Kinetics of peptide presentation by RNA-transfected DCs. Monocyte-derived DCs generated from an HLA-A*02–positive donor were electroporated with in vitro–transcribed MUC1 RNA and used as targets in a standard 51Cr-release assay at different time points following transfection as indicated (A: *, 1 hour; ×, 2 hours; ▴,3 hours; ▪, 4 hours; B: *, 6 hours; ×, 8 hours; ▴, 11 hours; ▪, 15 hours; ♦, 18 hours). Autologous CTLs specific for the HLA-A*02–binding MUC1-derived peptide M1.1 were used as effector cells.