Abstract
The programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) pathway have been shown to be involved in tumor-induced and sepsis-induced immunosuppression. However, whether this pathway is involved in the surgery-induced dysfunction of T lymphocytes is not known. Here, we analyzed expression of PD-1 and PD-L1 on human peripheral mononuclear cells during the perioperative period. We found that surgery increased PD-1/PD-L1 expression on immune cells, which was correlated with the severity of surgical trauma. The count of T lymphocytes and natural killer cells reduced after surgery, probably due to the increased activity of caspase-3. Caspase-3 level was positively correlated with PD-1 expression. Profile of perioperative cytokines and hormones in plasma showed a significantly increased level of interferon-α, as well as various inflammatory cytokines and stress hormones. In ex vivo experiments, administration of anti-PD-1 antibody significantly ameliorated T-cell proliferation and partially reversed the T-cell apoptosis induced by surgical trauma. We provide evidences that surgical trauma can induce immunosuppression through the PD-1/PD-L1 pathway. This pathway could be a target for preventing postoperative cellular immunosuppression.