The Ememging Pathogens Institute Seminar Series
Inflammasome Activation in Epithelial Cells Infected with Bacterial Pathogens
David Ojcius, Ph.D.
Microbiology and Immunology
University of California, Merced
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Inflammasomes have been extensively charcterized in monocytes and macrophages, but not in epithelial cells, which are the preferred host cells for many pathogens. Here we show that gingival and cervical epithelial cells express a functional NLRP3 inflammasome. Infection of gingival cells by Porphyromoas gingivalis leads to production of pro-1L-1B, but not secretion of the cytokine. Addition of the "danger signal" ATP to infected gingival cells leads to caspase-1 activation and IL-1B secretion. In contrast, infection of cervical epithelial cells by Chlamydia trachomatis leads to activation of caspase-1, throught a proces requiring the NLRP3 inflammasome. In monocytes and macrophages, caspase-1 is involved in procelling and secretion of pro-inflammatory cytokines such as IL-1B, caspase-1 has been recently shown to enhance lipid metabolism. We now show that, in cervical epithelial cells, caspase-1 activation is also required for optimal groth of the intracellular chlamydiae.