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.