INTRODUCTION A major pathophysiologic mechanism in sepsis is impaired host immunity which results in failure to eradicate invading pathogens and increased susceptibility to secondary infections. Although many immunosuppressive mechanisms exist, increased expression of the inhibitory receptor programmed cell death 1 (PD-1) and its ligand (PD-L1) are thought to play key roles. The newly recognize...

Background: Programmed cell death protein-1 (PD-1)/PD-L1 pathway is one of the immune checkpoint pathways involved in regulation of the immune responses and suppression of anti-tumor defense. PD-1/B7-H1-blocking antibodies improve immune responses such as cytotoxic activity of CD8+/CD4+T cells and also increase mortality of tumor cells; however their use is accompanied by adverse effects in pat...