Background:
The antigen HCA587 (also known as MAGE-C2), which is considered a cancer-testis antigen,
exhibits upregulated expression in a wide range of malignant tumors with unique immunological properties, and may thus
serve as a promising target for tumor immunotherapy.
Objective:
To explore the antitumor effect of the HCA587 protein vaccine and the response of humoral and cell-mediated
immunity.
Methods:
The HCA587 protein vaccine was formulated with adjuvants CpG and and ISCOM. B16 melanoma cells were
subcutaneously inoculated to C57BL/6 mice, followed by treatment with HCA587 protein vaccine subcutaneously. Mouse
survival was monitored daily, and tumor volume was measured every 2 to 3 days. The tumor sizes, survival time and
immune cells in tumor tissues were detected. And the vital immune cell subset and effector molecules were explored.
Results:
After treatment with HCA587 protein vaccine, the vaccination generated elicited significant immune responses,
which delayed tumor growth and improved animal survival. The vaccination increased the proportion of CD4+ T cells
expressing IFN-γ and granzyme B in tumor tissues. Depletion of CD4+T cells resulted in an almost complete abrogation of
the antitumor effect of the vaccination, suggesting that the antitumor efficacy was mediated by CD4+ T cells. In addition,
knockout of IFN-γ resulted in a decrease in granzyme B levels which were secreted by CD4+ T cells, and the antitumor
effect was also significantly attenuated.
Conclusion:
The HCA587 protein vaccine may increase the levels of granzyme B expressed by CD4+ T cells, and this
increase is dependent on IFN-γ, and the vaccine resulted in a specific tumor immune response and subsequent eradication
of the tumor.
