Table 1.

Cytokines involved in osteoclastogenesis

Cytokine	Main producer cells	Primary target in osteoclastogenesis	Effect on osteoclastogenesis	Role in osteoimmunology
RANKL	T-cells; Osteoblasts	Osteoclast precursor cells	Activation	Induction of osteoclast differentiation
TNF-α	Macrophages; Th1 cells	Osteoclast precursor cells; mesenchymal cells	Activation	RANKL induction on mesenchymal cells, RANKL synergy, inflammation
IL-6	Th2 cells; dendritic cells	Mesenchymal cells; T cells	Activation	RANKL induction on mesenchymal cells, Th17-cell differentiation, inflammation
IL-17	Th17 cells; memory T cells	Mesenchymal cells	Activation	RANKL induction on mesenchymal cells, inflammation
IFN-γ	Th1 cells; natural killer cells	Osteoclast precursor cells	Inhibition	RANKL signaling inhibition, cellular immunity
IL-4	Th2 cells; natural killer T cells	Osteoclast precursor cells	Inhibition	RANKL signaling inhibition, humoral immunity
IL-10	Th2 cells	Osteoclast precursor cells	Inhibition	RANKL signaling inhibition, antiinflammatory
IL-12	Macrophages; dendritic cells	T cells	Inhibition	Th1-cell differentiation, IFN-γ and GM-CSF induction
IL-18	Macrophages; dendritic cells	T cells	Inhibition	Th1-cell differentiation, IFN-γ induction
GM-CSF	Th1 cells	Osteoclast precursor cells	Inhibition	RANKL signaling inhibition, granulocyte differentiation

GM-CSF granulocyte–macrophage colony-stimulating factor, IFN interferon, IL, interleukin, RANKL receptor activator of nuclear factor-κB ligand, Th T-helper, TNF tumor necrosis factor