Fig. 6.
Effect of oral administration of L.E.M. extract on the induction of anti-CT26 CTLs and protective immunity. a (Left) Similarly to Fig. 3a, naïve aged (45 W) BALB/c mice were vaccinated with 1 × 106 DTX-treated CT26 cells. In some groups, oral administration of PBS or L.E.M extract was initiated 1 week before CT26 vaccination and continued until spleen cell harvesting. Two weeks after CT26 vaccination, the spleen cells were harvested and cultured with the AH1 peptide and IL-2 (20 U/mL) for 4 days and examined for their cytotoxicity against CT26 cells using the 51Cr-release assay. Each group consisted of six mice. *P < 0.05. **P < 0.01. (Right) The results at an E/T ratio of 100 are shown. b Similar experiments were performed using young (7 W) mice. Each group consisted of five mice. The results at an E/T ratio of 100 are shown. **P < 0.01. NS not significant. c (Left) Naïve young (7 W) and aged (60 W) BALB/c mice were vaccinated s.c. with DTX-treated 1 × 106 CT26 cells. In some groups, oral administration of PBS or L.E.M extract was initiated 1 week before CT26 vaccination and continued until 1 week after vaccination. Two weeks after CT26 vaccination, 5 × 105 viable CT26 cells were inoculated s.c. and tumor growth was measured. Each group consisted of six or seven mice, and each line represents the tumor growth of an individual mouse. (Right) The tumor sizes on day 11 after CT26 challenge are shown. *P < 0.05. **P < 0.01. NS not significant