Programmed death-1 (PD-1) was initially isolated from apoptosis-induced cells by subtractive hybridization. It is a type I transmembrane protein, and its extracellular region consists of a single Ig-like variable (IgV) domain. The amino acid sequence of mouse PD-1 is 59.4 % identical to the human counterpart, and a putative tyrosine kinase-association motif is well conserved. PD-1 is an inhibitory molecule expressed by activated B and T cells and has been implicated in immune tolerance. Mice deficient in PD-1 develop lupus-like proliferative arthritis and glomerulonephritis. PD-1 ligand 1 (PD-L1) and then PD-1 ligand 2 (PD-L2) are the ligands of PD-1. Binding of PD-1 to its ligand PD-L1 leads to the inhibition of T cell receptor-mediated lymphocyte proliferation and cytokine secretion. PD-1/PD-L1 interaction suppresses immune responses against autoantigens and tumors and plays an important role in the maintenance of peripheral immune tolerance. Antibodies against PD-1 or PD-L1 leads to increased antitumor immunity. PD-1 and its ligand PD-L1 are overexpressed in many autoimmune diseases, including inflammatory bowel disease, rheumatoid arthritis, and type 1 diabetes. Interactions between PD-1 and PD-L1 promote tolerance by blocking the TCR-induced stop signal. PD-L1 expression by tumor cells may induce and maintain regulatory T cells in the tumor, allowing tumor progression by enhanced suppression of antitumor T-cell responses. PD-1, PD-L1 and PD-L2 also have soluble forms aside from their membrane bound form.
Size
10 μg
Concentration
n/a
Applications
BA
Other Names
Programmed Cell Death Protein 1, PD1, PDCD1, CD279