Inflammasomes Coordinate Pyroptosis and Natural Killer Cell Cytotoxicity to Clear Infection by a Ubiquitous Environmental Bacterium.

ABSTRACT: Defective neutrophils in patients with chronic granulomatous disease (CGD) cause susceptibility to extracellular and intracellular infections. Microbes must first be ejected from intracellular niches to expose them to neutrophil attack, so we hypothesized that inflammasomes detect certain CGD pathogens upstream of neutrophil killing. Here, we identified one such ubiquitous environmental bacterium, Chromobacterium violaceum, whose extreme virulence was fully counteracted by the NLRC4 inflammasome. Caspase-1 protected via two parallel pathways that eliminated intracellular replication niches. Pyroptosis was the primary bacterial clearance mechanism in the spleen, but both pyroptosis and interleukin-18 (IL-18)-driven natural killer (NK) cell responses were required for liver defense. NK cells

SUBMITTER: Maltez VI 

PROVIDER: S-EPMC4654968 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature