Glycopeptides and Other Non-Natural Variants: Probes of Carbohydrate Function

糖肽和其他非天然变体：碳水化合物功能的探针

• 批准号: 8540481
• 负责人: Laura L Kiessling
• 金额: $ 10.4万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 2013-04-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8540481
• 关键词: Address; Affinity; Antigens; Bacteria; Bacterial Infections; Binding; Biology; C-Type Lectins; Carbohydrates; Cell Adhesion; Cell Communication; Cell Surface Receptors; Cell surface; Cells; Cessation of life; Chemicals; Collaborations; Dendritic Cells; Development; Disease; Escherichia coli; Glycopeptides; Goals; HIV; HIV-1; Health; Human; Image; Immune response; Immune system; Immunity; Immunotherapy; Infection; Investigation; Label; Lead; Lectin; Libraries; Life; Ligands; Magnetic Resonance Imaging; Mediating; Mediator of activation protein; Methods; Microbe; Modeling; Molecular; Monitor; Mycobacterium tuberculosis; Organism; Play; Process; Proteins; Reagent; Reporter; Research; Role; S Phase; Signal Transduction; Solid; Specificity; Structure; Surface; T-Lymphocyte; Toll-Like Receptor 2; Toll-like receptors; Tuberculosis; Variant; Viral Proteins; Virus; Virus Diseases; Work; antigen processing; base; carbohydrate binding protein; cell motility; chemical synthesis; combat; design; fluorophore; fungus; high throughput screening; inhibitor/antagonist; insight; migration; mimetics; novel; pathogen; prevent; receptor; research study; response; small molecule; tool; trafficking; tumor; uptake; vaccine effectiveness

DESCRIPTION (provided by applicant): Lectins play critical roles in the immune system. The lectins on dendritic cells participate in antigen recognition and internalization and thereby serve as critical mediators of immunity. One such lectin, DC-SIGN, which mediates the beneficial process of antigen uptake for processing, can be co-opted by pathogens to suppress immune responses and promote their dissemination. For example, DC-SIGN can bind to HIV and facilitate its dissemination. It also has been shown to suppress immune responses to Mycobacterium tuberculosis. Because HIV and Mycobacterium tuberculosis are the two most significant threats to human health worldwide, it is critical to elucidate the molecular mechanisms underlying the function of DC-SIGN. The long-term goals of the proposed research are to use chemical biology to illuminate how DC-SIGN functions in signaling, antigen recognition, and antigen internalization. Insight into these processes can facilitate the design of agents to enhance the effectiveness of vaccines or prevent pathogen infection. The specific aims of the project follow: (1) to identify non-carbohydrate, small-molecule ligands for DC- SIGN, (2) to develop chemical imaging strategies to follow DC-SIGN-mediated antigen internalization and dendritic cell migration, and (3) to develop new chemical approaches to explore bacteria-dendritic cell interactions mediated by DC-SIGN. The first specific aim focuses on providing a novel set of inhibitors of DC-SIGN. These also can serve as tools for exploring the consequences of engaging this lectin. The DC-SIGN ligands identified to date are based on carbohydrates, which bind weakly and can interact with other dendritic cell-surface lectins. We envision that non-carbohydrate-based ligands will bind to DC-SIGN with higher specificity and affinity. In Aim 2, we shall use the ligands identified in Aim 1 to explore the consequences of antigen interaction with DC-SIGN. DC-SIGN interacts with a variety of different types of antigens (proteins, viruses, bacteria, and fungi); therefore, it is critical to understand how antigen structure influences internalization and trafficking. We shall use chemical synthesis to vary DC-SIGN ligand structure and to endow these model antigens with fluorogenic reporter groups for imaging. Aim 3 addresses how dendritic cell internalization and processing of organisms is influenced by DC-SIGN engagement. To investigate this process, we shall chemically modify bacteria such that they display specific DC-SIGN ligands. The results of the investigations proposed in Aim 3 can provide insight into the role of DC-SIGN and offer new strategies to explore the role of specific receptors in host-pathogen interactions. Relevance. The carbohydrate-binding protein DC-SIGN is found on the surface of dendritic cells, where it functions in the immune system. In addition to its normal function in humans, DC-SIGN can be used by viruses, like HIV, to facilitate their dissemination, and by some bacteria, like those that cause tuberculosis, to suppress immune responses. Because of its role in facilitating the two diseases that cause the most deaths worldwide, how DC- SIGN works and how to control it is important. This project is aimed at identifying DC-SIGN inhibitors and using compounds that bind to DC-SIGN to study its function.

描述（由申请人提供）：凝集素在免疫系统中起关键作用。树突状细胞上的凝集素参与抗原识别和内在化，从而作为免疫的关键介质。一种这样的凝集素，DC-SIGN介导了抗原吸收来处理的有益过程，可以通过病原体选择以抑制免疫反应并促进其传播。例如，DC-Sign可以与HIV结合并促进其传播。还显示出它抑制对结核分枝杆菌的免疫反应。由于艾滋病毒和结核分枝杆菌是全世界人类健康的两个最重要的威胁，因此阐明DC-sign功能的分子机制至关重要。拟议的研究的长期目标是使用化学生物学来阐明DC符号在信号传导，抗原识别和抗原内部化中的功能。对这些过程的深入了解可以促进药物的设计，以增强疫苗的有效性或防止病原体感染。该项目的具体目的如下：（1）确定用于DC-符号的非碳水化合物，小分子配体，（2）制定化学成像策略，以遵循DC-签署介导的抗原内在化和树突状细胞迁移，（3）以开发新的化学方法来开发新的化学方法，以探索细菌型细胞式培养媒介物介导的细菌。第一个特定的目的是提供一组新型DC-Sign抑制剂。这些也可以用作探索与这种凝集素接合的后果的工具。迄今为止确定的DC符号配体是基于碳水化合物的，碳水化合物弱结合并可以与其他树突状细胞表面凝集素相互作用。我们设想，非碳水化合物的配体将具有更高的特异性和亲和力与DC-SIGN结合。在AIM 2中，我们将使用AIM 1中确定的配体来探索与DC-Sign抗原相互作用的后果。 DC-SIGN与多种不同类型的抗原（蛋白质，病毒，细菌和真菌）相互作用；因此，了解抗原结构如何影响内在化和贩运是至关重要的。我们将使用化学合成来改变DC-sign配体结构，并将这些模型抗原赋予荧光报告基团进行成像。 AIM 3解决了生物体的树突状细胞内在化和加工如何受到DC-Sign参与度的影响。为了研究这一过程，我们将化学修改细菌，使其显示特定的DC符号配体。 AIM 3中提出的调查结果可以洞悉DC-SIGN的作用，并提供新的策略来探索特定受体在宿主 - 病原体相互作用中的作用。 关联。碳水化合物结合蛋白DC-sign在树突状细胞的表面上发现，该蛋白在免疫系统中起作用。除了其在人类中的正常功能外，DC-SIGN还可以由HIV等病毒使用，以促进其传播，以及某些细菌（如引起结核病的细菌）来抑制免疫反应。由于它在促进两种造成全球死亡人数最多的疾病中的作用，DC-标志的工作原理以及如何控制它很重要。该项目旨在识别DC符号抑制剂，并使用与DC-SIGN结合以研究其功能的化合物。