IMMUNOPATHOGENESIS OF HANTAVIRUS PULMONARY SYNDROME

本项目的目的是确定汉坦病毒的发病机制 肺综合征（HPS），我们假设是由于免疫病理学 由汉坦病毒特异性免疫反应引发。 毛细血管渗漏 综合征发生在肺部的感染患者，增加 血细胞比容和血小板减少使人联想到毛细血管渗漏 综合征，血液浓缩和血小板减少症，在病例中观察到 登革出血热（DHF） 我们之前报道过， DHF患者的T细胞活化水平显著高于 没有并发症的登革热患者。 水平的可溶性 CD 8、可溶性IL-2受体和可溶性CD 4显著高于对照组。 登革出血热的儿童比单纯登革热的儿童。 这些 在临床和实验室测量的相似性， HPSD DHF综合征使我们假设HPS综合征是由以下原因引起的： 感染者肺部出现大量毛细血管渗漏综合征， 感染的靶器官中显著的T细胞活化的结果， 肺 与DHF不同，DHF通常发生在 先前感染过血清学相关的登革热病毒，HPS 似乎是一个主要的汉坦病毒感染的结果，在非免疫 但我们假设， 免疫发病机制相似。 我们已经开始确定汉坦病毒特异性T细胞反应， HPS患者 我们已经成功地分离出T细胞克隆， HPS患者，并已在FCV上确定了人CD 8 +T细胞表位 核衣壳蛋白，不与其他汉坦病毒交叉反应。 在所提出的实验中，我们将定义 肺组织、胸腔积液和肺内单核细胞浸润 HPS患者外周血细胞的表型鉴定 定义这些细胞的细胞因子产生和TCR使用 以及它们与病毒感染的肺内皮细胞的关系。 我们有 开发了鉴定特定细胞因子产生细胞的技术， 从病理标本中获得的冷冻组织。 我们将确定 从HPS患者获得的血液和胸膜液细胞是否具有 可检测的HV特异性细胞毒性T细胞活性。 我们将测量 肺组织、胸腔积液和 外周血定量PCR。 我们将评估结果是否 感染与免疫反应研究结果相关，和/或 病毒负担。 这些研究的结果应该提供 基本的，新的信息HPS的发病机制，并作为一个 考虑预防治疗措施的依据。

The purpose of this project is to define the pathogenesis of the hantavirus pulmonary syndrome (HPS) which we hypothesize is due to immunopathology triggered by hantavirus specific immune responses. The capillary leak syndrome occurring in the lungs of the infected patients, the increase in hematocrit and decrease in platelets are reminiscent of the capillary leak syndrome, hemoconcentration and thrombocytopenia which is observed in cases of dengue hemorrhagic fever (DHF). We reported earlier that individuals experiencing DHF have significantly higher levels of T cell activation than do individuals experiencing uncomplicated dengue fever. Levels of soluble CD8, soluble IL2 receptors and soluble CD4 are significantly higher in children with DHF than in children with uncomplicated dengue fever. These similarities in clinical and laboratory measurements in patients with the HPSD DHF syndromes led us to hypothesize that the HPS syndrome is caused by massive capillary leak syndrome in the lungs of infected individuals as a result of marked T cell activation in the infected target organ which is the lung. Unlike DHF which usually occurs in individuals who have been infected previously with the serologically related dengue virus, HPS appears to be the result of a primary hantavirus infection in a non-immune individual but we hypothesize that the underlying mechanisms of immunopathogenesis are similar. We have begun to define hantavirus specific T cell responses in the patients with HPS. We have succeeded in isolating T cell clones from patients with HPS and have defined a human CD8+T cell epitope on the FCV nucleocapsid protein which does not cross-react with other hantaviruses. In the proposed experiments we will define the in vivo activity of mononuclear cell infiltrates in lung tissues, pleural effusions and in peripheral blood cells from patients with HPS by identifying the phenotype of these cells, defining cytokine production and TCR usage by these cells and their relationship to virus infected lung endothelial cells. We have developed techniques for identifying specific cytokine producing cells on frozen tissues obtained from pathological specimens. We will determine whether blood and pleural fluid cells obtained from patients with HPS have detectable HV-specific cytotoxic T cell activity. We will measure the virus burden in the same samples of lung tissues, pleural effusion and peripheral blood by quantitative PCR. We will assess whether the outcome of infection correlates with results of studies of immune responses and/or with virus burden. The results of these studies should provide fundamental, novel information on the pathogenesis of HPS and serve as a basis for consideration of prevention of therapeutic measures.