TY - JOUR
T1 - Cytosolic double-stranded RNA activates the NLRP3 inflammasome via MAVS-induced membrane permeabilization and K+ efflux
AU - Franchi, Luigi
AU - Eigenbrod, Tatjana
AU - Muñoz-Planillo, Raúl
AU - Ozkurede, Ulas
AU - Kim, Yun Gi
AU - Chakrabarti, Arindam
AU - Gale, Michael
AU - Silverman, Robert H.
AU - Colonna, Marco
AU - Akira, Shizuo
AU - Núñez, Gabriel
N1 - Publisher Copyright:
Copyright © 2014 by The American Association of Immunologists, Inc.
PY - 2014/10/15
Y1 - 2014/10/15
N2 - The nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (Nlrp3) inflammasome plays an important role in inflammation by controlling the maturation and secretion of the cytokines IL-1β and IL-18 in response to multiple stimuli including pore-forming toxins, particulate matter, and ATP. Although the pathways activated by the latter stimuli lead to a decrease in intracellular K+ concentration, which is required for inflammasome activation, the mechanism by which microbial RNA activates Nlrp3, remains poorly understood. In this study, we found that cytosolic poly(I:C), but not total RNA from healthy macrophages, macrophages undergoing pyroptosis, or mitochondrial RNA, induces caspase-1 activation and IL-1β release through the Nlrp3 inflammasome. Experiments with macrophages deficient in Tlr3, Myd88, or Trif, indicate that poly(I:C) induces Nlrp3 activation independently of TLR signaling. Further analyses revealed that the cytosolic sensors Rig-I and melanoma differentiation-associated gene 5 act redundantly via the common adaptor mitochondrial antiviral signaling (Mavs) to induce Nlrp3 activation in response to poly(I:C), but not ATP or nigericin. Mechanistically, Mavs triggered membrane permeabilization and K+ efflux independently of the inflammasome which were required for poly(I:C)-induced Nlrp3 activation. We conclude that poly (I:C) activates the inflammasome through an Mavs-dependent surveillance pathway that converges into a common K+ lowering step in the cytosol that is essential for the induction of Nlrp3 activation.
AB - The nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (Nlrp3) inflammasome plays an important role in inflammation by controlling the maturation and secretion of the cytokines IL-1β and IL-18 in response to multiple stimuli including pore-forming toxins, particulate matter, and ATP. Although the pathways activated by the latter stimuli lead to a decrease in intracellular K+ concentration, which is required for inflammasome activation, the mechanism by which microbial RNA activates Nlrp3, remains poorly understood. In this study, we found that cytosolic poly(I:C), but not total RNA from healthy macrophages, macrophages undergoing pyroptosis, or mitochondrial RNA, induces caspase-1 activation and IL-1β release through the Nlrp3 inflammasome. Experiments with macrophages deficient in Tlr3, Myd88, or Trif, indicate that poly(I:C) induces Nlrp3 activation independently of TLR signaling. Further analyses revealed that the cytosolic sensors Rig-I and melanoma differentiation-associated gene 5 act redundantly via the common adaptor mitochondrial antiviral signaling (Mavs) to induce Nlrp3 activation in response to poly(I:C), but not ATP or nigericin. Mechanistically, Mavs triggered membrane permeabilization and K+ efflux independently of the inflammasome which were required for poly(I:C)-induced Nlrp3 activation. We conclude that poly (I:C) activates the inflammasome through an Mavs-dependent surveillance pathway that converges into a common K+ lowering step in the cytosol that is essential for the induction of Nlrp3 activation.
UR - http://www.scopus.com/inward/record.url?scp=84907494143&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.1400582
DO - 10.4049/jimmunol.1400582
M3 - Article
C2 - 25225670
AN - SCOPUS:84907494143
SN - 0022-1767
VL - 193
SP - 4214
EP - 4222
JO - Journal of Immunology
JF - Journal of Immunology
IS - 8
ER -