Dissecting global protective immune response to dengue virus at a single-cell resolution

登革热病毒（DENV）感染是一种蚊媒疾病，每年感染3.9亿人。尽管过去十年来感染病例急剧增加，但目前没有具体的治疗方法。已经开发出一种疫苗，但效力有限，并且已被证明在给予幼儿时会引起严重的副作用。据观察，一些感染病毒的人没有出现症状或出现非常轻微的症状并清除病毒，而其他人则出现发烧和严重症状，如出血和休克。在这里，我们的目标是比较感染者与没有这些有害症状，以更好地了解免疫系统的哪些部分负责清除病毒，哪些部分负责导致通常非常严重的症状，而没有有效地清除病毒。人类的“先天”免疫反应对一般的危险信号做出反应，例如在病毒感染期间产生的那些信号，而“适应性”免疫反应识别入侵者的形状并对其进行特异性反应。B和T淋巴细胞是适应性免疫应答的介质。每个T和B淋巴细胞携带一个独特的受体，能够识别感染因子的不同形状。因此，理想情况下，免疫反应需要在单细胞水平上进行研究。在Wellcome Trust桑格研究所（WTSI UK），最近开发了能够在单细胞水平上对免疫细胞进行分析的尖端技术。复杂的“转录组学”数据的产生，并成功地分析这种类型的大规模数据的计算工具，直到最近才被开发出来。我们现在建议将单细胞谱分析技术应用于在泰国组装的最全面的登革热患者队列之一，泰国是登革热病例的主要中心之一。通过鉴定患有和没有疾病的个体的免疫应答的特定差异，我们将（1）鉴定负责清除病毒的先天性和适应性免疫应答的特定细胞亚型，（2）提供B和T细胞中能够结合病毒的受体的分子描述。所获得的知识将有助于开发更有效的疫苗和抗病毒治疗。此外，该项目还将允许Mahidol大学（MU，泰国）开发一个单细胞分析平台，未来可用于研究其他传染病。

Dengue virus (DENV) infection is a mosquito-borne disease that infects 390 million people each year. Despite a sharp rise in the number of infected case over the past decade, there is currently no available specific treatment. A vaccine has been developed but is of limited efficacy and has been shown to cause severe side-effects when given to young children. It has been observed that some individuals who are infected with the virus either develop no or very mild symptoms and clear the virus, whereas other individuals develop fever and severe symptoms such as bleeding and shock. Here we aim to compare infected individuals with and without these harmful symptoms to better understand which parts of the immune systems are responsible for clearing the virus and which parts are responsible for causing the often very severe symptoms without clearing the virus effectively. Human "innate" immune response reacts to general danger signals such as those generated during a viral infection, whereas the "adaptive" immune response recognises the shape of an invader and mount a specific response against this. B and T lymphocytes are the mediators of the adaptive immune response. Each individual T and B lymphocyte carries a unique receptor that is able to recognise a different shape on the infectious agent. Therefore, ideally, immune responses need to be studied at the level of the single cell. At the Wellcome Trust Sanger Institute (WTSI UK), cutting-edge technology has recently been developed that is able to profile immune cells at the single cell level. Complex "transcriptomics" data are generated, and computational tools for the successful analysis of this type of large-scale data have only recently been developed. We now propose to apply single cell profiling techniques to one of the most comprehensive Dengue patient cohort assembled in Thailand, one of the main hubs of dengue cases By identifying specific differences in the immune response of individuals with and without disease, we will (1) identify the specific cell subtypes of both the innate and adaptive immune response that is responsible for clearing the virus, (2) provide a molecular description of the receptors in B and T cells that are able to bind the virus. The knowledge gained will help to develop more effective vaccines and anti-viral treatments. In addition, the project will allow Mahidol University (MU, Thailand) to develop a single-cell analysis platform that can be applied to study other infectious diseases in the future.