Antitumor immunity induced by recombinant vaccine alpha-fetoprotein-heat shock protein 70 complex

摘要

Aim: To construct a recombinant vaccine alpha-fetoprotein (AFP)-heat shock protein (HSP70) complex, and study its ability to induce specific cytotoxic T lymphocyte (CTL) response and its protective effect against AFP-producing tumor. Methods: A recombinant vaccine was constructed by conjugating mouse alpha-fetoprotein to heat shock protein 70. By way of intracutaneous injection, mice were primed and boosted with recombinant vaccine mAFP/HSP70, whereas single mAFP or HSP70 injection as controls. The ELISPOT and ELISA were used to measure the frequency of cells producing the cytokine IFN-γ in splenocytes and the level of anti-AFP antibody of serum from immunized mice respectively. In vivo tumor challenge were carried out to assess the immune effect of the recombinant vaccine. Results: By recombinant mAFP/HSP70 vaccine immunization, the results of ELISPOT and ELISA showed that the number of splenic cells producing IFN-γand the level of anti-AFP antibody of serum were significantly higher in mAFP/HSP70 group than those in mAFP and HSP70 groups (108.50±11.70 IFN-γspots/10{sup}6 cells vs 41.60 ±10.40 IFN-γspots/10{sup}6 cells, 7.32 ±3.14 IFN-γspots/10{sup}6 cells, P<0.01; 156.32±10.42μg/mL vs 66.52±7.35 μg/mL, 5.73±2.89μg/mL, P<0.01). The tumor volume in mAFP/HSP70 group was significantly smaller than that in mAFP and HSP70 groups (42.44±7.14mm{sup}3 vs 392.23±12.46mm{sup}3, 838.63± 13.84mm{sup}3, P<0.01). Conclusions: The study further confirmed the function of heat shock protein 70's immune adjuvant. Sequential immunization with recombinant mAFP/HSP70 vaccine could generate effective antitumor immunity on AFP-producing tumor. The recombined mAFP/HSP70 vaccine may be suitable for serving as an immunotherapy for HCC.