Vaccination with scFvNLDC-145-HER2 protects mice from challenge with HER2-expressing tumor cells and induces memory immune responses. A animals (10 mice per group) were vaccinated with HER2, neu, scFvNLDC-145-HER2 or scFvNLDC-145-neu on days -21 and -7. Control animals received pcDNA3.1. On day 0, mice were inoculated s.c. with D2F2/E2 tumor cells. Tumor developments were monitored, and animal survival was calculated. Left panel, kinetics of tumor growth; Right panel, survival curve. B the vaccinated animals were challenged with parental HER2-negative D2F2 cells on day 0. C the long-term surviving mice from scFvNLDC-145-HER2 group were rechallenged with D2F2/E2, D2F2, or syngeneic unrelated 4 T1 tumor cells 3 months after initial tumor challenge. Tumor growth was followed. Bars, SE. *, P < 0.001, scFvNLDC-145-HER2 compared with other groups.