[The study of anti-tumor activities of DC vaccine loaded with multi-epotipes of survivin].

AIM: To observe the anti-tumor activity of dendritic cell (DC)vaccine loaded with multi-epitopes of survivin. METHODS: The recombinant plasmid pPIRESneo3.0-survivin (4)/Th which include four survivin HLA-A2-restricted CD8(+); CTL epitopes and a CD4(+);Th epitope, pPIRESneo3.0-survivin (4) which include four survivin CD8(+); CTL epitopes, were transfected into human dendritic cells respectively. There were five groups, which included survivin(4)/Th group, survivin(4)group, empty plasmid group, untransfected group and T lymphocytes group The expression of CD83 and CD86 on the surface of DCs, the expression of CD4 and CD8a on the surface of T lymphocytes, the apoptotic rates of MCF-7 cells after treated by DC vaccine were measured by flow cytometry; IFN-γ levels of all groups were detected by ELISA and the growth inhibition of MCF-7 cells after being treated with DC vaccine was tested by MTT colorimetry. RESULTS: The results of flow cytometry revealed that high levels CD83 and CD86 were expressed on the surface of DCs; high levels CD4 and CD8a were expressed on the surface of T lymphocytes; the IFN-γ levels in survivin(4)/Th group [(66.50±3.34)ng/L]were significantly higher than that in survivin(4)group[(46.10±1.35)ng/L], empty plasmid group[(25.17±0.32)ng/L], untransfected group [(25.47±0.95)ng/L] or T lymphocytes group[(23.73±0.50)ng/L](P<0.05). The inhibition rate of MCF-7 cells in survivin(4)/Th group was significantly higher than that in survivin(4)group, empty plasmid group, untransfected group or T lymphocytes group(P<0.05). The apoptotic rate of MCF-7 cells in survivin(4)/Th group was (10.63±0.29)% after treated by DC vaccine, which was significantly higher than that in in survivin(4)group, empty plasmid group, untransfected group or T lymphocytes group(P<0.05). CONCLUSION: The DCs vaccine loaded with multi- CD8(+); CTL epitopes of survivin has strong anti-tumor effects. CD4(+); Th cells can promote the anti-tumor activity of CD8(+);CTL.

[Construction of the eukaryotic expression vector encoding multi-epitope fusion protein of human survivin and its expression in dendritic cells].

AIM: To construct a eukaryotic expression vector encoding the multi-epitope fusion protein of human survivin, and express it in human dendritic cells. METHODS: Recombinant cDNA sequence encoding four HLA-A2-restricted CD8+ CTL epitopes and a CD4+ Th epitope was synthesized and cloned into pBluescript II SK (+) vector. After confirmed by sequencing, the cDNA fragment was inserted to eukaryotic expression vector pIRESneo3.0 to generate the recombinant plasmid pPIRESneo3.0-survivin (4)/Th. The pPIRESneo3.0-survivin (4)/Th was then transfected into human dendritic cells and the transfectants were selected for stable expression. RESULTS: The eukaryotic expression vector encoding the multi-epitope fusion protein of survivin was constructed, and successfully transfected into human dendritic cells. CONCLUSION: The eukaryotic expression vector encoding the multi-epitope fusion protein of survivin has been constructed successfully, and stably expressed in human dendritic cells, which provides clues for further research on multi-epitope cancer vaccine.