Inhibition of osteoclastogenesis by IL-3.

(A) The c-Fms⁺RANK⁻ cells were cultured in the presence of M-CSF and sRANKL with or without IL-3 and IL-5. Osteoclast differentiation was inhibited by addition of IL-3 but not IL-5. (B) The c-Fms⁺RANK⁻ cells were cultured in 1.2% methylcellulose medium containing 100 ng/mL M-CSF, IL-5, IL-3, or various concentrations of GM-CSF. Colony formation was observed in the presence of M-CSF, IL-3, and GM-CSF but not IL-5.