Elucidating the Role of Tregs in Cancer Metastasis and T Cell Dysfunction

阐明 Tregs 在癌症转移和 T 细胞功能障碍中的作用

• 批准号: 10679834
• 负责人: Zoe Schmiechen
• 金额: $ 3.26万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10679834
• 关键词: Ablation; Adoptive Transfer; Antigens; Automobile Driving; Biological Response Modifiers; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; CD8B1 gene; CRISPR/Cas technology; Cancer Etiology; Cancer cell line; Cell Line; Cell Separation; Cells; Cessation of life; Characteristics; Combined Modality Therapy; Cytotoxic T-Lymphocytes; DDR2 gene; Data; Detection; Development; Disease; Disseminated Malignant Neoplasm; Doctor of Philosophy; FOXP3 gene; Flow Cytometry; Functional disorder; Gene Expression Profile; Genes; Genetic Models; Goals; Grant; Histologic; Human; Immune Evasion; Immune System Diseases; Immune response; Immunocompetent; Immunologic Surveillance; Immunotherapy; Implant; Infiltration; Intrinsic factor; Invaded; Investigation; Knock-out; Knowledge; Link; Malignant Neoplasms; Malignant neoplasm of pancreas; Microscopy; Modeling; Mus; Neoplasm Metastasis; Newly Diagnosed; Organ; Pancreas; Pancreatic Diseases; Pancreatic Ductal Adenocarcinoma; Patients; Phenotype; Population; Receptor Protein-Tyrosine Kinases; Regimen; Regulatory T-Lymphocyte; Research; Research Personnel; Resistance; Role; Signal Transduction; Survival Rate; T cell differentiation; T-Cell Activation; T-Cell Depletion; T-Lymphocyte; T-Lymphocyte Subsets; Technical Expertise; Testing; Tumor Antigens; Tumor Burden; Tumor Cell Line; Variant; cancer cell; cytotoxic; cytotoxic CD8 T cells; discoidin domain receptor 2; effective therapy; exhaust; exhaustion; immune checkpoint blockade; implantation; neoantigens; novel; overexpression; pancreatic cancer patients; pancreatic ductal adenocarcinoma model; prevent; public health relevance; retroviral transduction; single-cell RNA sequencing; standard of care; therapeutic development; therapeutic target; therapy resistant; transcriptome sequencing; tumor; tumor growth; tumor microenvironment; tumor progression; tumor-immune system interactions

PROJECT ABSTRACT Pancreatic ductal adenocarcinoma (PDA) is the 4th leading cause of cancer related deaths and has a dismal 5-year survival rate of 10%. Lethality is attributed to early metastasis, late detection, and therapeutic resistance. Cytotoxic CD8 T cells are the principal mediators of immune surveillance and critical for cancer eradication. However, in PDA and other cancers, CD8 T cells progressively lose their cytotoxic function, and are thus characterized as exhausted. Immune checkpoint blockade aims to correct T cell exhaustion by blocking inhibitory signaling and has revolutionized the treatment of many malignancies. However, PDA is largely resistant. As such, this grant seeks to understand the mechanisms driving CD8 T cell exhaustion in PDA and how PDA evades an activated immune response after immunotherapy treatment. Additionally, this grant will study cancer cell-intrinsic and -extrinsic mechanisms of PDA metastasis, to develop rational therapies. My lab derived new cancer cell lines from immunotherapy resistant tumors, termed escape variants, to study mechanisms of immune evasion. I found that orthotopic implantation of escape variant cells into immunocompetent mice yields multi-organ metastatic disease, which is not seen with the immunotherapy na·1ve cell line. Thus, escape variant tumors can model metastatic disease of PDA patients. Bulk RNA sequencing identified a single gene, Ddr2, that was significantly upregulated across multiple escape variant lines compared to immunotherapy na"ive cells. Ddr2 encodes a receptor tyrosine kinase, is linked to metastasis in other malignancies, and is correlated with reduced patient survival in PDA. Investigation into the tumor microenvironment of escape variant tumors identified an accumulation of intratumoral regulatory T cells (Tregs). I found that Treg depletion significantly reduced tumor burden and metastasis and reduced the development of CD8 T cell exhaustion. I will test the central hypothesis that immunotherapy selects for metastatic cancer cells that promote intratumoral Tregs that cause CD8 T cell dysfunction. In the first Aim, I will investigate how immunotherapy escape drives Treg accumulation and metastasis. First, I will test if Treg accumulation occurs through conventional CD4 T cell differentiation within the tumor. Next, I will test if forced expression of Ddr2 drives metastasis and ablation of Ddr2 prevents metastasis. In the second Aim, I will identify the CD8 T cell subset critical for preventing PDA metastasis. First, I will determine if CD8 T cells are required for the reduction in tumor burden and abrogation of metastasis seen with Treg depletion. Next, I will use single cell RNA sequencing to identify the transcriptional signature of anti-metastatic CD8 T cells enriched with Treg depletion. Completion of the proposed research strategy will reveal mechanisms of metastasis and CD8 T cell dysfunction in PDA and identify a therapeutic target(s) in the hope of reducing PDA lethality.

项目摘要 胰腺导管腺癌（PDA）是癌症相关死亡的第四个主要原因，5年生存率为10％。致死性归因于早期转移，晚期检测和治疗性抗性。细胞毒性CD8 T细胞是免疫监视的主要介质，对于癌症放射性至关重要。但是，在PDA和其他癌症中，CD8 T细胞逐渐失去了细胞毒性功能，因此被筋疲力尽。免疫检查点阻滞旨在通过阻断抑制性信号传导来纠正T细胞耗尽，并彻底改变了许多恶性肿瘤的治疗。但是，PDA在很大程度上具有抗性。因此，该赠款旨在了解PDA中驱动CD8 T细胞耗尽的机制，以及PDA在免疫疗法治疗后如何逃避激活的免疫响应。此外，该赠款将研究PDA转移的癌细胞中性和 - 肢体机制，以开发理性疗法。我的实验室从抗免疫疗法的肿瘤中得出了新的癌细胞系，称为逃生变体，以研究免疫抗性的机制。我发现将逃生变体细胞的原位植入到免疫能力的小鼠中会产生多器官转移性疾病，而免疫疗法Na·1VE细胞系未见。那就是逃生变体肿瘤可以模拟PDA患者的转移性疾病。与免疫疗法的NA“ IVE细胞相比，大量的RNA测序鉴定出一个单个基因DDR2，该基因在多个逃生变异线上显着上调。DDR2编码受体酪氨酸激酶，与其他恶性肿瘤中的转移相关，与PDA的逃生量相关。肿瘤内调节性T细胞（Treg）。转移。首先，我将通过肿瘤内的常规CD4 T细胞分化进行测试，我将测试DDR2的强迫表达是否能驱动转移和DDR2的消融。在第二个目标中，我将确定CD8 T细胞子集可预防PDA转移。首先，我将确定是否需要CD8 T细胞减少肿瘤燃烧和treg耗尽的转移促成。接下来，我将使用单细胞RNA测序来识别富含Treg定义的抗中转移CD8 T细胞的转录特征。拟议的研究策略的完成将揭示PDA中转移和CD8 T细胞功能障碍的机制，并确定一个治疗靶标，以降低PDA致死性。