PD-L1表达抑制剂的筛选及其抗肿瘤活性  

Screening of PD-L1 Expression Inhibitor and its Anti-tumor Activity

作　　者：景磊 赵苗苗 姜博 李玉银[1] 刁爱坡[1] JING Lei;ZHAO Miaomiao;JIANG Bo;LI Yuyin;DIAO Aipo(College of Biotechnology,Tianjin University of Science&Technology,Tianjin 300457,China)

机构地区：[1]天津科技大学生物工程学院

出　　处：《天津科技大学学报》2020年第1期26-32,50,共8页Journal of Tianjin University of Science & Technology

基　　金：国家自然科学基金资助项目(31471335)

摘　　要：为了筛选PD-L1启动子活性抑制剂,研究其抑制肿瘤细胞中PD-L1蛋白表达对机体抗肿瘤免疫活性的调节作用.利用荧光素报告基因检测系统对小分子化合物库中的311种化合物进行筛选,发现硫酸长春新碱(vincristine sulfate,VCR)以浓度依赖性抑制PD-L1基因启动子活性.RT-PCR、免疫印迹实验(Western blot)等生物学评价实验显示:VCR抑制MDA-MB-231乳腺癌细胞中PD-L1表达以及B16细胞PD-L1蛋白表达和成瘤;VCR增强Jurkat细胞对MDA-MB-231细胞的杀伤活性,并促进C57BL/6小鼠细胞因子IL-2和γ-IFN的分泌,增强抗肿瘤活性.研究结果表明,VCR通过抑制PD-L1启动子活性下调肿瘤细胞中PD-L1蛋白表达,从而解除PD-1/PD-L1信号通路介导的免疫抑制,增强机体对肿瘤细胞的免疫应答和杀伤作用.The aim of this study is to screen a compound inhibiting the expression of PD-L1 protein in tumor cells and study its anti-tumor immune activity.311 compounds of a small molecule library were screened using a fluorescein reporter gene assay system and then it was found that VCR could inhibit the activity of PD-L1 promoter in a concentration-dependent manner.RT-PCR,Western blot and other biological evaluation showed that VCR could inhibit the expression of PD-L1 in MDA-MB-231 cells,the expression of PD-L1 protein and tumorigenesis of B16 cells.VCR treatment enhanced the killing activity of Jurkat cells to MDA-MB-231 cells,and promoted the secretion of IL-2 andγ-IFN,which in turn could enhance the anti-tumor activity in C57BL/6 mice.These results indicate that VCR down-regualtes the expression of PD-L1 in tumor cells by inhibiting the activity of PD-L1 promoter,which leads to abolishing of immunosuppression mediated by PD-1/PDL1 signaling pathway and thus enhancing the immune response and killing activity of the agent to tumor cells.

关 键 词：PD-L1 免疫检验点 硫酸长春新碱 小鼠成瘤 细胞因子 

分 类 号：Q291[生物学—细胞生物学]