Tumor and Immune Cell Dynamics during Immunotherapy and Cancer Progression

免疫治疗和癌症进展过程中的肿瘤和免疫细胞动力学

• 批准号: 10462816
• 负责人: Kathryn Elizabeth Yost
• 金额: $ 9.25万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10462816
• 关键词: Academic Training; Affect; Antigen-Presenting Cells; Biological Process; Biopsy; CTLA4 blockade; Cell Culture Techniques; Cells; Centromere; Clinical; Clone Cells; Colorectal; Complex; Computer Analysis; Cytoplasm; DNA; DNA amplification; Data; Dendritic Cells; Flow Cytometry; Genetic; Genomics; Goals; Human; Immune; Immune signaling; Immune system; Immunologic Surveillance; Immunotherapy; Impairment; Intrinsic factor; Link; MC38; Modeling; Mus; Mutation; Oncogenes; PD-1 blockade; Pathway interactions; Patients; Phase; Population; Postdoctoral Fellow; Process; Production; RNA; Relapse; Research; Research Project Grants; Role; Scientist; Signal Transduction; Site; Source; Stimulator of Interferon Genes; System; T cell receptor repertoire sequencing; T cell response; T-Lymphocyte; Technology; Testing; Therapeutic; Tumor-Infiltrating Lymphocytes; Tumor-infiltrating immune cells; Work; anticancer research; cancer cell; cancer immunotherapy; cancer therapy; cancer type; career; design; draining lymph node; efficacy evaluation; extrachromosomal DNA; immune activation; immune checkpoint blockade; improved; in vivo; in vivo Model; insight; mouse model; neoplastic cell; novel; patient subsets; peripheral blood; pre-doctoral; programmed cell death ligand 1; programmed cell death protein 1; receptor; recruit; response; secondary lymphoid organ; single cell sequencing; single-cell RNA sequencing; targeted treatment; treatment response; tumor; tumor microenvironment; tumor progression

PROJECT SUMMARY Treatment of cancer has been transformed by immunotherapies that aim to reactivate tumor-specific immune cell responses, in particular checkpoint blockade therapies that target inhibitory receptors on T cells. Although these therapeutics have achieved durable clinical responses, many patients do not respond or shortly relapse. Rationale design of effective immunotherapy strategies requires a detailed understanding of the dynamics between tumors and the immune system. My goal is to decode these dynamic interactions using a combination of in vivo models, genomic technologies, and large-scale analyses of patient data to gain novel insights into the biological processes that underlie cancer progression and response to immunotherapy. In the F99 phase, I aim to identify to origin of immune cells that respond to checkpoint blockade. An outstanding question is whether the T cell response to checkpoint blockade relies on reinvigoration of pre-existing tumor-infiltrating lymphocytes or on recruitment of novel T cells. In my dissertation work so far, I have used single cell RNA and T cell receptor (TCR) sequencing of site-matched tumor biopsies before and after PD-1 blockade to profile clonal T cell dynamics in response to immunotherapy. I found that T cells that clonally expand in response to PD-1 blockade are enriched for novel clones that have not been previously observed in the same tumor, a phenomenon we term clonal replacement. However, the source of novel T cells as well as the role of other immune cell populations in this process remain unclear. I hypothesize that novel T cells are derived from secondary lymphoid organs and that overcoming deficiencies in T cell priming by antigen presenting cells is required for clonal replacement following PD-1 blockade. I will use a combination of flow cytometry, single cell sequencing, and bulk TCR sequencing of in vivo syngeneic mouse tumor models to determine the origin of T cells that respond to PD-1 and CTLA-4 blockade. Further, I will use genetic mouse models to determine the role of PD-L1 expression on antigen presenting cells, in particular conventional type 1 dendritic cells, on PD-1 blockade efficiency. In the K00 phase, I aim to elucidate the relationship between extrachromosomal DNA amplification, innate immune signaling, and the efficacy of checkpoint blockade. Copy number alterations leading to oncogene amplification frequently occurs on circular extrachromosomal DNA (ecDNA), which are commonly found in the cytoplasm due to lack to centromeres and associate with loss of cytosolic DNA sensing through the cGAS-STING pathway. Further, innate immune signaling through cGAS-STING has been shown to improve the efficacy of checkpoint blockade. I propose that loss of cytosolic DNA sensing is permissive for extrachromosomal DNA production, which promotes tumor progression not only through oncogene amplification but also through impaired innate immune signaling, limiting immune surveillance and the efficacy of checkpoint blockade. Together, this work will provide novel insights into immune and tumor dynamics that underlie cancer progression and response to immunotherapy.

项目摘要 癌症的治疗已经被旨在重新激活肿瘤特异性免疫应答的免疫疗法所改变。 细胞应答，特别是靶向T细胞上的抑制性受体的检查点阻断疗法。虽然 这些治疗剂已经获得了持久的临床反应，许多患者没有反应或很快复发。 有效的免疫治疗策略的基本原理设计需要详细了解动态 肿瘤和免疫系统之间的联系我的目标是用一种组合来解码这些动态的相互作用 体内模型、基因组技术和大规模患者数据分析，以获得对疾病的新见解 生物学过程是癌症进展和对免疫疗法的反应的基础。在F99阶段，我的目标是 以确定对检查点封锁作出反应的免疫细胞的来源。一个悬而未决的问题是， T细胞对检查点阻断的应答依赖于预先存在的肿瘤浸润淋巴细胞或肿瘤浸润淋巴细胞的再活化。 募集新的T细胞。到目前为止，在我的论文工作中，我使用了单细胞RNA和T细胞受体， (TCR)在PD-1阻断之前和之后对位点匹配的肿瘤活检进行测序以分析克隆T细胞 免疫治疗的反应动力学。我发现T细胞对PD-1阻断的反应是克隆性扩增 富集了以前在同一肿瘤中未观察到的新克隆， 术语克隆替代。然而，新型T细胞的来源以及其他免疫细胞群的作用 在这个过程中仍然不清楚。我假设新型T细胞来源于次级淋巴器官， 克服抗原呈递细胞引发T细胞的缺陷是克隆替代所必需的， PD-1阻断后我将联合使用流式细胞术，单细胞测序， 体内同基因小鼠肿瘤模型的测序以确定响应PD-1的T细胞的起源， CTLA-4阻断。此外，我将使用遗传小鼠模型来确定PD-L1表达对抗原的作用。 在一些实施方案中，本发明提供了一种对呈递细胞（特别是常规1型树突细胞）的PD-1阻断效率的影响。在K 00阶段， 我的目的是阐明染色体外DNA扩增，先天免疫信号， 检查站封锁的有效性。拷贝数改变导致癌基因扩增经常发生 在环状染色体外DNA（ecDNA）上，由于缺乏 在一些实施方案中，细胞质中的DNA通过cGAS-STING途径与着丝粒结合，并且与通过cGAS-STING途径的细胞质DNA感测的损失相关。此外，本发明还 已经显示通过cGAS-STING的先天免疫信号传导改善检查点阻断的功效。 我认为细胞质DNA感应的丧失允许染色体外DNA的产生， 促进肿瘤进展不仅通过癌基因扩增，而且通过受损的先天免疫 信号传导，限制免疫监视和检查点阻断的功效。这项工作将提供 对免疫和肿瘤动力学的新见解，这些动力学是癌症进展和对 免疫疗法。