Dangerous Liaisons: Caspase-11 and Reactive Oxygen Species Crosstalk in Pathogen Elimination.

Recently, the focus of murine caspase-11 and human orthologs caspase-4, -5 research has been on their novel function to induce noncanonical inflammasome activation in direct response to Gram-negative bacterial infection. On the other hand, a new role in anti-bacterial autophagy has been attributed to caspase-11, -4 and -5, which currently stands largely unexplored. In this review, we connect lately emerged evidence that suggests these caspases have a key role in anti-bacterial autophagy and discuss the growing implications of a danger molecule--extracellular ATP--and NADPH oxidase-mediated ROS generation as novel inducers of human caspase-4, -5 signaling during infection.