RNA-directed targeting of AID in immunity and genomic integrity

RNA 引导的 AID 免疫和基因组完整性靶向

基本信息

批准号：
9210606
负责人：
Jayanta Chaudhuri
金额：
$ 42.85万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-01 至 2021-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9210606
关键词：
Adaptive Immune System Affect Affinity Alpha Cell Archaea B-Cell Lymphomas B-Lymphocytes Bacteria Binding Biochemical CRISPR/Cas technology Cell Death Cell physiology Cellular biology Chromosomal translocation Clustered Regularly Interspaced Short Palindromic Repeats DNA DNA Damage DNA Double Strand Break Deaminase Defect Development Elements Engineering Enzymes Failure G-Quartets Generations Genes Genetic Genetic Transcription Genome Genome Stability Genome engineering Genomic Segment Genomics Growth Guide RNA Heavy-Chain Immunoglobulins Human Hybrids Immune response Immunity Immunoglobulin Class Switching Immunoglobulin Genes Immunoglobulin M Immunoglobulin Switch Recombination Immunologic Deficiency Syndromes Impairment Knock-in Lead Lesion Lymphoma Lymphomagenesis Maintenance Malignant Neoplasms Mature B-Lymphocyte Mediating Modeling Molecular Molecular Chaperones Mus Mutation Oncogenes Oncogenic Patients Physiological Point Mutation Process RNA RNA Binding RNA Splicing Recruitment Activity Rest Role Shelter facility Specificity Structure System Testing Toxic effect Transcript Untranslated RNA activation-induced cytidine deaminase base design endonuclease experimental study genome integrity genome-wide in vitro testing in vivo prevent public health relevance tool tumor tumorigenesis variable region gene

项目摘要

DESCRIPTION (provided by applicant): DNA double strand breaks (DSBs) constitute one of the most toxic lesions to occur in a cell. Unrepaired DSBs can either lead to cell death or can participate in chromosomal translocations that are hallmarks of many kinds of tumors, including lymphomas. Despite the toxicity associated with DSBs, during the immunoglobulin (Ig) gene diversification process of class switch recombination (CSR), DSBs are deliberately introduced into defined regions, called switch (S) regions, of the B cell genome, and a failure to introduce such DSBs leads to immunodeficiency syndromes. The DNA deaminase AID (activation induced cytidine deaminase) is essential for the generation of DSBs. While S regions (and the Ig gene associated variable region gene segments) are primary targets, AID has the potential to induce DSBs at non-Ig genes, including oncogenes. Such off-target DSBs are the major lesions behind the ontogeny of a large number of mature B cell lymphomas. Despite the relevance of AID targeting to both immunity and cancer, the molecular mechanisms underlying AID specificity are yet to be fully elucidated. We have now shown that noncoding RNA emanating from S regions act as molecular guides to recruit AID to S regions. This proposal tests the hypothesis that switch transcripts not only recruit AID to S regions to facilitate CSR but also sequester AID from other genomic regions to prevent collateral damage during B cell gene diversification. In aim 1, we test the notion that the RNA-guided recruitment of AID is critical fo CSR in vivo. In aim 2, we examine if RNA-guided AID recruitment serves to shelter the B cell genome from collateral AID-induced DNA damage. In aim 3, we design chimeric RNA molecules for ectopic targeting of AID. These studies will have far-reaching implications into our fundamental understanding of both immunity and how simple aberrations in the process could lead to B cell lymphomas.

描述（由申请人提供）：DNA 双链断裂 (DSB) 是细胞中发生的最具毒性的损伤之一，未修复的 DSB 要么导致细胞死亡，要么参与染色体易位，而染色体易位是多种肿瘤的标志。尽管 DSB 具有毒性，但在类别转换重组 (CSR) 的免疫球蛋白 (Ig) 基因多样化过程中，DSB 是故意的。 DNA 脱氨酶 AID（激活诱导胞苷脱氨酶）对于 DSB 的产生至关重要。区域（以及与 Ig 基因相关的可变区基因片段）是主要靶标，AID 有可能在非 Ig 基因（包括癌基因）上诱导 DSB。大量成熟 B 细胞淋巴瘤个体发育背后的主要病变尽管 AID 靶向与免疫和癌症相关，但 AID 特异性的分子机制尚未完全阐明。该提议测试了这样的假设：转换转录物不仅将 AID 招募到 S 区域以促进 CSR，而且还将 AID 与其他基因组区域隔离以防止 B 细胞基因过程中的附带损伤。在目标 1 中，我们测试了 RNA 引导的 AID 募集对于体内 CSR 至关重要的概念。在目标 3 中，我们设计了用于 AID 异位靶向的嵌合 RNA 分子，这些研究将对我们对免疫以及该过程中的简单畸变如何导致 B 细胞淋巴瘤的基本理解产生深远的影响。