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Caspase-8 Scaffolding Function And Mlkl Regulate Nlrp3 Inflammasome Activation Downstream Of Tlr3., Seokwon Kang, Teresa Fernandes-Alnemri, Corey Rogers, Lindsey Mayes, Ying Wang, Christopher Dillon, Linda Roback, William Kaiser, Andrew Oberst, Junji Sagara, Katherine A Fitzgerald, Douglas R Green, Jianke Zhang, Edward S Mocarski, Emad S Alnemri

Department of Biochemistry and Molecular Biology Faculty Papers

TLR2 promotes NLRP3 inflammasome activation via an early MyD88-IRAK1-dependent pathway that provides a priming signal (signal 1) necessary for activation of the inflammasome by a second potassium-depleting signal (signal 2). Here we show that TLR3 binding to dsRNA promotes post-translational inflammasome activation through intermediate and late TRIF/RIPK1/FADD-dependent pathways. Both pathways require the scaffolding but not the catalytic function of caspase-8 or RIPK1. Only the late pathway requires kinase competent RIPK3 and MLKL function. Mechanistically, FADD/caspase-8 scaffolding function provides a post-translational signal 1 in the intermediate pathway, whereas in the late pathway it helps the oligomerization of RIPK3, which together with …