Immunity, Granzymes and Cell Killing

Abstract

Abstract Cytotoxic lymphocytes protect us from viral infection and cancer by directly killing tumour cells, or cells harbouring a virus. One crucial mechanism they use to kill their targets is known as the ‘granule exocytosis’ pathway. This involves secretion of a potent mix of toxins, resulting in transfer of granule proteases (granzymes) from the killer cell into the target cell, where they cleave various intracellular substrates to activate diverse signalling pathways to cell death. Access to the target cell cytosol depends on a pore‐forming protein toxin, perforin. Because granule exocytosis is a crucial part of the body's natural defence against such ..