Immunoblotting was performed as previously described (24 (link), 25 ). For immunoblotting of in vivo samples, day 3 post-infection lung tissue was used. The antibodies used were: anti–caspase-1 (AdipoGen, AG-20B-0042, 1:2000), anti–caspase-3 (CST, #9662, 1:1000), anti-cleaved caspase-3 (CST, #9661, 1:1000), anti–caspase-7 (CST, #9492, 1:1000), anti-cleaved caspase-7 (CST, #9491, 1:1000), anti–caspase-8 (CST, #4927, 1:1000), anti-cleaved caspase-8 (CST, #8592, 1:1000), anti-pMLKL (CST, #37333, 1:1000), anti-MLKL (Abgent, AP14272b, 1:1000), anti-GSDMD (Abcam, ab209845, 1:1000), anti-GSDME (Abcam, ab215191, 1:1000), anti–β-actin (Proteintech, 66009–1-IG, 1:5000), and HRP-conjugated secondary antibodies (Jackson ImmunoResearch Laboratories, anti-rabbit [111–035-047], 1:5000; anti-mouse [315–035-047], 1:5000). Densitometry of the bands was quantified in ImageJ and normalized to the band density of β-actin. IL-18 release was measured using ELISA kits (Invitrogen, BMS618–3). IL-1β and TNF release were measured by multiplex ELISAs (Millipore MCYTOMAG-70K). Cytokines from BALF were measured as previously described (26 ).