Cytokines Source Primary functions
IL-1 MǾ, PMN, Oc, Epithelial cells Chemotactically attracts and activates PMNs; Stimulates the production of prostaglandines, proteolytic enzymes and cytokines IL-6, IL-8; Stimulates bone resorption and inhibits bone formation
IL-8 MǾ, PMN, Th1 Chemotactically attracts and activates PMNs; Stimulates osteoclast recruitment and activity
IL-6 MǾ, PMN, Th2, B lymphocytes, endothelial cells Activates PMNs, T cells; Stimulates the differentiation of B lymphocytes into plasma cells; Induces bone resorption; Down-regulates the production of IL-1
TNFα MǾ, Th1, PMN Activates lymphocytes and MǾ's; Stimulates bone resorption
GCP-2 Endothelial cells Chemotactically attracts PMNs
IL-17 Th17 Activates IL-1, IL-6, TNFα, GCP-2 and IL-8 secretion; Stimulates bone resorption
GM-CSF MǾ, T lymphocytes, endothelial cells, PMN Functionally activates MǾ and PMNs
MCP-3 Endothelial cells, lymphocytes, fibroblasts, plasma cells Chemotactically attracts MǾ
MIP-1 Th1 Chemotactically attracts and activates MǾ and Oc
TGFβ MǾ, lymphocytes, fibroblasts, Ob, Oc Suppresses the proliferation and differentiation of T and B lymphocytes; Down regulates the production of IL-1, IL-6, TNFα and IFNγ; Blocks the production of nitric oxide by MǾ; Inhibits bone resorption; Inhibits Th17 formation and promotes Treg formation
IFNγ Th1 Activates MǾ; Induces IL-1, NO and O2production
IL-12 MǾ, dendritic cells Stimulates the production of IL-1 and IFNγ; Stimulates Th1 differentiation; Suppresses Th2 differentiation
IL-10 MǾ, dendritic cells Suppresses the production of IL-1 and IFNγ
IL-4 Th2 Inhibits bone resorption; Inhibits Th17 formation, Suppresses the production of IL-1

MǾ = macrophages; PMN = polymorphonuclear leucocytes; Th = T helper cells; Ob = osteoblasts; Oc = osteoclasts; NO = nitric oxide.