Figure 2
IL-4 gene transfected glioma cell vaccine elicited an IFN-γ response against EphA2 883–891 epitope. PBMC samples were obtained on days 1 (pre-vaccine on the day of the first vaccine), 8, 15 (on the day of the second vaccine), and 42, and saved as frozen cells until all these cells were thawed at the same time, cultured in the presence of 20 IU/ml hIL-2 and autologous glioma cells for 5 days, and evaluated for the frequency of IFN-γ-producing cells in response to T2 cells loaded with the HLA-A2-binding EphA2883–891 peptide using ELISPOT assay. Each well contained 5 × 104 CD8+ cells and each group was evaluated in triplicate. Specific IFN-γ spots were calculated by subtracting the average of control spots (triplicate variation within a group was less than 10% in non-peptide-loaded T2 cell groups) from the total numbers of spots in peptide-loaded groups. Values indicate averages of triplicate samples for each time point, and bars indicate standard deviations. The number of spots in each post-vaccine time point was at least three times the standard-deviation of the pre-vaccine value.