人肿瘤细胞培养上清对树突状细胞表型和功能的影响

Effect of tumor cell supernatants on phenotypes and function of dendritic cells

目的 :观察肿瘤细胞分泌的可溶性因子对树突状细胞表型和功能的影响 ,以进一步揭示肿瘤的免疫逃逸机制。 方法 :体外分离单核细胞 ,加入白细胞介素 4 (IL - 4 )、粒 -巨噬细胞集落刺激因子 (GM- CSF)和肿瘤细胞培养上清体外培养树突状细胞 ,采用流式细胞术、同种异体混合淋巴细胞反应等方法观察肿瘤细胞上清对树突状细胞表型和功能的影响 ,并用逆转录 -聚合酶链反应 (RT- PCR)法检测了免疫抑制因子 IL - 10、血管内皮生长因子 (VEGF)和转化生长因子β1 (TGF-β1 )的 m RNA在人结肠、人卵巢和人肝脏肿瘤细胞中的表达。 结果 :当培养体系中加入人肿瘤细胞培养上清后 ,树突状细胞表面 MHC 类分子和 CD80等共刺激分子的表达较低 ,树突状细胞刺激 T细胞增殖能力下降 ,且 IL - 10 m RNA、VEGF m RNA和 TGF-β1 m RNA在 3种肿瘤细胞中均有不同程度的表达。 结论 :提示肿瘤细胞培养上清可能抑制树突状细胞的抗原提呈能力 ,肿瘤细胞分泌的免疫抑制因子可能是导致肿瘤微环境中的树突状细胞功能低下、机体的免疫系统无法有效激活和启动抗肿瘤免疫反应的原因之一。

Objective: To study the effect of tumor cell supernatants(TCS) on phenotypes and function of dendritic cell(DC), and to investigate the mechanism by which tumors escape from immune recognition. Methods: Isolated monocytes from human peripheral blood were cultured with 100 ng/ml hGM CSF, 500 U/ml IL 4 and TCS for one week,and a large number of DCs were generated, their phenotypes were investigated by flow cytometric method and its stimulating proliferation of allogeneic T lymphocytes.Reverse transcript polymerase chain reaction(RT PCR) was used to detect IL 10,VEGF and TGF β 1 mRNA expression in 3 kinds of tumor cell. Results: The expression of molecular such as MHC class Ⅱand costimulating factors(CD80)on the surface of DC generated with TCS were down regulated, so were its function of antigen presenting.IL 10,VEGF and TGF β 1 mRNA were expressed in 3 kinds of tumor cell to different degree. Conclusion: Tumor derived soluble factors,including IL 10,VEGF and TGF β 1, may affect DC function of antigen presenting, decreasing ability of the immune system to generate effective antitumor immune responses.