Mechanisms of Vascular Leakage in Viral Hemorrhagic Fevers

病毒性出血热的发病率和死亡率很大程度上是由血管渗漏和血管渗漏引起的。 随之而来的并发症。导致血管渗漏的机制还没有得到很好的描述。 该项目将继续研究登革热和汉坦病毒引起的血管渗漏是由 病毒刺激的内皮细胞对T细胞来源的炎性反应的时间和差异反应 血管生成介质。第一个目标将描绘早期激活的先天免疫信号通路 病毒刺激的人微血管内皮细胞导致I型干扰素的产生。I型干扰素 介导内皮屏障功能增强和抗血管生成作用。屏障功能将是 通过测量人微血管内皮单分子层对大分子的通透性进行评估 (70 kDa葡聚糖)和小分子溶质(3 kDa葡聚糖)在Transwell检测系统中。早期血管生成 对人微血管内皮细胞的影响将通过细胞/基质侵袭试验来衡量。第二 AIM将描述关键的抗病毒T细胞反应和表型，它们与内皮细胞相互作用并导致 渗透性增强。登革热病毒和汉坦病毒特异性的CD4+和CD8+T细胞将被激活 在各种条件下，并检测它们调节血管内皮生长因子的能力 上述体外试验中的信号、通透性和细胞侵袭性。第三个目标将衡量 汉坦病毒感染患者血液样本中的炎性和血管生成标志物。多路传输 选定的生物标志物的蛋白质免疫分析将在连续的每日血浆和尿液样本中进行 收集自普玛拉病毒(东半球汉坦病毒)感染患者。目标是开发一种 可预测疾病严重程度和血管渗漏发展的生物标记物“血管生成概况”。这个 这一“血管生成图谱”对病毒感染的微血管内皮细胞通透性的影响将在 体外培养。对登革热和汉坦病毒出血热发病机制中血管渗漏的认识 将导致针对这些病原体的新的诊断、治疗和预防方法。

The morbidity and mortality of viral hemorrhagic fevers are largely caused by vascular leakage and its ensuing complications. The mechanisms that lead to the vascular leakage have not been well characterized. This project will pursue the hypothesis that dengue and hantavirus-induced vascular leakage is caused by a temporal and differential responsiveness of virus-stimulated endothelium to T-cell derived inflammatory and angiogenic mediators. The first aim will delineate the early innate immune signaling pathways activated in virus-stimulated human microvascular endothelial cells that lead to Type I IFN production. Type I IFN mediates the enhancement of endothelial barrier function and anti-angiogenic effects. Barrier function will be assessed by measuring the permeability of human microvascular endothelial monolayers to macromolecules (70 kDa dextran) and small molecule solutes (3 kDa dextran) in a transwell assay system. Early angiogenic effects on human microvascular endothelium will be measured by a cell/matrix invasion assay. The second aim will delineate key anti-viral T-cell responses and phenotypes that interact with endothelium and lead to augmented permeability. Dengue virus and hantavirus-specific CD4+ and CD8+ T-cells will be activated under a variety of conditions and examined for their abilities to modulate vascular endothelial growth factor signaling, permeability, and cell invasion in the in vitro assays noted above. The third aim will measure inflammatory and angiogenic markers in blood samples from patients with hantavirus infections. Multiplex protein immunoassays for selected biomarkers will be performed on serial daily plasma and urine samples collected from patients with Puumala virus (Old World hantavirus) infections. The objective is to develop a biomarker "angiogenic profile" that can predict disease severity and development of vascular leakage. The effects of this "angiogenic profile" on virus-infected microvascular endothelium permeability will be tested in vitro. A better understanding of vascular leakage in dengue and hantavirus hemorrhagic fever pathogenesis will lead to new diagnostic, therapeutic, and preventive approaches to these pathogens.