Utilizing VEGF165b mutant as an effective immunization adjunct to augment antitumor immune response.

•mVEGF165b as an immunization adjunct was able to induce high titers of anti-VEGF antibody.•High anti-VEGF antibody titers decrease immunosuppression by reducing the proportion of Tregs in the spleen or in peripheral circulation.•The decrease immunosuppression augments the immune response induced by peptide vaccine from Mucin-1.•mVEGF165b can be used as a potential adjunct with other tumor vaccines to increase anti-tumor efficacy and also promote the T cell infiltration into tumor.