THE HUMAN VIROME IN CHILDREN AND ITS RELATIONSHIP TO FEBRILE ILLNESS

人类微生物组的定义是一个重要的科学优先事项。这项研究将扩大调查范围，将病毒纳入其中，病毒在传染病发病率和死亡率中占很大比例，尤其是在儿童中。该项目的长期目标是描述儿童中的人类病毒组，并研究其与儿童发热性疾病的相关性。该项目还将寻求了解免疫系统与病毒组组成的关系。因此，该项目的具体目标是：1）阐明可以使用健康儿童血液、呼吸道和胃肠道分泌物样本的无偏倚、高通量测序检测到的病毒谱，并将此信息用作理解病毒在没有明显来源的急性发热性疾病中的作用的基础，2）研究各种形式的免疫抑制对儿童中检测到的病毒谱的影响，并将此信息作为理解病毒在这些儿童发生的急性发热性疾病中的作用的基础。我们的初步研究表明，在未确诊的发热儿童中可以检测到多种病毒。为了实现具体目标，健康儿童将在进行择期手术之前入组，发热儿童将从圣路易斯儿童医院急诊科入组。免疫功能低下的儿童将从同一家医院的造血干细胞和实体器官移植诊所、艾滋病毒/艾滋病诊所和风湿病/免疫学诊所招募。 发热儿童将在发热性疾病发生时以及1个月和6个月随访访视时采集样本。将在华盛顿大学（GCWU）基因组中心使用下一代454高通量测序对每个研究组的选定样本进行分析，以检测并测序存在的所有病毒序列。我们预计检测和测序范围广泛的病毒，包括以前未识别的代理。将使用各种技术来研究检测到的病毒的意义。 将使用病毒特异性PCR检测试剂盒，使用采集的全部样本，通过测序确定检出病毒的频率和程度。将使用血清学分析、细胞因子分析和微阵列研究宿主对检出病毒的反应，以表征宿主基因表达。这些研究将利用随访样本比较急性反应与恢复期反应。这项研究将利用世界上最强大的测序中心之一的专业知识和技术资产，为研究界提供一个全面的儿童病毒序列数据库，可用于提高我们对幼儿发热性疾病原因的理解，其中许多疾病目前尚未诊断。公共卫生相关性：病毒是儿童发热性疾病的主要原因，但病毒性疾病的具体原因往往无法确定。该项目将确定存在于正常儿童和免疫系统受到抑制的儿童中的所有病毒，并将比较在发热性疾病期间发现的病毒与儿童健康时存在的病毒。这些信息将提供深入了解病毒在儿童发热性疾病中的作用，并将成为未来全面研究病毒感染对儿童健康影响的基础。

DESCRIPTION: Definition of the human microbiome is an important scientific priority. This study will expand the scope of the investigation to include viruses, which account for a substantial proportion of infectious disease morbidity and mortality, especially in children. The long-term goal of this project is to describe the human virome in children and to investigate its relevance to febrile illnesses in children. The project will also seek to understand the relationship of the immune system to the composition of the virome. Thus, the project's specific aims are 1) To elucidate the spectrum of viruses that can be detected using non-biased, high throughput sequencing on samples of blood, respiratory, and gastrointestinal secretions from healthy children and to use this information as a basis for understanding the role of viruses in acute febrile illnesses without an obvious source, and 2) to investigate the effect of various forms of immunosuppression on the spectrum of viruses detected in children, and to use this information as a basis for understanding the role of viruses in acute febrile illnesses occurring in these children. Our preliminary studies show that diverse viruses can be detected in children having undiagnosed fever. To carry out the specific aims, well children will be enrolled prior to having elective surgery, and febrile otherwise well children will be enrolled from the Emergency Department at St. Louis Children's Hospital. Immunocompromised children will be recruited from hematopoietic stem cell and solid organ transplant clinics, the HIV/AIDS clinic, and the rheumatology/immunology clinic from the same hospital. Children with fever will have samples obtained at the time of the febrile illness and at 1 and 6-month follow-up visits. Selected samples from each study group will be analyzed at the Genome Center at Washington University (GCWU) using next generation 454 high throughput sequencing to detect and sequence all viral sequences present. We anticipate detecting and sequencing a broad range of viruses, including previously unrecognized agents. A variety of techniques will be used to investigate the significance of viruses detected. Virus-specific PCR assays will be used to determine the frequency and extent of viruses detected by sequencing, using the full range of samples collected. Host response to the detected viruses will be investigated using serologic analysis, cytokine profiling, and microarrays to characterize host gene expression. These studies will take advantage of follow-up samples to compare the acute response with the response in the convalescent period. This study will draw upon the expertise and technological assets of one of the world's most powerful sequencing centers to provide the research community with a comprehensive sequence database of the viruses that are present in children, which can be used to improve our understanding of the causes of febrile illnesses in young children, many of which are currently undiagnosed. PUBLIC HEALTH RELEVANCE: Viruses are a major cause of febrile illness in children, but the specific cause of viral illnesses is often not determined. This project will define all of the viruses present in normal children and children whose immune systems are suppressed, and will compare the viruses found during periods of febrile illness with the viruses present when the children are well. This information will provide insights into the role of viruses in febrile illness in childhood and will be the basis for future comprehensive studies of the effects of viral infection on the health of children.