Interactions between dengue 3 and human dendritic cells

描述（申请人提供）：每年有数百万生活在热带和亚热带地区的人感染登革热病毒。登革病毒（DV）感染在一些人中发展为严重的、威胁生命的血管渗漏综合征，称为登革出血热（DHF）。NIAID在其最近的新兴感染和生物防御倡议中将登革热列为A类优先病原体。宿主和病毒因素都有助于登革热感染的最终临床结果。本申请中描述的研究集中在从斯里兰卡登革热（DF）或DHF暴发中分离的登革热血清型3（DEN3）、亚型III分离株的集合。所有DEN3、III亚型病毒都非常密切相关（在核苷酸水平上>95%相同），但在系统发育研究中，DF和DHF流行病的分离株分为不同的遗传组。我们的假设是，DV和人类细胞之间的相互作用的差异负责DEN3基因型与斯里兰卡轻度和严重疾病流行的流行病学关联。在这项研究中，我们建议开发一种基于流式细胞术的检测方法，用于在人细胞中滴定DV和登革热感染。流式细胞术测定和其他测定将用于表征DEN3、亚型III分离株感染细胞的能力。具体而言，我们建议测试的假设，即从DF和DHF流行病的DEN3分离株不同的能力，感染人骨髓树突状细胞。这些探索性研究的结果将成为未来对DEN3，III亚型病毒分子发病机制进行更深入研究的基础。

DESCRIPTION (provided by applicant): Millions of people living in tropical and subtropical regions are infected by dengue viruses each year. Dengue virus (DV) infections in some people progress to a severe, life threatening vascular leakage syndrome known as dengue hemorrhagic fever (DHF). NIAID has classified dengue as a class A priority pathogen in its recent Emerging Infections and Biodefense Initiative. Both host and viral factors contribute to the ultimate clinical outcome of a dengue infection. The studies described in this application center around a collection of dengue serotype 3 (DEN3), subtype III isolates that have been isolated from dengue fever (DF) or DHF outbreaks in Sri Lanka. All DEN3, subtype III viruses are very closely related (>95% identical at the nucleotide level), yet in phylogenetic studies the isolates from DF and DHF epidemics separate into distinct genetic groups. Our hypothesis is that differences in the interactions between DV and human cells are responsible for the epidemiological association of DEN3 genotypes with mild and severe disease epidemics in Sri Lanka. In this study we propose to develop a flow cytometry based assay for titrating DV and following dengue infection in human cells. The flow cytometry assay and other assays will be used to characterize the ability of DEN3, subtype III isolates to infect cells. Specifically, we propose to test the hypothesis that the DEN3 isolates from DF and DHF epidemics differ in their ability to infect human myeloid dendritic cells. The results of these exploratory studies will be the basis of more in-depth future studies on the molecular pathogenesis of DEN3, subtype III viruses.