1.C.39.2.8
Perforin 1, PRF1 of 555 aas.  Plays a key role in secretory granule-dependent cell death and in defense against virus-infected and 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 (Law et al. 2010). Promotes cytolysis and apoptosis of target cells by facilitating the uptake of cytotoxic granzymes. Perforin gene mutations contribute to hereditary cancer predisposition (Chaudhry et al. 2016). After perforin is secreted by CD8+ cytotoxic T-lymphocytes (CTLs) and disrupts the membranes of extracellular vesicles (EVs), adenosine is released from the EVs and acts as an immunosuppressive metabolite by binding to the adenosine receptor on the CTL membrane. This mechanism provides a novel survival strategy using cancer cell-derived EVs (Tadokoro et al. 2020).