1. Volume 45, Issue 4, Pages 468-472 (October 2006)
Turning on the off switch: Regulation of anti-viral T cell responses in the liver by the PD- 1/PD-L1 pathway 
Arash Grakoui, E. John Wherry, Holly L. Hanson, Christopher Walker, Rafi Ahmed 
Journal of Hepatology 
Volume 45, Issue 4, Pages (October 2006)
DOI: /j.jhep
Copyright © 2006 European Association for the Study of the Liver Terms and Conditions

2. Fig. 1
Achieving T cell balance. Pathogen-specific CD8+ T cells are “turned on” through interaction of their TCR with MHC I presenting antigen in the presence of appropriate costimulation. These same T cells may be “turned off” through the interaction of PD-1 on their cell surface and PD-L1 expressed on hepatocytes and liver-resident parenchymal cells.
Journal of Hepatology  , DOI: ( /j.jhep )
Copyright © 2006 European Association for the Study of the Liver Terms and Conditions

3. Fig. 2
T cell activation and proliferation require positive signaling through the TCR receptor complex. The interaction of PD-1 with PD-L1 leads to phosphorylation of the ITSM domain of PD-1, recruitment of SHP-2, and cell cycle arrest.
Journal of Hepatology  , DOI: ( /j.jhep )
Copyright © 2006 European Association for the Study of the Liver Terms and Conditions