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.

项目摘要/摘要我建议在功能上询问癌症免疫避免和免疫疗法抗性的机制在强大的结直肠癌的新小鼠模型中。免疫检查点封锁（ICB）具有彻底改变了多种实体瘤类型的治疗，但在大多数癌症中仍然无效。假设这部分是由于对T细胞功能障碍的不同程序对ICB的反应不佳，这样如次优的T细胞启动编程。虽然微卫星不稳定（MSI）CRC反应非常明显这是ICB，这可能是由于突变衍生的抗原负担很高（新抗原），大多数CRC（〜88％）是微卫星稳定（MSS），没有响应。但是，MSS CRC的特征是较高的燃烧突变比其他对ICB的实体瘤类型，例如肾癌。我自己对人的分析 MSS CRC测序表明，所有肿瘤至少表达两个具有强预测的克隆新抗原与HLA-I结合，但这些新抗原的水平明显低于MSI CRC的水平。这表明新抗原的表达水平除了燃烧外，还可能在抗肿瘤T细胞反应。为了测试这一点，我开发了CRC的结肠镜检查引导的原位移植模型使用具有不同水平的CD8+ T细胞新抗原表达水平的同源器官。高的表达导致器官排斥，而低表达导致T细胞启动不良，立即功能障碍和肿瘤逸出。在我的低新抗原模型和人类的肿瘤浸润T细胞中 MSS CRC显示出耐受性功能障碍的签名，不同于规范的“疲惫”和一致与次优启动。这些分析还确定了孤儿核接收器4a亚家族基因NR4A1， NR4A2和NR4A3（这是一类令人兴奋的T细胞检查点的令人兴奋的新型T细胞检查点），这是该过程的潜在中心介体。 AIM 1将在T细胞启动和功能障碍中功能询问NR4A1-3，并研究其潜力作为 CRC中的治疗靶标。 AIM 2将确定是否可以增强T细胞启动的现有疗法（CD40）激动剂，疫苗接种）可以挽救CRC中的次优T细胞启动，并描绘出T细胞的内在和外在的细胞效率和抵抗的机制。这些目标的总体目标是加深我们的机械了解CRC中非典型的T细胞功能障碍，并确定逆转其新的治疗策略。这对大多数不反应ICB的CRC和其他癌症具有很大的承诺指导新型组合临床试验。该建议是将尖端鼠标汇总在一起的创新性癌症模型和免疫学上的高级工具。它的完成应该使杰出的 CRC为什么在全球癌症死亡的第二大原因CRC通常没有反应措施当前的免疫疗法。 K22奖将帮助我执行这些目标并生成初步数据将构成竞争性R01应用程序，出版物和成功的独立研究的基础计划，并为我提供通过NASDC课程来增加免疫学培训的灵活性。