Fig. 3.

Effects of IL-6 and TNF-α on the in vitro induction and in vivo priming of tumor-specific CTLs. a (Left) Naïve young (7 W) and aged (60 W) BALB/c mice were injected s.c. with DTX-treated 1 × 10⁶ CT26 cells. Two weeks later, spleen cells were harvested and cultured with the AH1 peptide and IL-2 (20 U/mL) for 4 days. These cultured cells were examined for their cytotoxicity against CT26 cells using the ⁵¹Cr-release assay. Each group consisted of four mice. (Right) The results at an E/T ratio of 100 are shown *P < 0.05, **P < 0.01. NS not significant. Y young, A aged. Similar results were obtained in two independent experiments. b (Upper) Naïve aged (45–50 W) BALB/c mice were injected s.c. with DTX-treated 1 × 10⁶ CT26 cells. Anti-IL-6 or anti-TNF-α neutralizing mAb (100 μg) was i.p. injected twice (1 day before and on the same day of immunization with DTX-treated CT26). Two weeks later, spleen cells were harvested and cultured with the AH1 peptide and IL-2 (20 U/mL) for 4 days. These cultured cells were examined for their cytotoxicity against CT26 cells using the ⁵¹Cr-release assay. Each group consisted of three mice. (Lower) The results at an E/T ratio of 100 are shown *P < 0.05. c The similar experiment described in (b) was performed using aged (60 W) mice. Each group consisted of four mice. NS not significant