Measurement of CTL activity and IFN-γ release in mice vaccinated with prophylactic IL-13Rα2 DNA and boosted with ECDα2. Splenocytes restimulated with MCA304 (A) or 4T1 (C) tumor cells for 1 week in culture medium containing IL-2 (20 IU/mL) were used as effector cells. MCA304 or 4T1 target cells labeled with 51Cr for 2 hours, washed thrice, and then plated into 96 well plates with effector cells. Specific lysis was calculated as described in materials and methods after 4 hours of culture. Culture supernatants of splenocytes restimulated with mitomycin C-treated MCA304 (B) or 4T1 (D) tumor cells for 48 hours and were assessed by ELISA for murine IFN-γ production. Experiments were repeated twice; bars, SD.