PD-1 is an immune checkpoint and guards against autoimmunity through two mechanisms. First, it promotes apoptosis (programmed cell death) of antigen -specific T-cells in lymph nodes. Second, it reduces apoptosis in regulatory T cells (anti-inflammatory, suppressive T cells). [8][9]

PD-1 inhibitors and PD-L1 inhibitors are a group of checkpoint inhibitor anticancer drugs that block the activity of PD-1 and PDL1 immune checkpoint proteins present on the surface of cells. Immune checkpoint inhibitors are emerging as a front-line treatment for several types of cancer.

Programmed Cell Death Protein 1 (PD-1) plays a vital role in inhibiting immune responses and promoting self-tolerance through modulating the activity of T-cells, activating apoptosis of antigen-specific T cells and inhibiting apoptosis of regulatory T cells.

In order to avoid the attacking against ‘slightly altered’ aged somatic cells by the exquisitely evolved immune system of higher vertebrates, we obtained PD-1. Here, PD-1 functions to widen and re-define the border between ‘slightly altered self’ in aged individuals and ‘nonself’.

This review focuses on the small molecule agents targeting PD-1 checkpoint pathway for cancer immunotherapy and highlights various chemotypes/scaffolds and their characterization including binding and functionality along with reported mechanism of action.

PD-1 extends from the surface of T-cells, and interacts with two similar ligand proteins, PD-L1 and PD-L2, that are found on the surface of regulatory cells such as the cells that present antigens harvested from invaders.

Nov 13, 2017 · Programmed cell death protein 1 (PD1) is an inhibitory receptor that is expressed by all T cells during activation. It regulates T cell effector functions during various physiological...

The programmed cell death protein 1 (PD-1) is expressed by activated T cells that act as an immunoregulatory molecule, and are responsible for the negative regulation of T cell activation and peripheral tolerance.

Aug 1, 2017 · PD-1 and PD-L1 are membrane protein receptors with canonical immunoglobulin (Ig)-like extracellular domains responsible for interaction and signal transduction to intracellular domains.

Nov 3, 2016 · Here, I provide a brief overview of the molecular and biochemical events that are regulated by PD-1 ligation and their implications for mechanisms intrinsic and extrinsic to the cell that...