Figure 3.

TRAP-induced IL-10-producing B cells inhibit T cell immune response and their antitumor efficacy in a non-antigen specific manner. Tumor-bearing mice (n = 8) were s.c. vaccinated with DC_OVA (1 × 10⁶), and then adoptively transferred (i.v.) with E.G7-OVA or B16-F10 cells-derived TRAP-activated B cells (1 × 10⁷). (A-F) At day 7 after last vaccination, the frequencies of the IL-10⁺ CD19⁺ B cells in the spleens from mice of each group (n = 3) (A and B) and the IFN-γ⁺ CD8⁺ T cells (C and D) and IFN-γ⁺ CD4⁺ T cells (E and F) cells in the spleen were determined by flow cytometry. (G) The secretion of IFN-γ by splenocytes when re-stimulated in vitro with OVA was measured by ELISA. (H and I) remaining five mice were continuously monitored and measured tumor volume (H) and percentage of survival (I). Data (mean ± s.e.m) are representative of three independent experiments. NS: p > 0.05, * p < 0.05, ** p < 0.01, *** p < 0.001 by unpaired t-test (B, D, F and G), two-way analysis of variance (H), and log-rank test (I).