B cell responses in heparin-induced thrombocytopenia

肝素诱导的血小板减少症中的 B 细胞反应

• 批准号: 10671678
• 负责人: DEMIN WANG
• 金额: $ 64.53万
• 依托单位: VERSITI WISCONSIN, INC.
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10671678
• 关键词: Affect; Affinity; Alpha Granule; Antibodies; Antibody Formation; Antibody Response; Autoantibodies; B cell repertoire; B-Lymphocytes; Biological Assay; Blood Platelets; Cells; Characteristics; Chromatin; Clonal Expansion; Color; Complement 3d Receptors; Complex; Development; Diagnosis; Disease; Disease Progression; Epigenetic Process; Evolution; Exhibits; Flow Cytometry; Future; Gene Expression Profiling; Genetic Transcription; Grant; Helper-Inducer T-Lymphocyte; Heparin; Heterogeneity; High-Throughput RNA Sequencing; Human; Humoral Immunities; ITGAX gene; Idiopathic Thrombocytopenic Purpura; Immune Tolerance; Immune response; Immunoglobulin G; Immunologic Memory; Mediating; Memory; Memory B-Lymphocyte; Molecular; Mus; Nature; PF4 Gene; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Plasmablast; Play; Prevention; Prevention strategy; Production; Proteins; Regulatory T-Lymphocyte; Role; Severities; Severity of illness; Sorting; Specificity; Structure of germinal center of lymph node; T-Lymphocyte; Testing; Thrombosis; Transposase; Trees; antigen binding; comparison control; complementarity-determining region 3; disorder prevention; epigenetic profiling; gene regulatory network; heparin-induced thrombocytopenia; indexing; insight; mouse model; novel; novel therapeutics; platelet phenotype; response; single-cell RNA sequencing; study characteristics; targeted treatment

ABSTRACT Heparin-induced thrombocytopenia (HIT) is the most common drug-induced immune thrombocytopenia and can lead to catastrophic thrombosis in an affected patient. Antibodies that recognize the platelet alpha-granule protein, platelet factor 4 (PF4), in a complex with heparin are central to HIT pathogenesis. Human B cells have extensive heterogeneity. Innate-like B cells, such as B1 and marginal zone (MZ) B cells, later germinal center (GC) B cells, different types of memory B cells, and extrafollicular plasmablasts all play an importance and unique role in the development of humoral immunity. Rapid onset of HIT antibody production and apparent lack of immunologic memory suggest T-cell independence whereas IgG antibodies typical of HIT argue for T cell involvement. The profound heterogeneity of human B cells and the ambiguous features of the HIT antibody response have confounded efforts to identify the pathogenic B cells and characterize the atypical immune response in HIT patients. In a mouse model, we have demonstrated that MZ B cells play a critical role in HIT antibody production. In the immediate past grant period, we discovered that in mice, breakdown of immunologic tolerance was involved in HIT antibody production and T helper cells and regulatory T cells could mediate the production of PF4/heparin-specific HIT antibodies. We also identified several novel pathways controlling B cell tolerance that was critical for controlling production of autoantibodies. Importantly, from HIT human patients, we cloned PF4/heparin-specific and platelet-activating antibodies possessing a unique RKH- or Y5-motif in the heavy chain complementarity determining region 3 (HCDR3) region that contributes the most to affinity and specificity of antigen binding. We found that a higher percentage of PF4/heparin-specific B cells, compared to the control B cells, exhibited extrafollicular B-cell features and an atypical memory B cell (atyMB) phenotype. Based on these findings, we hypothesize that PF4/heparin-specific B cells undergo extrafollicular response to follow a distinct differentiation path from activated naïve B cells first into atyMBs and then into plasmablasts in HIT patients. To test this hypothesis, we will (1) study the characteristics of PF4/heparin-specific B cells in HIT patients through integrative analysis of phenotypical, transcriptional and epigenetic responses of these B cells and (2) investigate the origin and developmental trajectory of PF4/heparin-specific B cells that produce platelet- activating antibodies in HIT patients. The proposed studies will identify the key features of PF4/heparin-specific B cells and their correlation with disease progression and severity and will discover the evolution of PF4/heparin- specific B-cell response. Completion of the proposed studies will provide novel insights into the molecular pathogenesis of HIT and guide future diagnosis, prevention and treatment of this potentially devastating disease.

