Screening Vaccine Adjuvant From Four Kinds Of Chinese Herbal Monomer In Vitro And Application Of Procyanidin As Tumor Cell Vaccine Adjuvant In A Murine Melanoma Model

Objective To detect immune-activating effects of procyanidin, gastrodin, baicalein and apigenin on antigen presenting cells of RAW264.7 and DC2.4 and search for new tumor vaccine adjuvant, then evaluate anti-tumor activity of procyanidin in a murine melanoma model. Methods After different concentrations of four kinds of Chinese herbal monomer were used to stimulate RAW264.7 or DC2.4 for 48 hours, cells were obtained and stained with antibody, protein expression of CD80, CD86, MHC I and MHC II on RAW264.7 and DC2.4 were analyzed by FCM; C57BL/6 mice were immunized with the combination of irradiated murine melanoma B16F10 tumor cells and procyanidin via intramuscular injection in order to evaluate anti-tumor effects of procyanidin as an adjuvant in vivo. Results Results showed that after 48 hours stimulation with different concentrations of four kinds of Chinese herbal monomer in vitro, the expression levels of CD80, CD86, MHC I, MHC II were all up-regulated on both RAW264.7 and DC2.4 in comparison with control, procyanidin exhibited stronger immune-activating effects; results showed procyanidin promoted immune-activating effects on DC in vivo, the treatment with a combination of tumor antigen and procyanidin induced some degree of anti-tumor effects as evaluated by the inhibition of tumor growth and the prolongation of survival, the tumor-bearing mice showed a high level of specific cytotoxic activity and had activated CD8 T cells that secreted perforin, IFN-γ and TNF-α in response to stimulation with the antigen in vitro. Conclusion Procyanidin was found having potential application value as a tumor vaccine adjuvant, and this study have laid theoretical foundation for further application of procyanidin being used as a promising vaccine adjuvant.