M. bovis triggers caspase-1 activation and IL-1β secretion in THP-1 macrophages.

A. Cells were infected at the indicated MOIs and samples were harvested at 14 hpi. Culture supernatant was analyzed for IL-1β and caspase-1, and cell lysates were analyzed for proIL-1β, procaspase-1, and β-actin by immunoblotting. B. Cells were pretreated with 50 μM Z-YVAD-FMK for 1 h, and then infected with M. bovis at an MOI of 10 in the presence or absence of Z-YVAD-FMK. Culture supernatant and lysates were analyzed by immunoblotting. C. Cells were treated with 1 μg/mL cytochalasin D to block phagocytosis for 1 h, and then infected with M. bovis in the presence or absence of cytochalasin D. Culture supernatant and lysates were analyzed by immunoblotting. Abbreviations: Sup, culture supernatant; Lys, cell lysates; Z-YVAD, Z-YVAD-FMK; cyto D, cytochalasin D. Data from one representative experiment of three are presented.