Elucidating the role of cis-regulatory elements in mediating V(D)J recombination

阐明顺式调控元件在介导 V(D)J 重组中的作用

• 批准号: 8891528
• 负责人: Sherry Ginging Lin
• 金额: $ 3.52万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8891528
• 关键词: Alleles; Antibodies; Antibody Repertoire; Autoimmunity; B-Lymphocytes; Back; Beryllium; Binding; Biological Assay; Chromatin Loop; DNA; Defect; Development; Distal; Elements; Enhancers; Epigenetic Process; Equilibrium; Exons; Feedback; Feeds; Gene Expression Regulation; Gene Rearrangement; Genes; Genetic; Genetic Recombination; Genetic Transcription; Genomics; Goals; Heavy-Chain Immunoglobulins; IGH@ gene cluster; Immunoglobulin Constant Region; Immunoglobulin Variable Region; Immunologic Deficiency Syndromes; Indium; Individual; Intercistronic Region; Laboratories; Lead; Light; Locales; Lymphocyte; Lymphoma; Mediating; Mouse Cell Line; Mus; Mutant Strains Mice; Mutate; Oncogenic; Pathway interactions; Pattern; Play; Positioning Attribute; Process; Property; Recruitment Activity; Regulation; Regulator Genes; Regulatory Element; Role; Site; Specificity; Staging; T-Cell Receptor; T-Lymphocyte; Testing; Translating; V(D)J Recombination; adaptive immunity; base; endonuclease; global run on sequencing; human disease; insight; premature; prevent; progenitor; promoter; public health relevance

 DESCRIPTION (provided by applicant): Adaptive immunity is dependent on the ability of B and T cell receptors (BCR; TCR) to recognize and bind foreign substances within the body. Primary diversity in these BCR and TCR repertoires is dependent on the gene rearrangement process termed V(D)J recombination, in which controlled rearrangements of V, D, and J segments occur across large genomic distances in developing lymphocytes to produce genetically unique BCRs or TCRs. Importantly, deregulation of V(D)J recombination can underlie immunodeficiency and autoimmunity, and also lead to oncogenic translocations. At the Immunoglobulin heavy chain (IgH) locus, V(D)J recombination is tightly regulated. This regulation can be summarized into the following four properties: 1. Lineage specificity - Complete VHDJH joins from VH to DJH rearrangements are only observed in B cells and not T cells 2. Stage specificity - IgH rearrangements in progenitor B cells prior to light chain rearrangements, which occur in pre-B cells. 3. Order - D to JH rearrangements occur on both IgH alleles before joining of a VH to DJH rearrangement. VHs do not join to unrearranged Ds. 4. Feedback regulation - A productive VHDJH rearrangement on one allele will produce a heavy chain that feeds back to prevent further VH to DJH rearrangements on the second allele, if it is still in DJH configuration. The Alt lab has demonstrated that a 4kb region within the 100b IgH VH-D intergenic region, termed Intergenic Control Region 1 (IGCR1), contains two CTCF-binding elements (CBEs) that are essential in cis for ordered, lineage-specific, and feedback regulated assembly of VH, D, and JH segments. These functions of IGCR1 diversify primary antibody repertoires by preventing premature rearrangements of VH81X. IGCR1 also forms chromatin loops with other enhancer and CBE sites within the locus, but a specific mechanism for how these loops or other elements may participate in IGCR1 functions is not known. Thus, my proposal aims to (1) elucidate individual roles of the CBEs within IGCR1 and a set of ten CBEs at the 3' end of the IgH locus in V(D)J recombination control, and (2) test for transcription- and position-dependent aspects of IGCR1 functions. My proposed project should provide new insights into the interplay of genetic and epigenetic factors that that govern V(D)J recombination, which also will translate into a broader understanding of gene regulation.

 描述（通过应用证明）：自适应免疫取决于BCR中B和细胞受体（BCR； TCR）物质的能力。在大型基因组距离上进行了控制，D，D和J段的重排出现，以产生遗传独特的BCR或TCR，重要的是，V（d）J重组的放松是免疫非平反应和自身免疫性的基础，也导致了致癌的转运。可以将他的调节总结到以下四个属性中：1。在B细胞而不是t -cells 2。阶段特异性 - 祖细胞范围内的阶段特异性重排时，在B细胞中观察到DJH重排的谱系特异性 - 在PRE -B细胞中出现的重新排列。等位基因在将VH重新排列之前，如果它仍处于DJH配置状态，则会产生一个重新供电的链条。区域1 IGCR1）包含两个CTCF结合元素（CBE），这些元素在fordered fordered，rineage特异性和VH，D和JH节段的反馈组件中是必不可少的。增强剂和CBE Sithin座位，但是这些循环或其他元素的特定机制可能参与IGCR1函数，因此我的建议旨在（1）CBES在IGCR1中的单个角色，而在3''的10 CBE中V（d）J重组控制中的3'igH轨迹的末端，（2）转录测试 - IGCR1功能的位置依赖性方面。