NOD2 and RIP2 specifically regulate NLRP3 inflammasome activation.

<p><b>(A–B)</b> WT, <i>Nod2^−/−</i> and <i>Rip2^−/−</i> BMDM were infected with 1MOI <i>Salmonella typhimurium</i> for 4 h and combined supernatant and lysates were examined by Western blot for caspase-1 cleavage (casp-1p20) visually (A) and by densitometry (B). <b>(C)</b> Supernatants were examined 4 h after <i>S. typhimurium</i> infection for IL-18 secretion. <b>(D–F)</b> WT, <i>Nod2^−/−</i> and <i>Rip2^−/−</i> BMDM were infected with 10MOI <i>S typhimurium Δfljb/flic</i> mutant for 18 h. Caspase-1 activation and IL-18 were examined as in panels A–C. <b>(G–I)</b> WT and <i>Rip2^−/−</i> BMDM were infected with 20MOI of <i>C. rodentium</i> for 2 h and <i>Rip2^−/−</i> cells were subsequently treated with the NLRP3 specific inhibitor glyburide or mock treated as a control. Caspase-1 activation and IL-18 were examined as in panels A–C. <b>(J–L)</b> WT and <i>Rip2^−/−</i> BMDM were infected with 1MOI of <i>S. typhimurium</i> and <i>Rip2^−/−</i> cells were simultaneously treated with the NLRP3 specific inhibitor glyburide or mock treated as a control. Caspase-1 activation and IL-18 were examined as in panels A–C. (A–L) Data are representative of three independent experiments with n = 2–3 wells per experiment and displayed as the mean ± SEM. (*, p<0.05; **, p<0.01; ***, p<0.001).