IL-32-induced THP-1 differentiation via activation of caspase-1. THP-1 cells were treated with recombinant IL-32 (0.1 μg/ml) or caspase-1 inhibitor (50 nM) for 6 days in the absence of FBS. (A) Individual THP-1 cells were photographed. (B) Real-time PCR of macrophage markers, CD11b and CD14 after simulation of THP-1 cells. (C) FACS analysis of protein expression of macrophage markers, CD11b and CD14. Blank, unstimulated cells; Cas-1 inhi, caspase-1 inhibitor. *P < 0.05; significantly different from the unstimulated cells' value, **P < 0.05; significantly different from the IL-32-stimulated cells' value. (Original magnification × 400). FACS, fluorescence-activated cell sorter; FBS, fetal bovine serum; IL, interleukin; PCR, polymerase chain reaction.