Pyroptosis: A Caspase-1-Dependent Programmed Cell Death and a Barrier to Infection

Infection elicits a number of innate protective responses in the host that cooperate to promote effective pathogen clearance. Increasingly, the inflammatory response to infection appears to be coupled to cell death as an important mediator of host defence. In this chapter we review the modalities of “pyroptosis”, a highly inflammatory form of cell death mediated by the inflammasome and caspase-1 activation. Occurring in the context of infection, pyroptosis is morphologically, mechanistically and physiologically distinct from other forms of cell death. The pathogenic factors that initiate pyroptosis and the cellular mechanisms and signalling pathways responsible for its execution are examined, with a focus on the role of the inflammasome in these processes. Finally, we discuss the possible physiological significance of this unique form of cell death during infection, that is, how pyroptosis can favour pathogen elimination on one hand, while contributing to the pathophysiology of disease on the other. K. Labbé Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada H3A 2B4 M. Saleh (*) Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada H3A 2B4 and Department of Medicine, McGill University, McGill Life Sciences Complex, Montreal, QC, Canada H3A 1A1 and McGill Life Sciences Complex, Bellini Pavillion, Room 364, 3649 Promenade Sir-William Osler, Montreal, QC, Canada H3G 0B1 e-mail: [email protected] I. Couillin et al. (eds.), The Inflammasomes, Progress in Inflammation Research, DOI 10.1007/978-3-0348-0148-5_2, # Springer Basel AG 2011 17