New therapeutic approaches in clonal hematopoiesis and atherosclerosis

项目摘要 尽管降低LDL的治疗取得了成功，但动脉粥样硬化性心血管疾病仍然是主要原因。 死亡在美国。最近采用抗炎疗法的临床试验显示， 但导致了感染的增加。这表明迫切需要更精确的抗炎靶向治疗。 治疗炎症风险较高的患者。克隆性造血（CH）起源于体细胞突变 例如JAK 2或TET 2，其为造血干细胞和克隆生长提供适合性优势 的血细胞。随着年龄的增长，CH的频率增加，已成为一个主要的独立危险因素， CVD。Tet 2-/-和Jak 2 VF小鼠模型的研究表明巨噬细胞炎性小体的中心作用 activation.我们发现动脉粥样硬化增加，缺陷性红细胞增多，坏死增加， 在造血细胞和CH模型中表达Jak 2 VF的小鼠中的炎性骨髓细胞群体。 炎性体产物IL-1β的抑制改善了斑块稳定性的特征，包括增加了斑块稳定性。 纤维帽和坏死核心减少。我们建议研究连接CH， 炎性小体和IL-1β下游作用途径对动脉粥样硬化斑块稳定性的影响。低频 Jak 2 VF等位基因在3-4%的普通人群中发现，并增加CVD风险。我们最近的发现表明， 仅移植1.5%Jak2VF细胞导致具有受损的红细胞增多的病变增加， 坏死这表明了一种新的假设，即从Jak 2 VF M φs到旁观者WT M φs或WT M φ s的炎性串扰可能是一种新的假设。 基质细胞，促进斑块不稳定。在目标1中，我们将评估CH对旁观者细胞的影响， 病变集中在Jak 2 VF-WT M φ串扰上。我们将评估炎症信号来自 Jak 2 VF至WT巨噬细胞，如炎性小体衍生的IL-1，增加炎性巨噬细胞和巨噬细胞增殖。 减少Trem 2 Hi非炎性巨噬细胞，导致红细胞增多受损和炎症增加 在Aim 2中，我们将评估CH对Jak 2 VF或Jak 2 VF中基质细胞的影响。 Tet 2-/- CH小鼠，建立在初步研究的基础上，表明IL-1b拮抗作用增加了帽中的成纤维细胞， 动脉粥样硬化病变。我们还将采用一种新的Dre-Cre小鼠模型，使Jak 2 VF失活 在病变消退期间，以检验这增加了纤维化Trem 2 Hi巨噬细胞和 病变帽中的成纤维细胞。在目标3中，我们将与慕尼黑血管生物库合作评估影响 CH对人颈动脉斑块炎症的影响。拟议的研究可能揭示新的基因和途径， 克隆造血中炎性小体激活的下游，使斑块不稳定，并指出新的和 更精确的靶向治疗方法，其免疫抑制性低于IL-1β的全面抑制 或炎性小体。

PROJECT SUMMARY Despite the success of LDL lowering treatments, atherosclerotic cardiovascular disease remains the major cause of death in the US. Recent clinical trials employing anti-inflammatory therapies have shown a reduction in CVD but led to increased infections. This indicates an urgent need for more precise targeting of anti-inflammatory treatments to patients with higher inflammatory risk. Clonal hematopoiesis (CH) arises from somatic mutations such as in JAK2 or TET2 that provide a fitness advantage to hematopoietic stem cells and outgrowth of clones of blood cells. CH, which increases in frequency with aging, has emerged as a major independent risk factor for CVD. Studies in Tet2-/- and Jak2VF mouse models indicate a central role of macrophage inflammasome activation. We have shown increased atherosclerosis, defective efferocytosis, increased necrosis and inflammatory myeloid cell populations in mice expressing Jak2VF in hematopoietic cells and in CH models. Inhibition of the inflammasome product lL-1β improved features of plaques stabilization including increased fibrous caps and decreased necrotic cores. We propose to investigate the mechanisms linking CH, inflammasomes and pathways acting downstream of lL-1β to atherosclerotic plaque stability. Low frequency Jak2VF alleles are found in 3-4% of general populations and increase CVD risk. Our recent findings indicate that transplantation of only 1.5% Jak2VF cells leads to increased lesions with impaired efferocytosis and increased necrosis. This suggests a new hypothesis that inflammatory crosstalk from Jak2VF Μφs to bystander WT Μφs or stromal cells, promotes plaque destabilization. In Aim 1 we will assess the impact of CH on bystander cells in lesions focusing on Jak2VF -WT Μφ crosstalk. We will evaluate the hypothesis that inflammatory signals from Jak2VF to WT macrophages, such as inflammasome-derived IL-1, increase inflammatory macrophages and decrease Trem2Hi non-inflammatory macrophages, leading to impaired efferocytosis and increased inflammation in mice with low allele burden Jak2VF CH. In Aim2 we will assess the impact of CH on stromal cells in Jak2VF or Tet2-/- CH mice, building on preliminary studies showing that IL-1b antagonism increases fibroblasts in the cap of atherosclerotic lesions. We will also employ a novel Dre-Cre mouse model that allows Jak2VF to be inactivated during lesion regression to test the hypothesis that this increases fibrogenic Trem2Hi macrophages and fibroblasts in lesion caps. In Aim 3 we will collaborate with the Munich Vascular Biobank to assess the impact of CH on human carotid plaque inflammation. Proposed studies may reveal novel genes and pathways acting downstream of inflammasome activation in clonal hematopoiesis to destabilize plaques, and point to new and more precisely targeted therapeutic approaches that are less immunosuppressive than global inhibition of IL-1β or inflammasomes.