B cell intrinsic interferon-beta regulates autoreactive B cell development

B 细胞内在干扰素-β 调节自身反应性 B 细胞发育

• 批准号: 10326335
• 负责人: John D Mountz
• 金额: $ 47.13万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-13 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10326335
• 关键词: African American; Antinuclear Antibodies; Autoantibodies; Autocrine Communication; Autoimmune Responses; B-Cell Activation; B-Cell Antigen Receptor; B-Cell Development; B-DNA; B-Lymphocytes; Bioinformatics; Caucasians; Cell Survival; Cells; Computer Analysis; Coupled; Cues; DNA; Data; Development; Disease; Event; Exhibits; Female; Flare; Gene Expression; Gene Expression Profile; Genes; Genetic Transcription; Heterogeneity; Human; Immune; Incidence; Interferon Type I; Interferon-alpha; Interferon-beta; Interferons; Kidney; Ligands; Lupus; Mediating; Memory B-Lymphocyte; Modeling; Mus; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Peripheral Blood Mononuclear Cell; Phenotype; Play; Production; RNA; Regulation; Role; Severities; Shapes; Signal Transduction; Source; Systemic Lupus Erythematosus; TLR7 gene; Technology; Testing; Transgenic Mice; Transitional Cell; Validation; Work; anti-dsDNA autoantibody; autocrine; autoreactive B cell; autoreactivity; clinical heterogeneity; clinically relevant; design; ds-DNA; effective therapy; genetic signature; imprint; in vivo; insight; mouse model; new therapeutic target; novel; patient subsets; precision medicine; response; transcriptome

Project Summary/Abstract A considerable body of evidence implicates type I interferons (IFNs) in systemic lupus erythematosus (SLE); however, the “interferon signature” does not address the source and the key pathogenic type I IFNs in SLE, making it challenging to design effective precision medicine for SLE. We propose the novel hypothesis that it is the endogenous production of IFNβ by B cells that plays a defining role in shaping the autoantibody response and disease activity in a substantial subset of patients with SLE. We have found, in humans and mice, that the transitional (Tr) stage of B-cell development is characterized by heterogeneity in IFNβ expression at the single- cell level. Our preliminary data further suggest that: (i) Tr B cells with high endogenous production of IFNβ undergo strong IFNβ autocrine signaling and changes in the transcriptome signature in a manner that supports RNA/RNP-associated TLR7 responses. This imprinted signature promotes subsequent survival and development of RNP-reactive B cells including their differentiation into long-lived memory B cells; and (ii) Anti- dsDNA autoAb producing cells are derived from Tr cells that do not express high levels of endogenous IFNβ expression; however, high levels of endogenous IFNβ in memory B cells play a critical role in the differentiation of short-lived anti-dsDNA memory B cells. The model is supported by compelling preliminary data including analyses of PBMCs from SLE patients that indicated significantly higher IFNβ expression in B cells from SLE patients with renal involvement and significantly higher expression of intracellular IFNβ in B cells from female African-American (AA) SLE patients as compared with non-AA patients and healthy controls. In Aim 1, we will establish if lupus flare is associated with increases in IFNβhi memory B cells and if this phenotype is more common in AA SLE patients. High-throughput single-cell transcriptome analysis coupled with state-of-the-art computational analysis will be used to identify transcriptional signatures in DNA- and RNA-reactive B cells to refine this marker; to establish if, as predicted, there is commonality between the RNP-reactive Tr and memory B cell transcriptome; and to identify the association of enhanced IFNβ signaling with stage-specific dysregulation of downstream pathways. Functional and target-specific analysis of sorted human PBMCs will then be used to determine if endogenous B-cell IFNβ and its downstream pathways are essential for RNA- vs DNA-ligand mediated Tr and memory B-cell activation and survival. In Aim 2, we will use the same approaches in the BXD2 lupus model and BCR transgenic mice to determine if endogenous IFNβ is essential for, and differentially regulates, anti-RNP and anti-DNA B cell development in vivo. This hypothetical model does not negate the contributions of other cells and factors to the pathogenesis of SLE but reframes the current paradigm. The data generated will provide novel insights into the pathogenesis of SLE, identify novel therapeutic targets and provide the basis for development of precision medicine-guided approaches to utilization of currently available therapies in a significant subset of patients.

项目总结/摘要 大量证据表明I型干扰素（IFN）与系统性红斑狼疮（SLE）有关; 然而，“干扰素标记”并没有解决SLE中的来源和关键致病性I型IFN， 这使得为SLE设计有效的精确药物变得具有挑战性。我们提出了一个新的假设， B细胞内源性产生IFNβ，在形成自身抗体应答中起决定性作用 和疾病活动性之间的关系。我们发现，在人类和小鼠中， B细胞发育的过渡期（Tr）的特征是单个细胞中IFNβ表达的异质性， 细胞水平。我们的初步数据进一步表明：（i）具有高内源性IFNβ产生的Tr B细胞 经历强的IFNβ自分泌信号传导和转录组特征的变化， RNA/RNP相关的TLR 7应答。这种印记的签名促进了随后的生存， RNP反应性B细胞的发育，包括它们分化成长寿记忆B细胞;和（ii）抗- 产生dsDNA autoAb的细胞来源于不表达高水平内源性IFNβ的Tr细胞 然而，在记忆B细胞中高水平的内源性IFNβ在分化中起关键作用。 短寿命抗双链DNA记忆B细胞。该模型得到了令人信服的初步数据的支持，包括 SLE患者PBMC的分析表明SLE患者B细胞中IFNβ表达显著升高 女性B细胞内IFNβ表达显著增高的肾脏受累患者 非裔美国人（AA）SLE患者与非AA患者和健康对照组相比。在目标1中，我们 确定狼疮发作是否与IFNβhi记忆B细胞的增加相关，以及这种表型是否更 常见于AA SLE患者。高通量单细胞转录组分析结合最先进的 计算分析将用于鉴定DNA和RNA反应性B细胞中的转录特征， 完善这一标志物;以确定是否如预测的那样，RNP反应性Tr和记忆之间存在共性。 B细胞转录组;并确定增强的IFNβ信号传导与阶段特异性 下游通路的失调。分选的人PBMC的功能和靶特异性分析将 然后用于确定内源性B细胞IFNβ及其下游途径是否是RNA- vs DNA-配体介导的Tr和记忆B细胞活化和存活。在目标2中，我们将使用相同的 在BXD 2狼疮模型和BCR转基因小鼠中确定内源性IFNβ是否是必需的方法 用于并差异调节体内抗RNP和抗DNA B细胞发育。这个假设的模型 并不否定其他细胞和因子对SLE发病机制的贡献，而是重新定义了 当前的范式。所产生的数据将为SLE的发病机制提供新的见解， 治疗目标，并为开发精确的医学指导方法提供基础， 在重要的患者亚组中使用当前可用的疗法。