Seigo Terawaki    Department   Kawasaki Medical School  Kawasaki Medical School, Department of Molecular and Genetic Medicine,    Position   Assistant Professor with Special Assignment
Article types	原著
Language	English
Peer review	Peer reviewed
Title	PD-1 inhibits antiviral immunity at the effector phase in the liver.
Journal	Formal name：The Journal of experimental medicine Abbreviation：J Exp Med ISSN code：00221007/00221007
Domestic / Foregin	Foregin
Volume, Issue, Page	198(1),pp.39-50
Author and coauthor	Iwai Yoshiko, Terawaki Seigo, Ikegawa Masaya, Okazaki Taku, Honjo Tasuku
Authorship	2nd author
Publication date	2003/07
Summary	Unlike naive T cells, effector T cells can be activated by either T cell receptor signal or costimulatory signal alone and therefore the absence of costimulatory molecules on tissue cells cannot explain the tolerance mechanism at the effector phase. Here we report that PD-L1, the ligand for the immunoinhibitory receptor PD-1, was expressed on vascular endothelium in peripheral tissues. Liver nonparenchymal cells including sinusoidal endothelial cells and Kupffer cells constitutively expressed PD-L1 and inhibited proliferation and cell division of activated T cells expressing PD-1. The absence of PD-1 induced proliferation of effector T cells in the adenovirus-infected liver and resulted in rapid clearance of the virus. These results indicate that PD-1 plays an important role in T cell tolerance at the effector phase and the blockade of the PD-1 pathway can augment antiviral immunity.
DOI	10.1084/jem.20022235
PMID	12847136