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.