Antigen-Independent, Autonomous B-cell Receptor Signalling in Diffuse Large B-cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) comprises two major cell-of-origin subtypes, germinal center B-cell (GCB) type and activated B-cell (ABC) type. ABC-DLBCL is characterized by chronic active B-cell receptor (BCR) signalling and NFκB activation, which is explained by activating mutations of the BCR signalling cascade in a minority of cases. We here demonstrate that autonomous BCR signalling, akin to its essential pathogenetic role in chronic lymphocytic leukemia (CLL), can explain chronic active BCR signalling in DLBCL. We show that 13 of 18 tested DLBCL-derived BCR induced spontaneous calcium flux in murine triple knock-out pre-B cells10 in the absence of antigenic stimulation or external BCR crosslinking. Autonomous BCR signalling was associated with IgM isotype, dependent on somatic BCR mutations, and largely restricted to non-GCB DLBCL. Autonomous BCR signaling represents a novel immunological driver mechanism originating from individual BCR sequences and adds a new dimension to ..., Cell lines and biopsies Fresh-frozen biopsies of histologically confirmed DLBCL samples were identified in the pathology archive at Leiden University Medical Center (LUMC). The study was approved by the Scientific Review Committee of the LUMC Dept of Hematology under an applicable waiver of consent by the LUMC Ethical Committee (B16.048). Genetic analyses Whole exome sequencing (WES) was performed on fragmented DNA with the SureSelect Human All Exon V7 kit (Agilent) capture on the HiSeq2000 (Illumina) platform to an average coverage of 50x. For the variant calling analysis, FASTQ files were processed using the Sarek workflow v2.7 and aligned to the human reference genome GRCh38 using the Burrows-Wheeler Algorithm (BWA) v0.7.17. 35,36 Duplicated mapped reads were marked, local realignment of regions flanking indels, and recalibration of base quality scores were performed to obtain more accurate bases according to the Genome Analysis ToolKit (GATK) best practices version v4.1.7.0. 37 S..., , , # Antigen-independent, autonomous B cell receptor signaling drives activated B cell DLBCL [https://doi.org/10.5061/dryad.612jm647m](https://doi.org/10.5061/dryad.612jm647m) This dataset contains raw whole-exome sequencing (WES) data in paired-end FASTQ format for 15 patient samples diagnosed with diffuse large B-cell lymphoma (DLBCL). These data were generated to support downstream analyses, including variant calling, copy number variation (CNV) detection, structural variant identification, and molecular classification using the LymphGen algorithm. --- **Principal Investigator Contact Information** Name: Hendrik Veelken Institution: Leiden University Medical Center Email: [[e-mail]](mailto:[e-mail]) **Alternate Contact Information** Name: Cornelis van Bergen Institution: Leiden University Medical Center Email: [[e-mail]](mailto:[e-mail]) --- ## Description of the Data and File Structure ### File Format and Structure * ...弥漫性大B细胞淋巴瘤（diffuse large B-cell lymphoma, DLBCL）包含两种主要的细胞起源亚型：生发中心B细胞（germinal center B-cell, GCB）型与活化B细胞（activated B-cell, ABC）型。ABC型DLBCL以慢性活化B细胞受体（B-cell receptor, BCR）信号转导与核因子κB（NFκB）活化为特征，少数病例中BCR信号级联的激活突变可解释这一病理表型。本研究证实，自主BCR信号转导——如同其在慢性淋巴细胞白血病（chronic lymphocytic leukemia, CLL）中发挥的关键致病作用——可解释DLBCL中的慢性活化BCR信号转导。本研究发现，在无抗原刺激或外源性BCR交联的情况下，18株经检测的DLBCL来源BCR中有13株可在小鼠三重敲除前B细胞[10]中诱导自发性钙流。自主BCR信号转导与IgM亚型相关，且依赖于体细胞BCR突变，同时主要局限于非GCB型DLBCL。自主BCR信号转导代表了一种源自个体BCR序列的新型免疫学驱动机制，并为相关研究开辟了新维度。 ### 细胞系与活检样本 本研究从莱顿大学医学中心（Leiden University Medical Center, LUMC）病理档案中筛选出经组织学确认的DLBCL样本的冰冻活检组织。本研究经莱顿大学医学中心血液科科学审查委员会批准，并获得莱顿大学医学中心伦理委员会的知情同意豁免（审批号：B16.048）。 ### 遗传分析 本研究采用SureSelect人类全外显子V7捕获试剂盒（安捷伦, Agilent）对片段化DNA进行捕获，依托Illumina HiSeq2000平台开展全外显子测序（whole exome sequencing, WES），平均测序深度达50×。变异识别分析中，研究人员使用Sarek工作流v2.7处理FASTQ文件，并通过Burrows-Wheeler比对工具（Burrows-Wheeler Algorithm, BWA）v0.7.17将序列比对至人类参考基因组GRCh38[35,36]。随后依据基因组分析工具包（Genome Analysis ToolKit, GATK）v4.1.7.0最佳实践流程，完成重复比对读段标记、插入缺失侧翼区域局部重比对以及碱基质量值重校准，以获得更精准的碱基信息[37]。 # 抗原非依赖性自主B细胞受体信号转导驱动活化B细胞型弥漫性大B细胞淋巴瘤 [https://doi.org/10.5061/dryad.612jm647m](https://doi.org/10.5061/dryad.612jm647m) 本数据集包含15例确诊为弥漫性大B细胞淋巴瘤（DLBCL）患者样本的原始全外显子测序（WES）数据，格式为双端FASTQ。这些数据用于支撑后续分析，包括变异识别、拷贝数变异（copy number variation, CNV）检测、结构变异鉴定以及采用LymphGen算法开展的分子分型。 --- **主要研究者联系方式** 姓名：亨德里克·维尔肯（Hendrik Veelken） 所属机构：莱顿大学医学中心 电子邮箱：[e-mail] **备选联系方式** 姓名：科内利斯·范·贝根（Cornelis van Bergen） 所属机构：莱顿大学医学中心 电子邮箱：[e-mail] --- ## 数据与文件结构说明 ### 文件格式与结构 * ...