背景
Cytolytic T lymphocytes (CTL) and natural killer (NK) cells share the remarkable ability to
recognize, bind, and lyse specific target cells.They are thought to protect their host by
lysing cells bearing on their surface 'nonself' antigens, usually peptides or proteins resulting
from infection by intracellular pathogens.The protein described here is a T cell- and natural
killer cell-specific serine protease that may function as a common component necessary for
lysis of target cells by cytotoxic T lymphocytes and natural killer cells.
