[Research advances of myeloid-derived suppressor cells mediated by programmed death-1/programmed death-ligand 1 pathway in sepsis-induced immunosuppression].

Sepsis is a life-threatening organ dysfunction due to dysregulation of the body's response to infection. The immunosuppressive phase of sepsis is also an important cause of high morbidity and mortality in patients with advanced sepsis. Myeloid-derived suppressor cell (MDSC), as a heterogeneous population of Gr1+CD11b+ immature cells, play a pivotal role in the immune process of advanced sepsis together with programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) with immunosuppressive properties. This review summarized the research progress of PD-1/PD-L1 pathway-mediated mechanism of MDSC in septic immunosuppression in recent years. The mechanism of action of PD-1/PD-L1 pathway in the immunosuppressive stage, the effects of PD-1/PD-L1 pathway on the "dual-signaling" model of MDSC through the signaling pathway and cytokines, as well as the time course of PD-1/PD-L1 pathway mediation in sepsis were described.