抗PD-1单克隆抗体联合CIK细胞对肺癌细胞株杀伤作用的研究

目的:研究程序性死亡受体1（program cell death-1,PD-1）单克隆抗体联合细胞因子诱导的杀伤细胞（cytokine-induced killer cells,CIK cells）对肺癌细胞株的杀伤作用及相关机制，探究该治疗方法在肺癌治疗中的可行性。方法:患者外周血单个核细胞（peripheral blood mononuclear cell,PBMC）在体外采用多种细胞因子诱导为CIK，并用流式细胞术(flow cytometry,FCM)分析CIK细胞的表型。培养A520 及H1975肺癌细胞，利用FCM检测其表面HLA-ABC,HLA-A2,HLA-DR及PD-L1的表达情况。将CIK细胞和抗PD-1单抗Nivolumab单独或者联合作用于A520 及H1975肺癌细胞。用ELISPOT法测定不同组γ干扰素（interferon gamma,IFN-γ）的释放，用CCK8法检测CIK细胞对肺癌细胞株的杀伤率。结果:CIK细胞对于肺癌细胞株的杀伤随着效靶比（effect target ratio,E∶T）的增加而加强；对于PD-L1高表达的肺癌细胞，Nivolumab与CIK细胞联合使用对肺癌细胞株的杀伤优于单一的CIK细胞及Nivolumab。结论:对于PD-L1高表达的A520肺癌细胞，PD-1单抗Nivolumab能够提升CIK细胞的杀伤作用，而对于PD-L1表达水平低的H1975细胞，Nivolumab不能提升CIK细胞的杀伤作用。

Cytokine-induced killer cells combined with immune checkpoint inhibitor against lung cancer cells

Objective:To investigate whether blockade of inhibitory receptor on cytokine-induced killer cells (CIK cells) could enhance their cytotoxicity against lung cancer targets.Methods:CIK cells were acquired from patients with lung cancer and the expression of surface markers on CIK cells were detected by flow cytometry (FCM).A520 and H1975 lung cancer cells were used as target cells and the expression of surface markers HLA-ABC,HLA-A2,HLA-DR,and PD-L1 were detected by FCM.CIK cells combined with immune checkpoint inhibitor (Nivolumab),CIK cells alone or Nivolumab alone were used as effective cells against A520 and H1975 lung cancer cells.The cytotoxic activity of CIK cells were assessed by CCK8.Enzyme-linked Immunospot Assay (ELISPOT) was used for the detection of IFN-γ.Results:The tumoricidal ability of both CIK cells combined with Nivolumab and CIK cells alone are in an E∶T ratio-dependent manner.Nivolumab increased the tumoricidal ability of CIK cells against lung cancer cell lines A520 with the high expression of PD-L1,but not H1975 cell lines with a low expression of PD-L1.Conclusion:Blockade of inhibitory receptor on CIK cells by immune checkpoint inhibitor can increase their anti-tumor potency against lung malignancies with high PD-L1 expression.