Fig. 6.

H₂O₂-mediated IL-1β release is a result of NLRP3 inflammasome activation. Unprimed human bronchial epithelial cells were infected with D39∆cps at MOI 50 (a, b), or stimulated with 150 μM H₂O₂ (c, d). Cells were treated with Ac-YVAD-cmk, Ac-DEVD-CHO, and MCC950, 1 h prior to the other stimuli. Cytotoxicity (a, c) and IL-1β release (b, d) were evaluated at the 6-h time point. The data are displayed as box plots. The level of significance was determined using Kruskal-Wallis test with Dunn's post-test (n ≥ 4; *p < 0.05; **p < 0.01; ***p < 0.001). Western blot analyses of D39∆cps-infected (e) and H₂O₂-stimulated (f) 16HBE cells. e 16HBE cells were infected with different D39 mutant strains or (f) stimulated with H₂O₂ for indicated time points, cells were lysed, and 20 μg of total protein was separated via SDS-PAGE. Representative images of GSDMD and β-actin as a loading control from 5 independent experiments are displayed (n = 5). g Western blot analyses of Streptococcus pyogenes 5448 or Staphylococcus aureus LUG2012-infected 16HBE cells. Original uncropped versions of the blots are shown in online suppl. Fig. 7. GSDMD, gasdermin-D.