Fig 8. The viability of H. capsulatum is critical to signal 2 in inflammasome activation.

(A and B) BMDCs were stimulated with live or heat-killed H. capsulatum for 18 h. (A) Secreted IL-1β and TNF in culture supernatants were quantified by ELISA (n = 3). (B) Culture supernatants and cell lysates were subjected to Western blotting. (C and D) Acridine orange and Magic Red^® were added 1 h before (C) or after (D) stimulation with live or heat-killed H. capsulatum. The nuclei were stained by Hoechst reagent. White arrows point to ingested-H. capsulatum yeasts in DIC/Hoechst field. Cells were viewed under confocal microscope. (E) Collected cell lysates and supernatants from live or heat-killed H. capsulatum stimulated cells were subjected to cathepsin B activity assay. Error bars indicate standard deviation of the mean. One representative of three (A) or two (B and E) independent experiments is presented. * p < 0.05, *** p < 0.001 [2-tailed t-test (A and E)].