Perforin [PRF1/2470]

Perforin is a potent cytolytic poreforming protein. It is a specific marker of functionally active cytotoxic T-lymphocytes (CTLs) and natural killer (NK) cells. Perforin is a key effector mechanism in T cellmediated cytotoxicity. It mediates cytolysis of target cells by membrane damage and apoptosis. Plays a key role in secretory granule-dependent cell death, and in defense against virus-infected or neoplastic cells. Plays an important role in killing other cells that are recognized as non-self by the immune system, e.g. in transplant rejection or some forms of autoimmune disease. Can insert into the membrane of target cells in its calcium-bound form, oligomerize and form large pores. Promotes cytolysis and apoptosis of target cells by facilitating the uptake of cytotoxic granzymes.