Inhibition of DNA methylation to prevent tumor-induced immune tolerance

描述（由申请人提供）：项目概述/摘要候选人本人是约翰霍普金斯大学医学院儿科肿瘤科二年级讲师。在这个提案中，我的目标是通过正式的生物信息学教育来补充正在进行的免疫学研究，使我能够分析淋巴细胞DNA甲基化的全基因组模式，特别是在被肿瘤抗原激活的T细胞中。我的直接目标是验证DNA甲基化和T细胞激活基因沉默导致癌症免疫反应无效的假设。我的长期目标是利用这一建议建立一个独立的研究路线，可能转化为临床相关的免疫治疗儿童肿瘤部门的患者。我之前的工作已经确定了DNA甲基转移酶3a （DNMT3a）在T细胞活化后催化细胞因子基因的从头DNA甲基化中的关键作用。在本提案中，我将检验这种甲基化导致无效抗肿瘤免疫的假设。我将使用一个健壮的小鼠模型，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激活的T细胞来识别DNA甲基化的未被发现的靶标。我将确定是否缺乏这种甲基化是观察到的DNMT3a 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抑制是一种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。环境：我的提案将在Jonathan Powell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员。他领导着一个高效率的实验室，并成功地指导了四名研究生和三名博士后。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基因组DNA甲基化的全球模式测量。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。这些因素结合在一起，为我作为一名独立的医生和科学家的职业发展奠定了坚实的基础。

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.