Structural mechanism of integrin-mediated TGF-b activation

整合素介导的TGF-b激活的结构机制

• 批准号: 10407522
• 负责人: Yifan Cheng
• 金额: $ 73.79万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-04 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10407522
• 关键词: Adaptor Signaling Protein; Address; Airway Fibrosis; Anabolism; Architecture; Binding; Biochemical; Biological Assay; Cell surface; Cells; Chronic; Chronic Obstructive Pulmonary Disease; Clinical; Complex; Cryoelectron Microscopy; Crystallization; Data; Diffuse; Diffusion; Epithelial; Event; Exposure to; Fibrosis; Funding; Goals; Human; Immune; Inflammation; Inflammatory; Integrins; Lead; Location; Lung; Lung diseases; Mediating; Mediator of activation protein; Mesenchymal; Methods; Modeling; Molecular Conformation; Mutation; Pathologic; Pathology; Peptides; Primates; Process; Pulmonary Fibrosis; Regulation; Risk; Rodent; Sentinel; Series; Signal Transduction; Structure; Toxic effect; Transforming Growth Factor beta; Transforming Growth Factor beta Receptors; airway inflammation; arm; base; chronic inflammatory lung disease; clinical development; cytokine; design; effective therapy; flexibility; improved; in vivo; inflammatory lung disease; integrin alphavbeta8; particle; receptor; receptor binding; therapeutic target; Adaptor Signaling Protein; Address; Airway Fibrosis; Anabolism; Architecture; Binding; Biochemical; Biological Assay; Cell surface; Cells; Chronic; Chronic Obstructive Pulmonary Disease; Clinical; Complex; Cryoelectron Microscopy; Crystallization; Data; Diffuse; Diffusion; Epithelial; Event; Exposure to; Fibrosis; Funding; Goals; Human; Immune; Inflammation; Inflammatory; Integrins; Lead; Location; Lung; Lung diseases; Mediating; Mediator of activation protein; Mesenchymal; Methods; Modeling; Molecular Conformation; Mutation; Pathologic; Pathology; Peptides; Primates; Process; Pulmonary Fibrosis; Regulation; Risk; Rodent; Sentinel; Series; Signal Transduction; Structure; Toxic effect; Transforming Growth Factor beta; Transforming Growth Factor beta Receptors; airway inflammation; arm; base; chronic inflammatory lung disease; clinical development; cytokine; design; effective therapy; flexibility; improved; in vivo; inflammatory lung disease; integrin alphavbeta8; particle; receptor; receptor binding; therapeutic target

Summary/Abstract: TGF-Beta drives the fibroinflammatory processes that leads to lung and airway fibrosis. The long-term goal of this project is to acquire a deep understanding of the regulation of TGF-Beta activity to develop new strategies and treatments for fibrosing lung disease. There are few effective therapies to treat chronic fibrosing and inflammatory diseases of the lung. The cytokine TGF-Beta is a central mediator of fibrosis and pathologic inflammation and is a potential therapeutic target in fibrosing lung disease. However, the practical utility of targeting TGF-Beta itself or its receptors is limited by risk of toxicities seen in rodents, primates and humans. More specific methods to target the fibroinflammatory effects of TGF-Beta are highly desirable. A promising method to more specifically target local effects of TGF-Beta is to target its “activation” since it is always produced in a latent form (L-TGF-Beta) that must be activated in order to function. Another feature of L-TGF-Beta that could facilitate more specific targeting is that it is covalently bound to specific cell surfaces by GARP. L-TGF-Beta binding to the integrin alphavBeta8 is essential for TGF-Beta activation in vivo. For the alphavBeta8 activation mechanism, as well as all others, it has long been assumed that TGF-Beta must be released from LAP so that free TGF-Beta can diffuse and bind its receptors on target cells. Based on recent structural data obtained using single particle electron cryomicroscopy (cryo-EM), we have recently proposed a new model whereby alphavBeta8 can bind to L-TGF-Beta on cells presenting the L-TGF-Beta/GARP complex and induce signaling without release and diffusion of TGF-Beta. Here in three aims, we address three critical questions concerning this new model of L-TGF-Beta activation. (1) Which flexible domains of L-TGF-Beta of the alphavBeta8/L-TGF-Beta/GARP ternary complex shield TGF-Beta from its receptors? (2) Is flexibility of L-TGF-Beta induced by binding to alphavBeta8 necessary to mediate TGF-Beta activation? (3) Do TGF-Beta receptors (TGF-BetaRs) bind to TGF-Beta within the alphavBeta8/L-TGF-Beta/GARP complex? To answer these questions, we will use cryo-EM to determine the structure of the alphavBeta8/L-TGF-Beta/GARP complex to determine how flexibility of L-TGF-Beta contributes to TGF-Beta activation, and finally we will capture the multimeric complex of TGF-BetaRs with alphavBeta8/LTGF-Beta/GARP. These studies will improve mechanistic understanding of TGF-Beta activation and therapeutic targeting strategies to inhibit it.

摘要/摘要：TGF-beta驱动导致肺和气道纤维化的纤维炎症过程。这 该项目的长期目标是对TGF-beta活动的调节有深入的了解 纤维化肺部疾病的新策略和治疗方法。几乎没有有效治疗慢性的疗法 肺的纤维化和炎症性疾病。细胞因子TGF-β是纤维化和 病理炎症，是纤维化肺部疾病的潜在治疗靶标。但是，实用 靶向TGF-beta本身或其接收器的效用受到啮齿动物，私人和毒性风险的限制 人类。非常需要靶向TGF-β的纤维炎症作用的更具体的方法。一个 更具体地针对TGF-β的局部效应的有前途的方法是针对其“激活”，因为它始终是 以潜在形式（L-TGF-BETA）产生，必须激活才能发挥作用。 l-tgf-beta的另一个功能 可以促进更具体的靶向是通过GARP共价与特定的细胞表面结合。 l-tgf-beta 与整联蛋白alphavbeta8结合对于体内TGF-β激活至关重要。对于alphavbeta8激活机制， 与其他所有其他人一样，长期以来一直认为TGF-beta必须从膝盖上释放，以便免费的TGF-beta可以 扩散并将其接收器绑定在靶细胞上。基于使用单个粒子获得的最新结构数据 电子冷冻显微镜（Cryo-EM），我们最近提出了一个新模型，在该模型中，Alphavbeta8可以在呈现L-TGF-Beta/GARP复合物的细胞上与L-TGF-BETA结合，并诱导信号传导而无需释放和扩散 tgf-beta。在三个目标中，我们解决了有关这种新模型L-TGF-Beta的三个关键问题 激活。 （1）alphavbeta8/l-tgf-beta/garp三元三元复合盾TGF-beta的L-TGF-beta的灵活域 从接收器？ （2）是与介导TGF-beta所必需的与Alphavbeta8结合引起的L-TGF-β的灵活性 激活？ （3）TGF-beta受体（TGF-BETAR）是否与Alphavbeta8/L-TGF-Beta/GARP复合物内的TGF-beta结合？到 回答这些问题，我们将使用Cryo-Em来确定Alphavbeta8/L-TGF-Beta/GARP Complex的结构 为了确定L-TGF-beta的灵活性如何有助于TGF-beta激活，最后我们将捕获 带有Alphavbeta8/ltgf-beta/garp的TGF-Betars的多药综合体。这些研究将改善机械性 了解TGF-β激活和抑制其治疗性靶向策略。