Study of Bone Marrow Failure Caused by B19 Virus Infection

B19病毒感染引起骨髓衰竭的研究

基本信息

批准号：
8190805
负责人：
Jianming Qiu
金额：
$ 23.6万
依托单位：
UNIVERSITY OF KANSAS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-07-01 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8190805
关键词：
AIDS/HIV problem Acute Anemia Apoptosis Apoptosis Promoter Apoptotic Autonomous Replication Biological Assay Bone Marrow Caspase Cell Death Cells DNA biosynthesis Data Analyses Disease Dose Equilibrium Erythrocytes Erythroid Progenitor Cells Erythropoiesis Fetal Liver Fetus Homeostasis Human Human Parvovirus B19 Hydrops Fetalis Hypoxia Immunity Immunocompromised Host Individual Infant Infection Intravenous Immunoglobulins Kansas Knowledge Laboratories Lead Libraries Life Malignant - descriptor Mediating Molecular PTPN11 gene Pancytopenia Pathogenesis Pathway interactions Patients Pharmaceutical Preparations Play Production Proteins Pure Red-Cell Aplasia Recurrence Research Research Personnel Screening procedure Sickle Cell Anemia Signal Pathway Signal Transduction Symptoms System Time Transplant Recipients Universities Vaccines Viremia Virus Virus Diseases Work base caspase-10 cytotoxicity design drug candidate drug development experience fetal infection high throughput screening improved insight luminescence novel response small molecule small molecule libraries

项目摘要

DESCRIPTION (provided by applicant): Parvovirus B19 (B19V) infection causes human bone marrow failure by destroying the bone marrow resident erythroid progenitor cells (EPCs), which support autonomous replication of the virus. In patients with a high demand for erythrocyte production due to high levels of erythrocyte destruction (e.g., sickle-cell disease patients), acute B19V infection can cause transient aplastic crisis. In immunocompromised patients, persistent B19V infection may manifest as pure red-cell aplasia. In the fetus, B19V infection can cause hydrops fetalis, a severe form of anemia. B19V infection induces damage of EPCs, which results in the above bone marrow failures. B19V-infected EPCs undergo cell death with clear apoptotic features. This cell death is induced mainly by high expression of the non-structural 11kDa protein (11kDa) during infection, and involves a caspase cascade triggered by caspase-10. In the proposed research, we aim, firstly, to reveal the molecular mechanism underlying caspase-10- mediated apoptosis in response to 11kDa. To this end, we will determine which apoptotic pathway the extrinsic or the intrinsic activates the initiator caspase-10 during B19V infection-induced apoptosis. As both the apoptotic and anti-apoptotic pathways play key roles in erythropoiesis and the homeostasis of EPCs, we propose to identify the cellular proteins that interact 11kDa and transduce the apoptotic signal in EPCs. Secondly, having recently established a B19V culture system that mimics native B19V infection of human EPCs in bone marrow under hypoxic conditions, we will carry out high throughput screening (HTS) of a library of small molecules (available at the University of Kansas HTS Core Laboratory; contains over 100,000 druglike small compounds) for anti-B19V infection drug candidates. The B19V culture system can generate virus in sufficient quantity for such screening, and the cell death marker can be readily applied to assess B19V infection as a readout. We will use a cell-based luminescent cytotoxicity assay to screen the library. Because B19V vaccine is currently unavailable, and immunocompromised patients would be unable to respond to a vaccine, there are currently no viable treatment options for diminishing the bone marrow failure caused by B19V infection in patients with acute or persistent B19V infection. The study proposed in this application is expected to identify targets for the development of drugs capable of eliminating B19V from human EPCs, and this will ultimately lead to diminished bone marrow failures in these patients. In addition, our analysis of the mechanism underlying apoptosis of EPCs is expected to reveal pathways that may be involved in erythropoiesis or the disruption of erythropoiesis under certain disease conditions. PUBLIC HEALTH RELEVANCE: Human parvovirus B19 is pathogenic to humans, causes bone marrow failure in some severe circumstances. Study of B19 infection-induced cell death will help us to understand the mechanism of B19 caused bone marrow failure in general. Our proposed work will thus answer critical questions in the pathogenesis of parvovirus B19 infection, and have the potential to identify candidates of anti-B19 drugs for treating B19 infection-caused bone marrow failure.

描述（由申请人提供）：细小病毒 B19 (B19V) 感染通过破坏支持病毒自主复制的骨髓驻留红系祖细胞 (EPC) 导致人类骨髓衰竭。对于因红细胞破坏程度较高而对红细胞生成有较高需求的患者（例如镰状细胞病患者），急性 B19V 感染可导致短暂的再生障碍性危象。在免疫功能低下的患者中，持续的 B19V 感染可能表现为纯红细胞再生障碍性贫血。在胎儿中，B19V 感染可导致胎儿水肿，这是一种严重的贫血。 B19V感染会诱导EPCs损伤，从而导致上述骨髓衰竭。 B19V 感染的 EPC 发生细胞死亡，并具有明显的凋亡特征。这种细胞死亡主要是由感染过程中非结构 11kDa 蛋白 (11kDa) 的高表达引起的，并涉及由 caspase-10 触发的 caspase 级联反应。在拟议的研究中，我们的目标首先是揭示 caspase-10 介导的细胞凋亡响应 11kDa 的分子机制。为此，我们将确定在 B19V 感染诱导的细胞凋亡过程中，外源性或内源性哪种凋亡途径激活起始 caspase-10。由于凋亡和抗凋亡途径在红细胞生成和 EPC 稳态中发挥着关键作用，我们建议鉴定与 11kDa 相互作用并在 EPC 中转导凋亡信号的细胞蛋白。其次，最近建立了一个 B19V 培养系统，模拟缺氧条件下骨髓中人类 EPC 的天然 B19V 感染，我们将对小分子文库（可在堪萨斯大学 HTS 核心实验室获得）进行高通量筛选（HTS） ; 含有超过 100,000 种药物样小化合物），用于抗 B19V 感染候选药物。 B19V 培养系统可以产生足够数量的病毒用于此类筛选，并且细胞死亡标记可以很容易地应用于评估 B19V 感染作为读数。我们将使用基于细胞的发光细胞毒性测定来筛选该文库。由于目前尚无 B19V 疫苗，且免疫功能低下的患者无法对疫苗产生反应，因此目前尚无可行的治疗方案来减少急性或持续性 B19V 感染患者因 B19V 感染而导致的骨髓衰竭。本申请中提出的研究预计将确定开发能够从人类 EPC 中消除 B19V 的药物的靶标，这最终将减少这些患者的骨髓衰竭。此外，我们对 EPC 凋亡机制的分析有望揭示在某些疾病条件下可能参与红细胞生成或红细胞生成破坏的途径。公共卫生相关性：人类细小病毒 B19 对人类具有致病性，在某些严重情况下会导致骨髓衰竭。对B19感染诱导的细胞死亡的研究将有助于我们了解B19引起骨髓衰竭的一般机制。因此，我们提出的工作将回答细小病毒 B19 感染发病机制的关键问题，并有可能确定用于治疗 B19 感染引起的骨髓衰竭的抗 B19 药物的候选药物。