Conjugation of toll-like receptor-7 agonist to gastric cancer antigen MG7-Ag exerts antitumor effects

Figure 1 Chemical structures of the synthetic vaccines. MG1: Monoclonal gastric cancer 7 antigen mono-epitope; MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.

Figure 2 Vaccines induced cytokine release of mouse bone marrow dendritic cells and mouse spleen lymphocytes in vitro. Cells were incubated with vaccines for 24 h. Quantification of A: Tumor necrosis factor-α (TNF-α); and B: Interleukin-12 (IL-12) in bone marrow dendritic cells; and C: Interferon-γ (IFN-γ); and D: IL-12 in lymphocytes. Data are presented as mean ± SE (n = 3). MG1: Monoclonal gastric cancer 7 antigen mono-epitope; MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.

Figure 3 Vaccines reduced Ehrlich ascites carcinoma tumor burden in BALB/c mice. Mice were immunized with vaccines or PBS as control every 2 wk for a total of three times. Data are presented as mean ± SE (n≥ 5); ^aP < 0.05, ^bP < 0.01 vs control group. MG1: Monoclonal gastric cancer 7 antigen mono-epitope; MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.

Figure 4 Vaccines induced serum antibody against monoclonal gastric cancer 7 antigen in BALB/c mice. Every two weeks after immunization (week 2, 4, 6) and after sacrifice (week 9), serum samples were collected and antibody titers were determined by ELISA. Data points represent mean ± SE (n = 5); ^aP < 0.05, ^bP < 0.01 vs control group. MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.

Figure 5 Vaccines induced antibody-dependent cell-mediated cytotoxicity. Serum samples were collected from BALB/c mice immunized with vaccines or PBS controls. Antibody-dependent cell-mediated cytotoxicity activities were indicated by lysis of Ehrlich ascites carcinoma (EAC) cells using the lactate dehydrogenase method. Data are presented as mean ± SE (n = 5); ^bP < 0.01 vs control group. MG1: Monoclonal gastric cancer 7 antigen mono-epitope; MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.

Figure 6 Vaccines induced cytotoxic T cell responses. Lymphocytes were separated from the spleens of mice immunized with vaccines or PBS as control. Cytotoxic T lymphocyte activities were indicated by lysis of Ehrlich ascites carcinoma (EAC) cells using the lactate dehydrogenase method. Data are presented as mean ± SE (n = 5); ^bP < 0.01 vs control group; ^cP < 0.05 vs T7+MG3 group. MG1: Monoclonal gastric cancer 7 antigen mono-epitope; MG3: Monoclonal gastric cancer 7 antigen tri-epitope; T7: Toll-like receptor-7 agonist.