免疫检查点在肿瘤放疗中的应用进展

放射治疗诱导DNA损伤与细胞死亡，并且通过改变肿瘤表型、肿瘤微环境，参与内源性免疫反应的调节。免疫检查点信号途径在抗微生物免疫反应中参与维持自身耐受，限制组织损伤，但其在抗肿瘤免疫中抑制细胞毒T细胞活化与功能，增强免疫抑制细胞作用，导致免疫逃逸。阻断免疫检查点信号能够恢复抗肿瘤免疫，延缓肿瘤进程。近年来，放疗与免疫治疗联合应用已成为基础与临床研究的热点。在此就放疗对机体免疫系统的作用、免疫检查点的负性调控机制以及放疗联合阻断免疫检查点用于肿瘤治疗的研究进展进行总结，以期为拓展肿瘤综合治疗提供新思路。

Research progress of the application of immune checkpoints in tumor radiotherapy

Radiation could induce DNA damage, cell death, and changes of tumor phenotype and tumor microenvironment leading to the regulation of immune response. Immune checkpoint signaling pathways are involved in the immune tolerance of anti-microorganism responses and thus limit tissue damage. In the anti-tumor immune response, these pathways are associated with anti-functional activation of specific cytotoxic T cells and also enhance the inhibition effect of immune response, which always result in immune escape. Blockade of the immune checkpoint signaling pathways benefits to the anti-tumor immune responses and could delay tumor progress. As a result, the combination treatment of radiotherapy and immune checkpoint blockade has attracted more attentions in clinical application. This paper reviews the recent research progresses in the radiation effect of immune system, the regulation of immune checkpoints and the combination treatment of radiotherapy and immune checkpoint blockade in tumor therapy, trying to arouse some new clues in cancer therapy.