Redox regulation of apoptotic cell death in the immune system.

Apoptosis is a special form of cell death, which can be triggered by a variety of signals and pathophysiological conditions, including oxidative stress. Activation of members of the caspase family of cysteine proteases is a crucial event in the apoptotic death program. Being cysteine proteases, the caspases are sensitive to the redox status of the cell, and their activity is blocked by excessive oxidative stress. Thus, alterations of intracellular redox status may either trigger or block the apoptotic death program, depending on the severity of the oxidative stress.