摘要
AIM:To construct a DNA vaccine encoding human alpha-fetoprotein (hAFP)/heat shock protein 70 (HSP70), and to study its ability to induce specific CTL response and its protective effect against AFP-expressing tumor.METHODS: A DNA vaccine was constructed by combiningh AFP gene with HSP70 gene. SP2/0 cells were stably transfected with pBBS212-hAFP and pBBS212-hAFP/HSP70 eukaryotic expression vectors. Mice were primed and boosted with DNA vaccine hAFP/HSP70 by intramuscular injection, whereas plasmid with hAFP or HSP70 was used as controls. ELISPOT and ELISA were used to detect IFN-γ-producing splenocytes and the level of serum anti-AFP antibody from immunized mice respectively. In vivo tumor challenge was measured to assess the immune effect of the DNA vaccine.RESULTS: By DNA vaccine immunization, the results of ELISPOT and ELISA showed that the number of IFN-γ-producing splenocytes and the level of serum anti-AFP antibody were significantly higher in rhAFP/HSP70 group than in hAFP and empty plasmid groups (95.50±10.90 IFN-γ spots/10^6 cells vs 23.60±11.80 IFN-γ spots/10^6 cells,7.17±4.24 IFN-γ spots/106 cells, P<0.01; 126.50±8.22μg/mL vs 51.72±3.40μg/mL, 5.83±3.79μg/mL, P<0.01). The tumor volume in rhAFP/HSP70 group was significantly smaller than that in pBBS212-hAFP and empty plasmid groups (37.41±7.34 mm^3 vs 381.13±15.48 mm^3, 817.51±16.25 mm^3,P<0.01). CONCLUSION: Sequential immunization with a recombinant DNA vaccine encoding AFP and heat shock protein70 could generate effective AFP-specific T cell responses and induce definite antitumor effects on AFP-producing tumors, which may be suitable for some clinical testing as a vaccine for HCC.
AIM:To construct a DNA vaccine encoding human alpha- fetoprotein(hAFP)/heat shock protein 70(HSP70),and to study its ability to induce specific CTL response and its protective effect against AFP-expressing tumor. METHODS:A DNA vaccine was constructed by combining hAFP gene with HSP70 gene.SP2/0 cells were stably transfected with pBBS212-hAFP and pBBS212-hAFP/HSP70 eukaryotic expression vectors.Mice were primed and boosted with DNA vaccine hAFP/HSP70 by intramuscular injection,whereas plasmid with hAFP or HSP70 was used as controls.ELISPOT and ELISA were used to detect IFN- γ-producing splenocytes and the level of serum anti-AFP antibody from immunized mice respectively.In vivo tumor challenge was measured to assess the immune effect of the DNA vaccine. RESULTS:By DNA vaccine immunization,the results of ELISPOT and ELISA showed that the number of IFN-γ- producing splenocytes and the level of serum anti-AFP antibody were significantly higher in rhAFP/HSP70 group than in hAFP and empty plasmid groups(95.50±10.90 IFN-γ spots/10~6 cells vs 23.60±11.80 IFN-γ spots/10~6 cells, 7.17±4.24 IFN-γ spots/10~6 cells,P<0.01;126.50±8.22μg/mL vs 51.72±3.40 μg/mL,5.83±3.79 μg/mL,P<0.01).The tumor volume in rhAFP/HSP70 group was significantly smaller than that in pBBS212-hAFP and empty plasmid groups (37.41±7.34 mm^3 vs381.13±15.48 mm^3,817.51+16.25 mm^3, P<0.01). CONCLUSION:Sequential immunization with a recombinant DNA vaccine encoding AFP and heat shock protein70 could generate effective AFP-specific T cell responses and induce definite antitumor effects on AFP-producing tumors,which may be suitable for some clinical testing as a vaccine for HCC.
基金
Supported by the Research Fund for Young Scholars of Beijing,No.02120031
