Tumor cell-intrinsic STING signaling and IFN-Beta gene regulation in cancer

癌症中肿瘤细胞固有的 STING 信号传导和 IFN-Beta 基因调控

• 批准号: 9766811
• 负责人: Blake Flood
• 金额: $ 5万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9766811
• 关键词: ATAC-seq; Activation Analysis; Affect; Agonist; Biological Assay; Biopsy; CD8-Positive T-Lymphocytes; Cell Line; Cells; Clinic; DNA; DNA Binding; Data; Defect; Dendritic Cells; Epigenetic Process; Gene Expression Regulation; Genes; Genetic Transcription; Genomics; Health; Human; Human Cell Line; IRF3 gene; Immune; Immune signaling; Immunity; Immunotherapy; In Vitro; Injections; Innate Immune System; Interferon-beta; Interferons; Intervention; Knowledge; Laboratories; Lead; Life; Light; Malignant Neoplasms; Melanoma Cell; Mission; Molecular; Mouse Cell Line; Mutation; NF-kappa B; Natural Immunity; Nature; Nuclear; Nuclear Translocation; Organism; Pathway interactions; Patients; Pharmacology; Phenotype; Pre-Clinical Model; Production; Promoter Regions; Public Health; Receptor Signaling; Research; Signal Transduction; Signal Transduction Pathway; Site; Stains; T cell response; T-Lymphocyte; Testing; Therapeutic; Time; Tumor Antigens; Tumor Cell Line; Tumor Suppressor Proteins; Tumor-infiltrating immune cells; United States National Institutes of Health; Work; anti-tumor immune response; base; cancer immunotherapy; cancer therapy; cancer type; cell type; design; experimental study; heterokaryon; immune checkpoint blockade; immunogenic; improved; in vivo; macrophage; neoplastic cell; outcome forecast; p65; preservation; prevent; prostate cancer cell; recruit; response; success; therapy design; transcription factor; treatment strategy; tumor; tumor microenvironment; tumorigenesis

Patients with evidence of spontaneous anti-tumor T cell responses have a better prognosis and are likely to respond to checkpoint blockade immunotherapies currently used in the clinic. Identifying why some patients lack spontaneous anti-tumor immune responses and finding ways to promote endogenous responses will likely expand efficacy to these patients. Our lab has previously shown immunogenic tumors spontaneously activate the innate immune system through the STING pathway. The STING pathway senses cytosolic DNA, which activates a signal transduction pathway culminating in nuclear translocation of transcription factors IRF3 and NF-κB that, in turn, induce expression of several genes including IFN-β. STING signaling and IFN-β receptor signaling in tumor-infiltrating immune cells are both required for optimal priming of CD8+ T cells against tumor antigens. Likewise, intratumoral injection of STING agonists increases IFN-β expression, anti-tumor T cell priming, and causes dramatic tumor rejection in pre-clinical models. As part of our work with intratumoral STING agonists we observed that the tumor cells themselves were the only cell type present in the tumor microenvironment unable to express IFN-β in response to cytosolic DNA or direct STING agonists. We tested a range of tumor cell lines and found the vast majority was unable to express IFN-β downstream of STING signaling, arguing that loss of activation of this pathway might occur regularly as a component of oncogenesis. Our over-arching hypothesis is that determining why tumor cells lack IFN-β expression and reversing this phenotype could lead to a new strategy to induce endogenous anti-tumor immune responses. Our preliminary data indicates that STING signaling is largely in tact in tumor cells up to and including nuclear translocation of IRF3. We find tumor cells have a defect in IRF3 DNA binding at the IFN-β locus and that the lack of IFN-β expression following STING activation is a dominant phenotype. To better understand tumor cell-intrinsic STING signaling, and how it is defective in tumor cells, we propose to: 1) identify and reverse the molecular mechanism preventing STING induction of IFN-β in tumor cells using pre-clinical models where we can observe how this affects the tumor/immune interface in vivo 2) understand the potential for STING signaling in human cancer by analyzing both cell lines and tumor biopsies. Preliminary data suggests tumor cells differ from control cells in the epigenetic accessibility of the IFN locus and NF-κB signaling after STING activation. Therefore we will study NF-kB signaling in tumor cells and it's affect on accessibility of the IFN locus. We will also silence the STING pathway in the few tumor cells capable of expressing IFN-β to observe how this modulates the interface with host immunity. As we analyze human tumor cell lines and biopsies we will begin to determine what fraction of patients might respond to therapies designed to enable tumor cells to express IFN-β. Ultimately our work will be an important part of a growing body of evidence indicating a deeper connection between oncogenesis and innate immunity that implicates the latter as a tumor suppressor. !

有自发性抗肿瘤T细胞应答证据的患者预后较好， 对目前临床上使用的检查点阻断免疫疗法有反应。为什么有些病人 缺乏自发的抗肿瘤免疫反应，寻找促进内源性反应的方法将可能 扩大对这些患者的疗效。我们的实验室先前已经证明免疫原性肿瘤自发激活 通过STING途径激活先天免疫系统。STING途径感测胞质DNA， 激活信号传导途径，最终导致转录因子IRF 3的核转位， NF-κB，进而诱导包括IFN-β在内的几种基因的表达。STING信号传导和IFN-β受体 肿瘤浸润性免疫细胞中的信号传导都是CD 8 + T细胞针对肿瘤的最佳引发所必需的 抗原同样地，肿瘤内注射STING激动剂增加IFN-β表达，抗肿瘤T细胞增殖，以及肿瘤细胞增殖。 引发，并在临床前模型中引起显著的肿瘤排斥。作为我们肿瘤内研究的一部分， 我们观察到肿瘤细胞本身是肿瘤中存在的唯一细胞类型。 在一些实施方案中，所述微环境不能响应于胞质DNA或直接STING激动剂表达IFN-β。我们测试了 一系列肿瘤细胞系，发现绝大多数不能表达STING下游的IFN-β 信号，认为这一途径的活化丧失可能作为肿瘤发生的一个组成部分定期发生。 我们的过度假设是，确定肿瘤细胞缺乏IFN-β表达的原因并逆转这种情况， 表型的改变可能导致诱导内源性抗肿瘤免疫应答的新策略。我们的初步 数据表明，STING信号在肿瘤细胞中大部分是完整的，直到并包括 IRF3。我们发现肿瘤细胞在IFN-β位点的IRF 3 DNA结合缺陷， STING激活后的表达是显性表型。为了更好地了解肿瘤细胞的内在 STING信号传导，以及它在肿瘤细胞中是如何缺陷的，我们建议：1）识别和逆转 使用临床前模型预防肿瘤细胞中IFN-β的STING诱导的机制， 观察这如何影响体内肿瘤/免疫界面2）了解STING信号传导的潜力， 通过分析细胞系和肿瘤活组织检查来研究人类癌症。初步数据显示肿瘤细胞 与对照细胞相比，STING激活后IFN基因座和NF-κB信号传导的表观遗传可及性。 因此，我们将研究肿瘤细胞中的NF-kB信号及其对IFN位点可及性的影响。我们将 还沉默了少数能够表达IFN-β的肿瘤细胞中的STING途径，以观察这是如何发生的。 调节与宿主免疫的界面当我们分析人类肿瘤细胞系和活检时，我们将开始 以确定哪部分患者可能对旨在使肿瘤细胞表达 IFN-β。最终，我们的工作将成为越来越多的证据的重要组成部分，这些证据表明， 肿瘤发生和先天免疫之间的联系，暗示后者是肿瘤抑制因子。 !