肠复方对肠癌荷瘤小鼠MDSCs及免疫相关细胞因子表达的影响

Effect of Changfufang on MDSCs and immune-related cytokines expression in colorectal cancer-bearing mice

关键词:  肠复方  肠癌  髓源抑制性细胞  TGF-β  IL-10  IL-2  TNF-α

Key words:  Changfufang  colorectal cancer  myeloid-derived suppressor cell  TGF-β  IL-10  IL-2  TNF-α

摘要:

[目的] 探讨肠癌小鼠瘤体髓源抑制性细胞（MDSCs）与血清免疫相关细胞因子水平的相关性以及肠复方干预的研究。[方法] 选取SPF级BALB/c小鼠40只，随机抽取10只为空白对照组，其余30只小鼠采用动物移植性肿瘤实验法，在小鼠右腋下接种CT26肠癌细胞，制备小鼠荷瘤实验模型。将造模成功的小鼠随机分成3组，分别给予肠复方、香菇多糖、蒸馏水干预（模型组），空白对照组亦用蒸馏水干预，连续干预4周，每周5 d。观察小鼠的生长状态。干预结束后计算各组小鼠的抑瘤率，以流式细胞仪、免疫组化法分别检测各组荷瘤小鼠瘤体中CD11b⁺Gr-1⁺的MDSCs百分比和瘤体MDSCs（Gr-1）的表达含量。酶联免疫吸附实验（ELISA）检测各组小鼠血清白介素（IL）-2、肿瘤坏死因子-α（TNF-α）、IL-10、转化生长因子-β（TGF-β）的表达。进行瘤体组织中MDSCs的表达与瘤体质量、免疫相关细胞因子之间的相关性及各组间差异分析。[结果] 1）模型组血清IL-2、TNF-α、IL-10、TGF-β的含量明显高于空白对照组（P<0.01）；2）与模型组相比，肠复方组、香菇多糖组能够下调瘤体组织MDSCs的表达，且肠复方组优于香菇多糖组，差异具有统计学意义（P<0.01）；3）与模型组相比，肠复方组、香菇多糖组TNF-α、IL-2的表达均显著增高（P<0.01），肠复方组、香菇多糖组血清TGF-β的表达明显下降（P<0.01），香菇多糖组血清IL-10的表达下降（P<0.05），而在肠复方组下降更显著（P<0.01），且肠复方组均优于香菇多糖组（P<0.01）；4）应用Spearman相关性研究发现：肠癌瘤体中MDSCs表达与瘤体质量呈正相关（P<0.05），与血清IL-10、TGF-β呈正相关（P<0.05），与血清TNF-α呈负相关（P<0.05），与血清IL-2不具有相关性。[结论] 肠癌组织中MDSCs表达与瘤体负荷密切相关，且MDSCs与TGF-β、IL-10具有协同作用，肠复方可能通过上调TNF-α、IL-2表达，下调MDSCs、TGF-β、IL-10发挥免疫抗肠癌作用。

Abstract:

[Objective] To explore the correlation between tumor myeloid-derived suppressor cells (MDSCs) and serum immune-related cytokines in mice with colorectal cancer and the intervention of Changfufang.[Methods] Forty SPF grade BALB/c mice were selected, and 10 of them were randomly selected as the blank control group. The other 30 mice were inoculated with CT26 colorectal cancer cells in the right armpit of mice to prepare the tumor-bearing experimental model. The successful mice were randomly divided into three groups, which were intervened by Changfufang, lentinan and distilled water (model group), and the blank control group was intervened by distilled water for 4 weeks, 5 days a week. Observe the growth state of mice. After the intervention, the tumor inhibition rate of mice in each group was calculated. The percentage of MDSCs of CD11b Gr-1 and the expression of MDSCs (Gr-1) in tumor-bearing mice in each group were detected by flow cytometry and immunohistochemistry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of IL-2, TNF-α, IL-10 and TGF-β in serum of mice in each group. The relationship between MDSCs expression in tumor tissues and tumor weight, immune-related cytokines and the differences among groups were analyzed.[Results] 1)The contents of serum IL-2, TNF-α, IL-10 and TGF-β in the model group were significantly higher than those in the blank control group (P<0.01). 2)Compared with the model group, Changfufang group and lentinan group could down-regulate the expression of MDSCs in tumor tissue, and the expression of MDSCs in Changfufang group was better than that in lentinan group (P<0.01). 3)Compared with the model group, the expressions of TNF-α and IL-2 in Changfufang group and lentinan group were significantly increased (P<0.01). The expression of serum TGF-β in Changfufang group and lentinan group decreased significantly (P<0.01). The expression of serum IL-10 in lentinan group decreased (P<0.05), but decreased more significantly in Changfufang group (P<0.01), and Changfufang group was superior to lentinan group (P<0.01). 4)Spearman correlation study showed that the expression of MDSCs was positively correlated with tumor weight (P<0.05), positively correlated with serum IL-10 and TGF-β (P<0.05), negatively correlated with serum TNF-α (P<0.05), but not correlated with serum IL-2.[Conclusion] The expression of MDSCs in colorectal cancer is closely related to the tumor load, and MDSCs has a synergistic effect with TGF- β and IL-10. The Changfufang may play an immune anti-colorectal effect by up-regulating the expression of TNF-α and IL-2 and down-regulating MDSCs, TGF-β and IL-10.