Figure 5.

Anti–CTLA-4/1MT treatment increases the ratio of effector T cells to T reg cells in tumor and elicits a tumor-specific T cell response. B16F10 tumors from untreated, anti–CTLA-4–treated, and anti–CTLA-4/1MT–treated C57BL/6 mice were harvested 15 d after tumor challenge and analyzed by flow cytometry for their content of effector T cells and T reg cells. (A) Tumor weights. (B) Percentage of CD8⁺, CD4⁺Foxp3⁻, and CD4⁺Foxp3⁺ T cells of total CD45⁺ cells. (C) Immune infiltrate analysis expressed as a percentage of total CD45⁺ cells. (D) Percentage of CD11b⁺Gr-1⁺ MDSCs of total CD45⁺ cells and representative dot plots. (E) Ratio of CD4⁺Foxp3⁻ to CD4⁺Foxp3⁺ cells and CD8⁺ to CD4⁺Foxp3⁺ cells. (F) Absolute numbers of CD8⁺ T cells per gram of tumor. (G) Frequency of CD8⁺GrB⁺ T cells of total CD45⁺ cells. TILs were restimulated for 4 h with PMA/Ionomycin (H) or overnight with DCs loaded with B16F10 tumor lysate or DCs with MC38 lysate as a nonmelanoma control tumor (I), and production of IFN-γ was determined by flow cytometry. Data were analyzed by two-way ANOVA (A, B, E, and F; *, P < 0.05; **, P< 0.01; NS, P = 0.06, P = 0.1) and Student’s t test (H; *, P < 0.05). Data represents one of three experiments with five independently analyzed mice/group.