The Multiple Faces of Programmed Cell Death Ligand 1 Expression in Malignant and Nonmaliqnant Cells

摘要

Programmed cell death ligand 1 (PD-L1, also known as CD274 and B7-H1) is a major immune checkpoint protein that mediates antitumor immune suppression and response.1 The importance of PD-Ll-based immune suppression is highlighted by the advent of anti-PD-Ll immunotherapies, which have moved to the forefront of cancer treatment.2'3 PD-L1 is an immunomodulatory transmembrane glycoprotein with approximately 43 KDa, and it is a member of the B7 family of costimulatory molecules.4 A wide variety of human malignancies, including melanoma, kidney cancers, and lung cancers, were recently shown to express PD-L1. The recent development of agents blocking the interaction between PD-L1 and its receptor, PD-1, has provided a new therapeutic strategy.3