Identification of Specific Roles for Ets-1 in B Cell Tolerance

鉴定 Ets-1 在 B 细胞耐受中的具体作用

基本信息

批准号：
8070010
负责人：
LEE ANN Garrett-Sinha
金额：
$ 39.98万
依托单位：
STATE UNIVERSITY OF NEW YORK AT BUFFALO
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-05-15 至 2015-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8070010
关键词：
Adaptor Signaling Protein Antibodies Antibody Formation Antigen-Antibody Complex Autoantibodies Autoantigens Autoimmune Diseases Autoimmune Process Autoimmune Responses B cell differentiation B-Lymphocytes Binding Biological Biological Assay Blocking Antibodies Bone Marrow Cell Differentiation process Cell physiology Cells Cues DNA Binding DNA Binding Domain DNA Sequence Data Defect Development Disease Enhancers Exhibits Gene Expression Gene Targeting Genes Glean Hematopoietic Homeostasis Immune response Immunoglobulin G Immunoglobulin M Immunoglobulin-Secreting Cells In Vitro Infection Kidney Diseases Knockout Mice Ligands Modeling Molecular Molecular Profiling Mus Nuclear Antigens Nucleic Acid Regulatory Sequences Organ Pathology Pathway interactions Peripheral Plasma Cells Prevention Process Production Proteins Receptor Signaling Regulation Relative (related person)Rheumatoid Factor Role Serum Signal Transduction T-Lymphocyte TLR7 gene Tissues Toll-like receptors Transcriptional Regulation Transgenic Mice Transgenic Model Transgenic Organisms anergy autoreactive B cell cell type cohort differentiated B cell fighting in vitro Assay in vivo inhibiting antibody insight mouse model novel pathogen prevent promoter public health relevance response transcription factor

项目摘要

DESCRIPTION (provided by applicant): The production of antibodies by antibody-secreting cells (ASCs) is critically important for immune responses to many different pathogens. However, in autoimmune diseases where B cell tolerance is broken, many ASCs secrete autoantibodies and contribute in a major way to organ pathology. The differentiation of B cells into ASCs is controlled by a cohort of key transcription factors including Ets-1, which serves as a negative regulator of this process. In the absence of Ets-1, B cells undergo enhanced differentiation into ASCs many of which secrete autoantibodies as demonstrated by high titers of IgM and IgG autoantibodies in the serum. Recently Toll- like receptor (TLR) signaling, particularly via TLR7 and TLR9, has been implicated in the activation of autoreactive B cells to differentiate into ASCs. Interestingly, Ets-1 deficient B cells exhibit enhanced responses to TLR7 and TLR9 ligands in vitro and Ets-1 knockout mice lacking the TLR adaptor protein Myd88 have reduced autoantibody production. Toll-like receptor signaling is a potent inducer of the expression of Blimp-1, a key transcription factor that drives ASC differentiation. Ets-1 physically interacts with Blimp-1 to inhibit the ability of Blimp-1 to bind target DNA sequences. In contrast, a closely related transcription factor Ets-2 is unable to block Blimp-1 binding or to inhibit ASC differentiation. Ets-1 also is thought to regulate the expression of critical target genes controlling ASC formation, but the identity of most of these targets remains unclear. In this application we propose a variety of assays to further define the role of Ets-1 in regulating target gene expression, Blimp-1 activity and ASC differentiation. These studies will be aided by comparing biological activities of Ets-1, which can block ASC differentiation, with the closely related Ets-2 protein, which lacks this activity. The specific aims of the proposal are (1) to determine which cell types require Ets-1 activity to limit ASC formation, autoantibody secretion and autoimmune disease, (2) to examine the in vivo role of TLR7 and 9 ligands in activating Ets-1 deficient B cells, (3) to identify Ets-1 dependent gene expression pathways regulating ASC formation and (4) to identify structural features of Ets-1 that impart a unique ability to regulate ASC development. Together our studies will provide novel insights into the transcriptional regulation of B cell differentiation particularly in situations of autoantibody secretion. PUBLIC HEALTH RELEVANCE: As part of the immune response to pathogens, B cells differentiate into antibody-secreting cells (ASCs) that produce high levels of antibodies to fight infection. In autoimmune disease, there are large numbers of ASCs that secrete antibodies that react with self-tissues. Information gleaned from the studies proposed will help define the molecular details of how B cells differentiate into ASCs and how that process is defective in autoimmune disease, thereby potentially identifying new strategies to stimulate or inhibit this process clinically.

描述（由申请人提供）：抗体分泌细胞（ASC）产生抗体对于针对许多不同病原体的免疫反应至关重要。然而，在 B 细胞耐受性被破坏的自身免疫性疾病中，许多 ASC 会分泌自身抗体，并对器官病理学产生重要影响。 B 细胞向 ASC 的分化是由一组关键转录因子控制的，其中包括 Ets-1，Ets-1 是该过程的负调节因子。在缺乏 Ets-1 的情况下，B 细胞会增强分化为 ASC，其中许多 ASC 会分泌自身抗体，如血清中高滴度的 IgM 和 IgG 自身抗体所证明的那样。最近，Toll 样受体 (TLR) 信号传导，特别是通过 TLR7 和 TLR9，与自身反应性 B 细胞分化为 ASC 的激活有关。有趣的是，Ets-1缺陷的B细胞在体外表现出对TLR7和TLR9配体的增强的反应，而缺乏TLR接头蛋白Myd88的Ets-1敲除小鼠自身抗体的产生减少。 Toll 样受体信号传导是 Blimp-1 表达的有效诱导剂，Blimp-1 是驱动 ASC 分化的关键转录因子。 Ets-1 与 Blimp-1 发生物理相互作用，抑制 Blimp-1 结合靶 DNA 序列的能力。相反，密切相关的转录因子 Ets-2 无法阻断 Blimp-1 结合或抑制 ASC 分化。 Ets-1也被认为可以调节控制ASC形成的关键靶基因的表达，但大多数这些靶基因的身份仍不清楚。在此应用中，我们提出了多种测定法来进一步确定 Ets-1 在调节靶基因表达、Blimp-1 活性和 ASC 分化中的作用。通过比较可以阻止 ASC 分化的 Ets-1 与缺乏这种活性的密切相关的 Ets-2 蛋白的生物活性，将有助于这些研究。该提案的具体目标是 (1) 确定哪些细胞类型需要 Ets-1 活性来限制 ASC 形成、自身抗体分泌和自身免疫性疾病，(2) 检查 TLR7 和 9 配体在激活 Ets-1 中的体内作用缺陷 B 细胞，(3) 鉴定调节 ASC 形成的 Ets-1 依赖性基因表达途径，(4) 鉴定 Ets-1 的结构特征，这些特征赋予调节 ASC 发育的独特能力。我们的研究将为 B 细胞分化的转录调控提供新的见解，特别是在自身抗体分泌的情况下。公共卫生相关性：作为对病原体免疫反应的一部分，B 细胞分化为抗体分泌细胞 (ASC)，产生高水平的抗体来对抗感染。在自身免疫性疾病中，存在大量的 ASC 分泌与自身组织发生反应的抗体。从所提出的研究中收集的信息将有助于确定 B 细胞如何分化为 ASC 的分子细节，以及该过程在自身免疫性疾病中如何存在缺陷，从而有可能确定临床上刺激或抑制这一过程的新策略。