靶向PD-L1分子的RNAi增强树突状细胞疫苗对胰腺癌治疗作用的实验研究  

RNAi targeting PD-L1 enhances DC vaccination antitumor immunologic therateupic effect against pancreatic cancer

作　　者：蒋浩海 赵鑫[1,2] 赵华[1] 朱新国[1] 李德春[1,2] 

机构地区：[1]苏州大学附属第一医院普外科,江苏苏州215006 [2]苏州大学附属第一医院胰腺疾病研究中心,江苏苏州215006

出　　处：《南京医科大学学报（自然科学版）》2018年第1期40-43,79,共5页Journal of Nanjing Medical University(Natural Sciences)

基　　金：国家自然科学基金(81302146);中国博士后基金(2016M591913);江苏省青年医学人才(QNRC2016732);江苏省自然科学基金(BK20161225);江苏省卫生计生委科研课题(H201620);苏州市科技计划(SYS201539)

摘　　要：目的:研究通过RNA干扰敲减程序性死亡受体配体1(programmed death receptor ligand 1,PD-L1)分子能否增强树突状细胞疫苗对胰腺癌的治疗作用。方法:免疫组化法检测42例胰腺癌及对应胰腺组织中PD-L1的表达差异;纯化CD8+T细胞和制备成熟的树突状细胞(DC),将低表达PD-L1的Panc-1细胞Panc-1/PD-L1-RNAi、阴性对照Panc-1/LV-Control细胞以及野生型Panc-1细胞分别与CD8+T细胞+DC疫苗共同培养,检测细胞上清中干扰素(IFN)-γ表达水平;3组肿瘤细胞分别建立人源化严重免疫缺陷(severe combined immunodeficiency,SCID)小鼠胰腺癌皮下移植瘤模型,以DC疫苗为治疗手段进行尾静脉注射,观察肿瘤生长情况。结果:免疫组化实验显示,胰腺癌组织较胰腺组织中PD-L1高表达,差异有统计学意义(P<0.001)。T细胞反应实验显示,PD-L1敲减肿瘤细胞组与DC和CD8+T细胞共同培养的上清中IFN-γ表达水平明显高于其他2个对照组,差异有统计学意义(P<0.001)。人源化SCID小鼠体内荷瘤实验显示,敲减PD-L1表达与应用DC疫苗治疗胰腺癌皮下移植瘤具有协同作用。结论:胰腺癌较胰腺组织中PD-L1高表达,敲减胰腺癌细胞PD-L1表达与应用DC疫苗治疗可能是胰腺癌免疫治疗的有效策略。Objective：To investigate whether knocking down PD-L1 expression can enhance the effects of DC vaccine to treat pancreatic cancer. Methods：PD-L1 expression in normal pancreatic tissues and pancreatic cancer tissue specimens were detected by immunohistochemistry in tumor specimen of 42 pancreatic carcinoma patients respectively. A Panc-1 cell line with low PD-L1 expression established by lentivirus mediated RNA interference targeting PD-L1 was named Panc-1/PD-L1-RNAi. At the same time,negative control cells Panc-1/LV-Control and wide type Panc-1 cell line was used in this study. These three groups of pancreatic cancer cells were co-cultured with CD8＋T cells and mature DC,and then IFN-γ production was detected by ELISA. Pancreatic cancer tumor-bearing huSCID mice model was established. DC vaccination was performed to investigate tumor inhibition effects. Results：Higher expressions of PD-L1 were detected in pancreatic carcinoma than in normal pancreatic tissue（P0.001）detected by immunohistochemistry examination. In the T cell reaction study,IFN-γ production is much higher in the PD-L1 knocking down group than that in the other two control groups（P0.001）. In vivo,PD-L1 knocking down combined with DC vaccination could significantly prevent tumor growth in the hu-SCID model. Conclusion：PD-L1 is expressed higher in pancreatic cancer than in normal pancreatic tissue. Suppressing PD-L1 expression in cancer cells during DC vaccination might be a more efficient strategy in immunotherapy for pancreatic cancer.

关 键 词：胰腺癌 PD-L1 树突状细胞 疫苗 

分 类 号：R657.5[医药卫生—外科学]