近年来 ，免疫检查点抑制剂在抗肿瘤治疗方面取得了令人振奋的进展 ，通过不断探索 ，对 PD-L1、PD-1、CD80、CTLA-4等免疫分子间相互作用模式有了更深入的了解。除经典地作为T细胞抑制性受体外，研究者发现PD-L1可与PD-1或CD80分子在同一细胞上共表达并通过顺式相互作用发挥正性免疫调节功能，显著影响肿瘤细胞与免疫细胞间互作网络及免疫治疗疗效，为肿瘤免疫治疗作用机制的认识带来新的变革。本文对顺式PD-L1/PD-1、顺式PD-L1/CD80通路及其与CTLA-4、CD28分子组成的复杂网络间的相互作用进行了深入分析，并概述了这种顺式互作通路的阻断对T细胞信号、细胞毒性功能和抗肿瘤免疫治疗疗效的影响。

In recent years, investigation on immune checkpoint inhibitors has made exciting progress in anti-tumor therapy. Through continuous exploration, there is a deeper understanding of intermolecular interaction patterns among PD-L1, PD-1, CD80, CTLA-4, etc.In addition to classically acting as a T cell inhibitory receptor, PD-L1 was found to be co-expressed with PD-1 or CD80 on the same cell and play a positive immunoregulatory function through cis-interaction, significantly affecting the interaction network between tumor cells and immune cells and the efficacy of immunotherapy, and bringing new changes to the understanding of the mechanisms of cancer immunotherapy. This review provides an in-depth analysis of the cis-PD-L1/PD-1 and cis-PD-L1/CD80 pathways and their interactions with a complex network of CTLA-4 and CD28 molecules, finally outlines the effects of blocking this cis-interaction pathway on T cell signaling, cytotoxic function, and the efficacy of anti-tumor immunotherapy.

国家重点研发项目（No. 2016YFC1303800）；吉林省科技厅科技发展计划项目（No.20190303146SF）；吉林省发展和改革委员会省级产业创新专项资金项目（No. 2017C022）；吉林省科技厅重点实验室建设项目（No. 20170622011JC）