类风湿关节炎血清中PGRN对肺癌细胞免疫逃逸的作用

Effect of PGRN in serum of rheumatoid arthritis on immune escape of lung cancer cells

[目的]探讨类风湿关节炎血清对非小细胞肺癌细胞免疫逃逸的潜在作用机制。[方法]构建了非小细胞肺癌细胞A549与CD8^(+)T细胞的共培养系统,避免细胞间的直接接触,分析分泌的肿瘤抗原与CD8^(+)T细胞的相互作用。类风湿关节炎血清处理后,检测CD8^(+)T细胞的增殖水平、活力水平、凋亡水平和关键细胞因子(IFN-γ、IL-4、IL-10)分泌水平,并鉴定类风湿关节炎血清中影响非小细胞肺癌免疫逃逸的关键分子。[结果]共培养系统中加入类风湿关节炎患者血清后CD8^(+)T细胞的增殖水平下降(0.10±0.01 vs 0.49±0.04,P<0.05)、活力水平下降(22.01±2.08 vs 45.05±6.16,P<0.05)、凋亡水平上升(59.38±6.19 vs 31.69±6.01,P<0.05)、关键细胞因子分泌水平下降(0.11±0.01 vs 0.51±0.04,P<0.05)。相比于健康志愿者的血清,类风湿关节炎血清中PGRN显著增多。PGRN处理后,A549细胞内以及分泌的外泌体中PDL1的蛋白水平均显著上升(0.44±0.05 vs 1.69±0.22,P<0.05)。PGRN处理A549细胞后的外泌体能够使CD8^(+)T产生与类风湿关节炎患者血清处理相似的效应,而敲低PDL1后获得相反的效应。[结论]类风湿关节炎患者血清中的PGRN能够显著增加非小细胞肺癌细胞中PDL1的表达水平。非小细胞肺癌细胞外泌体中PDL1可以使肿瘤免疫微环境中的CD8^(+)T细胞失活,引起非小细胞肺癌免疫逃逸。

[Objective]To investigate the potential effect and mechanism of rheumatoid arthritis serum on immune escape of non-small cell lung cancer.[Method]In this study,a co-culture system was established between NSCLC A549 and CD8^(+)T cells to avoid direct contact between cells,and the interaction between secreted tumor antigens and CD8^(+)T cells could be analyzed.CD8^(+)T cell proliferation,activity,apoptosis and secretion levels of key cytokines(IFN-γ,IL-4,IL-10)were detected after treatment with rheumatoid arthritis serum,and key molecules affecting the immune escape of NSCLC were identified in rheumatoid arthritis serum.[Result]In the co-culture system,the proliferation level of CD8^(+)T cells decreased(0.10±0.01 vs 0.49±0.04,P<0.05),and the activity level decreased(22.01±2.08 vs 45.05±6.16,P<0.05),increased apoptosis level(59.38±6.19 vs 31.69±6.01,P<0.05),and decreased key cytokine secretion level(0.11±0.01 vs 0.51±0.04,P<0.05).There was a significant increase in PGRN in the serum of rheumatoid arthritis compared with the serum of healthy volunteers.After PGRN treatment,PDL1 protein levels in A549 cells and secreted exosomes were significantly increased(0.44±0.05 vs 1.69±0.22,P<0.05).The exosomes of A549 cells treated with PGRN could induce CD8^(+)T to produce a similar effect to that of serum treatment in patients with rheumatoid arthritis,while the opposite effect was achieved by knocking down PDL1.[Conclusion]Serum PGRN in patients with rheumatoid arthritis can significantly increase the expression of PDL1 in non-small cell lung cancer cells.PDL1 in the exosomes of NSCLC cells can inactivate CD8^(+)T cells in the tumor immune microenvironment,resulting in NSCLC immune escape.