Genome Architecture in Human Germinal Center B Cell Development, Malignancy, and Somatic Hypermutation

人类生发中心 B 细胞发育、恶性肿瘤和体细胞超突变中的基因组结构

• 批准号: 10478178
• 负责人: David G. Schatz
• 金额: $ 64.07万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-15 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10478178
• 关键词: 3-Dimensional; Address; Affect; Antibodies; Antibody Affinity; Antibody-mediated protection; Architecture; B-Cell Development; B-Cell Lymphomas; B-Lymphocyte Subsets; B-Lymphocytes; Biology; Cell Line; Cell Lineage; Cells; Chromatin; Chromatin Loop; Chromosomal translocation; Chromosomes; Complex; DNA; DNA Folding; Development; Elements; Environment; Exhibits; Future; Generations; Genes; Genetic Transcription; Genome; Genomic Instability; Genomic Segment; Genomics; Human; Image; Imaging technology; Immune response; Immunobiology; Immunoglobulin Genes; Immunoglobulin Somatic Hypermutation; Immunoglobulins; Immunooncology; In Situ; Individual; Investigation; Lead; Length; Link; Lymphoma; Lymphoma cell; Malignant - descriptor; Malignant Neoplasms; Mammalian Cell; Methods; Mutate; Mutation; Normal Cell; Nuclear; Nuclear Lamina; Nuclear Pore; Nuclear Pore Complex; Oncogenic; Organelles; Phase; Point Mutation; Positioning Attribute; Predisposition; Process; Property; RNA; Research; Resistance; Resolution; Role; Sampling; Site; Structure; Structure of germinal center of lymph node; Techniques; Testing; Three-dimensional analysis; Tissue Sample; Tissues; Tonsil; Vaccines; Work; cancer cell; cell type; cohesion; human tissue; insight; multiplexed imaging; novel imaging technology; novel strategies; pathogen; programs; single molecule; tumorigenesis

SUMMARY During the humoral immune response, somatic hypermutation (SHM) introduces point mutations in rearranged immunoglobulin (Ig) genes of activated germinal center (GC) B cells. SHM is essential for the fine-tuning of antibody affinity, the generation of B cells expressing high-affinity antibody, and the efficacy of many vaccines. Mistargeted SHM activities can lead to mutations and chromosomal translocations that contribute to the development of B cell lymphoma. Recent studies suggest that the three-dimensional (3D) organization of the genome regulates SHM targeting and mistargeting. However, it is largely unknown how the genome is spatially organized across multiple length scales in GC B cell development and lymphoma, and how 3D genome architecture mechanistically affects the targeting and mistargeting of SHM. Conventional approaches cannot address these questions in the primary GC tissue environment due to technical limitations. Here, we propose to apply a new method recently developed by our team, termed Multiplexed Imaging of Nucleome Architectures (MINA), to primary human tonsil tissue samples and malignant GC-derived human B cell lymphomas. We will investigate and test the association between SHM susceptibility and a variety of 3D nucleome architectures, including topologically associating domain (TAD) architecture, phase separation, and nuclear positioning of genomic regions relative to nuclear lamina, nucleoli, and nuclear pores. Through targeted genomic perturbations in human B cell lymphomas, we will test specific hypotheses linking SHM targeting elements to elevated chromatin looping interactions, TAD phase separation, nuclear pore proximity, and mutation vulnerability. Our study will significantly advance our understanding of the role of 3D genome architecture and nuclear organization in GC B cells undergoing SHM in both the developmental and tumorigenesis contexts. We expect this study to establish a new research paradigm and transform 3D nucleome investigations in immunobiology.

概括 在体液免疫反应期间，体细胞超突变（SHM）在 重排激活的生发中心 (GC) B 细胞的免疫球蛋白 (Ig) 基因。 SHM 对于 抗体亲和力的微调、表达高亲和力抗体的 B 细胞的产生以及 许多疫苗。错误定位的 SHM 活动可能导致突变和染色体易位，从而导致 有助于 B 细胞淋巴瘤的发展。最近的研究表明三维 (3D) 基因组的组织调节 SHM 靶向和误靶向。然而，目前尚不清楚如何 在 GC B 细胞发育和淋巴瘤中，基因组在多个长度尺度上进行空间组织， 以及 3D 基因组架构如何机械地影响 SHM 的靶向和误靶向。 传统方法无法解决原代 GC 组织环境中的这些问题，因为 技术限制。在这里，我们建议应用我们团队最近开发的一种新方法，称为 核组结构多重成像 (MINA)，用于初级人类扁桃体组织样本和 恶性GC衍生的人B细胞淋巴瘤。我们将调查并测试SHM之间的关联 磁化率和各种 3D 核组结构，包括拓扑关联域 (TAD) 基因组区域相对于核纤层的结构、相分离和核定位， 核仁、核孔。通过针对人类 B 细胞淋巴瘤的基因组扰动，我们将 测试将 SHM 靶向元件与增强的染色质环相互作用 (TAD) 联系起来的特定假设 相分离、核孔接近度和突变脆弱性。我们的研究将显着推进我们的 了解 3D 基因组结构和核组织在 GC B 细胞中的作用 SHM 在发育和肿瘤发生方面的作用。我们期望这项研究能够建立一个新的 研究范式并改变免疫生物学中的 3D 核组研究。