Inhibition of DNA methylation to prevent tumor-induced immune tolerance

我是约翰霍普金斯大学医学院儿科肿瘤学系的二年级讲师。在这个提案中，我的目标是补充正在进行的免疫学研究与正式的生物信息学教育，让我分析淋巴细胞中DNA甲基化的全基因组模式，特别是在T细胞已被肿瘤抗原激活。我的近期目标是检验DNA甲基化和T细胞激活基因沉默导致免疫系统对癌症无效的假设。我的长期目标是利用这一提议建立一个独立的研究路线，可以转化为儿科肿瘤科患者的临床相关免疫治疗。研究我之前的工作已经确定了DNA甲基转移酶3a（DNMT3a）在催化活化后T细胞中细胞因子基因的从头DNA甲基化中的关键作用。在这个提议中，我将检验这样的甲基化导致无效的抗肿瘤免疫的假设。我将使用一个强大的小鼠模型，其T细胞缺乏DNMT3a，通过在全基因组甲基化分析中比较肿瘤暴露和活化的T细胞来识别DNA甲基化的未识别靶点。我将确定缺乏这种甲基化是否是观察到的DNMT 3a KO T细胞更好地排斥肿瘤的能力的基础，我将测试治疗DNMT抑制剂是否可以达到类似的效果。这一发现将确定DNMT抑制作为增强抗肿瘤免疫的新手段，并可能导致更有效的癌症疫苗策略。工作环境：我的建议将在乔纳森·鲍威尔博士的持续指导下进行，他是T细胞活化，效应分化和耐受性生物学的主要研究人员。他领导着一个高效的实验室，并成功地指导了四名研究生和三名博士后研究员。通过与下一代测序中心主任Srinivasan Yegnasubramanian博士的合作，我将把下一代测序的最新技术进展应用于测量基因组DNA甲基化的全球模式。生物技术教育中心和计算基因组学中心将为生物信息学的正规教育提供课程。这些因素联合收割机为我提供了一个坚实的基础，以发展作为一个独立的物理学家，科学家的职业生涯。 公共卫生相关性：我们提出肿瘤通过使用称为DNA甲基化的过程关闭T细胞内的基因来绕过和抑制T细胞免疫反应。该项目旨在识别由于DNA甲基化而被肿瘤关闭的T细胞基因，并测试阻断DNA甲基化是否能够增强对肿瘤的免疫反应。确定DNA甲基化在预防抗肿瘤免疫中的作用表明，阻断DNA甲基化的药物将增强免疫疗法对癌症的治疗。

DESCRIPTION (provided by applicant): Project Summary/Abstract Candidate I am a second year Instructor in the Division of Pediatric Oncology at the Johns Hopkins University School of Medicine. In this proposal I aim to complement ongoing research in immunology with a formal bioinformatics education to permit me to analyze genome-wide patterns of DNA methylation in lymphocytes, in particular in T cells that have been activated by tumor antigen. My immediate goals are to test the hypothesis that DNA methylation and silencing of T cell activation genes contributes to the ineffective immune responses against cancer. My long-term goal is to utilize this proposal to establish an independent line of research that may be translated into clinically relevant immunotherapy for patients in the Division of Pediatric Oncology. Research My prior efforts have identified a critical role for DNA Methyltransferase 3a (DNMT3a) in catalyzing de novo DNA methylation of cytokine genes in T cells following activation. In this proposal I will test the hypothesis that such methylation contributes to ineffective anti-tumor immunity. I will use a robust model of mice whose T cells lack DNMT3a to identify unappreciated targets of DNA methylation by comparing tumor exposed and activated T cells in an genome-wide methylation analysis. I will determine whether lack of such methylation underlies the observed ability of DNMT3a KO T cells to better reject tumors, and I will test whether treatment DNMT inhibitors can achieve a similar effect. Such a finding would identify DNMT inhibition as a novel means of enhancing anti-tumor immunity and potentially lead to more effective cancer vaccine strategies. Environment: My proposal will be carried out under the ongoing mentorship of Dr. Jonathan Powell, a leading researcher in the biology of T cell activation, effector differentiation, and tolerance. He leads a highly productive laboratory and has successfully mentored four graduate students and three postdoctoral fellows. Through collaboration with Dr. Srinivasan Yegnasubramanian, Director of the Next Generation Sequencing Center, I will apply the latest technological advances in next generation sequencing to the measurement of global patterns of genomic DNA methylation. The Center for Biotechnology Education and the Center for Computational Genomics will provide a curriculum for formal education in bioinformatics. These elements combine to provide me with a solid foundation to develop a career as an independent physician-scientist. PUBLIC HEALTH RELEVANCE: Project Narrative We propose that tumors bypass and suppress T cell immune responses by turning off genes within T cells using a process called DNA methylation. This project seeks to identify T cell genes turned off by tumors due to DNA methylation and test whether blocking DNA methylation is able to enhance immune responses against tumors. Identifying a role for DNA methylation in preventing anti-tumor immunity suggests that drugs that block DNA methylation will enhance treatment of cancer with immunotherapy.