Invitrogen™ Granzyme B Monoclonal Antibody (GrB-7)

Descripción

The antibody reacts with the 33 kD human serine protease granzyme B. It does not react with human granzyme A. It is used as a marker for NK-cells and activated cytotoxic T-cells (CTL). This protease is localized in cytoplasmic granules and gives a granular staining pattern. Granzyme B is involved in target cell apoptosis during lymphocyte mediated cyto-toxicity. Exocytosis of granzyme containing granules in the cytoplasm of the target cell will lead to induction of DNA fragmentation and apoptosis of the target cell.

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.