The immune system is responsible for defending an organism against the myriad of microbial invaders it constantly confronts. It has become increasingly clear that the immune system has a second major function: the maintenance of organismal homeostasis. Foxp3(+)CD4(+) regulatory T cells (Tregs) are important contributors to both of these critical activities, defense being the primary purview of Tregs circulating through lymphoid organs, and homeostasis ensured mainly by their counterparts residing in parenchymal tissues. This review focuses on so-called tissue Tregs. We first survey existing information on the phenotype, function, sustaining factors, and human equivalents of the three best-characterized tissue-Treg populations-those operating in visceral adipose tissue, skeletal muscle, and the colonic lamina propria. We then attempt to distill general principles from this body of work-as concerns the provenance, local adaptation, molecular sustenance, and targets of action of tissue Tregs, in particular.

中文翻译：

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组织调节剂。

免疫系统负责保护生物体免受其不断面临的无数微生物侵害。越来越清楚的是，免疫系统具有第二个主要功能：维持机体动态平衡。Foxp3（+）CD4（+）调节性T细胞（Tregs）是这两个关键活动的重要贡献者，防御是Tregs通过淋巴器官循环的主要功能，而稳态则主要由其驻留在实质组织中的对应物来确保。这篇综述着重于所谓的组织Tregs。我们首先调查关于三个最佳特征组织-Treg种群的表型，功能，维持因子和人类当量的现有信息，这些组织在内脏脂肪组织，骨骼肌和结肠固有层中起作用。