肺肿瘤小鼠MDSC、 Treg 及传统T 细胞变化研究

摘要： 目的 探讨肺肿瘤小鼠骨髓源性抑制细胞 （MDSC）、 调节性 T 细胞 （Treg） 和传统 T 细胞的变化及机制。方法 采用配对设计将 20 只 C57BL/6 小鼠随机均分为 Lewis 肺癌细胞注射组 （LLC 组） 和正常对照组 （NC 组）， LLC 组采用皮下注射 LLC 细胞 100 μL （1×106 ） 制备肺肿瘤小鼠模型， 对照组注射等量生理盐水。待肿瘤形成后取小鼠脾细胞， 采用流式细胞仪检测肺肿瘤小鼠 MDSC、 Treg 及 CD4+ 和 CD8+ T 细胞比例和数量变化， 膜联蛋白-V （Annexin-Ⅴ）染色检测 CD4+ 和 CD8+ T 细胞凋亡变化， 5-溴脱氧尿嘧啶核苷 （BrdU） 染色检测 CD4+ 和 CD8+ T 细胞增殖变化。结果 与 NC 组相比， LLC 组脾脏 MDSC 比例和数量明显增加， CD4+ Foxp3+ Treg 所占 CD4+ T 细胞比例和数量明显增加，而 CD4+ 和 CD8+ T 细胞所占脾细胞比例和数量明显降低 （均 P < 0.05）。与 NC 组相比， LLC 组 CD4+ 和 CD8+ T 细胞增殖明显降低， 同时 CD8+ T 细胞凋亡明显增加 （P < 0.05）。结论 MDSC 和 Treg 细胞在肺肿瘤小鼠数量增加， 同时， MDSC 和Treg 抑制 CD4+ 和CD8+ T 细胞增殖， 并促进 CD8+ T 细胞凋亡。

Changes of MDSC,Treg and traditional T cells in lung tumor mice

Abstract: Objective To explore changes of the myeloid derived suppressor cell (MDSC), regulatory T cell (Treg), traditional T cell, and their mechanisms in lung tumor mice. Methods Twenty C57BL/6 mice were randomly divided into the experimental and the normal control groups. The experimental group was injected with Lewis lung cancer cells (LLC, 100 μL 1×106 ) subcutaneously to prepare the lung tumor model mice, the normal control group was given the same amount of saline (NC). Spleen cells were obtained from LLC and NC groups. Flow cytometry was used to detect the ratio and number changes of MDSC, Treg, CD4+ and CD8+ T cells in the lung tumor of mice. CD4+ and CD8+ T cell apoptosis were detected by Annexin-Ⅴstaining, and their proliferation were detected by 5-bromine deoxidization uracil nucleoside (BrdU) incorporation. Results Compared with normal control mice, the ratio and number of MDSC in spleen increased significantly in LLC group (P < 0.01), in addition, the ratio of CD4+ Foxp3+ Treg in CD4+ T cells and their number in spleen increased significantly in LLC group. However, the ratio and number of CD4+ and CD8+ T cells in spleen decreased significantly in LLC group (P < 0.05). The proliferation of CD4+ and CD8+ T cells decreased significantly in LLC group compared with that of NC group (P < 0.05), while the apoptosis of CD8+ T cells increased significantly (P < 0.05). Conclusion MDSC and Treg cells increase in lung tumor model mice, which inhibit proliferation of CD4+ and CD8+ T cells and promote apoptosis of CD8+ T cells.