Seeing is believing: illuminating the source of in vivo interleukin-7.
Seeing is believing: illuminating the source of in vivo interleukin-7.
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DOI：
10.4110/in.2011.11.1.1
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发表时间：
2011-02
期刊：
影响因子：
6
通讯作者：
Park JH
中科院分区：
文献类型：
--
作者：
Kim GY;Hong C;Park JH
白介素 7 (IL-7) 是 T 细胞必需的细胞因子。然而，IL-7 不是由 T 细胞本身产生，因此 T 细胞依赖于外源性 IL-7。事实上，在缺乏 IL-7 的情况下，胸腺中 T 细胞的发育以及外周幼稚 T 细胞的存活都会受到严重损害。此外，通过遗传手段或其他实验方法调节体内IL-7的可用性决定了T细胞库的大小、组成和功能。因此，了解 IL-7 表达对于了解 T 细胞免疫至关重要。然而，直到最近，体内 IL-7 的时空表达仍然不清楚。此类信息的缺乏部分是由于 IL-7 本身的表达不足，但主要是由于缺乏足够的试剂来监测体内 IL-7 的表达。最近四项独立研究的出现极大地改变了这种情况，这些研究描述了 IL-7 报告小鼠的产生和表征，所有这些研究都利用了细菌人工染色体转基因技术。这些研究逐渐形成的共识证实胸腺基质细胞是 IL-7 的主要产生者，同时也确定了 IL-7 在各种外周组织（包括皮肤、肠道和淋巴结）中的报告活性。引人注目的是，发育和环境线索在体内积极调节 IL-7 报告基因活性，表明 IL-7 调节可能是塑造 T 细胞发育和稳态的新机制。总的来说，这些新工具的出现为评估 T 细胞及其他细胞中 IL-7 生物学中未解答的问题开辟了新的途径。
Interleukin-7 (IL-7) is an essential cytokine for T cells. However, IL-7 is not produced by T cells themselves such that T cells are dependent on extrinsic IL-7. In fact, in the absence of IL-7, T cell development in the thymus as well as survival of naive T cells in the periphery is severely impaired. Furthermore, modulating IL-7 availability in vivo either by genetic means or other experimental approaches determines the size, composition and function of the T cell pool. Consequently, understanding IL-7 expression is critical for understanding T cell immunity. Until most recently, however, the spatiotemporal expression of in vivo IL-7 has remained obscured. Shortage of such information was partly due to scarce expression of IL-7 itself but mainly due to the lack of adequate reagents to monitor IL-7 expression in vivo. This situation dramatically changed with a recent rush of four independent studies that describe the generation and characterization of IL-7 reporter mice, all utilizing bacterial artificial chromosome transgene technology. The emerging consensus of these studies confirmed thymic stromal cells as the major producers of IL-7 but also identified IL-7 reporter activities in various peripheral tissues including skin, intestine and lymph nodes. Strikingly, developmental and environmental cues actively modulated IL-7 reporter activities in vivo suggesting that IL-7 regulation might be a new mechanism of shaping T cell development and homeostasis. Collectively, the availability of these new tools opens up new venues to assess unanswered questions in IL-7 biology in T cells and beyond.