Inhibition of class I MHC–restricted presentation of endogenous OVA by CsA and tacrolimus. Indicated amounts of CsA (○), tacrolimus (▿), or rapamycin (□) were added to cultures of DC2.4 cells that were treated with mitomycin C and then loaded with soluble OVA by osmotic shock. After 2 hours, the cells were washed, and then class I MHC–restricted presentation assays were performed with B3Z cells as described in Figure 1A. Each data point represents the mean plus or minus SD of values obtained from 3 experiments.