Effect of PAO on the production of mature IL-1β by OCIM2 cells. Cells were incubated in the presence and absence of 0.1 μmol/L PAO. The amount of mature IL-1β protein produced by these cells was then assessed by Western immunoblotting. The arrow points to the 17.5-kD mature IL-1β protein. Lane C shows control mature IL-1β protein, lane 1 shows protein from cells incubated in tissue culture media with DMSO, and lane 2 shows protein from cells incubated with PAO.