Fig 6.

The cytotoxicity of bacterium-generated NO· can be partially inhibited by a pancaspase inhibitor. (A) HBE cells were cocultured with wild-type O35E in MEM* containing 1 mM nitrite and 100 μM caspase inhibitor control Z-FA-fmk, caspase-3 inhibitor Z-DEVD-fmk, or pancaspase inhibitor Z-VAD-fmk. The results shown are representative of data from three repeated experiments (each in triplicate). (B) A current working model of NO·-mediated bacterial pathogenesis. Bacterium-generated NO· may induce caspase-dependent and caspase-independent host cell death and modulate host cell gene expression through TNF-α signaling. The confocal microscopy images were captured using a 100× objective.