Stress signaling in the interaction between innate and adaptive immunity in Multiple Sclerosis

多发性硬化症（MS）是由适应性自身免疫和先天性炎症的不受控制的相互作用驱动的，但是在MS的发病机制中连接先天性和适应性免疫的炎症和（表观）遗传机制是完全理解的。我们以前已经表明，S100 A8/S100 A9蛋白质调节髓系抗原呈递细胞的分化，在小鼠和人类系统中的TLR 4依赖的方式。使用mRNA-Seq、ChIP-Seq和ATAC-Seq分析，我们已经证明连续的TLR 4激活诱导表观遗传变化，导致抗原呈递细胞的免疫抑制表型。使用转基因和敲除模型，我们已经表明，这种S100驱动的机制调节EAE模型中的神经炎症。在无偏见的生物信息学方法中，我们发现了我们的骨髓表型与MS和其他自身免疫性疾病的遗传背景的潜在联系。因此，我们已经确定了一种新的调节机制，抗原驱动的自身免疫通过S100-TLR 4 interactions.In目前的建议，我们将解决以下问题的串扰骨髓细胞与T细胞和脑实质：如何S100 A9改变骨髓细胞分化EAE期间，特别关注髓源性抑制细胞（MDSC）？内源性危险信号是如何导致EAE中MDSC和树突状细胞与自身反应性T细胞和脑实质细胞的相互作用的？S100 A8/A9如何调节EAE中的自身反应性T细胞？我们能否识别MS患者对S100 A8/A9 alarmin刺激的特异性白细胞表达模式？为了实现这些目标，我们将分析小鼠体外模型，并将研究将遗传修饰的骨髓细胞（HoxB 8系统）与新型核酸内切酶（CRISPR/Cas9）组合的候选基因的功能效应。将使用各种转基因小鼠品系确认体内生物学相关性。具体而言，我们将采用RNA-seq方法来表征S100预处理的先天免疫细胞在体外和体内诱导的自身反应性T细胞表达变化。通过在脑实质细胞中产生细胞类型特异性的alarmin受体缺陷，我们还将以细胞类型特异性的方式研究CNS自身免疫中先天免疫细胞和脑细胞之间的串扰。我们将这些数据转移到人骨髓细胞，我们将确认我们的研究结果的病理相关性，分析功能改变，表达谱和表观遗传变化，在纯化的白细胞群体的个别MS患者相比，对照。我们将在严格控制的刺激条件下使用选择的内源性TLR 4配体使用平行的mRNA和ATAC-Seq。通过这种方法，我们将定义MS中连接先天免疫和适应性免疫的新靶点。

Multiple sclerosis (MS) is driven by an uncontrolled interaction of adaptive autoimmunity and innate inflammation, but the inflammatory and (epi-)genetic mechanisms linking innate and adaptive immunity in the pathogenesis of MS are purely understood. We have previously shown that S100A8/S100A9 proteins modulate the differentiation of myeloid antigen-presenting cells in a TLR4-dependent manner in the murine and the human system. Using mRNA-Seq, ChIP-Seq and ATAC-Seq analysis we have demonstrated that continuous TLR4-activation induces epigenetic changes resulting in an immune-suppressive phenotype of antigen-presenting cells. Using transgene and knock-out models we have shown that this S100-driven mechanism regulates neural inflammation in the EAE-model. In an unbiased bioinformatics approach we found a potential link of our myeloid phenotype with the genetic background of MS and other autoimmune diseases. We have thus identified a novel regulatory mechanism of antigen-driven autoimmunity through S100-TLR4 interactions.In the present proposal we will address the following questions regarding the cross-talk of myeloid cells with T cells and brain parenchyma: How does S100A9 alter myeloid cell differentiation during EAE with special focus on myeloid derived suppressor cells (MDSC) ? How do endogenous danger signals contribute to the cross-talk of MDSC and dendritic cells with autoreactive T cells and brain parenchymal cells in EAE? How does S100A8/A9 modulate autoreactive T cells in EAE? Can we identify specific leukocyte expression patterns in MS patients in response to S100A8/A9 alarmin stimulation?To achieve these goals we will analyse murine in vitro models and will investigate functional effects of candidate genes combining genetically modified myeloid cells (HoxB8 system) with novel endonucleases (CRISPR/Cas9). Biological relevance in vivo will be confirmed using various genetically modified mouse strains. Specifically, we will employ an RNA-seq approach to characterize the expression changes induced in autoreactive T cells by S100-pretreated innate immune cells both in vitro and in vivo. By generating cell type-specific deficiency of alarmin-receptors in brain parenchymal cells, we will also study the cross-talk between innate immune cells and brain cells in CNS autoimmunity in a cell-type specific fashion. We will transfer these data to human myeloid cells and we will confirm pathological relevance of our findings analysing functional alterations expression profiles and epigenetic changes in purified leukocyte populations of individual MS patients compared to controls. We will use parallel mRNA- and ATAC-Seq under strictly controlled stimulatory conditions using selected endogenous TLR4-ligands. With this approach we will define novel targets linking innate and adaptive immunity in MS.