A reciprocal interaction exists between the gut microbiota and the immune system. Regulatory T (Treg) cells are important for controlling immune responses and for maintaining the intestinal homeostasis but their precise influence on the gut microbiota is unclear. We studied the effects of Treg cell depletion on inflammation of the intestinal mucosa and analysed the gut microbiota before and after depletion of Treg cells using the DEpletion of REGulatory T cells (DEREG) mouse model. DNA was extracted from stool samples of DEREG mice and wild-type littermates at different time-points before and after diphtheria toxin application to deplete Treg cells in DEREG mice. The V3/V4 region of the 16S rRNA gene was used for studying the gut microbiota with Illumina MiSeq paired ends sequencing. Multidimensional scaling separated the majority of gut microbiota samples from late time-points after Treg cell depletion in DEREG mice from samples of early time-points before Treg cell depletion in these mice and from gut microbiota samples of wild-type mice. Treg cell depletion in DEREG mice was accompanied by an increase in the relative abundance of the phylum Firmicutes and by intestinal inflammation in DEREG mice 20 days after Treg cell depletion, indicating that Treg cells influence the gut microbiota composition. In addition, the variables cage, breeding and experiment number were associated with differences in the gut microbiota composition and these variables should be respected in murine studies.

中文翻译：

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Foxp3 +调节性T细胞的耗竭伴随着鼠肠道微生物组中Firmicutes相对丰度的增加。

肠道菌群与免疫系统之间存在相互作用。调节性T（Treg）细胞对于控制免疫反应和维持肠道稳态很重要，但尚不清楚它们对肠道菌群的确切影响。我们研究了Treg细胞耗竭对肠粘膜炎症的影响，并使用“调节性T细胞耗竭”（DEREG）小鼠模型分析了Treg细胞耗竭前后的肠道菌群。在白喉毒素应用耗尽DEREG小鼠之前和之后的不同时间点，从DEREG小鼠的粪便样品和野生型同窝幼仔中提取DNA。16S rRNA基因的V3 / V4区用于通过Illumina MiSeq配对末端测序研究肠道菌群。多维标度将大多数小鼠肠道菌群样品与DEREG小鼠中Treg细胞耗尽后的晚期时间点分离，并将这些小鼠中Treg细胞耗尽前的早期时间点与野生型小鼠的肠道菌群样品分离。TREG细胞耗竭20天后，DEREG小鼠的Treg细胞耗竭伴随着Firmicutes门的相对丰度的增加以及DEREG小鼠的肠道炎症，表明Treg细胞影响肠道菌群的组成。另外，变量笼，繁殖和实验数量与肠道菌群组成的差异有关，这些变量在鼠类研究中应予以考虑。