Rv0652-treated DCs pulsed with OVA_257–264 enhances CTL activity and CD8⁺ T-cell tumor infiltration.

<p>C57BL/6 mice were immunized with PBS, iDC, DCs-OVA (DCs pulsed with OVA_257–264), Rv0652-DCs-OVA (Rv0652-treated DCs pulsed with OVA_257–264), or LPS-DCs-OVA (LPS-treated DCs pulsed with OVA_257–264) on days 1 and 7. (A) Splenocytes from the mice immunized with PBS or various DCs for 10 days were treated with OVA_257–264 (10 ug/ml) for 7 days and then co-cultured with EL4 (CFSE^low) or E.G7 (CFSE^high) cells. After 2 days, mixed lymphocyte tumor cultures were analyzed by flow cytometry. Histograms show antigen-specific lysis of tumor cells. The percentage in each panel indicates specific lysis of E.G7 cells (i). Bar graphs show the percentage of specific lysis of E.G7 cells representing 4 independent experiments (ii). ***<i>P</i><0.001. (B) Splenocytes (i) and tumor infiltrating CD8⁺ T cells (ii) from the mice immunized with PBS or various DCs for 10 days were treated with OVA_257–264 (10 ug/ml) for 24 h IL h IL-2 and IFN-gamma production was measured in supernatants by ELISA. Data are the mean and SEM of 4 experiments. *<i>P</i><0.05 and ***<i>P</i><0.001. (C) C57BL/6 mice were challenged s.c. with E.G7 tumor cells to the right flank area. One, 3, and, 5 days after the tumor challenge, mice were injected intravenously with PBS, iDC, DCs-OVA (DCs pulsed with OVA_257–264), or Rv0652-DCs-OVA (Rv0652-treated DCs pulsed with OVA_257–264) (n = 3). At day 20, the cells in the tumor area were analyzed for the presence of CD8⁺CD69⁺ T cells. The percentage in each panel indicates the infiltration of CD8⁺CD69⁺ T cells into the tumor area. Data are the mean and SEM of 3 experiments. **<i>P</i><0.05 and ***<i>P</i><0.001.