Differential capacity to induce costimulatory molecules among 4 histone HDACIs.

(A) Cell viability curve of HL60 cells incubated by various concentrations of HDACIs for 48 hours. Cell viability was examined by PI exclusion method. Each agent was subsequently used at the concentrations indicated by a closed circle (●) for the induction of CD86. (B) Expression of CD86 was examined in the presence of each HDACI (SB, TSA, FR, and TPX) for 48 hours at the concentrations indicated. Closed histograms (in black) represent medium-treated cells (MFI = 5.5), whereas open histograms with solid or broken lines represent HDACI-treated cells at the various concentrations indicated in each box.