Figure 3

Effects of IL-18 on osteoclast formation. Mouse spleen cells and osteoblasts from wild-type mice (WT), IFN-γ receptor type II-knockout mice (IFNγR KO) or granulocyte–macrophage colony-stimulating factor-knockout mice (GM-CSF KO) were cocultured with 1-α,25(OH)₂D₃ and prostaglandin E₂ (PGE₂) in the presence or absence of IL-18. In some cocultures, T-cell-depleted spleen cells and osteoblasts were cocultured in the presence and absence of WT T cells or GM-CSF KO T cells. In each coculture, numbers of tartrate-resistant acid phosphatase-positive osteoclasts formed were scored.