Deciphering the role of the IRF4 interactome in differentiating regulatory T and T helper 17 cells in health and autoimmune disease

虽然辅助性T (Th) 17细胞与自身免疫性疾病的发生和发展有关，但CD4+FOXP3+调节性T （Treg）细胞已被证明通过阻止这些自身侵袭性免疫反应来维持外周耐受性。研究表明，转录因子IRF4在Th17和Treg细胞谱系的确定中起着关键作用。蛋白激酶CK2参与irf4引导的基因转录调控，CK2活性基本上有助于Th17和Treg细胞之间的微妙平衡。此外，数据表明，在T细胞分化过程的某些阶段，IRF4执行不同的任务，要么作为同型二聚体，要么与不同的伙伴协同工作。然而，对于IRF4在分化过程中不同时间点的潜在机制和结合伙伴，我们仍然知之甚少。此外，IRF4及其结合伙伴诱导的事件在多大程度上解释了该转录因子在Treg细胞和Th17细胞等功能对立的T细胞亚群中的关键作用仍然是难以捉摸的。目前拨款申请的主要目标之一是阐明CK2和IRF4对Th17和Treg细胞谱系测定的影响。为此，我们将在上述T细胞亚群中整合时间分辨相互作用组、ChIPSeq、转录组和蛋白质组分析，以鉴定ck2依赖性和ck2非依赖性IRF4蛋白和DNA靶点。时间分辨的多“组学”数据集将使用从转基因报告小鼠体内产生的Th17和Treg细胞来生成。该项目创建的数据资源将使我们能够选择与IRF4相互作用的候选基因和蛋白，并阐明它们对多发性硬化症（实验性自身免疫性脑脊髓炎（EAE））临床前模型中Th17和Treg细胞谱系测定的影响。

While T helper (Th) 17 cells have been implicated in the initiation and progression of autoimmune diseases, CD4+FOXP3+ regulatory T (Treg) cells have been shown to crucially contribute to the maintenance of peripheral tolerance by preventing these autoaggressive immune responses. It has been shown, that the transcription factor IRF4 plays a key role in Th17 and Treg cell lineage determination. The protein kinase CK2 is involved in the IRF4-steered regulation of gene transcription and CK2 activity essentially contributes to the delicate equilibrium between Th17 and Treg cells. Moreover, data indicate that IRF4 executes different tasks acting either as homodimer or in concert with different partners at certain stages during the course of T cell differentiation. However, there is still little knowledge about the underlying mechanisms and binding partners of IRF4 at distinct time points during the differentiation process. Further, it still remains elusive to which extent the events induced by IRF4 and its binding partners explain the pivotal role of this transcription factor in functionally opposed T cell subsets like Treg cells and Th17 cells.One of the major goals of the present grant application is to shed light on the impact of CK2 and IRF4 on Th17 and Treg cell lineage determination. Towards this purpose we will integrate time-resolved interactome, ChIPSeq, transcriptome and proteome analyses in the above-mentioned T cell subsets for the identification of CK2-dependent and CK2-independent IRF4 protein and DNA targets. The time-resolved multi"omics" dataset will be generated using Th17 and Treg cells generated ex vivo from transgenic reporter mice. The data resource created in the proposed project will allow us to pick candidate genes and proteins interacting with IRF4 and elucidate their impact on Th17 and Treg cell lineage determination in the preclinical model of multiple sclerosis, named experimental autoimmune encephalomyelitis (EAE).