Asb2 in CD4+ T cell lineage differentiation and its plasticity

Asb2在CD4 T细胞谱系分化及其可塑性中的作用

• 批准号: 8452778
• 负责人: Xiao-Hong Sun
• 金额: $ 23.69万
• 依托单位: OKLAHOMA MEDICAL RESEARCH FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8452778
• 关键词: Animal Model; Ankyrin Repeat; Antigens; Asthma; Autoimmunity; Biological Assay; Bone Marrow; Bone Marrow Transplantation; Boxing; CD4 Positive T Lymphocytes; Cell Differentiation process; Cell Lineage; Cells; ChIP-seq; Complex; Effector Cell; Ensure; Equilibrium; Evaluation; Exhibits; F-Box Proteins; Funding; Genes; Genetic Recombination; Helper-Inducer T-Lymphocyte; Immune System Diseases; Immunity; In Vitro; Infection; Inflammatory Bowel Diseases; Investigation; Knockout Mice; Laboratories; MADH4 gene; Maintenance; Measures; Mediating; Modeling; Multiple Sclerosis; Mus; Notch Signaling Pathway; Parasites; Pattern; Play; Process; Production; Proteins; Reaction; Regulation; Regulatory T-Lymphocyte; Role; Schistosoma mansoni; Serum; Signal Transduction; T cell differentiation; T-Lymphocyte; T-Lymphocyte Subsets; TCF3 gene; Testing; Th2 Cells; Therapeutic; Transplantation; Ubiquitin; Ubiquitination; Viral; Work; aluminum sulfate; base; cytokine; egg; fighting; genome wide association study; in vivo; interest; mouse model; notch protein; promoter; protein degradation; public health relevance; response; transcription factor; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The overall objective of this R21 application is to explore the role of ankyrin-repeat SOCS-box containing protein 2 (Asb2) in the regulation of CD4 helper T cell differentiation. Our previous studies have shown that the Asb2 gene is transcriptionally activated by Notch signaling and Asb2 mediates Notch-induced protein ubiquitination through bridging the formation of dimeric E3 ubiquitin ligase complexes. Asb2 promotes the degradation a large number of proteins including some related to T helper cell differentiation. Interestingly, genome-wide studies have revealed that Asb2 is highly expressed in Th2 cells and repressed in Treg cells. The interesting pattern of expression suggests a potential role for Asb2 in helper T cell differentiation. We hypothesize: (1) Asb2 is crucial for T2 differentiation and maintenance of Th2 lineage fate; (2) Asb2 favors T effector cell fates while suppressing Treg differentiation and destabilizing Treg identifies. We have already generated mouse models in which gain or loss of Asb2 function can be achieved via Cre- mediated recombination. These animal models will be used to test these hypotheses in two aims. Aim1 will explore the role of Asb2 in Th2 differentiation and the stability of the Th2 fate. We will use Asb2 knockout mice to test if loss of Asb2 impairs Th2 differentiation in vitro or destabilizes the Th2 fate when switched to polarizing conditions for Th1, Th17 or Treg. We will then evaluate the role of Asb2 in Th2 responses in vivo by immunizing wild type and Asb2-/- mice with a parasite antigen, the soluble egg antigen (SEA) from Schistosoma mansoni or with OVA in alum. Th2 cytokine secretion and Th2-dependent Ig production in immunized mice will be measured. Aim2 will explore the role of Asb2 in suppressing Treg differentiation. We will ectopically express Asb2 from the ROSA26 promoter in na¿ve T cells and test if Asb2 can block iTreg differentiation in vitro or if Asb2 potentiates the conversion of Treg cells into Th1, Th2 and Th17 lineages. We will also examine Treg differentiation in vivo in Asb2-expressing mice and assess the ability of Asb2- expressing bone marrow to rescue the immune disorder caused by Foxp3-deficient scurfy bone marrow transplanted into RAG1 deficient hosts. Finding from these studies will provide an initial evaluation concerning the role of Asb2 in T helper cell differentiation and lay the ground work for a full-blown in-depth investigation. This line of investigation examines the regulation of T helper cell differentiation from a unique perspective, namely ubiquitin-mediated degradation of regulators of the differentiation. Fresh ideas will likely emerge from these studies that will be o therapeutic value in the contest of immunity and autoimmunity.

描述(由申请人提供)：本R21申请的总体目标是探索Ankyrin-Repeat SoCS-box Containing Protein 2(Asb2)在调节CD4辅助T细胞分化中的作用。我们以前的研究表明，Asb2基因是由Notch信号在转录上激活的，Asb2通过桥接二聚体E3泛素连接酶复合体来介导Notch诱导的蛋白质泛素化。Asb2促进大量蛋白质的降解，其中包括一些与T辅助细胞分化相关的蛋白质。有趣的是，全基因组研究显示Asb2在Th2细胞中高表达，而在Treg细胞中被抑制。这种有趣的表达模式表明Asb2在辅助性T细胞分化中具有潜在的作用。我们假设：(1)Asb2对T2分化和Th2系命运的维持至关重要；(2)Asb2有利于T效应细胞的命运，同时抑制Treg分化和破坏Treg识别的稳定。我们已经建立了小鼠模型，其中Asb2功能的获得或丧失可以通过Cre介导的重组来实现。这些动物模型将被用来检验这些假设有两个目的。目的探讨Asb2在Th2细胞分化中的作用及Th2细胞命运的稳定性。我们将使用 Asb2基因敲除小鼠测试Asb2基因缺失是否会损害体外Th2分化或破坏Th2细胞的稳定 当Th1、Th17或Treg切换到极化条件时，Th2的命运。然后，我们将用寄生虫抗原、曼氏血吸虫可溶性虫卵抗原(SEA)或明胶中的OVA免疫野生型和Asb2-/-小鼠，评估Asb2在体内Th2反应中的作用。将检测免疫小鼠Th2细胞因子的分泌和Th2依赖的Ig的产生。AIM2将探讨Asb2在抑制Treg分化中的作用。我们将在NAVE T细胞中异位表达来自rosa26启动子的Asb2，并测试Asb2是否能在体外阻止iTreg分化，或者Asb2是否促进Treg细胞向Th1、Th2和Th17系的转化。我们还将在体内检测表达Asb2的小鼠的Treg分化，并评估表达Asb2的骨髓对移植到RAG1缺陷宿主的Foxp3缺陷的Scrfy骨髓所引起的免疫紊乱的拯救能力。这些研究的发现将为Asb2在T辅助细胞分化中的作用提供初步的评估，并为全面深入的研究奠定基础。这条调查路线审查了对 辅助性T细胞分化的独特视角，即泛素介导的降解调节分化。这些研究可能会产生新的想法，在免疫和自身免疫的竞争中具有治疗价值。