FIG. 6.

Double-edged sword of targeting TLR4 for sepsis intervention. In lethal endotoxin shock or gram-negative bacterial sepsis, TLR4 plays a deleterious role in mediating cytokine storm, CV collapse, organ damage, and death. In contrast, in nonlethal or low-grade bacterial sepsis, TLR4 plays a beneficial defense role in neutrophil migration, neutrophil phagocytosis, and bacterial clearance. However, targeting TLR4 by genetic deletion or pharmacological inhibition would thus generate opposite outcomes. CV, cardiovascular. Color images are available online.