Small-molecule exploitation of ZBP1-driven nuclear necroptosis for cancer immunotherapy

ZBP1 驱动的核坏死性凋亡的小分子开发用于癌症免疫治疗

• 批准号: 10586659
• 负责人: SIDDHARTH BALACHANDRAN
• 金额: $ 75.9万
• 依托单位: RESEARCH INST OF FOX CHASE CAN CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10586659
• 关键词: Abscopal effect; Adjuvant; Affinity; Agonist; Antitumor Response; Architecture; Binding; Biology; Cell Death; Cell Death Signaling Process; Cell Nucleus; Cells; Chromatin; Chromatin Structure; Clinical; Cytoplasm; DNA; Data; Dose; Double-Stranded RNA; Eukaryotic Cell; Extracellular Space; Fibroblasts; Genetically Engineered Mouse; Genomic DNA; Goals; Histones; Immune; Immune system; Immunologic Adjuvants; Immunotherapy; Inflammatory; Influenza A virus; Innate Immune Response; Interphase Cell; Left; Ligands; Linker DNA; Malignant Neoplasms; Mediating; Modality; Molecular Chaperones; Molecular Conformation; Neoplasm Metastasis; Nuclear; Nucleosomes; Pathway interactions; Patients; Process; Proteins; RIPK3 gene; RNA; Reporting; Research; Role; Route; Rupture; Signal Pathway; Signal Transduction; T cell response; T-Lymphocyte; Testing; Treatment outcome; UV-induced melanoma; Ubiquitination; Viral; Virus Diseases; Work; Xenograft procedure; Z-Form DNA; anti-PD-1; cancer immunotherapy; cancer therapy; cell killing; cell type; clinically relevant; combinatorial; genome-wide; immune checkpoint blockade; immunogenic; immunogenicity; improved; intercalation; melanoma; mouse model; neoantigens; neoplastic cell; recruit; sensor; small molecule; theories; tumor; tumor microenvironment; viral RNA; viral detection

PROJECT SUMMARY/ABSTRACT. Immune checkpoint blockade (ICB) and other immunotherapies have revolutionized cancer treatment, but the non-responsiveness of most cancers to ICB-based monotherapy remains a significant problem. A major reason for the non-responsiveness of these so-called ‘cold’ tumors is that they lack an immunogenic tumor microenvironment (TME) and thus escape T-cell killing despite expressing ICB targets. How to selectively intensify the immunogenicity of the TME has been an unmet challenge. Here we propose a new small-molecule approach that activates necroptosis and triggers robust innate immune responses in the TME. This new avenue derives from our work on influenza A virus (IAV). Our early findings showed that IAV activates necroptosis in infected cells. Necroptosis kills infected cells and is highly immunogenic. It is initiated when viral RNAs activating the host protein ZBP1. Recently, and highly relevant for cancer immunotherapy, we found that ZBP1 activates necroptosis from the nucleus. Such ‘nuclear necroptosis’ is significantly more immunogenic than conventional (cytoplasm-initiated) necroptosis because it ruptures the nucleus and releases hyper-inflammatory nuclear DAMPs into the extracellular space. We also found that the viral RNAs that activate ZBP1 are Z-RNAs. Although these unique ZBP1 activators should be superb adjuvants for ICB, Z-RNA is unstable and hard to produce absent virus infection. Z-DNA, however, is structurally almost identical to Z-RNA, binds ZBP1 with the same affinity, and can be stably produced in eukaryotic cells by distorting DNA into the Z-conformation. This suggested that a compound that can generate Z-DNA in cells would activate ZBP1 and trigger on-demand nuclear necroptosis without need for virus infection. Such a compound would fill the long-unmet need for a necroptosis agonist for use in cancer immunotherapy. We have now identified a small molecule, curaxin, which induces Z-DNA formation in live cells and directly activates ZBP1 to trigger ‘on-demand’ nuclear necroptosis in cells of the TME. These and other findings allow us to propose the hypotheses that curaxin alters chromatin structure and induces the formation of Z-DNA; that such Z-DNA recruits ZBP1 to the nucleus and triggers nuclear necroptosis; and that curaxin-induced nuclear necroptosis will greatly improve ICB treatment outcomes. In this proposal, we will ask how curaxin triggers Z-DNA formation (Aim 1), how Z-DNA activates ZBP1 and nuclear necroptosis (Aim 2), and whether induction of nuclear necroptosis by curaxin has combinatorial benefit with ICB in clinically-relevant mouse models of melanoma (Aim 3). The successful completion of these Aims will outline an entirely new small- molecule based strategy to activate a highly inflammatory form of necroptosis and potentiate ICB-based immunotherapies, with important clinical ramifications.

