MOLECULES

Full name: Interleukin-12

Aliases: IL-12A, IL-12B, CLMF, NFSK, and NKSF^1,2

Size: 75 kDa³

Family: IL-12 family (IL-12, IL-23, IL-27, and IL-35)^3,4

Receptors: IL-12Rβ1 and IL-12Rβ2³

Major cellular sources: DCs, macrophages, activated monocytes, neutrophils, microglia, and B cells^3,4

Major cellular targets: T cells Th1 cells, NK cells, and DCs³

Disease states associated with: Bacterial infections, inflammatory bowel disease, psoriasis, chronic inflammatory diseases, and autoimmune diseases^3,4

Major physiologic functions:

• Members of the IL-12 cytokine family are important regulators of host immunity.⁴
• IL-12 is a pro-inflammatory cytokine that mediates the development and maintenance of Th1 cells by inducing IFN- production by Th1 and NK cells.³
• IL-12 plays an important role in the induction of ILC1s.³
• IL-12 indirectly activates the antimicrobial, antiparasitic, and antitumor activities of macrophages and promotes the cytolytic activity of NK cells and lymphokine-activated killer cells.³
• IL-12 has also been associated with autoimmune response and IL-12–induced differentiation of Th1 cells and is speculated to be associated with the development of various organ-specific autoimmune diseases.⁴
• An additional function of IL-12 is controlling the homeostasis of Treg cells by eliminating them.³

CLMF: cytotoxic lymphocyte maturation factor; DC: dendritic cell; IFN- : interferon-gamma; IL: interleukin; IL-12R: IL-12 receptor; ILC: innate lymphoid cell; NK: natural killer; NFSK: NF cell stimulatory factor; NKSF: natural killer cell stimulatory factor; Th: T helper; Treg: regulatory T.