Regulation of immunity by the cGAS-STING pathway

cGAS-STING 通路对免疫的调节

• 批准号: 10583763
• 负责人: JONATHAN C KAGAN
• 金额: $ 78.49万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-19 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10583763
• 关键词: Address; Amino Acids; Binding; Bioinformatics; Biology; CD8-Positive T-Lymphocytes; Catalytic Domain; Cell physiology; Cells; Clinical; Complex; Cyclic GMP; DNA; Data; Detection; Discrimination; Disease; Disease Progression; Ensure; Enzymes; Event; Genetic; Goals; Health; Human; Immune response; Immune system; Immunity; In Vitro; Individual; Infection; Inflammation; Inflammatory; Inflammatory Response; Interferons; Malignant Neoplasms; Mediating; Motion; Mus; Nature; Organism; Outcome; Pan Genus; Pathway interactions; Physiological; Play; Pongo pygmaeus; Pre-Clinical Model; Primates; Proteins; Regulation; Regulatory Element; Reporting; Research Proposals; Resolution; Role; Second Messenger Systems; Sensory; Signal Transduction; Source; Specific qualifier value; Sugar Phosphates; System; T-Lymphocyte; Tissues; Tumor Immunity; Vertebral column; Work; adaptive immune response; base; cancer cell; cell mediated immune response; cell type; comparative; cytokine; expectation; immunoreaction; macrophage; microbial; mutant; protein function; response; scaffold; small molecule; synthetic biology; tool; tumor; tumor growth; tumor microenvironment; virtual

Project Summary The goal of this proposal is to dissect the mechanisms of self-DNA detection by the enzyme cyclic GMP-AMP synthase (cGAS), and to determine the relative contribution of its diverse signaling activities to inflammation in the microenvironment of implantable murine tumors. cGAS operates in virtually all cell types as a DNA sensory protein, which synthesizes the second messenger cyclic GMP-AMP (cGAMP) upon binding DNA. This second messenger stimulates interferon (IFN) and inflammatory activities via the downstream protein STING. Because cGAS detects the sugar-phosphate backbone of DNA, a major question relates to how this enzyme is regulated to ensure self-nonself discrimination. This question relates to much fundamental biology and the answer will impact the increasing number of clinical endeavors that target the cGAS-STING pathway. The cGAS-STING pathway is oft-discussed in the context of antitumor immunity, but the activities of this pathway that are beneficial (or not) to immunity remain unclear. For example, inflammatory activities induced by cGAS-STING in the tumor microenvironment (TME) have been reported to induce protective inflammatory and cytolytic CD8+ T cells. But cGAS-STING signaling events have also been reported to promote tumor growth and disease progression. A central idea that drives our work is that the ubiquitous presence of the cGAS-STING pathway in most cell types, along with its diverse signaling effectors (cGAMP, IFNs, cytokines), can create a complex TME prone to unpredictable outcomes (e.g. disease resolution or progression). In order to understand each activity of this pathway, new experimental tools are needed to disentangle its effector functions. Herein, we describe new synthetic biology-based genetic circuits that can dissect the effector functions of cGAS-STING, within cancer cells specifically. Notably, these systems led to the discovery of specifies-specific differences in the ability of primate and murine cGAS proteins to detect self-DNA. This finding raises questions of the suitability of mice and certain primates as accurate preclinical models for cGAS-STING function, and provide a mandate to define the mechanisms and consequences of cGAS-mediated self-DNA activities. The work in this proposal is based on the hypothesis that the cGAMP, IFNs and cytokines induced by the cGAS-STING pathway play differential roles in tissue inflammation and immunity, and that understanding the role of each of these activities, within specific cell types, requires a detailed characterization of the mechanisms of self (and nonself) DNA detection. To address this hypothesis, we propose to determine how distinct intra-tumoral cGAS activities influence protective T cell immunity (Aim 1). In Aim 2, we propose to determine mechanisms of self-DNA reactivity by human cGAS through comparative analysis of the human, mouse, chimpanzee and orangutan proteins, each of which display distinct means of self-DNA reactivity.

项目摘要 这个提议的目的是剖析自身DNA检测的酶环GMP-AMP的机制 合成酶（cGAS），并确定其不同的信号传导活性对炎症的相对贡献， 移植性小鼠肿瘤的微环境。cGAS作为DNA传感器在几乎所有细胞类型中起作用 蛋白质，其在结合DNA时合成第二信使环GMP-AMP（cGAMP）。该第二 信使通过下游蛋白STING刺激干扰素（IFN）和炎症活性。因为 cGAS检测DNA的糖-磷酸骨架，一个主要问题涉及如何调节这种酶 以确保自我和非自我的区别。这个问题涉及到许多基础生物学，答案将 影响越来越多的靶向cGAS-STING途径的临床努力。cGAS-STING 在抗肿瘤免疫的背景下经常讨论该途径，但该途径的有益活性 (or（不）豁免权仍不明确。例如，在肿瘤中由cGAS-STING诱导的炎性活动 已经报道了微环境（TME）诱导保护性炎性和细胞溶解性CD 8 + T细胞。但 cGAS-STING信号传导事件也被报道促进肿瘤生长和疾病进展。一 推动我们工作的中心思想是cGAS-STING途径在大多数细胞类型中的普遍存在， 沿着其不同的信号传导效应物（cGAMP、IFN、细胞因子），可以产生复杂的TME， 不可预测的结果（例如疾病消退或进展）。为了理解这一过程中的每一个活动， 通路，需要新的实验工具来解开其效应器功能。在此，我们描述了新的 基于合成生物学的遗传电路，可以剖析cGAS-STING的效应子功能， 细胞具体值得注意的是，这些系统导致了物种特异性差异的发现， 灵长类和鼠cGAS蛋白检测自身DNA。这一发现引发了对小鼠是否适用的问题 和某些灵长类动物作为cGAS-STING功能的准确临床前模型，并提供了定义 cGAS介导的自身DNA活性的机制和后果。本提案中的工作基于 假设cGAS-STING途径诱导的cGAMP、IFN和细胞因子在细胞内发挥差异作用， 在组织炎症和免疫中的作用，以及了解这些活动中每一种的作用， 特定的细胞类型，需要对自身（和非自身）DNA检测的机制进行详细的表征。 为了解决这一假设，我们建议确定不同的肿瘤内cGAS活动如何影响肿瘤细胞的生长。 保护性T细胞免疫（Aim 1）。在目标2中，我们建议通过以下方法确定自身DNA反应性的机制： 通过对人类、小鼠、黑猩猩和猩猩蛋白质的比较分析， 它们显示出独特的自身DNA反应性。