Gasdermin E-mediated pyroptosis in promoting antitumor immunity and cancer treatment

项目总结/摘要 大多数癌症在免疫学上是“冷的”，只有有限的T细胞浸润， 免疫治疗的比率。增强肿瘤浸润淋巴细胞募集和功能的新策略 (TIL)迫切需要改善癌症免疫疗法。癌细胞如何在压力下死亡， 细胞毒性淋巴细胞和药物对癌症的免疫景观有着深远的影响。虽然大多数癌症 细胞死亡被认为是非炎症性的，我们最近的研究表明， E（GSDME）在肿瘤细胞中表达时，将非炎症性细胞凋亡转化为细胞凋亡，这是一种高度表达的蛋白质。 程序性细胞死亡的炎症形式。GSDME有效地抑制肿瘤生长，并增加肿瘤细胞的数量。 以及CD 8+和NK TIL的抗肿瘤功能。GSDME的抑瘤作用是通过杀伤TIL介导的 GSDME+靶向肿瘤细胞，其也可引发肿瘤细胞焦亡。我们的研究表明， 癌细胞焦亡在改善癌症免疫治疗方面具有巨大潜力，但目前尚不清楚如何改善 GSDME诱导的细胞凋亡增强抗肿瘤免疫力。这项研究旨在研究肿瘤如何 GSDME表达塑造肿瘤浸润免疫细胞及其相互作用以增加肿瘤免疫， 并开发一种新的策略来促进炎性癌细胞死亡，其长期目标是增强 癌症患者的免疫功效。具体来说，我将研究损伤相关的分子 GSDME+肿瘤细胞产生的DAMPs调节肿瘤细胞的组成、成熟和功能， 肿瘤浸润性树突状细胞（TIDCs）和肿瘤相关巨噬细胞（TAMs），诱导肿瘤细胞凋亡的关键参与者， 有效的抗肿瘤T细胞反应，通过使用CyTOF和DAMP或其受体的抑制剂（Aim 1）。援建 单细胞（sc）RNA-seq和骨髓嵌合小鼠，我将研究不同的TIDC亚群如何与 CD 8 + TIL促进GSDME介导的抗肿瘤免疫（目的2）。许多癌细胞表观遗传沉默 GSDME和RIPK 3（坏死性凋亡的关键介质，细胞死亡的另一种炎性形式）通过启动子 为了研究DNA甲基化抑制剂地西他滨是否能促进癌细胞的过度甲基化， 细胞凋亡和坏死凋亡，以抑制肿瘤生长和增强抗肿瘤免疫（目的3）。这些研究 将极大地推进我们对GSDME免疫刺激机制的理解，并提供新的机会 恢复未发炎的“冷”肿瘤患者的免疫功效。我的职业目标是 一个独立的学术实验室，致力于解决癌症免疫学和免疫治疗方面的问题。在 K99阶段，我将充分利用哈佛充满活力的研究社区的广泛资源 和优秀的导师和合作者团队接受全面的高级培训， 技术、生物信息学、小鼠模型和转化研究，以进一步建立合作关系， 提高我的专业技能。拟议的培训计划将作为一个极好的路线图，将引导我 我的目标是成为一名成功的独立研究者，并改变癌症患者的生活。

Project Summary/Abstract The majority of cancers, which are immunologically “cold” with limited T cell infiltration, show abysmal response rates to immunotherapy. Novel strategies to enhance recruitment and functions of tumor-infiltrating lymphocytes (TIL) are urgently needed to improve cancer immunotherapy. How cancer cells die in response to stress, cytotoxic lymphocytes, and drugs has a profound impact on the immune landscape of cancer. While most cancer cell death has been viewed as noninflammatory, our recent study showed that pore-forming protein Gasdermin E (GSDME), when expressed in tumor cells, converts noninflammatory apoptosis to pyroptosis, a highly inflammatory form of programmed cell death. GSDME potently inhibits tumor growth and enhances the numbers and antitumor functions of CD8+ and NK TILs. The tumor-inhibitory effect of GSDME is mediated by TIL killing of GSDME+ target tumor cells, which can also trigger tumor cell pyroptosis. Our study suggests that promoting cancer cell pyroptosis has excellent potential to improve cancer immunotherapy, but it remains unclear how GSDME-induced pyroptosis boosts antitumor immunity. The proposed research aims to investigate how tumor GSDME expression shapes the tumor-infiltrating immune cells and their interactions to increase tumor immunity, and to develop a novel strategy to promote inflammatory cancer cell death, with the long-term goal to enhance immunotherapeutic efficacy for cancer patients. Specifically, I will study how damage-associated molecular patterns (DAMPs) produced by GSDME+ tumor cells modulate the composition, maturation, and functions of tumor-infiltrating dendritic cells (TIDCs) and tumor-associated macrophages (TAMs), key players to induce potent antitumor T cell response, by using CyTOF and inhibitors of DAMPs or their receptors (Aim 1). Aided by single cell (sc)RNA-seq and bone marrow chimeric mice, I will study how different TIDC subsets interact with CD8+ TILs to promote GSDME-mediated antitumor immunity (Aim 2). As many cancer cells epigenetically silence GSDME and RIPK3 (key mediator of necroptosis, another inflammatory form of cell death) via promoter hypermethylation, I will investigate whether the DNA methylation inhibitor decitabine could promote cancer cell pyroptosis and necroptosis to suppress tumor growth and enhance antitumor immunity (Aim 3). These studies will greatly advance our understanding of GSDME’s immunostimulatory mechanism and offer new opportunities to revitalizing immunotherapeutic efficacy for patients with uninflamed “cold” tumors. My career goal is to lead an independent academic laboratory addressing questions on cancer immunology and immunotherapy. In the K99 phase, I will take full advantage of the extensive resources at the vibrant research community of Harvard and the outstanding team of mentors and collaborators to receive comprehensive training in advanced technologies, bioinformatics, mouse models, and translational research, to further establish collaborations and sharpen my professional skills. The proposed training plan will serve as a superb roadmap that will lead me to my goal of succeeding as an independent investigator, and to make a difference in the lives of cancer patients.