Host innate responses induced by intracellular bacteria and cyclic-di-nucleotides

由细胞内细菌和环二核苷酸诱导的宿主先天反应

• 批准号: 8234234
• 负责人: RUSSELL E VANCE
• 金额: $ 34.6万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8234234
• 关键词: Address; Antibodies; Bacteria; Bacterial Physiology; Belief; Binding; Biochemical; Characteristics; Communicable Diseases; Cyclic GMP; Cyclic Nucleotides; Cytosol; DNA; Detection; Dinucleoside Phosphates; Dissection; Ethylnitrosourea; Flagellin; Genes; Genetic; Genetic Screening; Goals; Immune Targeting; Immune response; Immune system; Immunologic Monitoring; Immunotherapeutic agent; Interferon Type I; Interferons; Listeria monocytogenes; Mammalian Cell; Molecular; Morbidity - disease rate; Mus; Mutagenesis; Mutant Strains Mice; Mycobacterium tuberculosis; Natural Immunity; Nucleic Acids; Nucleotides; Pathway interactions; Pattern; Play; Production; Prokaryotic Cells; Proteins; Radiolabeled; Role; Second Messenger Systems; Shapes; Vaccine Adjuvant; Work; base; bis(3' ,5' )-cyclic diguanylic acid; design; extracellular; improved; mortality; mutant; novel; novel vaccines; pathogen; radiotracer; research study; response; second messenger; sensor

Intracellular pathogens remain a major cause of global mortality and morbidity. By evasion of extracellular defenses, such as antibodies, intracellular pathogens pose a unique challenge to the immune systems of their hosts. A fundamental question we address is how intracellular pathogens are sensed by the innate immune system. In the past few years, we and others have discovered that intracellular pathogens trigger a variety of different cytosolic immunosurveillance pathways. These pathways appear to play important roles in shaping protective innate and adaptive responses. However, the molecular basis of cytosolic immunosurveillance remains poorly characterized, and it is likely that additional pathways remain to be discovered. Our studies are motivated by our belief that a better understanding of innate immunity is central to the improved design of new vaccines, adjuvants and immunotherapeutics. Exciting recent work from our group and others has shown that unique bacterial nucleotides, cyclic-di-GMP and cyclic-di-AMP, are novel and potent stimulator of innate and adaptive immune responses. The field now confronts a major outstanding question: what is the host sensor that specifically detects cyclic-di-nucleotides? We are taking genetic and biochemical approaches to address this fundamental question. In what we believe is an exciting advance, our unpublished experiments have now converged on identification of the sensor as a host protein called Sting (Stimulator of interferon genes). We identified a novel Sting mutant mouse in a forward genetic screen using ENU mutagenesis in mice. Using this mutant, we found Sting is essential for responses to c-dinucleotides. In addition, we have recently found that radiolabelled c-di-GMP binds specifically to Sting. Thus, our Specific Aims are: (1) Determine how the interaction of Sting with cyclic-di-nucleotides leads to an IFN response (2) Distinguish the role of Sting in the cytosolic response to cyclic-di-nucleotides from the role of Sting in the cytosolic response to DNA, and distinguish these functions of Sting in the response to three intracellular bacterial pathogens (L. monocytogenes, M. tuberculosis, and L. pneumophila) (3) Identify novel regulators of innate immunity to three intracellular bacterial pathogens (L. monocytogenes, M. tuberculosis, and L. pneumophila) by continuing to perform forward genetic screens in mice.

细胞内病原体仍然是全球死亡率和发病率的主要原因。通过逃避细胞外 防御性（例如抗体），细胞内病原体对免疫系统构成了独特的挑战 他们的主人。我们解决的一个基本问题是，先天性的细胞内病原体如何感知 免疫系统。在过去的几年中，我们和其他人发现细胞内病原体会触发A 各种不同的胞质免疫监视途径。这些途径似乎在 塑造保护性先天和适应性反应。但是，胞质的分子基础 免疫监测的特征仍然很差，并且可能仍有其他途径 发现。我们的研究是因为我们相信对先天免疫的更好理解是核心 改进了新的疫苗，佐剂和免疫治疗药的设计。激动人心的最近工作 组和其他人表明，独特的细菌核苷酸，环状-DI-GMP和环状-DI-AMP是新颖的 以及先天和适应性免疫反应的有效刺激剂。该领域现在面对一个主要的杰出 问题：专门检测循环 - 二核苷酸的宿主传感器是什么？我们正在采用遗传和 生化方法来解决这个基本问题。我们认为这是一个令人兴奋的进步， 我们未发表的实验现在已经融合了传感器作为宿主蛋白的识别 刺（干扰素基因的刺激剂）。我们在正向遗传筛选中确定了一种新颖的刺突变小鼠 在小鼠中使用ENU诱变。使用该突变体，我们发现STING对于对C-核苷酸的反应至关重要。 此外，我们最近发现，放射性标记的C-DI-GMP专门与STING结合。因此， 我们的具体目的是：（1）确定刺激与环状核苷酸的相互作用如何导致IFN 反应（2）区分刺激在胞质对环二核苷酸的胞质反应中的作用与 在胞质反应中对DNA的刺痛，并区分了对三个响应的刺激功能 细胞内细菌病原体（L.单核细胞增生菌，结核杆菌和肺炎乳杆菌）（3）鉴定新型 对三种细胞内细菌病原体的先天免疫调节剂 通过继续在小鼠中执行前向遗传筛选，而肺炎乳杆菌）。