Sepsis is characterized by high mortality and poor prognosis and is one of the leading causes of death among patients in the intensive care unit (ICU). In the past, drugs that block early inflammatory responses have done little to reverse the progression of sepsis. Programmed cell death receptor 1 (PD-1) and its two ligands, programmed cell death receptor ligand 1(PD-L1) and programmed cell death receptor ligand 2 (PD-L2), are negative regulatory factors of the immune response of the body. Recently, the role of the PD-1 signaling pathway in sepsis has been widely studied. Studies showed that the PD-1 signaling pathways are closely related to the mortality and prognosis of sepsis patients. In the immunotherapy of sepsis, whether in animal experiments or clinical trials, anti-PD-1/PD-L1 antibodies have shown good promise. In this review, firstly, we focus on the immunosuppressive mechanism of sepsis and the structure and function of the PD-1 signaling pathway. The variety of the PD-1 signaling pathways in sepsis is introduced. Then, the relationship between the PD-1 signaling pathway and immune cells and organ dysfunction and the regulatory factors of the PD-1 signaling pathway in sepsis is discussed. Finally, the application of the PD-1 signaling pathway in sepsis is specifically emphasized.

脓毒症的特点是死亡率高、预后差，是重症监护病房 (ICU) 患者死亡的主要原因之一。过去，阻断早期炎症反应的药物几乎没有逆转败血症的进展。程序性细胞死亡受体1（PD-1）及其两个配体程序性细胞死亡受体配体1（PD-L1）和程序性细胞死亡受体配体2（PD-L2）是机体免疫反应的负调控因子. 最近，PD-1 信号通路在脓毒症中的作用得到了广泛研究。研究表明，PD-1信号通路与脓毒症患者的死亡率和预后密切相关。在脓毒症的免疫治疗中，无论是动物实验还是临床试验，抗PD-1/PD-L1抗体都显示出良好的前景。在这次审查中，首先，我们关注脓毒症的免疫抑制机制以及PD-1信号通路的结构和功能。介绍了脓毒症中 PD-1 信号通路的多样性。然后讨论了PD-1信号通路与免疫细胞和器官功能障碍的关系，以及PD-1信号通路在脓毒症中的调控因素。最后，特别强调了 PD-1 信号通路在脓毒症中的应用。