Visualizing Effector Triggered Immunity in Response to Pore-Forming Toxins by Live-Cell Imaging.

The NLRP3 inflammasome senses the activity of pore-forming toxins secreted by Staphylococcus aureus. The bacterial toxins compromise plasma membrane integrity which activates the NLRP3 inflammasome to induce host pore-forming proteins and cellular suicide, termed pyroptosis. Host cell death rates are routinely determined at pre-defined time points and on whole cell populations. To capture the dynamic interactions between bacterial pore-forming toxins and host cell death factors, we have applied live-cell imaging techniques capable of analyzing single cell events in real time. Here, we describe methods using live-cell imaging to determine the host responses, such as plasma membrane integrity, mitochondrial health, and apoptotic caspases, towards pore-forming toxins.