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E3 ligase mediated control of Foxp3 expression and immune suppression-mechanisms and potential as immunotherapeutic target

E3连接酶介导的Foxp3表达和免疫抑制机制的控制以及作为免疫治疗靶点的潜力

基本信息

批准号：
10331033
负责人：
DREW M. PARDOLL
金额：
$ 37.91万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-02-01 至 2023-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10331033
关键词：
Achievement Advanced Malignant Neoplasm Affect Anti-Inflammatory Agents Autoimmune Autoimmune Diseases Autoimmunity Biochemical Biology Cancer Patient Cancer Vaccines Cell Compartmentation Cell Nucleus Cell physiology Cells Characteristics Chemicals Cytoplasm Detection Development Disease Disease model Dissection Down-Regulation Drug Screening Elements Enzymes FOXP3 gene Generations Genetic Homeostasis Host Defense Human IL2RA gene Immune Immune mediated destruction Immune response Immune system Immunomodulators Immunosuppression Immunotherapeutic agent Immunotherapy Infection Inflammatory Interruption Intervention Investigational Therapies Knock-out Lead Leukocytes Ligase Lipopolysaccharides Malignant Neoplasms Malignant neoplasm of ovary Mediating Modeling Modification Molecular Mus Mutate Outcome Pathology Pathway interactions Pharmacology Phenotype Phosphorylation Phosphotransferases Physiological Play Polyubiquitination Post-Translational Protein Processing Post-Translational Regulation Process Proteins Regulation Regulatory Pathway Regulatory T-Lymphocyte Reporter Research Risk Role Roswell Park Cancer Institute Signal Pathway Signal Transduction Site Small Interfering RNA Stimulus Stress T-Lymphocyte T-Lymphocyte Subsets Testing Therapeutic Tissues Transgenic Mice Tumor Escape Tumor Immunity Ubiquitin Work anti-cancer anti-tumor immune response base cancer immunotherapy cell bank cytokine efficacy testing experimental study fitness glycogen synthase kinase 3 beta inhibitor immune activation immunoregulation in vitro Model in vivo inflammatory milieu inhibitor knock-down melanoma neoplasm immunotherapy neoplastic cell novel overexpression prevent response restraint screening side effect targeted agent transcription factor tumor tumor eradication tumor growth tumor microenvironment ubiquitin-protein ligase vaccine efficacy

项目摘要

Project Summary Tumor cells exploit mechanisms of immune regulation to evade detection and eradication by host defenses. Foxp3+CD4+CD25+ regulatory T cell (Treg)-mediated immune suppression is crucial for immune evasion by tumor cells and an obstacle for successful tumor immunotherapy. Hence, the ability to disrupt Treg function is of major therapeutic significance. Recent work by us and others revealed that the key Treg transcription factor, Foxp3 is subject to polyubiquitination-dependent posttranslational regulation. Particularly, we found the E3 ubiquitin ligase Stub1, which is induced in response to a range of stress signals, facilitates the degradation of Foxp3 providing a potential target for dynamic modulation of Treg suppression. In the current proposal, we are seeking to: 1) Dissect molecular signaling pathways involved in Stub1 expression and its post-translational modification; 2) Understand the consequences of physiological Stub1 induction and genetic deletion for Treg cell homeostasis, differentiation and function; and 3) Test pharmacological activators of Foxp3 ubquitination as novel immunotherapic strategies to undermine immune suppression in the cancer setting. These studies will expand our understanding of the mechanisms behind posttranslational Foxp3 regulation. Specifically, we will further explore pathways determining Stub1 activity and expression, including the previously unappreciated phosphorylation of the ligase by the kinase GS3Kβ. To this end, we will utilize biochemical approaches and well-characterized models of in vitro and in vivo Treg function to establish the consequences of ablating these pathways. Furthermore, pharmacological modifiers of the Stub1/Ubiquitin-dependent pathway for Foxp3 degradation (identified in a drug screen and previous studies) will be tested for efficacy as breakers of immune suppression - a major obstacle for anti-cancer immunotherapy. This vetting will be carried out in an aggressive murine melanoma model (in vivo) as well as in ex vivo studies of human leukocytes obtained from healthy donors and advanced cancer patients. In so doing we will determine the potential therapeutic application of modulating Stub1 activity to boost anti-tumor immunity. Our experiments may reveal novel modes of regulating Stub1 activity and Foxp3 protein downregulation. Detailed assessment of physiological Stub1 induction and its impact on Foxp3 and Treg function is predicted to demonstrate a potent therapeutic application. Use of Stub1- activators in combination with proven checkpoint targeting agents may yield even better anti-tumor efficacy.

项目概要肿瘤细胞利用免疫调节机制来逃避宿主防御的检测和根除。 Foxp3+CD4+CD25+调节性T细胞（Treg）介导的免疫抑制对于免疫逃避至关重要肿瘤细胞和成功的肿瘤免疫治疗的障碍。因此，破坏 Treg 功能的能力是具有重要的治疗意义。我们和其他人最近的工作揭示了关键的 Treg 转录因子， Foxp3 受到多聚泛素化依赖性翻译后调控。特别是，我们发现了E3 泛素连接酶 Stub1 是响应一系列应激信号而诱导的，可促进泛素连接酶 Stub1 的降解 Foxp3 为 Treg 抑制的动态调节提供了潜在的靶标。在当前的提案中，我们是寻求：1) 剖析 Stub1 表达及其翻译后相关的分子信号通路修改; 2) 了解生理性Stub1诱导和基因缺失对Treg的影响细胞稳态、分化和功能； 3) 测试 Foxp3 泛素化的药理学激活剂破坏癌症环境中免疫抑制的新型免疫治疗策略。这些研究将扩大我们对翻译后 Foxp3 调控机制的理解。具体来说，我们将进一步探索决定 Stub1 活性和表达的途径，包括以前未被重视的途径连接酶被激酶 GS3Kβ 磷酸化。为此，我们将利用生化方法体外和体内 Treg 功能的良好表征模型，以确定消除这些功能的后果途径。此外，Foxp3 的 Stub1/泛素依赖性途径的药理学修饰剂降解（在药物筛选和之前的研究中确定）将被测试作为免疫破坏者的功效抑制——抗癌免疫治疗的主要障碍。此次审查将以积极的方式进行鼠黑色素瘤模型（体内）以及从健康人体内获得的人类白细胞的离体研究捐赠者和晚期癌症患者。在此过程中，我们将确定潜在的治疗应用调节 Stub1 活性以增强抗肿瘤免疫力。我们的实验可能揭示新的调节模式 Stub1 活性和 Foxp3 蛋白下调。 Stub1 生理诱导的详细评估及其对 Foxp3 和 Treg 功能的影响预计将证明其具有有效的治疗应用。使用 Stub1- 激活剂与经过验证的检查点靶向剂相结合可能会产生更好的抗肿瘤功效。