Résumé
Programmed death-1(PD-1)is a major co-suppression receptor expressed on T cells.Binding with its ligands (PD-L1 and PD-L2),PD-1 can inhibit T cell proliferation,activation and cytokine secretion.In normal organs,PD-1 /PD-Ls signaling pathway plays an important role in maintaining immune tolerance,while during tumorigenesis,it can suppress T cell immune response and promote tumor immune escape.This article reviewed the research progress on PD-1 /PD-Ls signaling pathway,comprised of structure and expression of PD-1 /PD-Ls, mechanism of the signaling pathway,as well as the expression characteristics of soluble form of PD-1 /PD-L1 (sPD-1 /sPD-L1),and summarized the categories of anti-PD-1 /PD-Ls antibodies and their clinical trials in canc-er immunotherapy.