ZFP36-family RNA-binding proteins in regulatory T cells reinforce immune homeostasis [bulk RNA-seq]

RNA binding proteins (RBP) of the ZFP36 family limit the differentiation and effector functions of CD4 and CD8 T cells, but little is known of their expression or function in regulatory T cells (Treg). By Treg-restricted deletion of Zfp36 family members we identify the essential role of Zfp36l1 and Zfp36l2 in Treg to maintain immune homeostasis. Mice with Tregs deficient in these RBP display an inflammatory phenotype with an expansion in the numbers of type-2 conventional dendritic cells, T effector cells, T follicular helper and germinal center B cells and elevated serum cytokines and immunoglobulins. In the absence of Zfp36l1 and Zfp36l2, the pool of cycling CTLA-4 in naïve Treg was reduced, Tregs were less sensitive to IL-2 and IL-7 but were more sensitive to IFN?. In mice lacking both RBP in Treg, the deletion of a single allele of Ifng is sufficient to ameliorate the pathology. Thus, ZFP36L1 and ZFP36L2 regulate multiple pathways that enable Tregs to enforce immune homeostasis. Overall design: RNA-seq in regulatory T cells, comparing naïve Treg from Zfp36l1/Zfp36l2 conditional KO (Foxp3-YFP-Cre) female mice with naïve Treg from Foxp3-YFP-Cre controls. Libraries from male floxed controls were also generated from naïve and effector Treg. 5-7 replicates were included for each cell/genotype.

RNA结合蛋白（RNA binding proteins, RBP）的ZFP36家族可抑制CD4与CD8 T细胞的分化及效应功能，但目前对该家族蛋白在调节性T细胞（regulatory T cells, Treg）中的表达与功能尚不清楚。
通过在Treg中特异性敲除Zfp36家族成员，本研究明确了Zfp36l1与Zfp36l2在Treg维持免疫稳态中的核心作用。
缺失这类RBP的Treg小鼠会呈现炎症表型，表现为2型常规树突状细胞（type-2 conventional dendritic cells）、效应T细胞（T effector cells）、滤泡辅助T细胞（T follicular helper）及生发中心B细胞（germinal center B cells）数量扩增，同时血清细胞因子与免疫球蛋白水平升高。
在缺乏Zfp36l1与Zfp36l2的情况下，初始Treg中循环CTLA-4的库水平降低，Treg对IL-2与IL-7的敏感性下降，但对IFN-γ的敏感性升高。
在Treg中同时缺失这两种RBP的小鼠中，仅敲除单等位基因Ifng即可缓解其病理表型。
综上，ZFP36L1与ZFP36L2可调控多条通路，使Treg能够维持免疫稳态。
整体实验设计：对调节性T细胞进行RNA测序，比较Zfp36l1/Zfp36l2条件性敲除（conditional KO, Foxp3-YFP-Cre）雌性小鼠的初始Treg与Foxp3-YFP-Cre对照小鼠的初始Treg。同时还从floxed雄性对照小鼠中获取初始Treg与效应Treg并构建测序文库。每个细胞/基因型组设置5-7个生物学重复。