Project 3: Regulation of atheroprotective IgM - producing B cells in murine and human atherosclerosis

项目 3：调节小鼠和人类动脉粥样硬化中产生动脉粥样硬化 IgM 的 B 细胞

• 批准号: 10334096
• 负责人: Coleen A McNamara
• 金额: $ 4.31万
• 依托单位: LA JOLLA INSTITUTE FOR IMMUNOLOGY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-06-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10334096
• 关键词: Anti-Inflammatory Agents; Antibodies; Antigens; Atherosclerosis; Attenuated; B-Cell Antigen Receptor; B-Lymphocytes; Blocking Antibodies; CCL20 gene; CCR6 gene; CXCR4 gene; Cell Communication; Cell physiology; Cells; Clinical; Coronary Arteriosclerosis; Cytometry; DNA Sequencing Facility; Data; Development; Diet; Disease Progression; Dissection; Epitopes; Event; Flow Cytometry; Frequencies; Human; Immune; Immunization; Immunoglobulin M; In Vitro; Inflammatory; Knock-out; Lesion; Link; Low-Density Lipoproteins; MS4A1 gene; Malondialdehyde; Mediating; Membrane Microdomains; Monoclonal Antibodies; Mus; Peripheral Blood Mononuclear Cell; Phenotype; Plasma; Production; Proteins; Receptor Signaling; Regulation; Research; Severity of illness; Sialoglycoproteins; Signal Pathway; Signal Transduction; Signaling Molecule; Spleen; Surface; Testing; Work; atheroprotective; burden of illness; chemokine receptor; clinically relevant; cohort; complementarity-determining region 3; cytokine; gain of function; high dimensionality; human subject; humanized mouse; improved; in vivo; innovation; insight; migration; mouse model; novel; oxidation; receptor function; sialic acid binding Ig-like lectin; trafficking; transcriptome sequencing

Project 3 Summary We and others have extensively studied B-1 cells in mice, clearly showing that these cells and the IgM to oxidation-specific epitopes (OSE) on LDL (IgMOSE) that they produce are anti- inflammatory and block atherosclerosis (AS) development. Yet, despite a wealth of evidence that plasma levels of IgM to the OSE, malondialdehyde-modified LDL (IgMMDA-LDL) in humans are associated with less CAD and fewer CV events, identification of the IgMMDA-LDL producing human B cell has remained elusive. Our novel data from the previous cycle, utilizing the well characterized CAVA cohort and high dimensional phenotyping of circulating B cells, are the first to identify human B cell subtypes that produce IgMMDA-LDL, and demonstrate that they are indeed associated with high plasma levels of IgMMDA-LDL and inversely correlated with CAD severity in humans. One of these subtypes (B27+IgM+24hi cells) trafficked to the spleen and could be stimulated by MDA antigen to produce higher levels of IgMMDA-LDL in vivo. Our findings revealed the novel discovery that the sialogycoprotein, CD24, regulated expression of the chemokine receptor CCR6 and splenic localization of these cells. CD24, a GPI-anchored sialoglycoprotein that resides in lipid rafts and regulates signaling of the IgM BCR, has not previously been implicated in murine or human AS. Utilizing our antibody and transcriptome sequencing core (Core B), we discovered that B27+IgM+24hi cells express more CCR6 and IgM specifically in subjects with low compared to high CAD and we identified signaling molecules downstream of CCR6 and the IgM BCR associated with CAD severity. Accordingly, we hypothesize that humans with severe CAD and rapid CAD progression have fewer B27+IgM+24hi cells and that CD24 acts as a rheostat promoting key surface receptor function and signaling pathways in B27+IgM+ cells leading to enhanced production of IgMOSE and atheroprotection. We will utilize novel clinical cohorts (aim 1) and loss- and gain- of function approaches in vitro and in vivo (aim 2) to define the mechanisms whereby CD24 regulates the B27+IgM+ phenotype with particular emphasis on CCR6, the BCR, key signaling events and the IgM repertoire in atherosclerosis.

项目3摘要 我们和其他人已经广泛研究了小鼠的B-1细胞，清楚地表明这些细胞和 它们产生的LDL（igmose）上的IgM到氧化特异性表位（OSE）是抗 炎症和阻断动脉粥样硬化（AS）发育。然而，尽管有很多证据 在人类中，IgM的血浆IgM水平为OSE，丙二醛改性的LDL（Igmmda-LDL） 与较少的CAD和更少的CV事件相关，识别IGMMDA-LDL产生 人类B细胞仍然难以捉摸。我们从上一个周期的新数据，利用井 循环B细胞的CAVA队列和高维表型的表征是第一个 识别产生Igmmda-LDL的人类B细胞亚型，并证明它们确实是 与高血浆IGMMDA-LDL水平高，与CAD严重程度成反比 人类。这些亚型（B27+IgM+24hi细胞）被运输到脾脏上，可能是 由MDA抗原刺激，在体内产生更高水平的IgMMDA-LDL。我们的发现揭示了 唾液科蛋白CD24调节趋化因子的表达的新颖发现 这些细胞的受体CCR6和脾定位。 CD24，GPI锚定 位于脂质筏中并调节IgM BCR的信号的唾液糖蛋白尚未 以前与鼠或人类有关。利用我们的抗体和转录组 测序核心（核心B），我们发现B27+IgM+24Hi细胞表达更多CCR6和IgM 与高CAD相比，特别是在较低的受试者中，我们确定了信号分子 CCR6的下游和与CAD严重程度相关的IgM BCR。因此，我们 假设患有严重CAD和快速CAD进展的人的人数较少 B27+IgM+24Hi细胞，该CD24充当促进钥匙表面受体功能的变阻器 B27+ IgM+细胞中的信号通路，导致iGmose和 动脉保护。我们将利用新颖的临床队列（AIM 1）以及功能的损失和增益 在体外和体内接近（目标2）来定义CD24调节的机制 B27+ IgM+表型特别强调CCR6，BCR，关键信号事件和 动脉粥样硬化中的IgM曲目。