The inhibition of caspase-1 activity by specific inhibitors in DH-VD₃–pretreated THP-1 cells is paralleled by a decrease in the release of mIL-1β. DH-VD₃–pretreated THP-1 cells were stimulated with 100 ng/mL of S minnesota Re 595 LPS in the presence of the caspase-1 inhibitors YVAD-CHO and YVAD-CMK, respectively, as indicated. Cell lysates and supernatants were prepared 18 hours after stimulation. (A) Caspase-1 activity assessed as described in the Materials and Methods. (B) Amount of IL-1β released as assessed by ELISA. Shown are mean values of four independent experiments ± SD. Differences are significantly with P < .01. (□) Without LPS; (▪) with LPS.