A novel DNA vaccine constructed by heat shock protein 70 and melanoma antigen-encoding gene 3 against tumorigenesis.

Melanoma antigen-encoding gene 3 (MAGE-3) is an ideal candidate for a tumor vaccine although its potency need to be increased. Heat shock proteins (HSPs) represents a potential approach for increasing the potency of DNA vaccines. In the present study, a fusion DNA vaccine composed of Mycobacterium tuberculosis HSP70 and MAGE-3 was constructed and used to immunize C57BL/6 mice against B16 or B16-MAGE-3 tumor cells. The results show that the HSP70-MAGE-3 fusion DNA vaccine enhanced the frequency of MAGE-3-specific cytotoxic T-cells as compared to the MAGE-3 DNA vaccine or the HSP70/MAGE-3 cocktail DNA vaccine (P < 0.05). In conclusion, the results indicate that the HSP70-MAGE-3 fusion DNA vaccine can strongly activate MAGE-3 specific cellular immunological reactions and thus significantly inhibit the growth of B16-MAGE-3 tumors, improving the survival of tumor-bearing mice, and the HSP70-MAGE-3 fusion DNA vaccine has a significant therapeutic effect on the tumors that express MAGE-3 antigens.