Mechanisms and strategies to rescue suboptimal T cell priming in colon cancer

挽救结肠癌 T 细胞启动不良的机制和策略

基本信息

批准号：
10644249
负责人：
Peter Maxwell Kienitz Westcott
金额：
$ 20.1万
依托单位：
COLD SPRING HARBOR LABORATORY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10644249
关键词：
Ablation Antigens Binding Biological Biological Assay CD8-Positive T-Lymphocytes CRISPR/Cas technology Cancer Etiology Cancer Model Candidate Disease Gene Cessation of life Chromatin Clinical Clinical Trials Colon Colon Carcinoma Colonoscopy Colorectal Cancer Combination immunotherapy Data Data Set Development ERG gene Flow Cytometry Foundations Functional disorder Genes Genetic Transcription Goals Human Immune Evasion Immune response Immunology Immunotherapy Investigation K22 Award Knock-out Knowledge Malignant Neoplasms Mediator Memory Microsatellite Instability Microsatellite Repeats Modeling Molecular Mutation NR4A1 gene NR4A2 gene Nuclear Orphan Receptor Organoids Phenotype Play Pre-Clinical Model Process Productivity Publications Publishing Receptor Signaling Refractory Renal carcinoma Research Resistance Role Solid Neoplasm T cell differentiation T cell infiltration T cell response T-Cell Receptor T-Lymphocyte T-Lymphocyte Subsets TNFRSF5 gene Techniques Testing Therapeutic Tissues Training Transposase Tumor Escape Tumor-Derived Vaccination Viral Cancer Virus Diseases Work cancer infiltrating T cells chemokine clinical investigation colon cancer patients cytokine engineered T cells exhaustion flexibility genetic signature immune checkpoint immune checkpoint blockade immunoengineering in vivo innovation lymph nodes mouse model neoantigens novel novel therapeutic intervention pre-clinical preclinical trial programs research clinical testing resistance mechanism responders and non-responders single cell sequencing single-cell RNA sequencing small molecule inhibitor success targeted treatment therapeutic target therapy resistant tool trafficking transcriptome sequencing transplant model treatment responders treatment response tumor tumor microenvironment

项目摘要

PROJECT SUMMARY/ABSTRACT I propose to functionally interrogate mechanisms of cancer immune evasion and immunotherapy resistance in powerful new mouse models of colorectal cancer (CRC). Immune checkpoint blockade (ICB) has revolutionized treatment of multiple solid tumor types but is nevertheless ineffective in most cancers. I hypothesize that this is due in part to distinct programs of T cell dysfunction that respond poorly to ICB, such as that programmed by suboptimal T cell priming. While microsatellite instable (MSI) CRC responds remarkably well to ICB, likely due to a high burden of mutation-derived antigens (neoantigens), most CRC (~88%) is microsatellite stable (MSS) and does not respond. However, MSS CRC is characterized by a higher burden of mutations than other solid tumor types that do respond to ICB, like kidney cancer. My own analysis of human MSS CRC sequencing revealed that all tumors expressed at least two clonal neoantigens with strong predicted binding to HLA-I, but that these neoantigens were expressed at significantly lower levels than those in MSI CRC. This suggests that neoantigen expression levels, in addition to burden, may play an important role in the antitumor T cell response. To test this, I developed a colonoscopy-guided orthotopic transplant model of CRC employing isogenic organoids with varying levels of expression of model CD8+ T cell neoantigens. High expression resulted in organoid rejection, while low expression resulted in poor T cell priming with immediate dysfunction and tumor escape. Tumor infiltrating T cells in my low neoantigen-expressing model and human MSS CRC showed signatures of tolerogenic dysfunction, distinct from canonical “exhaustion” and consistent with suboptimal priming. These analyses also identified the orphan nuclear receptor 4A subfamily genes Nr4a1, Nr4a2, and Nr4a3—an exciting new class of T cell checkpoint—as potentially central mediators of this process. Aim 1 will functionally interrogate Nr4a1-3 in T cell priming and dysfunction and investigate their potential as therapeutic targets in CRC. Aim 2 will determine whether existing therapies that boost T cell priming (CD40 agonism, vaccination) can rescue suboptimal T cell priming in CRC and delineate T cell intrinsic and extrinsic mechanisms of efficacy and resistance. The overarching goal of these aims is to deepen our mechanistic understanding of non-canonical T cell dysfunction in CRC and identify new therapeutic strategies to reverse it. This holds substantial promise for the majority of CRC and other cancers that do not respond to ICB and may guide novel combination clinical trials. This proposal is innovative in bringing together cutting-edge mouse models of cancer and advanced tools in immunology. Its completion should bring clarity to the outstanding question of why CRC, the second leading cause of cancer deaths worldwide, is generally nonresponsive to current immunotherapies. The K22 award will help me execute these aims and generate preliminary data that will form a foundation for competitive R01 applications, publications, and a successful independent research program, as well as give me the flexibility to augment my immunology training through NASDC course offerings.