摘要 肝素诱导的血小板减少症（HIT）是最常见的药物诱导的免疫性血小板减少症， 导致受影响患者中灾难性血栓形成。识别血小板α颗粒的抗体 血小板因子4（PF 4）与肝素复合是HIT发病机制的核心。人类B细胞具有 广泛的异质性先天性B细胞，如B1和边缘区（MZ）B细胞，后来的生发中心 (GC)B细胞、不同类型的记忆B细胞和滤泡外浆母细胞都在这些细胞中起着重要和独特的作用。 在体液免疫发展中的作用。HIT抗体的快速产生和明显缺乏 免疫记忆提示T细胞不依赖性，而HIT典型IgG抗体提示T细胞依赖性 参与。人类B细胞的高度异质性和HIT抗体的模糊特征 免疫应答的不确定性已经混淆了鉴定致病性B细胞和表征非典型免疫应答的努力。 对HIT患者的反应。在小鼠模型中，我们已经证明MZ B细胞在HIT中起关键作用 抗体生产。在刚刚过去的研究期间，我们发现，在小鼠中， 耐受参与HIT抗体的产生，辅助性T细胞和调节性T细胞可介导HIT抗体的产生。 产生PF 4/肝素特异性HIT抗体。我们还发现了几个新的途径控制B细胞 耐受性对于控制自身抗体的产生至关重要。重要的是，从HIT人类患者，我们 克隆的PF 4/肝素特异性和血小板活化抗体，在血小板膜上具有独特的RKH-或Y 5-基序， - 重链互补决定区3（HCDR 3）区，其对亲和力贡献最大， 抗原结合的特异性。我们发现，与对照组相比， 对照B细胞表现出滤泡外B细胞特征和非典型记忆B细胞（atyMB）表型。 基于这些发现，我们假设PF 4/肝素特异性B细胞对血小板活化的卵泡外反应， 遵循不同的分化途径，从活化的幼稚B细胞首先分化为atyMB，然后分化为浆母细胞。 打病人。为了验证这一假设，我们将（1）研究HIT中PF 4/肝素特异性B细胞的特性 通过综合分析这些B细胞的表型、转录和表观遗传反应， （2）研究产生血小板的PF 4/肝素特异性B细胞的起源和发育轨迹。 激活HIT患者的抗体。拟议的研究将确定PF 4/肝素特异性的关键特征， B细胞及其与疾病进展和严重程度的相关性，并将发现PF 4/肝素的演变- 特异性B细胞反应。完成拟议的研究将提供新的见解的分子 HIT的发病机制和指导未来的诊断，预防和治疗这种潜在的破坏性疾病。

项目成果

Regulatory T Cells Control PF4/Heparin Antibody Production in Mice.

调节性 T 细胞控制小鼠体内 PF4/肝素抗体的产生。

• DOI: 10.4049/jimmunol.1900196
• 发表时间: 2019
• 期刊: Journal of immunology (Baltimore, Md. : 1950)
• 作者: Zheng,Yongwei;Zhu,Wen;Haribhai,Dipica;Williams,CalvinB;Aster,RichardH;Wen,Renren;Wang,Demin
• 通讯作者: Wang,Demin

STAT5B, the dominant twin, in hematopoietic stem cells.

STAT5B，造血干细胞中的显性双胞胎。

• DOI: 10.1182/blood.2021013532
• 发表时间: 2021
• 期刊: Blood
• 影响因子: 20.3
• 作者: Chen,Yuhong;Wang,Demin
• 通讯作者: Wang,Demin

PTPRJ: a novel inherited thrombocytopenia gene.

PTPRJ：一种新型遗传性血小板减少症基因。

• DOI: 10.1182/blood-2019-01-895102
• 发表时间: 2019
• 期刊: Blood
• 影响因子: 20.3
• 作者: Wen,Renren;Wang,Demin
• 通讯作者: Wang,Demin

BAD inactivation exacerbates rheumatoid arthritis pathology by promoting survival of sublining macrophages.

• DOI: 10.7554/elife.56309
• 发表时间: 2020-12-03
• 期刊: eLife
• 影响因子: 7.7
• 作者: Li J;Zhang L;Zheng Y;Shao R;Liang Q;Yu W;Wang H;Zou W;Wang D;Xiang J;Lin A
• 通讯作者: Lin A

Transcription factor Hoxb5 reprograms B cells into functional T lymphocytes.

转录因子 Hoxb5 将 B 细胞重编程为功能性 T 淋巴细胞

• DOI: 10.1038/s41590-018-0046-x
• 发表时间: 2018-03
• 期刊: Nature immunology
• 影响因子: 30.5
• 作者: Zhang M;Dong Y;Hu F;Yang D;Zhao Q;Lv C;Wang Y;Xia C;Weng Q;Liu X;Li C;Zhou P;Wang T;Guan Y;Guo R;Liu L;Geng Y;Wu H;Du J;Hu Z;Xu S;Chen J;He A;Liu B;Wang D;Yang YG;Wang J
• 通讯作者: Wang J