辐射对肿瘤微环境中Treg细胞及其相关因子的影响

Effects of the microenvironment of irradiated tumor cells on Treg cells and related regulation factors

目的 检测照射后与肺腺癌A549细胞共培养的淋巴细胞中调节性T细胞（Treg细胞）及其相关细胞因子和共刺激分子表达的变化,探讨辐射对肿瘤微环境中免疫耐受机制的影响.方法 分离人外周血淋巴细胞单独培养或与肺腺癌A549细胞进行共培养一段时间后,以6GyX射线进行照射,继续共培养一段时间后,以流式细胞术检测淋巴细胞中CD4＋ CD25＋、CD4＋ CD25＋FoxP3^＋、CD4＋ CD25＋ NrP1^＋不同亚组的百分数、共刺激分子ICOS和CTLA-4的表达情况;ELISA法检测培养体系上清中IL-10、TGF-β、IL-17的分泌量.结果 与照射前后单独培养组相比,相应条件下共培养组中CD4＋ CD25＋、CD4＋ CD25＋ FoxP3^＋、CD4＋ CD25＋ NrP1^＋、ICOS、CTLA-4、IL-10和TGF-β比例均增加（t=2.78 ～40.61,P＜0.05）.而与照射前相比,照射后单独培养组和共培养组的CD4＋ CD25＋和CTLA-4比例增加（t=2.96、2.94、4.47、2.77,P＜0.05）.细胞因子IL-17的表达量在肺腺癌A549细胞和X射线分别作用下无明显变化,但共同作用后会明显增加（t=4.00、4.71,P ＜0.05）.结论 辐射刺激肺癌细胞肿瘤微环境中的CD4＋ CD25＋Treg细胞亚组及其相关CTLA-4和IL-17的表达,诱导肿瘤微环境中的免疫耐受作用.

Objective To explore the immune tolerance in tumor microenvironment,we detected the expressions of CD receptors and related cytokines in Treg cells after being co-cultured with irradiated lung cancer cells.Methods Lymphocytes were isolated from human peripheral blood and cultured with lung adenocarcinoma cells A549,after irradiation with 6 Gy X-rays,the expression of CD4 ＋ CD25 ＋,CD4 ＋ CD25 ＋ FoxP3^＋,CD4 ＋ CD25 ＋ NrP1^＋ and ICOS,CTLA-4 in the lymphocytes were tested by flow cytometry,and the contents of IL-10,TGF-β and IL-17 in the supernatant were detected by ELISA.Results Compared with lymphocytes alone culture,the expressions of CD4 ＋ CD25 ＋,CD4 ＋ CD25 ＋ FoxP3^＋,CD4 ＋ CD25 ＋ NrP1 ^＋,ICOS,CTLA-4,IL-10 and TGF-β in the co-culture groups with and without irradiation were all increased （t =2.78-40.61,P 〈 0.05）,the CD4 ＋ CD25 ＋ and CTLA-4 in the lymphocytes were increased after irradiation （t =2.96,2.94,4.47,2.77,P 〈 0.05）.The content of IL-17 in the supernant were increased after co-cuture with irradiated A549 cells （t =4.00,4.71,P 〈 0.05）,but it had no obvious changes after irradiation alone.Conclusions The immune tolerance of lung cancer cells microenvironment under irradiation might contribute to the up-promotion of CD4 ＋ CD25 ＋ Treg cells,CTLA-4 and IL-17 although the molecular mechanisms still need to be further investigated.