Regulation of RORγt in Th17-mediated inflammation

摘要 产生IL-17的Th17细胞在许多疾病中都是致病的，包括炎症性肠病(IBD)，但 矛盾的是，它们对于以非炎症方式维持肠道屏障的完整性至关重要。 然而，调节不同转录谱和功能多样性的细胞内机制 Th17细胞仍不清楚。Ror-γt是IL-17的转录因子，在病理性和非霍奇金淋巴瘤均有表达。 非致病性Th17细胞。RoR-γt由一个DNA结合域和一个配体结合域组成。 LBD含有激活功能2(AF2)区，负责招募辅激活子和辅阻遏子 蛋白质。RoR-γt常被称为“孤儿核受体”，因为其天然配体未知/不清楚。我们的 初步研究发现，Raftlin1是一种脂筏蛋白，是一种RoR-γt相互作用蛋白。Raftlin1形成一个 通过其保守的‘LLNSL’基序与AF2域结合，与RoR-γt形成复合体。用液相色谱 与质谱仪(LC-MS)联用，我们已经鉴定了几种脂类 [溶血磷脂酰乙醇胺(LPEs)、磷脂酰丝氨酸(PSS)和磷脂酰胆碱(PC)]与 基于这些新的发现，我们假设Raftlin1作为RoR-γt的接头。 并招募其天然脂质配体，促进Th17的致病作用。我们将在以下条件下测试这一假设 两个目标。AIM1将探讨RoR-γt-Raftlin1复合体在胃肠道炎症中的作用 2，将确定RoR-γt-Raftlin1复合体调节Th17细胞致病性的机制。 随着这些研究的完成，我们希望(1)确定RoR-γt-Raftlin1复合体在驾驶中的作用 Th17细胞的致病性；(2)探讨LPEs作为ror-γt天然配体在致病中的作用。 Th7细胞。

ABSTRACT Th17 cells that produce IL-17 are pathogenic in many diseases, including inflammatory bowel disease(IBD), but are paradoxically essential for maintaining the integrity of the intestinal barrier in a non-inflammatory manner. However, the intracellular mechanisms that regulate distinct transcriptional profiles and functional diversity of Th17 cells remain unclear. ROR-γt, the transcription factor for IL-17, is expressed in both pathogenic and nonpathogenic Th17 cells. ROR-γt is composed of a DNA-binding domain and a ligand-binding domain (LBD). The LBD contains the activation function 2 (AF2) region responsible for recruiting coactivator and corepressor proteins. ROR-γt is often called 'orphan nuclear receptor' because its natural ligands are unknown/unclear. Our preliminary studies have identified Raftlin1, a lipid raft protein, as a ROR-γt interacting protein. Raftlin1 forms a complex with ROR-γt by binding to the AF2 domain via its conserved 'LLNSL' motif. By liquid chromatography coupled to mass spectrometry (LC-MS), we have identified that a few lipid species [lysophosphatidylethanolamines(LPEs), Phosphatidylserines (PSs), and Phosphatidylcholines (PCs)] binds to Raftlin1 and ROR-γt. Based on these novel findings, we hypothesize that Raftlin1 acts as an adaptor for ROR-γt and recruits its natural lipid ligands, and promotes the pathogenicity of Th17. We will test this hypothesis under two aims. Aim1 will investigate the function of ROR-γt-Raftlin1 complex in gastrointestinal inflammation, and Aim 2, will determine the mechanism by which ROR-γt-Raftlin1 complex regulates the pathogenicity of Th17 cells. With the completion of these studies, we expect to (1) establish the role of ROR-γt-Raftlin1 complex in driving the pathogenicity of Th17 cells and (2) explore the function of LPEs as the natural ligands of ROR-γt in pathogenic Th7 cells.