Granzyme

Granzymes are a family of serine proteases stored in the cytoplasmic granules of cytotoxic T lymphocytes and natural killer cells. They play a central role in the immune system by inducing programmed cell death (apoptosis) in target cells that have become cancerous or infected with viruses or bacteria. Granzymes enter target cells through pores formed by perforin and cleave intracellular substrates to activate apoptotic pathways. There are five known human granzymes—A, B, H, K, M—each encoded by distinct genes (GZMA, GZMB, GZMH, GZMK, GZMM). While Granzyme B is best known for activating caspases leading to apoptosis via both caspase-dependent and -independent mechanisms, other granzymes like A and K also induce cell death but can promote inflammation through cytokine release. Elevated levels of certain granzymes have been linked to various diseases including infections, cancers, airway inflammation, and thermal injury. Granzymes remain an area of active research both as potential therapeutic targets/modulators and disease biomarkers.[1][2][3][4]

Other names

Serine protease family (granule-associated)Cytotoxic T lymphocyte serine proteaseT-cell associated protease 1TSP-1HuTPST-cell derived serine proteinase

Therapeutic modulation would likely involve inhibition or enhancement of granzyme-mediated apoptosis or immune activation, but no approved drugs exist yet.