Immune Checkpoint Protein

Immune checkpoint proteins are a class of molecules found on the surface of various immune cells, such as T cells and antigen-presenting cells, as well as some cancer cells. Their primary function is to regulate the immune response, ensuring it is strong enough to combat pathogens and abnormal cells but not so aggressive that it damages healthy tissues. These proteins act as critical modulators for maintaining self-tolerance (preventing autoimmunity) and controlling the magnitude and duration of immune responses. Tumors often exploit these pathways by upregulating inhibitory checkpoint ligands like PD-L1 to evade detection and destruction by the host’s immune system. Targeting immune checkpoint protein interactions has become a cornerstone in modern immuno-oncology.

Blocking immune checkpoint protein interactions to enhance anti-tumor T cell activity