Isolevuglandin-Modified Cardiac Proteins Drive CD4+ T-Cell Activation in the Heart and Promote Cardiac Dysfunction.
Isolevuglandin-Modified Cardiac Proteins Drive CD4+ T-Cell Activation in the Heart and Promote Cardiac Dysfunction.
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DOI：
10.1161/circulationaha.120.051889
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发表时间：
2021-03-23
期刊：
影响因子：
37.8
通讯作者：
Alcaide P
中科院分区：
文献类型：
--
作者：
Ngwenyama N;Kirabo A;Aronovitz M;Velázquez F;Carrillo-Salinas F;Salvador AM;Nevers T;Amarnath V;Tai A;Blanton RM;Harrison DG;Alcaide P
尽管 T 细胞介导的炎症与非缺血性心力衰竭 (HF) 之间存在明确的关联，但在 HF 进展过程中触发 T 细胞激活的具体机制以及所涉及的抗原仍知之甚少。我们假设心肌氧化应激诱导异黄兰素 (IsoLG) 修饰蛋白的形成，这些蛋白作为心脏新抗原，引发 CD4+ T 细胞受体 (TCR) 激活并促进心力衰竭。我们在小鼠中使用横向主动脉缩窄 (TAC) 来触发心肌氧化应激和 T 细胞浸润。我们通过 Nur77GFP 报告小鼠心肌内激活的 CD4+ T 细胞的 mRNA 测序来分析 TCR 库，这些细胞在 TCR 结合后瞬时表达 GFP。我们使用抗原呈递缺陷的 MhcII−/− 小鼠和缺乏内源性抗原特异性的 TCR 转基因 OTII 小鼠评估了抗原呈递和 TCR 特异性在心功能障碍发展中的作用。我们在衰竭的人类心脏中检测到 IsoLG 蛋白加合物。我们还通过在 TAC 期间用抗氧化剂 TEMPOL 和 IsoLG 清除剂 2-羟基苄胺 (2-HOBA) 处理小鼠，评估了活性氧 (ROS) 和 IsoLG 在体内引发 T 细胞免疫反应中的作用，并在体外 CD4+ T 细胞增殖响应 IsoLG 修饰的心脏蛋白的机制研究中。我们发现，随着心功能障碍的进展，左心室 (LV) 中的 TCR 抗原识别能力增强，并确定了 LV 中有限的活化 CD4+ T 细胞克隆型。尽管存在左室浸润的 CD4+ T 细胞，但用 CD4+ T 细胞重建的 MhcII−/− 小鼠和用同源抗原免疫的 OTII 小鼠仍能免受 TAC 诱导的心脏功能障碍，因此内源性抗原的抗原呈递是发展心脏功能障碍所必需的。用 2-HOBA 清除 IsoLG 可减少 TCR 激活并预防心脏功能障碍。从机制上讲，心脏压力超负荷导致 ROS 依赖性树突状细胞积累 IsoLG 蛋白加合物，从而诱导 CD4+ T 细胞强劲增殖。总的来说，我们的研究证明了 ROS 诱导的 IsoLG 修饰心脏新抗原形成的重要作用，可导致心脏内 TCR 依赖性 CD4+ T 细胞激活。
Despite the well-established association between T cell-mediated inflammation and non-ischemic heart failure (HF), the specific mechanisms triggering T cell activation during the progression of HF and the antigens involved are poorly understood. We hypothesized that myocardial oxidative stress induces the formation of isolevuglandin (IsoLG)-modified proteins that function as cardiac neoantigens to elicit CD4+ T cell receptor (TCR) activation and promote HF. We used transverse aortic constriction (TAC) in mice to trigger myocardial oxidative stress and T cell infiltration. We profiled the TCR repertoire by mRNA sequencing of intramyocardial activated CD4+ T cells in Nur77GFP reporter mice, which transiently express GFP upon TCR engagement. We assessed the role of antigen presentation and TCR specificity in the development of cardiac dysfunction using antigen presentation-deficient MhcII−/− mice, and TCR transgenic OTII mice that lack specificity for endogenous antigens. We detected IsoLG-protein adducts in failing human hearts. We also evaluated the role of reactive oxygen species (ROS) and IsoLGs in eliciting T cell immune responses in vivo by treating mice with the antioxidant TEMPOL, and the IsoLG scavenger 2-hydroxybenzylamine (2-HOBA) during TAC, and ex-vivo in mechanistic studies of CD4+ T cell proliferation in response to IsoLG-modified cardiac proteins. We discovered that TCR antigen recognition increases in the left ventricle (LV) as cardiac dysfunction progresses, and identified a limited repertoire of activated CD4+ T cell clonotypes in the LV. Antigen presentation of endogenous antigens was required to develop cardiac dysfunction since MhcII−/− mice reconstituted with CD4+ T cells, and OTII mice immunized with their cognate antigen were protected from TAC-induced cardiac dysfunction despite the presence of LV-infiltrated CD4+ T cells. Scavenging IsoLGs with 2-HOBA reduced TCR activation and prevented cardiac dysfunction. Mechanistically, cardiac pressure overload resulted in ROS dependent dendritic cell accumulation of IsoLG-protein adducts which induced robust CD4+ T cell proliferation. Collectively, our study demonstrates an important role of ROS-induced formation of IsoLG-modified cardiac neoantigens that lead to TCR-dependent CD4+ T cell activation within the heart.