胃癌患者调节性T细胞胞内外细胞因子的检测及其意义

背景与目的:目前认为CD4 CD25 调节性T细胞与胃癌患者的免疫功能抑制密切相关,但CD4 CD25 调节性T细胞发挥免疫抑制功能的作用机制并不十分清楚.本研究通过检测胃癌患者CD4 CD25 调节性T细胞产生具有不同生物活性的细胞因子干扰素-γ(interferon-γ,IFN-γ)、白介素4(interleukin-4,IL-4)、IL-10及肿瘤生长因子-β(tumor growth factor-β,TGF-β)的分泌情况,进一步探讨这些细胞因子在胃癌患者CD4 CD25 调节性T细胞发挥免疫抑制功能的作用.方法:按常规方法制备患者外周血单个核淋巴细胞,采用免疫磁珠分选方法分离CD4 CD25 T细胞及CD4 CD25-T细胞后,用细胞内细胞因子染色法及ELISA法分别研究CD4 CD25 T细胞在胞内及胞外产生具有不同生物活性的细胞因子IFN-γ、IL-4、IL-1O及TGF-β的水平.结果:(1)与健康对照组比较,胃癌患者分泌内细胞因子IFN-γ、IL-4及IL-10的CD4 CD25 T细胞占CD4 细胞的百分比均显著增高(P＜0.05).(2)培养96 h后,上清液的各种细胞因子水平,无论是胃癌患者还是健康对照组,CD4 CD25 T细胞分泌的IL-10及TGF-β均显著高于CD4 CD25-T细胞(P＜0.05).CD4 CD25 T细胞分泌的IFN-γ显著低于CD4 CD25-T细胞(P＜0.05).结论:CD4 CD25 调节性T细胞体外免疫抑制作用的发挥可能与一些抑制性细胞因子有关,特别是细胞因子TGF-β在胃癌CD4 CD25 调节性T细胞的免疫抑制功能中起着相当重要的作用.

Detection of intracellular and extracellular cytokines of CD4+CD25+ regulatory T cells in gastric cancer patients

BACKGROUND & OBJECTIVE: CD4+CD25+ regulatory T cells play a crucial role in the immunosuppression of gastric cancer patients, but the mechanism is still unknown. This study was to investigate the secretion of intracellular and extracellular cytokines interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-10 and tumor growth factor-beta (TGF-beta) from CD4+CD25+ regulatory T cells in gastric cancer patients, and evaluate their roles in the immunosuppression of gastric cancer. METHODS: Peripheral blood mononuclear lymphocytes of gastric cancer patients were prepared routinely. CD4+CD25+ T cells and CD4+CD25- T cells were isolated by magnetic activated cell sorting (MACS) method, and identified by flow cytometry. The cytokine secretion of CD4+CD25+ T cells and CD4+CD25- T cells was detected by intracellular analysis of cytokine production (IFN-gamma, IL-4 and IL-10) and ELISA (IFN-gamma, IL-10 and TGF-beta). RESULTS: The proportion of CD4+CD25+ T cells to CD4+ T cells was significantly higher in gastric cancer patients than in healthy controls (P<0.05). After 96-hour cell culture, no matter in gastric cancer patients or in healthy controls, the secretion of IL-10 and TGF-beta were significantly higher from CD4+CD25+ T cells than from CD4+CD25- T cells (P<0.05), but the secretion of IFN-gamma was significantly lower from CD4+CD25+ T cells than from CD4+CD25- T cells (P<0.05). CONCLUSION: The immunosuppression of CD4+CD25+ regulatory T cells in gastric cancer may relate to suppressive cytokines, especially TGF-beta.