Role of caspase-1 activation in HIV-1 associated atherogenesis

项目摘要/摘要：动脉粥样硬化相关心血管疾病(CVD)目前是 艾滋病毒携带者(PLWH)接受有效抗逆转录病毒治疗(ART)的主要死亡原因。我们的 目前对HIV相关动脉粥样硬化的发病机制的了解有限，而且在很大程度上得到了了解。 从临床观察来看。HIV诱导的动脉粥样硬化的明显病理特征是无钙化。 更容易破裂的炎性斑块。在接受抗逆转录病毒治疗的患者中，艾滋病毒感染不仅 激活免疫细胞，如巨噬细胞(MC)，但也激活一系列分子途径，如 炎症体途径，包括caspase-1(Casp-1)激活。然而，确切的细胞和 HIV相关动脉粥样硬化形成的分子机制尚未得到广泛研究。 了解这些机制将有助于更好地开发和设计新的治疗措施 艾滋病毒相关心血管疾病的治疗/预防。为了实现这一未实现的目标，我们成立了一个多学科的 由多名PI组成的团队秦博士(先天免疫和心血管疾病专家)和Burdo博士(艾滋病毒-1心血管疾病专家) 和巨噬细胞(Mɸ)生物学)，以及Co-I戈登博士(艾滋病毒-1感染专家)。通过这一共同努力，我们 使用了携带7.4kb前病毒DNA结构的HIV转基因小鼠(B6背景下的TG26) 携带缺失，包括大多数Gag和Poll基因，使其不具传染性。TG26小鼠模仿 慢性HIV患者接受抗逆转录病毒治疗，其中没有病毒复制，但仍会产生病毒蛋白。按顺序 为了将TG26引入动脉粥样硬化的背景，我们将这条线与载脂蛋白E(ApoE-/-)小鼠杂交， 过去25年来用于研究动脉粥样硬化形成的普通小鼠品系产生了TG26/ApoE-/-小鼠。 我们的初步结果表明：1)TG26/ApoE-/-在肾脏正常的情况下促进了动脉粥样硬化的形成 2)TG26/ApoE-/-在外周血单核细胞中具有较高的Casp-1活性 (3)TG26/ApoE-/-中的HIV-1转基因培养的MC形成泡沫细胞， 动脉粥样硬化的标志，以及4)HIV-1感染患者斑块中MC上的Casp-1被激活，以及 5)TG26患者血清IL-1β和IL-18水平升高，HIV阳性患者血清IL-18水平升高，并与 冠状动脉斑块。因此，我们假设慢性HIV感染通过CASP-1诱导MC激活 途径，有助于艾滋病毒相关的动脉粥样硬化形成。为了检验这一假设，我们建议调查 利用动物模型和现有的HIV样本研究HIV-1相关动脉粥样硬化的发病机制。我们 将使用几种新的模型和方法，包括我们新建立的HIV-1 TG-26转基因小鼠 在高脂血症条件下以及包括我们建立的体外模型在内的标准方法下维持 用于泡沫细胞形成的系统。建议的研究将为我们理解 HIV-1感染和免疫激活在动脉粥样硬化中的作用。

Project summary/Abstract: Atherosclerosis-associated cardiovascular disease (CVD) is currently one of the leading causes of mortality among people living with HIV (PLWH) on effective antiretroviral therapy (ART). Our current understanding of the pathogenesis of HIV-associated atherosclerosis is limited and largely obtained from clinical observations. The distinct pathologic features of HIV-induced atherosclerosis are noncalcified inflammatory plaques that are more vulnerable to rupture. In patients on ART treatment, HIV infection not only activates immune cells, such as macrophages (MC), but also activates an array of molecular pathways, such the inflammasome pathway, including caspase-1 (casp-1) activation. However, the exact cellular and molecular mechanisms underlying HIV-associated atherogenesis have not been extensively investigated. Understanding these mechanisms will help to better develop and design novel therapeutic interventions for the treatment/prevention of HIV-associated CVD. To achieve this unmet goal, we have formed a multidisciplinary team consisting of multiple PIs Dr. Qin (innate immunity and CVD expert) and Dr. Burdo (expert in HIV-1 CVD and macrophage (Mɸ) biology), and Co-I Dr. Gordon (expert in HIV-1 infection). Through this joint effort, we have utilized HIV-transgenic mice (Tg26 on a B6 background) carrying a 7.4-kb proviral HIV DNA construct carrying a deletion, encompassing most of the gag and pol genes, to render it noninfectious. Tg26 mice mimic chronic HIV patients on ART in which there is no viral replication, but viral proteins are still produced. In order to introduce Tg26 to an atherogenic background, we crossed this line with Apolipoprotein E (ApoE-/-) mice, a common mouse strain used for studying atherogenesis for the last 25 years to generate Tg26/ApoE-/- mice. Our preliminary results show that 1) Tg26/ApoE-/- developed an accelerated atherogenesis with normal renal function, 2) Tg26/ApoE-/- had significantly higher casp-1 activation in peripheral blood mononuclear cells (PBMC) and plaques than ApoE-/-, 3) The HIV-1 transgene in Tg26/ApoE-/- fostered MC to form the foam cells, a hallmark of atherogenesis, and 4) Casp-1 is activated on MC in the plaques of HIV-1-infected patients, and 5) serum IL-1β and IL-18 are elevated in Tg26 and IL-18 is elevated in HIV+ patients and correlates with coronary plaque. Therefore, we hypothesize that chronic HIV infection induces MC activation via casp-1 pathway, contributing to HIV-associated atherogenesis. To test this hypothesis, we propose to investigate the pathogenesis of HIV-1-associated atherosclerosis by using animal models and available HIV specimens. We will use several novel models and approaches including our newly established HIV-1 Tg-26 transgenic mice maintained under hyperlipidemia conditions as well as standard approaches including our established in vitro model systems for foam cell formation. The proposed studies will provide important insights into our understanding of the role of HIV-1 infection and immune activation in atherosclerosis.