Malek Thomas R, Yu Aixin, Zhu Linjian, Matsutani Takaji, Adeegbe Dennis, Bayer Allison L
Department of Microbiology and Immunology, University of Miami, RMSB 3119, Miami, FL, USA.
J Clin Immunol. 2008 Nov;28(6):635-9. doi: 10.1007/s10875-008-9235-y. Epub 2008 Aug 26.
Interleukin 2 (IL-2) induces an essential signal for T regulatory (Treg) cells. Without a functional IL-2R, only immature CD4(+) Foxp3(low) CD25(neg) T cells develop, and these cells fail to suppress autoreactive T cells in the periphery.
IL-2 functions during Treg cell development by upregulating Foxp3 and CD25 and by increasing the number of thymic Treg cells. Upon exiting the thymus during neonatal life, IL-2 is responsible for rapid amplification of the number of Treg cells in peripheral lymph nodes to insure suppression of autoreactive T cells that escape negative selection, thereby maintaining tolerance. The homeostasis of Treg cells in mature immunocompetent mice also depends on IL-2. However, there is an alternative mechanism for Treg cells homeostasis that may represent a minor IL-2-independent pathway or the consequence of weak and very transient IL-2R signaling.
Thus, IL-2 provides importance signals for Treg cell development and for their homeostasis in peripheral immune tissues.
白细胞介素2（IL-2）诱导调节性T（Treg）细胞产生关键信号。没有功能性的IL-2受体，仅会发育出未成熟的CD4(+) Foxp3(low) CD25(neg) T细胞，并且这些细胞无法在外周抑制自身反应性T细胞。
IL-2在Treg细胞发育过程中发挥作用，通过上调Foxp3和CD25以及增加胸腺Treg细胞的数量。在新生期离开胸腺后，IL-2负责在外周淋巴结中快速扩增Treg细胞数量，以确保抑制逃脱阴性选择的自身反应性T细胞，从而维持免疫耐受。成熟的免疫活性小鼠中Treg细胞的稳态也依赖于IL-2。然而，Treg细胞稳态存在另一种机制，这可能代表一条次要的不依赖IL-2的途径，或者是微弱且非常短暂的IL-2受体信号传导的结果。
因此，IL-2为Treg细胞发育及其在外周免疫组织中的稳态提供重要信号。
