Bioactive, Human PD1 Protein Dimer, His-Avi Tag

Human programmed cell death protein 1 (PD-1), is a Type I membrane protein and cell surface receptor on T cells and B cells and belongs to the immunoglobulin superfamily. PD-1 is also known as PDCD1, cluster of differentiation 279 (CD279), systemic lupus erythematosus susceptibility 2 (SLEB2), and systemic lupus erythematosus susceptibility (hSLE1). PD-1 contains an extracellular immunoglobulin-V-like (Ig-V-like) domain followed by a transmembrane region, and an intracellular tail. PD-1 is an immune checkpoint that binds two ligands, PD-L1 and PD-L2, which are members of the B7 family. PD-L1 serves as an immunosuppressive ligand for PD-1 and the overexpression of PD-L1 on many tumor cells can prevent the immune system from attacking tumors. Inhibition of the interaction between PD-1 and PD-L1 can enhance antitumor activity, which has led to a new class of drugs called PD-1 inhibitors to activate the immune system and treat certain types of cancer. Although previously considered monomeric, PD-1 has been shown to have a propensity for forming homodimers and this homodimerization increases the potency of its activity. Therefore, a recombinant protein mimicking the PD-1 dimer conformation can be crucial for cancer therapeutic discovery.