Invitrogen™ Granzyme B Monoclonal Antibody (16G6), eBioscience™, Invitrogen™

Granzyme B is a member of the granzyme serine protease family, and is found in the granules of cytotoxic T cells and NK cells. Granzyme B has been described as CGL1 (cathepsin G-like-1), a serine protease expressed only in cytotoxic T-lymphocytes after cell activation, and CTLA-1 (cytotoxic T lymphocyte-associated serine esterase 1) based on identification of mRNA in various cytotoxic T cells, but not observed in non-cytotoxic lymphoid cells. Granzyme B is crucial for the rapid induction of target cell death by apoptosis, induced by interaction with cytotoxic T cells. The receptor involved in this process has been identified as mannose 6-phosphate receptor which functions as a death receptor for Granzyme B during cytotoxic T cell-induced apoptosis. Granzyme B enters target cells to cleave caspase-3 and initiate the caspase cascade leading to DNA fragmentation and apoptosis. Granzyme B can also act through a mitochondrial apoptosis pathway by cleaving the Bid protein. Granzymes are neutral serine proteases, which are stored in specialized lytic granules of cytotoxic T lymphocytes (CTLs) and in natural killer (NK) cells. A number of granzymes (A to G) have been isolated and cloned from mouse CTLs and NK cells, however in man, fewer have been cloned and identified.