项目摘要/摘要。 免疫检查点阻断（ICB）和其他免疫疗法彻底改变了癌症治疗，但 大多数癌症对基于 ICB 的单一疗法无反应仍然是一个重大问题。一个主要原因 这些所谓的“冷”肿瘤的无反应性是因为它们缺乏免疫原性肿瘤 尽管表达了 ICB 靶标，但微环境 (TME) 仍逃脱了 T 细胞杀伤。如何有选择地 增强TME的免疫原性一直是一个未解决的挑战。在这里我们提出了一种新的小分子 激活坏死性凋亡并触发 TME 中强大的先天免疫反应的方法。这条新大道 源自我们对甲型流感病毒 (IAV) 的研究。我们的早期研究结果表明，IAV 会激活坏死性凋亡 被感染的细胞。坏死性凋亡会杀死受感染的细胞，并且具有高度免疫原性。当病毒RNA激活时就会启动 宿主蛋白ZBP1。最近，与癌症免疫疗法高度相关的是，我们发现 ZBP1 激活 来自细胞核的坏死性凋亡。这种“核坏死性凋亡”比传统的“核坏死性凋亡”具有更高的免疫原性。 （细胞质引发的）坏死性凋亡，因为它会破裂细胞核并释放高炎症细胞核 DAMP 进入细胞外空间。我们还发现激活ZBP1的病毒RNA是Z-RNA。虽然 这些独特的 ZBP1 激活剂应该是 ICB 的极好佐剂，Z-RNA 不稳定且难以生产。 病毒感染。然而，Z-DNA 在结构上几乎与 Z-RNA 相同，以相同的亲和力结合 ZBP1，并且 通过将 DNA 扭曲成 Z 构象，可以在真核细胞中稳定产生。这表明 可以在细胞中产生 Z-DNA 的化合物会激活 ZBP1 并触发按需核坏死性凋亡 无需病毒感染。这种化合物将满足长期以来对坏死性凋亡激动剂的需求。 在癌症免疫治疗中的应用。我们现在已经鉴定出一种小分子，curaxin，它可以诱导 Z-DNA 活细胞中形成并直接激活 ZBP1 以触发 TME 细胞中的“按需”核坏死性凋亡。 这些和其他发现使我们能够提出这样的假设：curaxin 改变染色质结构并诱导 Z-DNA的形成；这种 Z-DNA 将 ZBP1 招募到细胞核并引发核坏死性凋亡；还有那个 curaxin 诱导的核坏死性凋亡将大大改善 ICB 治疗结果。在这个提案中，我们会问 curaxin 如何触发 Z-DNA 形成（目标 1），Z-DNA 如何激活 ZBP1 和核坏死性凋亡（目标 2），以及 curaxin 诱导核坏死性凋亡是否与 ICB 在临床相关方面具有联合益处 黑色素瘤小鼠模型（目标 3）。这些目标的成功实现将勾画出一个全新的小型 基于分子的策略，激活高度炎症形式的坏死性凋亡并增强基于 ICB 的效果 免疫疗法具有重要的临床意义。