Investigation of Neonatal Influenza Pathogenesis

描述(申请人提供)：凯里博士是一名新生儿专家，在德雷克塞尔大学医学院兼任儿科学和微生物学/免疫学助理教授。她目前的调查工作旨在阐明早产儿呼吸道病毒感染发病率和死亡率的致病机制。新生儿面临着最高的感染死亡率和发病率之一。根据世界卫生组织的数据，2010年有370万名出生28天以下的新生儿死亡，其中37%死于感染原因1。具体地说，流感感染每年导致许多人住院和死亡，主要是儿童和老年人。关于新生儿对流感病毒的死亡率增加的原因，几乎没有数据，尽管我们知道他们没有成年人所拥有的成熟、完整的免疫系统。为了研究这种死亡率的增加，我们建立了一个与临床相关的新生小鼠流感病毒感染模型。我们希望阐明发病增加的机制，以开发针对极脆弱但未被研究的人群的治疗干预措施。在我们的前期工作中，我们确定当3日龄的小鼠感染流感时，死亡率很高，到感染后8天接近80%。与成年犬相比，幼崽感染后立即肺部的病毒含量更高。这种早期病毒控制的丧失不能归因于病毒特异性T细胞免疫，因为它是在成人或新生儿 在肺部安装免疫优势的病毒特异性CD8+T细胞反应。这表明新生儿的肺部先天宿主反应与成人的有本质的不同。通过使用我们的新生小鼠模型，我们正在提议进行研究，以确定新生小鼠对流感病毒感染的反应方式的关键差异。随着我们对这一情况的进一步研究，我们提出了两个研究目标：1)确定感染的新生小鼠肺细胞和成年小鼠肺细胞中基因激活的差异。通过使用一种新型的表达绿色荧光蛋白的重组流感病毒(PR8-GFP)和下一代RNA测序(RNAseq)的转录组分析，我们将检测新生儿肺上皮细胞和肺泡巨噬细胞对流感病毒感染的反应是否与成人细胞不同。2)确定提供益生菌是否有助于保护新生小鼠 不受流感感染。根据其对成人呼吸道感染的影响，我们假设微生物群与乳杆菌等益生菌一起定植可以改变对呼吸道病毒感染的免疫力，并可能作为一种潜在的治疗方法来帮助预防或减少婴儿呼吸道病毒感染的发病。然而，到目前为止，还没有关于鼻内益生菌用于婴儿呼吸道感染的调查。如果我们要开发针对流感病毒或其他呼吸道病毒的有效疫苗或疗法，获得更多关于新生儿免疫反应的知识是至关重要的。这一知识可能使我们能够开发针对病毒性呼吸道感染的新的治疗策略，以降低新生儿的发病率和死亡率。这项研究提案代表了实现候选人长期目标的关键一步：过渡到独立研究 职业生涯专注于早产儿呼吸道病毒致病机制的研究。除了拟议的研究，凯里博士还制定了一个多管齐下的培训计划，包括：授课课程、科学会议、临床服务和一支出色的指导团队。这项计划将培养她在生物统计学和免疫学方面的技能，磨练她对科学文献的批判性评论，培养她在国内和国际舞台上展示自己工作的能力，并获得管理实验室的能力。德雷克塞尔大学各院系的丰富资源和丰富的智力环境使这位候选人处于实现这一目标的有利地位。这一职业发展奖将成为凯里博士成功的动力，为这位候选人提供成为独立研究员所需的受保护的时间和额外的培训。

DESCRIPTION (provided by applicant): Dr. Carey is a Neonatologist and has a dual appointment as an Assistant Professor of Pediatrics and Microbiology/Immunology at Drexel University College of Medicine. Her current investigative efforts are directed towards elucidating the pathogenic mechanisms underlying morbidity and mortality of respiratory viral infections in the preterm infant. Neonates face one of the highest rates of mortality and morbidity from infection. According to the World Health Organization, 3.7 million neonates younger than 28 days of age died in 2010, and 37% of these deaths were due to infectious causes1. Specifically, influenza infection leads to many hospitalizations and deaths each year, mainly in children and the elderly. There are little data on why neonates exhibit increased mortality to influenza virus, although we know they do not have the mature, full immune repertoire that adults have at their disposal. In order to investigate this increased mortality, we have established a clinically-relevant model of neonatal influenza virus infection in 3-day old neonatal mice. We hope to elucidate mechanisms of increased pathogenesis in order to develop therapeutic interventions for an extremely vulnerable, but understudied, population. In our preliminary work, we determined that when 3-day old mice are infected with influenza, there is a high rate of death, approaching 80% by 8 days post infection. The amount of virus in the pup's lungs is higher immediately after infection as compared to adults. This early loss of viral control cannot be attributed to viral- specific T-cell immunity, as it is prior to the period when adults or neonates mount an immunodominant viral- specific CD8+ T-cell response in the lungs. This suggests that the lung innate host response in neonates is qualitatively different from that of adults. By using our novel neonatal mouse model, we are proposing studies to determine the critical differences in how the neonatal mice respond to influenza virus infection. As we investigate the situation further, we propose two research goals: 1) Determine differences in gene activation in infected neonatal mouse lung cells versus adult mouse lung cells. By using a novel recombinant Influenza virus that expresses Green Fluorescent Protein (PR8-GFP) and transcriptome analysis by Next Generation Sequencing of RNA (RNAseq), we will examine whether neonatal lung epithelial cells and alveolar macrophages respond differently to infection with influenza virus than adult cells. 2) Determine whether providing a probiotic will help protect neonatal mice from influenza infection. Based on its effects on adult respiratory infection, we hypothesize that microbiome colonization with probiotics like Lactobacillus can alter immunity to respiratory viral infection and may serve as a potential therapy to help either prevent or diminish the pathogenesis of respiratory viral infections in infants. However, up to this point, there have not been investigations into the use of intranasal probiotics for respiratory infections in infants. Attaining more knowledge of neonatal immune responses is essential if we are to develop effective vaccines or therapeutics against influenza virus or other respiratory viruses. This knowledge may allow us to develop novel therapeutic strategies against viral respiratory infections that reduce morbidity and mortality in neonates. This research proposal represents a critical step in attaining the candidate's long-term goal: to transition to an independent research career focused on mechanistic studies of respiratory viral pathogenesis in the preterm infant. In addition to the proposed research, Dr. Carey has formulated a multi- pronged training plan, including: didactic courses, scientific meetings, clinical service, and a superb mentoring team. This plan will build her skills in biostatistics and immunology, hone her critical review of the scientific literature, develop her ability to present her work in both the domestic and internationl arena, and acquire the ability to manage a laboratory. Continued access to the abundant resources and rich intellectual environment across departments and schools at Drexel University leave this candidate well-positioned to achieve this goal. This Career Development Award will serve as a driving force in Dr. Carey's success, providing the protected time and additional training required for this candidate to become an independent investigator.