Hepatitis C virus infection and apoptosis

Figure 1 Signal transduction pathway of apoptosis in hepatocytes. Immune cells induce apoptosis in hepatocytes by death receptor ligands (TRAIL, TNFα, CD95Ligand, TGF-β) and granzyme B/perforin. Ligand-induced apoptosis activates caspase-8, whereas intrinsic apoptosis occurs via the mitochondrial permeability transition (PT) pore and activation of caspase-9. Caspase-9 and -8 activation converge in activation of the effector caspases-3, -6 and -7, resulting in irreversible apoptosis induction. HSC: Hepatic stellate cells; KC: Kupffer cells; CTL: Cytotoxic T-lymphocytes; NK: Natural killer cells.