FIGURE 4: C. pneumoniae infection activates caspase-1 and IL-1β release. Equal numbers of GECs were infected with C. pneumoniae and cultured in equal volumes of medium for five days in (A) and four days in (B, C) at a MOI of 5. At 0, 1, 2, 3, 4 and 5 days post-infection, supernatants were collected and analyzed for the presence of mature IL-1β or activated caspase-1 protein. (A) IL-1β ELISA. Assays were performed in triplicates, n = 3 independent experiments. (B) Western blot representative gel and (C) quantification of active caspase-1 proteins. Three independent experiments were performed. For panels A and C: error bars represent ± SD; 2-sided, paired Student's t test, ***P < 0.001.