Cell death plays a major role in the homeostasis and development of multicellular organisms. There are two forms of cell death, necrosis and apoptosis. Necrosis is a passive type of death which occurs when a cell dies of physical alteration. Apoptosis, or programmed cell death, calls for active participation of the cell in its own death, implying the induction of a genetic program in reaction to specific stimuli.

Shigellosis, or bacillary dysentery, is an acute diarrheal disease that is characterized by the presence of blood and mucus in the stools. Upregulation of apoptosis has been shown in both animal models of shigellosis and in dysenteric patients. Shigella mediates apoptosis by the specific activation of the eukaryotic host cell programmed cell death mediator Interleukin-lb (IL-1) converting enzyme (ICE). We propose the model that ICE mediated apoptosis in macrophages allows the efficient release of IL-1b which triggers the acute inflammation typical of shigellosis.

Current research in the lab is focused on analyzing the mechanism of Shigella induced cell death as well as in understanding the role of apoptosis in pathogenesis.