Toll-like receptor 9 proteolytic processing and signaling

Toll 样受体 9 蛋白水解加工和信号转导

• 批准号: 8382948
• 负责人: CYNTHIA A LEIFER
• 金额: $ 7.7万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8382948
• 关键词: Address; Allergic Disease; Asthma; Autoantibodies; Autoimmune Diseases; Autoimmune Process; Autoimmunity; B-Lymphocytes; Biochemistry; Biological Models; C-terminal; Cells; Chemistry; Chimeric Proteins; Clinical; Critical Pathways; DNA; DNA Binding; DNA Structure; Data; Dendritic Cells; Development; Discrimination; Disease; Drug Delivery Systems; Endocytosis; Endosomes; Engineering; Event; Family; Host Defense; Immune; Immune response; Immunologic Receptors; Infection; Inflammation; Inflammatory; Interferons; Lead; Left; Ligands; Malignant Neoplasms; Measures; Mediating; Methylation; Microbe; Modeling; Molecular; Mutation; N-terminal; NF-kappa B; Natural Immunity; Nucleic Acids; Pathology; Pathway interactions; Peptide Hydrolases; Play; Positioning Attribute; Prevalence; Production; Proteolysis; Proteolytic Processing; Publishing; RNA; Reaction; Receptors, Antigen, B-Cell; Regulation; Regulatory Pathway; Role; Signal Transduction; Site; Site-Directed Mutagenesis; Specificity; Structure; Systemic Lupus Erythematosus; T-Lymphocyte; TEV protease; TLR4 gene; TLR9 gene; Testing; Therapeutic; Tissues; Toll-like receptors; Transfection; Translating; Vaccine Adjuvant; Vertebral column; Wound Healing; cell type; drug development; extracellular; innovation; macrophage; member; microbial; mouse model; mutant; new therapeutic target; novel; prevent; receptor; reconstitution; response; retroviral transduction; standard of care; tool; trafficking

DESCRIPTION (provided by applicant): Therapeutically targeting inflammation induced by innate immunity has the potential to reduce disease associated pathology; however, the first step in translating potential to clinical reality is defining the molecular pathways critical for regulating innate immunity, and identifying targets within these pathways that can be modulated. Significant progress has been made in delineating the molecular pathways regulating one member of the nucleic acids-sensing family of Toll-like receptors (TLRs), which have been implicated in development of autoimmune disease. Recent studies suggest that one of these TLRs, TLR9, is a pro-receptor that is activated by proteases in acidic endosomes. This cleavage removes an N-terminal fragment, leaving a C-terminal fragment, called p80, which is proposed to be the functional form of TLR9. This pathway has been touted as a new and potentially important drug target to reduce autoimmune inflammation. However, our preliminary results demonstrate that proteolytic cleavage of TLR9 does not occur in B cells, which respond robustly to TLR9 ligands. Moreover, we show that the p80 form of TLR9 is insufficient to support signaling in highly relevant macrophages, and dendritic cells. We review data that shows the N-terminal fragment, which is removed during the proteolytic event, has DNA binding activity. Therefore, we propose the hypothesis that the N-terminal fragment plays a critical role in determining the ligand specificity and response of the receptor. We will test this hypothesis in two aims, which define the role of the N-terminus in regulating specificity of the receptor, and the role of the cleavage event in regulating signaling and trafficking in various cell types including B cells, macrophages and dendritic cells. While we use TLR9 as a model system, recent published studies showed that other nucleic acid sensing TLRs are regulated by similar mechanisms. This study will provide critical new information that will help clarify controversies i the field. But more importantly, will determine whether proteolysis is, in fact, a promising new pathway for drug development, or of lesser significance compared with other regulatory mechanisms. PUBLIC HEALTH RELEVANCE: Innate immune receptors contribute to the development of inflammatory and autoimmune disease, and there is great promise to modulate their function for therapeutic benefit. However, a critical barrier to progress in this field is contradictory data on the importance of a newly discovered regulatory pathway for one family of innate immune receptors. At the completion of these studies we will have provided key data that will lead to paradigmatic shift in the current model of how these receptors are regulated and permit development of new therapeutic targets to treat autoimmune disease.

描述（由申请人提供）：治疗性靶向先天免疫诱导的炎症具有减少疾病相关病理的潜力;然而，将潜力转化为临床现实的第一步是定义对调节先天免疫至关重要的分子途径，并鉴定这些途径中可调节的靶标。Toll样受体（TLRs）是一种核酸敏感家族成员，与自身免疫性疾病的发生发展密切相关。最近的研究表明，这些TLR之一，TLR 9，是一种前受体，被酸性内体中的蛋白酶激活。这种切割去除了N-末端片段，留下了C-末端片段，称为p80，其被认为是TLR 9的功能形式。这一途径被吹捧为一种新的和潜在的重要药物靶点，以减少自身免疫性炎症。然而，我们的初步结果表明，蛋白水解裂解的TLR 9不发生在B细胞，强烈响应TLR 9配体。此外，我们发现TLR 9的p80形式不足以支持高度相关的巨噬细胞和树突状细胞中的信号传导。我们回顾的数据表明，N-末端片段，这是在蛋白水解过程中删除，具有DNA结合活性。因此，我们提出的假设，N-末端片段在决定配体的特异性和受体的反应中起着至关重要的作用。我们将在两个目标中测试这一假设，这两个目标定义了N末端在调节受体特异性中的作用，以及切割事件在调节各种细胞类型（包括B细胞、巨噬细胞和细胞）中的信号传导和运输中的作用。树突状细胞。虽然我们使用TLR 9作为模型系统，但最近发表的研究表明，其他核酸传感TLRs也受到类似机制的调控。这项研究将提供重要的新信息，有助于澄清该领域的争议。但更重要的是，这将决定蛋白水解是否是一个有希望的药物开发新途径，或者与其他调节机制相比意义较小。 公共卫生关系：先天免疫受体有助于炎症和自身免疫性疾病的发展，并且调节其功能以获得治疗益处是很有希望的。然而，在这一领域取得进展的一个关键障碍是关于以下方面的相互矛盾的数据： 一个新发现的先天免疫受体家族的调节途径的重要性。在这些研究完成时，我们将提供关键数据，这些数据将导致这些受体如何调节的当前模型的范式转变，并允许开发新的治疗靶点来治疗自身免疫性疾病。