Probing Function of the C-type Lectin DC-SIGN with Glycomimetic Ligands

C 型凝集素 DC-SIGN 与糖模拟配体的探测功能

• 批准号: 8002897
• 负责人: Lynne Prost
• 金额: $ 4.76万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8002897
• 关键词: Affinity; Antigens; Binding; C-Type Lectins; Cell Adhesion; Cells; Dendritic Cells; Disease; Fucose; Goals; Health; Immune; Immune Targeting; Immune system; Immunity; Infection; Investigation; Label; Lead; Lectin; Libraries; Life; Ligands; Mannose; Mediating; Molecular; Outcome; Polysaccharides; Property; Reporter; Research; Role; Route; Specificity; Structure; Surface; T-Lymphocyte; Testing; Time; Vaccines; Work; antimicrobial drug; base; carbohydrate binding protein; inhibitor/antagonist; interest; killings; novel; pathogen; public health relevance; receptor; receptor binding; receptor function; response; trafficking; tumor; uptake

DESCRIPTION (provided by applicant): The dendritic cell (DC) C-type lectin DC-SIGN can function in both cell adhesion and antigen recognition, and several pathogens appear to interact with DC-SIGN for their own benefit. DC-SIGN mediates myriad responses depending on the ligand it binds, and the molecular mechanisms that underlie different cellular responses are not understood. As some pathogens bind DC-SIGN to promote infection, inhibitors of DC-SIGN may function as novel antimicrobial agents. In addition, a better understanding of the mechanisms by which DC-SIGN mediates antigen uptake and presentation to T cells could lead to enhanced vaccine strategies. DC- SIGN is a carbohydrate-binding protein with relatively weak affinity for a set of mannose- and fucose- based glycans, and DCs also express other receptors that bind similar structures. Thus, it has been difficult to dissect the role of any one lectin. The goal of the proposed research is to elucidate the role of DC-SIGN in health and disease by describing the fate of ligands with different properties that bind DC-SIGN. Ligands that display high affinity for DC-SIGN have been generated, and these will be employed. These ligands can be labeled with a fluorogenic reporter to allow their cellular uptake and trafficking to be observed in real time in live cells. Such ligands will be used to accomplish the following Specific Aims: 1. Compare ligand specificity of DC-SIGN to that of other lectins. Ligands found to bind with high affinity to DC-SIGN will be tested for binding to additional C-type lectins present on dendritic cells. These additional lectins will be screened against a library of glycomimetic compounds to assess inhibitor specificity among the different receptors. These studies will also yield high-affinity inhibitors for further study of several immune cell lectins, in addition to DC-SIGN. 2. Determine the effect of ligand structure on DC-SIGN function. Ligands of varying properties, such as low or high valency, will be used to treat cells to study the downstream outcomes of binding to DC-SIGN. Outcomes of interest include the rate of antigen uptake and intracellular routing. These investigations will be carried out using transfected cells that lack other immune C-type lectins, to ascertain the function of DC- SIGN in isolation. 3. Explore the consequences of DC-SIGN co-activation with other receptors. The possibility that multiple receptors cooperate to control responses will be evaluated by using compounds that can engage multiple receptors simultaneously. The cellular uptake and intracellular routing will be evaluated using immune cells that also express additional receptors. This work will greatly increase our understanding of how DC-SIGN functions in immunity. I anticipate that it also will provide new probes for studying DC-SIGN and perhaps even other C-type lectins in the immune system. PUBLIC HEALTH RELEVANCE: Project Narrative DC-SIGN is a receptor on the surface of dendritic cells that can both recognize pathogens and promote interactions with other immune cells. We seek to elucidate the function of this receptor in terms of interactions with pathogens. A better understanding of how these types of receptors function may allow us to manipulate them for the purpose of killing pathogens, making better vaccines, or targeting immune cells to clear tumors.

描述（由申请人提供）：树突状细胞（DC）C型凝集素DC-SIGN可以在细胞粘附和抗原识别中起作用，并且几种病原体似乎与DC-SIGN相互作用以供自身利益。 DC-SIGN根据其结合的配体介导了无数的反应，并且尚不清楚不同细胞反应的分子机制。由于某些病原体结合DC-sign以促进感染，因此DC-SIGN的抑制剂可能起到新型抗菌剂的作用。此外，对DC-Sign介导抗原摄取和呈现T细胞的机制有更好的了解可能导致疫苗策略增强。 DC-标志是一种碳水化合物结合蛋白，对一组甘露糖和纤维糖基聚糖的亲和力相对较弱，并且DC还表达了其他结合相似结构的受体。因此，很难剖析任何一种凝集素的作用。拟议的研究的目的是通过描述具有结合DC符号的不同特性的配体的命运来阐明DC符号在健康和疾病中的作用。已经产生了对DC-SIGN高亲和力的配体，将使用这些配体。这些配体可以用荧光记者标记，以便在活细胞中实时观察到它们的细胞摄取和运输。这样的配体将用于完成以下特定目的：1。比较DC符号的配体特异性与其他凝集素的配体特异性。发现与DC-SIGN高亲和力结合的配体将测试与树突状细胞上存在的其他C型凝集素结合。这些额外的凝集素将与糖含量化合物库进行筛选，以评估不同受体之间的抑制剂特异性。这些研究还将产生高亲和力的抑制剂，以进一步研究多种免疫细胞凝集素，除了DC-SIGN。 2。确定配体结构对DC-sign函数的影响。各种特性的配体（例如低价或高价值）将用于治疗细胞以研究与DC-SIGN结合的下游结果。 感兴趣的结果包括抗原吸收和细胞内路由的速率。这些研究将使用缺乏其他免疫C型凝集素的转染细胞进行，以确定DC-标志的功能。 3。探索与其他受体共同激活DC-Sign的后果。通过使用可以同时吸收多个受体的化合物来评估多个受体控制反应的可能性。将使用也表达其他受体的免疫细胞评估细胞摄取和细胞内路由。这项工作将大大提高我们对DC-Sign如何在免疫功能中功能的理解。我预计它也将为研究免疫系统中的DC-SIGN甚至其他C型凝集素提供新的探针。 公共卫生相关性：项目叙事DC-SIGN是树突状细胞表面的受体，既可以识别病原体并促进与其他免疫细胞的相互作用。我们试图以与病原体的相互作用来阐明该受体的功能。更好地了解这些类型的受体功能如何使我们能够操纵它们，以杀死病原体，制造更好的疫苗或靶向免疫细胞清除肿瘤。