Pd1

Programmed cell death protein 1 (PD-1), also known as CD279, is a protein on the surface of cells that has a role in regulating the immune system's response to the cells of the human body by down-regulating the immune system and promoting self-tolerance by suppressing T cell inflammatory activity. This prevents autoimmune diseases, but it can also prevent the immune system from killing cancer cells.

Structure

PD-1 is a type I membrane protein of the immunoglobulin superfamily. It is encoded by the PDCD1 gene located on chromosome 2 in humans. The protein consists of an extracellular region, a transmembrane region, and an intracellular region. The extracellular region contains an immunoglobulin V-like domain.

Function

PD-1 is expressed on the surface of activated T cells, B cells, and myeloid cells. It interacts with its ligands, PD-L1 and PD-L2, which are expressed on the surface of antigen-presenting cells and some other cell types. The binding of PD-1 to its ligands inhibits T cell receptor signaling and reduces cytokine production and proliferation of T cells.

Clinical Significance

PD-1 and its ligands are important in the context of cancer immunotherapy. Tumors can exploit the PD-1 pathway to evade immune detection by expressing PD-L1, which binds to PD-1 on T cells and inhibits their activity. Blocking the interaction between PD-1 and PD-L1 with monoclonal antibodies can enhance the immune response against tumors. Drugs targeting PD-1, such as nivolumab and pembrolizumab, have been approved for the treatment of various cancers.

Research

Research on PD-1 continues to explore its role in various diseases, including autoimmune diseases, infectious diseases, and transplant rejection. Understanding the mechanisms of PD-1 signaling and its interactions with other immune checkpoints is crucial for developing new therapeutic strategies.

Related Pages

• PD-L1
• PD-L2
• Cancer immunotherapy
• T cell
• Autoimmune disease
• Nivolumab
• Pembrolizumab