Figure 1.

NYT synergistically enhances whole-cell vaccine effects in vivo. (A) Female BALB/c mice were fed the control diet or NYT diet for three weeks and then challenged s.c. with 1×10⁶ live syngeneic CT26 cells. These mice continued to be fed the same diets until four weeks following the tumor cell inoculation. Tumors were measured twice weekly using a caliper gauge and their sizes were determined as tumor length (mm) × width (mm). Each experiment comprised 4–6 mice/group. These experiments were repeated ≥2 times with similar results. Data are presented as the mean ± SD. (B) Irradiated (20,000 rad) CT26 cells (1×10⁵) were injected s.c. into BALB/c mice. Vaccinated mice were fed the control or NYT diet from the time of the vaccination until four weeks following the tumor cell inoculation. Three weeks following the vaccination, 1×10⁶ live CT26 cells were s.c. injected into these mice and tumors were then measured twice weekly. Each experiment included 6–8 mice/group. Results were pooled from two independent experiments. Data are presented as the mean + SD. P<0.0001, Mann-Whitney U test between the control diet group and vaccine + control diet group on day 28 following the CT26 inoculation; P<0.03, Mann-Whitney U test between the vaccine + control diet group and vaccine + NYT diet group on day 28 following the tumor cell inoculation. (C) Overall survival rate was compared using the log-rank test. Results were pooled from six independent experiments. A total of 14/34 mice (41.2%) from the vaccine + NYT diet group remained tumor-free for ≥51 days following the tumor cell inoculation, whereas only 7/34 mice (20.6%) in the vaccine + control diet group remained tumor-free in the same time period (P<0.02). NYT, ninjin'yoeito; s.c., subcutaneously; SD, standard deviation.