Pyroptosis

Injury and physical trauma may inflict accidental cell death, but we have come to realize during the past four decades that cells may also actively engage cell death when needed. These regulated cell death forms are intrinsically connected with human embryonic development, homeostatic maintenance and disease pathology. For instance, the human body is composed of approximately 1014 cells, millions of which are removed daily by apoptosis and replaced with newly differentiated cells in order to secure organ functionality. Apoptotic cells are orderly packed in ‘apoptotic bodies’ for uptake by neighboring cells and professional phagocytes, thereby avoiding deleterious inflammatory responses by circulating leukocytes. Unlike apoptosis, however, more recently identified forms of regulated cell death — such as necroptosis and pyroptosis — are characterized by an early breach of the plasma membrane integrity, which results in extracellular spilling of the intracellular contents. Here, we will describe and discuss this and other features of pyroptosis. Vande Walle and Lamkanfi discuss pyroptosis — a proinflammatory form of regulated cell death that relies on the enzymatic activity of inflammatory proteases of the caspase family.