Fig. (3) Th1/Th2 ratios of Ni immunized mice. Ratios of IFN-γ- and IL-10-producing capabilities (Th1/Th2 ratios) were examined in the mice inoculated with LPS and NiCl2 (12 weeks old) (a), and in the mice, further inoculated with NiCl4 (15 weeks old) (b). This figure demonstrates representative results from 4 repeated experiments. **, p < 0.01.