Human polymorphic variance in the Dectin-1 signaling pathway

Dectin-1 信号通路中的人类多态性变异

• 批准号: 7912815
• 负责人: Andrea Jean Wolf
• 金额: $ 5.05万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7912815
• 关键词: Acquired Immunodeficiency Syndrome; Affect; Biochemical; Biochemistry; Biological; Cancer Patient; Cell Culture System; Cell Wall; Cells; Comprehension; Environment; Genes; Genetic; Genetic Polymorphism; Glucans; Human; Immune; Immune response; Immune system; Immunocompromised Host; Immunologic Receptors; In Vitro; Individual; Inflammation; Knockout Mice; Leukocytes; Ligands; Molecular; Mycoses; Natural Immunity; Nature; Oxygen; Pathogenesis; Pathway interactions; Patients; Phagocytes; Phagocytosis; Predisposition; Production; Proteins; Role; Sampling; Signal Pathway; Signal Transduction; Signaling Molecule; Source; cytokine; dectin 1; disorder prevention; genetic variant; genome wide association study; in vivo; pathogen; public health relevance; research study; response; tool

DESCRIPTION (provided by applicant): Susceptibility to fungal pathogens is primarily restricted to immunocompromised individuals, despite ubiquitous nature of fungal pathogens in the environment. As the initial barrier to pathogenesis, the innate immune response is an integral component of disease prevention. Dectin-1 is an innate immune receptor expressed by phagocytic cells that recognizes fungal cell wall b-glucan. Through in vitro and in vivo experimental examination of knockout mice, a role has been established for the Dectin-1 signaling pathway in the phagocytosis, production of reactive oxygen, and induction of cytokines. The absence of a similar set of genetic tools in humans has hampered our comprehension of Dectin-1's significance during fungal infection in humans. However, we believe that genome-wide association screens in humans provide a valuable tool that can not only inform our understanding the biochemistry of innate immune pathways but also serves as source of genetically diverse biological samples for directly examining the functional consequences of altered innate immunity in humans. Therefore, in this application we propose two specific aims. In specific aim 1 we will characterize 5 polymorphisms in Dectin-1 that we expect will alter the level of expression or the ability of Dectin-1 to recognize its ligand. Specific aim 2 will examine 2 polymorphisms in the gene encoding CARD9, a signaling molecule downstream of Dectin-1, that we predict will be associated with altered CARD9 expression or function. For both specific aims, we propose in vitro experiments to characterize affects of the polymorphisms in Dectin-1 and CARD9 on the recognition, phagocytosis, and transcriptional responses to fungal pathogens in an isolated cell culture system. We will pair these in vitro biochemical and mechanistic studies with the isolation and characterization of primary cells from donors known to posses each of the polymorphisms. Studying the recognition and response to fungal pathogens by genetically defined primary cells will provide us with an understanding of Dectin-1's contribution to the recognition and control of fungal infection by the human innate immune system. PUBLIC HEALTH RELEVANCE: Fungal infections are common in cancer patients and AIDS patients among others, and inflammation activated by white blood cells is critical to mount a successful immune defense. A protein called Dectin-1 recognizes fungal pathogens and triggers inflammation through a signaling molecule called CARD9. We have discovered significant genetic variability between humans in the genes for these two proteins. In this project we will fully characterize the effects of these genetic variants on the molecular mechanisms of signaling.

描述（由申请人提供）：尽管真菌病原体在环境中无处不在的性质，但对真菌病原体的易感性主要限于免疫功能低下的个体。作为发病机理的最初障碍，先天免疫反应是预防疾病的组成部分。 Dectin-1是一种识别真菌细胞壁B-葡聚糖的吞噬细胞表达的先天免疫受体。通过对基因敲除小鼠的体外和体内实验检查，已经在吞噬作用中确定了Dectin-1信号通路的作用，活性氧的产生和细胞因子的诱导。人类没有类似的遗传工具，这阻碍了我们对人类真菌感染期间Dectin-1意义的理解。但是，我们认为，人类中的全基因组关联筛选提供了一种有价值的工具，不仅可以告知我们理解先天免疫途径的生物化学，而且还可以作为遗传多样的生物样品的来源，以直接研究人类先天免疫改变的功能后果。因此，在此应用程序中，我们提出了两个具体目标。在特定目标1中，我们将表征Dectin-1中5种多态性，我们期望将改变Dectin-1识别其配体的表达水平或能力。具体的目标2将检查编码CARD9的基因（一种信号分子）下游的2个多态性，我们预测，这将与Card9表达或功能改变有关。对于这两个具体目的，我们都提出了体外实验，以表征Dectin-1和card9对识别，吞噬作用以及对真菌病原体的识别，吞噬作用以及分离的细胞培养系统中对真菌病原体的转录反应的影响。我们将将这些在体外生化和机械研究与已知具有每种多态性的供体的原代细胞的分离和表征相结合。通过遗传定义的原代细胞研究对真菌病原体的识别和反应将使我们了解Dectin-1对人类先天免疫系统对真菌感染的识别和控制的贡献。 公共卫生相关性：真菌感染在癌症患者和艾滋病患者中很常见，而白细胞激活的炎症对于实施成功的免疫防御至关重要。一种称为Dectin-1的蛋白质识别真菌病原体，并通过称为Card9的信号分子触发炎症。我们发现，这两种蛋白质的基因中人类之间的遗传变异很大。在这个项目中，我们将充分表征这些遗传变异对信号传导分子机制的影响。