中文摘要：

目的检测shPD-1蛋白封闭肿瘤患者树突状细胞（DC）表面的PD—L1分子对DC功能的影响。方法体外诱导培养肿瘤患者DCs；观察给予或不给予shPD-1蛋白对DC的影响。应用流式细胞术检测DC免疫表型，采用MTT法检测DC刺激自体T淋巴细胞的增殖能力，采用ELISA法测定上清液中IL-12p70的水平，MTT法检测效应淋巴细胞对靶细胞的杀伤活性。结果封闭DC表面PD—L1分子后，DC刺激T细胞增殖，分泌IL—12p70能力显著提高，促进CTL杀伤反应的能力显著增强（P〈0．05）。结论可溶性人PD-1蛋白（shPD-1）封闭DC表面PD—L1分子后，能显著提高DC活化T细胞的能力，促进DC诱导的抗肿瘤免疫反应。

英文摘要：

Objective To detect the effect of PD-L1 blocked by shPD-1 on function of Dendritic Cells derived from patients with solid tumor. Methods DCs of tumor patients were obtained after incubation of monocytes in vitro. The functions of DCs were detected in the conditions of PD-L1 was blocked or not. The phenotypes of DCs were detected by flow cytometry, mixed lymphocyte reaction was analyzed by MTF assay and IL -12p70 in the cell culture supernatant were detected by ELISA. The cytotoxicity of CTLs to cancer cells was assayed by MTT. Results After blocking PD-L1 on DCs, DCs showed a stronger ability to stimulate T cells proliferation and secret IL -12p70. CTLs stimulated by DCs showed the higher killing effect on target cells（ P 〈 0.05 ）. Conclusion Blocking PD-LI on DCs can significantly enhance their ability to activate T cells,and to promote antitumor immunity.