Abstract: AIM: The DNA plasmid lipidosome (LP) vaccine based VEGFR2 extracellular region (exVEGFR2) was prepared in order to provide a new approach for cancer active immunotherapy.  METHODS: High fidelity PCR was used to amplify the target sequence of exVEGFR2 with two restriction site of KpnⅠ and XbaⅠ. The plasmid of pCMV/exVEGFR2 was constructed by connected exVEGFR2 with pCMV empty plasmid. The activity of immune activation was detected by ELISA. CTLs mediated cytotoxic activity was analyzed by 51Cr release assay. RESULTS: The 90 000 target specific band of VEGFR2 was detected by Western blot. After 6 weeks since the first time vaccination, an intense specific immune response of anti-VEGFR2 was detected by ELISA in the serum from the C57BL/6 mouse vaccinated with LP-pCMV/exVEGFR2 vaccine. The T cells from the spleen of mouse immunized with the vaccine induced the cytotoxicity effect on CT-26 with VEGFR2 positive. CONCLUSION: The results of the specific immune response of anti-VEGFR2 in vivo and the antitumor cytotoxicity in vitro by vaccinated with LP-pCMV/exVEGFR2 vaccine in mouse model, would lay the foundation for further study of VEGFR2 positive tumor treated in vivo by the active immunotherapy.

Key words: VEGFR2, lipidosome, pCMV plasmid, vaccine