Nlrp3 inflammasome activation and Gasdermin D-driven pyroptosis are immunopathogenic upon gastrointestinal norovirus infection
Fig 5
Nlrp3 as well as GSDMD contribute to MNV-induced lethality and intestinal inflammation in Stat1-/- mice.
(A, B) Unprimed BMDMs from Stat1-/-Nlrp3+/- and Stat1-/-Nlrp3-/- mice were left untreated (Control) or infected with either UV-inactivated or live MNV at MOI 5. 24 hours post-infection (A) culture supernatant was analyzed for secreted IL-1β and (B) cell lysates were immunoblotted for IL-1β, caspase-1 and GSDMD maturation. (C) Age- and sex-matched Stat1-/-Nlrp3+/- and Stat1-/-Nlrp3-/- littermates were infected with 10/ PFU MNV via oral gavage. Four days post-infection (C) spleen and (D) MLN lysates were prepared and were immunoblotted for proteolytic maturation of (C-D) IL-1β and (D) GSDMD. Each lane represents a different mouse. (E) Kaplan-Meier survival curve of Stat1-/-Nlrp3+/- and Stat1-/-Nlrp3-/- littermates infected with 106 PFU of MNV via oral gavage. (F) Kaplan-Meier survival curve, (G) fecal consistency and (H) fecal Lipocalin-2 levels at indicated days post-infection of age- and sex-matched Stat1-/-, Stat1-/-Nlrp3-/- and Stat1-/-Gsdmd-/- mice infected with 106 PFU of MNV via oral gavage. Six Stat1-/- mice from (F) were unable to produce feces at three days post-infection and were therefore omitted from the analyses in (G) and (H). Data shown in (A) are the means ± SD of triplicate wells from a representative experiment out of 2 independent experiments. Data shown in (B) is representative for 2 independent experiments. Data shown in (E-H) represent graphs each combined from 2 independent experiments. Statistics (E, F) Nonparametric log-rank test; (G, H) Mann Whitney U-test; ns not significant; *p<0.05; **p<0.01; ***p<0.001.