[Construction and anti-tumor efficacy of a pentameric peptide vaccine that targets S100A8].

Myeloid-derived suppressor cells(MDSC) play critical roles in immune escape of tumor. We hypothesized that elimination of tumor-induced MDSCs might help to block tumor growth. Therefore, we constructed a cholera toxin B based peptide vaccine that targets a MDSC surface marker S100A8. Immunized BALB/c mice with CTB-S100A8 plus aluminum hydroxide induced high titers of anti-S100A8 antibodies and reduced tumor burden significantly in 4T1 mice model. We also found the vaccination led to significant reduction of tumor-induced monocytic MDSC(M-MDSC), with no effect on innate MDSCs, dendritic cell(DC) and macrophage(Mφ), demonstrating that targeting tumor-induced MDSC may be a promising approach in cancer immunotherapy.