Fig. 4.
Induction of anti-Her-2 immunity by DNA versus cell vaccines in BALB Her-2 Tg mice. a BALB Her-2 Tg mice were injected i.p. with 0.5 mg anti-CD25 mAb, PC61, 10 days before mice were immunized by i.m. electro-vaccination with blank vector, pE2TM and pGM-CSF or by i.p. injection with 2 × 106 SKOV3 cells. The vaccination was repeated three times every 2 weeks. b Her-2 Ab was measured by flow cytometry at 2 weeks after each vaccination. c PBL were collected 2 weeks after the last vaccination and cells from each group were pooled. Her-2-specific T cells were enumerated by IFN-γ ELISPOT essay as described in “Materials and methods”. d At 2 weeks after the last immunization, mice were challenged s.c. with 2 × 105 D2F2/E2 tumor cells. ** P < 0.005 compared to vector-immunized group