IL-12 (Interleukin-12) is a cytokine produced by certain immune cells, particularly dendritic cells, macrophages, and B cells.
It plays a critical role in the regulation of immune responses and inflammation.
IL-12 is known to stimulate the production of interferon-gamma (IFN-gamma) by natural killer (NK) cells and T cells.
This cytokine helps activate cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, promoting their ability to target and destroy infected cells or cancer cells.
Interleukin 12 (IL-12) is involved in the stimulation and maintenance of Th1 cellular immune responses, including the normal host defense against various intracellular pathogens, such as Leishmania, Toxoplasma, Measles virus, and Human immunodeficiency virus 1 (HIV).
IL-12 also has an important role in enhancing the cytotoxic function of NK cells and role in pathological Th1 responses, such as in inflammatory bowel disease and multiple sclerosis.
Suppression of IL-12 activity in such diseases may have therapeutic benefit.
The administration of recombinant IL-12 may have therapeutic benefit in conditions associated with pathological Th2 responses.
Additionally, IL-12 enhances the differentiation of T helper type 1 (Th1) cells, which are involved in cellular immune responses against intracellular pathogens.
Interleukins 12 and 23 are cytokines that are produced by myeloid cells that stimulate the activation of T helper lymphocytes, which in turn release, immunoactivating cytokines, such as interferon gamma and Interleukin, 17 and 22.
IL-12 has also been used as a therapeutic agent in clinical settings: explored certain types of cancer, infectious diseases, and autoimmune disorders.
It acts either independently or synergizes with IL-18, promoting activation of the monocyte/macrophage system.