Table 1.

Role of Treg cells and Th17 cells cytokines in osteoimmune system

Cytokine	Source	Effect on bone mass	Function in bone homeostasis	References
IL-1	Macrophages	↓	Enhances the expression of RANKL to promote osteoclastogenesis	[31]
IL-5	Th2	↑	Inhibits osteoclastogenesis	[21]
IL-6	Macrophages	↓	Activates osteoclastogenesis	[31]
IL-10	Treg	↑	Inhibits bone resorption	[5, 19]
IL-17	CD4+ T cells	↓	Enhances the expression of RANKL and induces macrophages to produce a variety of inflammatory factors	[28, 30, 31]
IL-35	Treg	↑	Reduces the expression of IL-17 Inhibits osteoclastogenesis	[20]
RANK	Osteoclasts	↓	Osteoclast differentiation and activation	[9]
RANKL	Th17	↓	Osteoclast activation through RANK	[7]
GM-CSF	Th1	↑	Inhibits osteoclastogenesis	[17]
IFN-γ	Activated Th cells, NK cells	↑	Inhibits osteoclastogenesis	[17]
TGF-β	Multiple cells lines	uncertain	Activates osteoclast Induces osteoblast formation	[5, 23, 24]
TNF-α	Th17, macrophages	↓	Activates osteoclastogenesis through RANKL	[31]