FIGURE 8.

Pathogenic strategies to inhibit apoptosis and necroptosis. Pathogens block apoptosis and necroptosis at multiple levels. Pathogens block the caspase-9 pathway of apoptosis by modulating BCL-2 family proteins to restrict mitochondrial outer membrane permeabilization (MOMP) or by inhibiting the activation of executioner caspases. Pathogens disrupt the ability of receptors to sense their cognate ligands and inhibit the caspase-8 pathway of apoptosis by interfering with the functioning of caspase-8. Pathogens impair necroptosis by inhibiting the interactions between RIP homotypic interaction motif (RHIM) domain-containing proteins and the activation of MLKL. Specific strategies employed by bacteria and viruses to inhibit pyroptosis are presented in TABLES 3 and 4, respectively. Cyt. C, cytochrome c; DD, death domain; DED, death effector domain.