毒T淋巴细胞表位鉴定

目的 鉴定肿瘤增殖细胞核抗原(PCNA)的人白细胞抗原(HLA)-A2限制性细胞毒T淋巴细胞(CTL)表位,为肿瘤疫苗制备提供依据.方法 根据PCNACTL表位评分结果,合成8条候选肽;采用经典T2-肽结合实验检测候选肽与HLA-A2分子亲和力;采用酶联免疫斑点法(ELISPOT)检测候选肽刺激的HLA-A2阳性CTL分泌干扰素(IFN)-γ能力.结果 T2-肽结合实验结果显示PCNA 14-22、110-118位置候选肽与HLA-A2分子结合力较强,其荧光系数FI值最高,分别为0.30和0.34,显著高于其他候选肽.ELISPOT检测结果显示14-22和39-47位置候选肽形成的IFN-γ斑点数目(477.25±52.08、640.50±145.74)明显高于阴性对照(0.75±0.50)及其余候选肽.结论 PCNA抗原14-22位置候选肽KVLEALKDL可作为HLA-A2限制性CTL表位用于制备肿瘤疫苗.

Identification of HLA-A2-restricted cytotoxic lymphocyte Epitopes encoded by proliferating cell nuclear antigen

Objective To identify the HLA-A2-restricted cytotoxic lymphocyte (CTL) epitopes encoded by proliferating cell nuclear antigen(PCNA)for preparation of tumor vaccines.Methods Combined with two epitope prediction databases,BIMAS and SYFPEITHI databases,to predict the epitopes of PCNA and synthesized eight peptides as the candidates.The peptide-binding assay Was used to determine the affinity of the peptides with the Human leukocyte antigen A2(HLA-A2)molecule.ELISPOT was used to inspect the Interferon-γ(IFN-γ) secreted by CTLs in order to reflect the immunogenicity of the peptides.Results Affinity analysis displayed that KVLEALKDL(14-22)of PCNA could combine with HLA-A2 molecular more strongly than the other tested peptides.Meanwhile KVLEALKDL(14-22)Was found to generate strong peptide.specific T cell responses by virtue of its ability to induce increased frequencies of IFN-γ-producing T cells compared to negative control and the other tested peptides(P<0.05).Conclusion KVLEALKDL(14-22) might be the HLA-A2-restricted CTL epitope of PCNA.KVLEALKDL (14-22) based vaccines may be very useful for the immunotherapy for patients with advanced tumors.