目的：观察吉西他滨（gemcitabine，GEM）对卵巢癌移植瘤小鼠肿瘤免疫微环境的调节作用。 方法： C57BL/6 小鼠皮下注射卵巢癌ID8细胞构建卵巢癌移植瘤模型，实验组腹腔注射GEM，对照组注射生理盐水，观察肿瘤生长情况。流式细胞术检测小鼠脾脏及肿瘤组织的调节性T细胞（regulatory T cells，Treg)及髓来源抑制性细胞（myeloid-derived suppressor cell，MDSC），实时定量PCR检测小鼠肿瘤组织arginase-1 （Arg-1）和Foxp3 mRNA的表达，流式细胞仪检测小鼠脾脏CD8 + T细胞的比例，ELLSE法检测小鼠血清IFN-γ及IL-2的表达。 结果： GEM处理后的移植瘤小鼠肿瘤生长明显受到抑制[ （366.8±44.88）vs (499.3±24.14)mm 3 ，P<0.01]。移植瘤小鼠肿瘤组织及脾脏 Treg 比率明显降低[ （12.71±2.31)% vs (20.36±2.65)%、 （10.09±1.69)% vs (13.79±1.31)%，均P<0.01]。实验组的相关基因mRNA表达较对照组显著降低[Foxp3： （4.30±0.46）vs (6.35±0.58)；Arg-1： （16.32±0.38）vs(13.26±0.37)；均P<0.01]。实验组血清中的IFN-γ和IL-2含量明显高于对照组[IFN-γ： （71.90±2.28）vs (53.91±3.91) pg/ml；IL-2：（51.46±1.69）vs (40.90±1.50) pg/ml，均P<0.01]。 结论： GEM下调卵巢癌移植瘤小鼠免疫抑制活性，并可上调小鼠抗肿瘤免疫原性，该结果可为GEM作为卵巢癌免疫治疗干预措施提供实验依据。

Objective:To observe the interfering and regulating effect of gemcitabine (GEM) on the immune mi-croenvironment of ovarian tumor bearing mice. Methods: C57BL/6 mice were inoculated subcutaneousely with ID8 cells to construct ovarian cancer xenograft model. The mice in the experimental group were injected with GEM intraperitoneally and the control group was injected with saline. Growth of the tumor was observed. The percentage of the regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in spleen and tumor tissues of the mice were detected by FCM. RT-qPCR was used to detect the mRNA expression of arginase-1 (Arg-1) and Foxp3 in tumor tissues. The ratio of CD8 + T cells in spleen of the mice was detected by FCM. The serum IFN-γ and IL-2 level was detected by ELISA assay. Results: Tumor growth in tumor-bearing mice was significantly inhibited after GEM treatment ([366.8±44.88] vs [499.3±24.14] mm 3 , P<0.01). Tregs ratio in tumor tissues and spleen were significantly lower than controls, respectively ([12.71±2.31]% vs [20.36±2.65]%, [10.09±1.69]% vs [13.79±1.31]%; all P<0.01).The mRNA levels of Foxp3 ([4.30±0.46] vs [6.35±0.58], P<0.01) and Arg-1 ([13.26±0.37] vs [16.32±0.38], P<0.01)in the treatment group were significantly lower than that in the control group. Percentage of the CD8 + T lymphocytes in treatment and control groups had no significant difference ([11.08±1.29]% vs [11.12±1.06]%; P>0.05), but the se-rum level of IFN-γ ([71.90±2.28] vs [53.91±3.91] pg/ml，P<0.01) and IL-2 ([51.46±1.69] vs [40.90±1.50] pg/ml; P<0.01) was significantly increased compared with control group. Conclusion: GEM down-regulated immunosuppres-sive activity and up-regulated anti-cancer immunogenicity of tumor-bearing mice, which might provide the experi-mental basis of GEM serving as immunotherapy intervention for ovarian cancer.