Fig. 4.

Specific processing of the Cyp239 epitope by K562/A2 cells by cytolysis (a), γ-interferon ELISPOT (b), and γ-interferon ELISA (c). a The Cyp239 T-cell clone was cocultured with tumor cell targets (5,000 cells/well), and cytolytic activity was measured by standard europium release assay at the varying E:T ratios shown. Dendritic cells (DC) and K562/A2 cells were nucleofected with 20 μg of RNA-encoding Cyp1B1 antigen or the control CML66 tumor antigen. Only K562/A2/Cyp1B1 + cells are efficiently lysed by the T-cell clone. The positive control (T2 cells pulsed with Cyp239) and negative control targets (T2 cells pulsed with the Her2 369 peptide) are shown. b The target cells from A (25,000 cells/well) were cocultured with the Cyp239 T-cell clone (500 cells/well), and γ-interferon secretion was determined by ELISPOT assay. Only Cyp1B1-transfected K562/A2 cells and Cyp239 peptide-pulsed cells efficiently stimulated γ-interferon secretion. c The target cells from a and b were titrated as shown for their ability to stimulate the Cyp239 T-cell clone (10,000 cells/well), and γ-interferon secretion was measured by ELISA assay