Pyroptotic death storms and cytopenia.

For over two decades, we have embraced the cytokine storm theory to explain sepsis, severe sepsis and septic shock. The failure of numerous large-scale clinical trials, which aimed to treat sepsis by neutralizing inflammatory cytokines and LPS, indicates that alternative pathophysiological mechanisms are likely to account for sepsis and the associated immune suppression in patients with severe infection. Recent insights that extricate pyroptotic death from inflammatory cytokine production in vivo have highlighted a need to investigate the consequences of apoptotic and non-apoptotic death in contributing to cytopenia and immune suppression. In this review, we will focus on the biochemical and cellular mechanisms controlling pyroptosis, a Caspase-1/11 dependent form of cell death during infection.