sPD-1封闭PD-L促进抗瘤免疫的机制研究  

Mechanism of antitumor immunity of PD-L blockade with sPD-1

作　　者：贺兰湘[1] 张桂梅[1] 贺宇飞[1] 张慧[1] 项锦毅[1] 朱汉钢[1] 冯作化[1] 

机构地区：[1]华中科技大学同济医学院生物化学与分子生物教研室,武汉430030

出　　处：《中华微生物学和免疫学杂志》2006年第5期463-467,共5页Chinese Journal of Microbiology and Immunology

基　　金：国家重点基础研究发展(973)计划资助项目(No.2002CB513100)

摘　　要：目的研究本室构建的可溶性PD-1(sPD-1)真核表达质粒pPD-1A的抑瘤机理。方法用转染了pPD-1A的BHK细胞分泌产物去封闭树突状细胞上的PD-1配体(PD-L),并用MTT法检测树突状细胞(DC)对小鼠脾细胞的增殖激活作用。BALB/c小鼠接种H22肝癌细胞后次日开始接受质粒pPD-1A的注射。用RT-PCR法分析小鼠脾细胞的细胞因子和共刺激分子的mRNA表达水平,用流式细胞术测定肿瘤内T淋巴细胞的数量。结果在淋巴细胞活化的早期sPD-1对IL-10-DC激活淋巴细胞的作用有一定的促进,但作用并不十分显著(P>0.05)。注射了质粒pPD-1A的小鼠产生了较强的抗瘤免疫反应,H22肝癌细胞的生长明显受到抑制(P<0.01)。脾脏淋巴细胞的4-1BB、B7.1、IFN-γ和TNF-α表达均上调,以IFN-γ的增加最明显;OX40、IL-10表达下调。肿瘤内TIL数量明显增多(75.86%)。结论sPD-1通过对PD-L的封闭,不仅增加了肿瘤内部CD3+T细胞的数量,而且可以调节细胞因子和共刺激分子的表达,从而促进抗瘤免疫。Objective To study the meeting-of a eukaryofic expression plasmid （pPD- 1A） on antitumor immunity . Methods sPD-1 （soluble PD-1） expressed by pPD-1A-transfected BHK cells was used to block PD-L on DC in vitro. Activation of lymphocytes stimulated by dendritic cells was measured with MTr colorimetry. Mice inoculated with murine hepatoma （H22 cells） were treated by intramuscular injection of pPD-1A. The mRNA expression was analyzed with RT - PCR . T lymphocytes in the tumor were detected by Flow cytometry . After treatment with sPD-1, activation of lymphocytes stimulated by DC in vitro improved partly was at early phase of activation（P 〉 0.05）. The growth of H22 cells was significantly inhibited after pPD-1A administration（ P 〈 0.01）. The mBNA expression of 4-1BB, B7. 1, IFN-γ and TNF-α of lymphocytes was upregulated and that of OX40 and IL-10 was downregulated. CD3^＋ T lymphocytes in tumor injected with pPD-1A increased significantly （ 75.86% ）. Conclusion Blockade of PD- L by sPD- 1 remits in not only the increase of T cells in the tumor, but also the regulation of both cytokines and costimulatory molecules in splenocytes, so that anfitumor immunity was improved.

关 键 词：PD-1 小鼠肝癌 免疫治疗 

分 类 号：R730.3[医药卫生—肿瘤]