Inhibition of osteoclastogenesis.

(A) HPCs were cocultured with ATL cells and soluble RANKL with or without RANK/Fc in culture dishes with inserts to prevent direct interaction in the presence of M-CSF and IL-2. Suppression of TRAP activity indicated differentiation of cells into OCLs. (B) HPCs were cocultured with ATL cells and soluble RANKL with or without OPG/Fc. Suppression of TRAP activity indicated differentiation of cells to OCLs. Suppression caused by OPG/Fc was statistically significant. Statistical analysis was performed by using the Studentt test.