Background: Immune responses including Microglia and macrophage activation and peripheral
immune cells infiltration have been founded in the central nervous system (CNS) in recent
years. Thus, the traditional view of the adult brain as an immune-privileged organ has been changed.
Methods: A systematic literature search was performed using Pubmed and Embase electronic databases
without any limitations for a retrospective analysis.
Results: The increase a number of studies indicated that the PD-1(programmed cell death-1)/PD-Ls
signal pathway played an important role in regulating the immunopathogenesis of brain after injured.
The relevant knowledges about PD-1/PD-Ls signal pathway, and potential effect with immune cells,
cerebral ischemia, brain tumors and multiple sclerosis were reviewed in this paper.
Conclusion: PD-1/PD-Ls played important roles in maintaining immunity balance and the development
and prognosis of CNS diseases, but the specific mechanism was still not well understood.