中文摘要：

目的观察结肠癌患者血浆外泌体（exosomes）表面膜结合型转化生长因子β1（m TGF-β1）表达,探讨其生物学作用。方法选取结肠癌患者20例（观察组）,同期体检健康者10例（对照组）,提取两组血浆exosomes,采用流式细胞仪分析exosomes表面m TGF-β1表达。从结肠癌患者肝素抗凝全血中分离外周血单个核细胞（PBMCs）,分选获得纯化的CD4^＋T细胞,采用CD3、CD28诱导细胞增殖,将细胞随机分为三组,A组加入TGF-β1阻断性单抗处理的结肠癌患者血浆exosomes（1μg/m L）,B组加入Ig G1同型对照抗体处理的结肠癌患者血浆exosomes（1μg/m L）,C组加入健康人血浆exosomes（1μg/m L）,培养3天时进行台盼蓝染色计数活细胞数;采用ELISA法检测细胞培养上清液中TNF-α和IFN-γ水平。结果观察组血浆exosomes表面m TGF-β1表达阳性率为36.52%±4.26%,高于对照组的9.23%±3.77%（P〈0.01）。与C组比较,B组CD4^＋T细胞数量及其分泌的TNF-α、IFN-γ水平均降低（P均〈0.05）;与B组比较,A组CD4~＋T细胞数量及其分泌的TNF-α、IFN-γ水平均增加（P均〈0.05）。结论结肠癌患者血浆exosomes表面高表达m TGF-β1,m TGF-β1表达增加可能是构成结肠癌免疫抑制环境的重要因素,可促进结肠癌的发生、发展。

英文摘要：

Objective To explore the membrane-bound transforming growth factor-β1（ m TGF-β1） expression on the surface of exosomes in the plasma from patients with colorectal cancer and its biological function. Methods The expression of m TGF-β1on the surface of exosomes from 20 samples of patients with colorectal cancer（ observation group） and 10 healthy donors（ control group） were analyzed by flow cytometry. Peripheral blood mononuclear cells（ PBMCs） were isolated from heparin anticoagulated whole blood of colon cancer patients,and CD4^＋T cells were purified and obtained by sorting. Meanwhile,CD3 and CD28 were used to induce cell proliferation,and the cells were randomly divided into three groups： groups A,B and C,group A was added with 1 μg/ml exosomes from plasma of patients treated with anti-TGF-β1monoclonal antibody（ m Ab）,group B was added with 1 μg/ml exosomes from plasma of patients treated with control Ig G1 m Ab and group C was added with 1 μg/m L exosomes from plasma of healthy donors. The cell count was calculated by Trypan blue stainin,and the levels of TNF-α and IFN-γ was detected by ELISA on day 3 after culture. Results The positive rate of m TGF-β1expression in the observation group was 36. 52% ± 4. 26%,which was higher than that（ 9. 23% ± 3. 77%） in the control group（ P〈0. 01）. Compared with group C,the number of CD4^＋T cells and the levels of TNF-α and IFN-γ secreted in the group B were all lower than those in the group C（ all P〈0. 05）. Compared with group B,the number of CD4^＋T cells and the levels of TNF-α and IFN-γ secreted in the group A were higher（ all P〈0. 05）. Conclusion The m TGF-β1expression is highly expressed on the surface of exosomes in the plasma from patients with colorectal cancer,and the increased expression of m TGF-β1may play an important role in the colon cancer immunosuppressive environment,which promotes the occurrence and development of colon cancer.