Immunosuppressive checkpoint proteins

Immunosuppressive checkpoint proteins are regulatory surface proteins (such as PD-1, PD-L1, CTLA-4, LAG-3, TIM-3) primarily found on T cells and other immune cells, which help to suppress immune activation and maintain self-tolerance. Their physiological role is to prevent excessive immune responses and protect healthy tissue, but in cancer and chronic infections, their overactivation or dysregulation can allow pathological cells to evade immune detection and destruction. Therapies known as immune checkpoint inhibitors target these proteins to block their inhibitory signals, thereby reactivating immune responses against tumors and some other diseases. These therapies are now standard-of-care for many cancers but are associated with unique immune-related adverse events and require specific biomarkers for patient selection.

Other names

Immune checkpointsinhibitory immune checkpointsco-inhibitory receptors

Blockade of receptor-ligand interaction (e.g. PD-1/PD-L1, CTLA-4/CD80/CD86), preventing inhibitory signal transduction and restoring T cell activity. Enhancement of immune response against tumors by disabling immunosuppressive signaling.