FIG 7.

The effect of IL-12 and IFN-γ on osteoclastogenesis. (A) BM cells were differentiated to osteoclasts with RANKL (100 ng/ml) in the presence or absence of IL-12 (50 ng/ml). (B) BM cells were differentiated to osteoclasts, and 3 days after RANKL addition, M1 macrophages derived from WT or IFN-γ knockout (IFNKO) mice were added with or without IL-12 neutralizing antibody (filled columns). As a control, IL-12 neutralization antibody alone was also applied to the BM cells (3 days after RANKL addition) without addition of macrophage (slashed columns). Seven days after RANKL addition, TRAP staining was performed. Data are means and SD. No osteoclasts were observed without RANKL addition (data not shown) (n = 6). The asterisks indicate significant differences (*, P < 0.05; **, P < 0.01) by Student's t test for panel A and by two-way ANOVA Tukey's test for panel B.