Conformational regulation of TGF-β activation by integrin αvβ6

整合素 αvβ6 对 TGF-β 激活的构象调节

• 批准号: 10655988
• 负责人: Yifan Cheng
• 金额: $ 79.97万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10655988
• 关键词: Address; Apical; Binding; Binding Proteins; Biological; Biological Assay; Cell surface; Cells; Clinical; Complex; Cryoelectron Microscopy; Crystallography; Data; Development; Diffuse; Diffusion; Event; Extracellular Matrix; Fibrosis; Gene Deletion; Goals; Head; Homeostasis; Human; Immune; Inflammatory; Integrins; LRRC32 gene; Length; Ligand Binding; Lung diseases; Mediating; Mediator; Medical; Membrane; Methods; Modeling; Molecular Conformation; Monoclonal Antibodies; Pathologic; Pathology; Peptides; Pharmaceutical Preparations; Phase II Clinical Trials; Physiological; Play; Pre-Clinical Model; Primates; Property; Proteins; Pulmonary Fibrosis; Regulation; Research; Resolution; Risk; Rodent; Role; Safety; Series; Signal Induction; Signal Transduction; Structure; Techniques; Testing; Therapeutic; Toxic effect; Transforming Growth Factor beta; Transforming Growth Factor beta Receptors; Transforming Growth Factors; Visualization; chronic inflammatory lung disease; conformational conversion; cytokine; design; effective therapy; idiopathic pulmonary fibrosis; improved; in vivo; insight; latent TGF-beta binding protein; particle; protein complex; receptor; therapeutic target; therapy development

Summary/Abstract: TGF-b is a key driver of lung fibrosis. The long-term goal of our research is to acquire a deep understanding of the regulation of TGF-b activity to develop new strategies and treatments for fibrosing lung disease. Currently, there are no effective therapies to treat lung fibrosis. The multifunctional cytokine TGF- b is a potent mediator of fibrosis and is a potential therapeutic target in fibrosing lung disease. However, targeting TGF-b itself or its receptors is associated with demonstrated risks as evidenced by toxicities in rodents, primates and humans. More selective targeting of the fibroinflammatory effects of TGF-b, without perturbing its normal essential functions are highly desirable. One property of TGF-b that may allow more selective targeting is to target its “activation” since it is always produced in a latent form (L-TGF-b) that requires activation in order to function. Another feature of L-TGF-b that could facilitate more specific targeting is to that it is normally covalently bound to the extracellular matrix or to the surface of cells by association with TGF-b binding proteins such as latent-TGF-b binding protein (LTBP) or glycoprotein-A repetitions predominant (GARP). We and others have shown that L-TGF-b binding to two integrins, a 8 and a vb vb 6 is essential for TGF-b activation in vivo. For the integrin a 6 activation mechanism, it has long been assumed that TGF-b vb must be released from LAP so that free TGF-b can diffuse and bind its receptors on target cells. The structural mechanism for such release of TGF-b is incompletely understood since full-length a vb 6 has not been studied in complex with TGF-b bound to TGF-b binding proteins. Based on recent structural data obtained using single particle electron cryomicroscopy (cryo-EM), we have recently proposed a new model whereby a vb 8 can bind to L-TGF-b on cells presenting the L-TGF-b/GARP complex and induce signaling without release and diffusion of TGF-b. These two different models of TGF-b activation may be able to be separately targeted, which could help mitigate therapeutic risk. Here in four aims, we will employ a structure-based approach to address the mechanism of a vb 6-mediated TGF-b activation. We will use the technique of electron cryomicroscopy (cryo- EM), which is a technique that allows for high-resolution structures of proteins and protein complexes in physiologically relevant conditions. Cryo-EM will be used to examine the role of integrin a vb 6 conformation in the mechanism of TGF-b activation. These studies will improve mechanistic understanding of TGF-b activation and therapeutic targeting strategies to more selectively and safely inhibit it.

摘要/摘要：TGF-B是肺纤维化的关键驱动力。我们研究的长期目标是获得 对TGF-B活动的调节，以开发新的策略和治疗方法 肺部病。目前，尚无治疗肺纤维化的有效疗法。多功能细胞因子TGF- B是纤维化的潜在介体，是纤维化肺部疾病的潜在治疗靶标。然而， 针对TGF-B本身或其接收器与表现出的风险相关 啮齿动物，私人和人类。更具选择性的靶向TGF-B的纤维炎症效应，没有 扰动其正常的基本功能是非常可取的。 TGF-B的一个属性可能允许更多 选择性定位是针对其“激活”，因为它始终以潜在形式（L-TGF-B）产生 激活以发挥作用。 L-TGF-B的另一个功能可以促进更具体的定位 它通常通过与TGF-B的结合而共价结合到细胞外基质或细胞表面 结合蛋白，例如潜在-TGF-B结合蛋白（LTBP）或糖蛋白A-A重复蛋白 （GARP）。我们和其他其他 VB VB 6对于 体内TGF-B激活。对于整联蛋白A 6激活机制，长期以来一直认为TGF-B VB 必须从膝盖中释放出来，以便游离TGF-B可以扩散并结合其在目标细胞上的接收器。结构 这种释放TGF-B的机制不完全理解，因为全长A VB 6尚未研究 与TGF-B结合到TGF-B结合蛋白的复合物。基于最新的结构数据，使用了单个 颗粒电子冷冻显微镜（冷冻EM），我们最近提出了一个新模型 VB 8可以结合 在呈现L-TGF-B/GARP复合物的细胞上的L-TGF-B，并诱导信号传导而无需释放和扩散 TGF-B。这两种不同的TGF-B激活模型可能能够分别针对 帮助减轻治疗风险。在四个目标中，我们将采用一种基于结构的方法来解决 a的机制 VB 6介导的TGF-B激活。我们将使用电子冷冻显微镜技术（冷冻 - em），这是一种允许在蛋白质和蛋白质复合物中的高分辨率结构的技术 生理上相关的条件。冷冻EM将用于检查整联蛋白的作用 VB 6构象 TGF-B激活的机制。这些研究将提高对TGF-B激活的机械理解 以及治疗性靶向策略，以更有选择性，安全地抑制它。