Figure 5.
Effect of increasing number of old DCs on tumor growth and Ag-specific induction and function. Mice bearing 7-day established subcutaneous B16-OVA tumors were treated with 2× 106 young PP-DCs (1×), 2 × 106 old PP-DCs (1×) or 4 × 106 old PP-DCs (2×) or saline (DPBS), and tumors and spleens harvested 7 days later. (A) Graph depicts tumor size (n = 6 tumors per treatment group). (B) Splenocytes were stimulated for 6 hrs with OVA peptide, labeled with OVA pent-PE, CD8-FITC and IFNγ-PE-CY7 and analyzed by flow cytometry. Dot plots show OVA-pent staining and intracellular IFN-γ production by splenic CD8+ T cells. The indicated number shows the percentage of the gated population within the total CD8+ live cells (C) The percentage of IFN-γ+ cells among OVA-specific CD8+ T cells (determined using the elliptical gate in B) was assessed in three independent experiments, and the mean +/− SEM is shown. (D) IFN-γ CD8+ T cells were purified from spleens as described in Materials and Methods and assessed for cytotoxicity using B16-OVA tumor cells as targets. Data are expressed as mean +/− SEM of 3 independent experiments.