项目概要/摘要我建议从功能上探讨癌症免疫逃避和免疫治疗抵抗的机制在强大的新型结直肠癌（CRC）小鼠模型中，免疫检查点阻断（ICB）具有显着的效果。彻底改变了多种实体瘤类型的治疗，但对大多数癌症无效。这部分是由于 T 细胞功能障碍的独特程序对 ICB 反应不佳，例如而微卫星不稳定 (MSI) CRC 的反应却令人惊讶。对于 ICB 来说，可能是由于突变衍生抗原（新抗原）的高负担，大多数 CRC（约 88%）是微卫星稳定（MSS）并且不响应，但是MSS CRC的特点是负担较高。比其他对 ICB 有反应的实体瘤类型（例如肾癌）的突变。 MSS CRC 测序显示，所有肿瘤均表达至少两种克隆性新抗原，且具有很强的预测性与 HLA-I 结合，但这些新抗原的表达水平明显低于 MSI CRC 中的表达水平。这表明，除了负荷之外，新抗原表达水平可能在为了测试这一点，我开发了结肠镜引导下的 CRC 原位移植模型。采用具有不同表达水平的模型 CD8+ T 细胞新抗原的同基因类器官。表达导致类器官排斥，而低表达导致 T 细胞立即启动不良我的低新抗原表达模型和人类中的肿瘤浸润 T 细胞的功能障碍和肿瘤逃逸。 MSS CRC 显示出耐受性功能障碍的特征，与典型的“衰竭”不同，并且一致这些分析还鉴定了核孤儿受体 4A 亚家族基因 Nr4a1， Nr4a2 和 Nr4a3——一类令人兴奋的新型 T 细胞检查点——作为这一过程的潜在中心调节者。目标 1 将在功能上询问 Nr4a1-3 在 T 细胞启动和功能障碍中的作用，并研究它们作为 CRC 的治疗靶点将确定现有疗法是否能够促进 T 细胞启动（CD40）。激动剂、疫苗接种）可以挽救 CRC 中次优的 T 细胞启动并描绘 T 细胞内在和外在这些目标的首要目标是深化我们的机制。了解结直肠癌中非典型 T 细胞功能障碍并确定逆转它的新治疗策略。这对于大多数对 ICB 没有反应的 CRC 和其他癌症来说具有巨大的希望，并且可能该提案在汇集尖端小鼠方面具有创新性。癌症模型和免疫学先进工具的完成应该使杰出的研究变得清晰。为什么结直肠癌（CRC）作为全球癌症死亡的第二大原因，通常对以下问题没有反应： K22 奖将帮助我实现这些目标并生成初步数据将为有竞争力的 R01 应用、出版物和成功的独立研究奠定基础计划，并让我能够通过 NASDC 课程灵活地增强我的免疫学培训。