title: Redundant roles for inflammasome receptors NLRP3 and NLRC4 in host defense against Salmonella.
abstract: Intracellular pathogens and endogenous danger signals in the cytosol engage NOD-like receptors (NLRs), which assemble inflammasome complexes to activate caspase-1 and promote the release of proinflammatory cytokines IL-1beta and IL-18. However, the NLRs that respond to microbial pathogens in vivo are poorly defined. We show that the NLRs NLRP3 and NLRC4 both activate caspase-1 in response to Salmonella typhimurium. Responding to distinct bacterial triggers, NLRP3 and NLRC4 recruited ASC and caspase-1 into a single cytoplasmic focus, which served as the site of pro-IL-1beta processing. Consistent with an important role for both NLRP3 and NLRC4 in innate immune defense against S. typhimurium, mice lacking both NLRs were markedly more susceptible to infection. These results reveal unexpected redundancy among NLRs in host defense against intracellular pathogens in vivo.
authors.affiliation: Department of Microbiology and Immunology, Stanford School of Medicine, Stanford University, Stanford, CA, USA.
authors.forename: Petr
authors.initials: P
authors.lastname: Broz
authors.forename: Kim
authors.initials: K
authors.lastname: Newton
authors.forename: Mohamed
authors.initials: M
authors.lastname: Lamkanfi
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Mariathasan
authors.forename: Vishva M
authors.initials: VM
authors.lastname: Dixit
authors.forename: Denise M
authors.initials: DM
authors.lastname: Monack
mesh_terms: D000825:Animal Structures / Q000382:microbiology; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D001769:Blood / Q000382:microbiology; D053468:CARD Signaling Adaptor Proteins; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D020170:Caspase 1 / Q000235:genetics / Q000378:metabolism; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D022083:Cytoplasmic Structures / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D005408:Flagellin / Q000235:genetics; D007113:Immunity, Innate / Q000502:physiology*; D007375:Interleukin-1 / Q000378:metabolism; D020382:Interleukin-18 / Q000097:blood / Q000378:metabolism; D053583:Interleukin-1beta / Q000097:blood / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D018448:Models, Immunological; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D011498:Protein Precursors / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics / Q000276:immunology; D012480:Salmonella Infections / Q000276:immunology* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000235:genetics / Q000276:immunology
chemical_list: D051017:Apoptosis Regulatory Proteins; D001426:Bacterial Proteins; D053468:CARD Signaling Adaptor Proteins; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D003598:Cytoskeletal Proteins; D007375:Interleukin-1; D020382:Interleukin-18; D053583:Interleukin-1beta; C512299:Ipaf protein, mouse; D008565:Membrane Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; D011498:Protein Precursors; C498534:Pycard protein, mouse; C440638:SPI-2 protein, Salmonella; C419942:Spi1 protein, Salmonella; C043830:interleukin 1 precursor; D005408:Flagellin; D020170:Caspase 1