The diverse functions of the PD1 inhibitory pathway

  title={The diverse functions of the PD1 inhibitory pathway},
  author={Arlene H. Sharpe and Kristen E. Pauken},
  journal={Nature Reviews Immunology},
T cell activation is a highly regulated process involving peptide–MHC engagement of the T cell receptor and positive costimulatory signals. Upon activation, coinhibitory 'checkpoints', including programmed cell death protein 1 (PD1), become induced to regulate T cells. PD1 has an essential role in balancing protective immunity and immunopathology, homeostasis and tolerance. However, during responses to chronic pathogens and tumours, PD1 expression can limit protective immunity. Recently… 

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