IL-12サイトカインファミリー

IL-12 cytokine family

　IL-12関連サイトカイン，IL-27, 23は抗原提示細胞から産生され，Th1細胞の分化・維持を制御する．さらに，IL-23は炎症誘導作用をもつTh17の分化を促進する．一方，IL-27には，IL-23と逆にTh17の分化を抑制するほか，様々なサイトカイン産生を抑制し，炎症を抑制する作用をもつ．IL-27に類似した作用をもつIL-35は，制御性T細胞から産生され，その免疫抑制作用の一部を担う．IL-12サイトカインファミリーは，ヘルパーT細胞の分化や機能を微細に制御している．

Cytokines are important in regulation of immune responses. Interleukin(IL-)27, IL-23, and IL-35 belong to the IL-12 cytokine family and play roles in development and maintenance of Th1 cells. In addition, IL-23 is required for development of Th17 cells, which are involved in pathogenesis of inflammatory diseases. IL-27 in turn suppresses Th17 differentiation and attenuates inflammatory responses by suppressing production of various cytokines. IL-35 is reportedly produced by regulatory T(Treg)cells and is involved in immune suppression by Treg cells. IL-12 family cytokines thus regulate differentiation and functions of helper T cells and Tregs in a coordinate fashion.