Mechanisms and Modulation of Accelerated Atherosclerosis in Clonal Hematopoiesis

项目摘要/摘要 随着年龄的增长，人类可以在血液中积累因骨髓体细胞突变而产生的白细胞克隆 促进扩增的干细胞：不确定潜能的克隆性造血(CHIP)。基因突变 DNMT3A和TET2代表了这些克隆中的多个。CHIP使心血管(CV)高度升高 风险，独立于传统的风险因素。我们发现动脉粥样硬化的加速形成和 IL-1和IL-6在TET2或DNMT3A功能缺失及IL-6信号转导基因缺失小鼠中的表达 消除了携带DNMT3A或TET2芯片的人的心血管风险升高。我们对Cantos审判的分析表明 在使用DNMT3A或TET2芯片的人中，抑制IL-1β的效果更好。这些结果指出了一种 以基因型为导向的治疗分配，这一方法已经改变了肿瘤学，但仍是雄心勃勃的 动脉硬化。经典与反式IL-6信号在动脉粥样硬化血栓形成中的作用需要进一步研究 相互矛盾的证据。特定目标1将检验这样一个假设，即模拟芯片的动脉粥样硬化小鼠 一种通过中和IL-6来阻断全局IL-6信号转导的抗体治疗DNMT3A的髓系缺陷 受体α(IL-6R，CD126R)可以减轻病变、血液和其他组织中的动脉粥样硬化和炎症 器官部分通过单细胞RNA测序(scRNA-seq)进行测量。我们进一步假设IL-6R 抑制将限制突变克隆的扩张。《特定目标2》将探讨经典与反式IL-6的作用 用Il6rflx/Flox/Lyz2-Cre小鼠骨髓在CHIP中加速动脉粥样硬化中髓系细胞的信号转导 嵌合LDLR-/-小鼠(阻断白细胞经典信号)和注射gp130-IgG1-Fc嵌合体 使用类似的程序和终点的蛋白质(以阻止反式信号)。这一结果将照亮 关于经典和反式IL-6信号对 动脉粥样硬化的形成。具体目的3.我们的初步实验表明，雌性髓系Tet2-/-Ldlr-/-小鼠具有 与TET2/Ldlr-/-雄性小鼠相比，TET2/Ldlr-/-雄性小鼠对动脉粥样硬化的加速作用更大，而且与雄性小鼠不同的是， 通过中和IL-1β减少动脉粥样硬化的发生。我们将本地化这种性别差异在 炎症体-IL-1DNMT3A-/-β-IL-6途径，并检验雌性DNMT3A-/-LDLR-/-小鼠有更大的 对IL-6R抑制的反应优于男性。我们将通过性腺消融实验和通过 分析scrna-seq数据，初步数据显示常驻巨噬细胞表达IL-1β 来自TET2-/-女性的动脉粥样硬化，但不是男性。这项工作将加深对心力衰竭机制的理解。 芯片内动脉粥样硬化加速。我们新的临床试验数据显示，一种抗IL-6抗体可以沉默 人类的炎症。因此，这里提出的工作将为验证提供不可或缺的一步。 以及提供可立即翻译的靶向治疗策略的基本基础 芯片基因分型。

Project Summary/Abstract With age, humans can accumulate leukocyte clones in blood that arise from somatic mutations in bone marrow stem cells that enhance expansion: clonal hematopoiesis of indeterminate potential (CHIP). Mutations in DNMT3A and TET2 account for the plurality of these clones. CHIP confers highly elevated cardiovascular (CV) risk, independent of traditional risk factors. We have found accelerated atherogenesis and the involvement of IL-1 and IL-6 in mice with myeloid loss of Tet2 or Dnmt3a function and that genetically reduced IL-6 signaling abrogates the elevated CV risk in humans with DNMT3A or TET2 CHIP. Analyses of our CANTOS trial showed greater efficacy of IL-1β inhibition in humans with DNMT3A or TET2 CHIP. These results point the way to a genotype-directed allocation of therapy, an approach that has transformed oncology but remains aspirational in atherosclerosis. The roles of classical vs. trans IL-6 signaling in atherothrombosis requires further study due to conflicting evidence. Specific aim 1 will test the hypothesis that atherosclerotic mice that mimic CHIP due to myeloid deficiency in Dnmt3a treated with an antibody that interrupts global IL-6 signaling by neutralizing IL-6 receptor α (IL-6r, CD126) have decreased atherosclerosis and inflammation within the lesions, blood and other organs as gauged in part by single-cell RNA sequencing (scRNA-seq). We further hypothesize that IL-6r inhibition will limit expansion of the mutant clone. Specific aim 2 will probe the role of classical vs. trans IL-6 signaling in myeloid cells in accelerated atherogenesis in CHIP using Il6rflox/flox/Lyz2-Cre mice bone marrow chimeric LDLR-/- mice (to block leukocyte classical signaling), and administration of a gp130-IgG1-Fc chimeric protein (to block trans signaling) using similar procedures and endpoints. The results will illuminate the controversy and unsettled science regarding the contributions of classical and trans IL-6 signaling to atherogenesis. Specific aim 3. Our preliminary experiments show that female myeloidTet2-/-Ldlr-/- mice have greater acceleration of atherogenesis than Tet2+/+ Ldlr-/- male mice and, unlike their male counterparts, show reduced atherogenesis with IL-1β neutralization. We will localize where this sex difference operates in the inflammasome–IL-1β–IL-6 pathway, and test the hypothesis that female Dnmt3a-/-Ldlr-/- mice have greater response to IL-6r inhibition than males. We will probe mechanisms by gonadal ablation experiments and by analysis of scRNA-seq data, which in preliminary data shows IL-1β expression in resident macrophages cells from atheroma from Tet2-/- females but not males. This work will deepen understanding of the mechanisms of accelerated atherosclerosis in CHIP. Our new pilot clinical data show that an anti-IL-6 antibody can mute inflammation in humans. Thus, the work proposed here will provide an indispensable step toward validating and furnishing the fundamental basis of an immediately translatable targeted therapeutic strategy based on CHIP genotype.