FIG 1.

K1-CPS induces IL-1β secretion through caspase-1. (A and B) J774A.1 macrophages were incubated for 5.5 h with or without K1-CPS or K1-CPS-TFA and then for 30 min with or without 5 mM ATP. The levels of activated caspase-1 (p10) in the cells (A) and IL-1β in the culture medium (B) were measured by Western blotting and ELISA, respectively. (C and D) J774A.1 macrophages were incubated for 30 min with or without the caspase-1 inhibitor YVAD-CHO, for 5.5 h with or without 1 μg/ml of K1-CPS, and then for 30 min with or without 5 mM ATP. The levels of activated caspase-1 (p10) in the cells (C) and IL-1β in the culture medium (D) were measured by Western blotting and ELISA, respectively. In panels A and C, the results are representative of three separate experiments. In panels B and D, the data are expressed as the means ± SD from three separate experiments. ***, P < 0.001.