The role of surfactant protein-A genetic variant and sex in pathogenesis of neonatal respiratory syncytial virus infection

项目概要：本K 08提案描述了一个5年研究和培训计划， Chintan Gandhi博士转变为肺部先天免疫和宿主领域的独立研究员 防御甘地博士正在建立自己作为一个基础和翻译研究人员专注于先天免疫 对呼吸道感染的反应，重点是呼吸道合胞病毒（RSV）。虽然RSV是 病毒性呼吸道疾病是全世界儿童死亡的主要原因，目前还没有病毒特异性 现有的疫苗或治疗方法。这部分是由于对相互作用的不完全理解 病毒和未成熟的宿主免疫系统之间的联系初次感染的年龄和男性是独立的 RSV严重程度的风险因素。表面活性剂蛋白A（SP-A）是一种先天性免疫蛋白，调节吞噬细胞和 肺泡巨噬细胞（AM）的炎症功能通过表面活性剂蛋白-A-受体210（SP-210）来调节。 R210）。SP-A遗传变异和低水平SP-A与RSV严重程度相关。甘地博士报告说， 儿童中年幼和SFTPA 2的1A 0变体（SFTPA 2 - 1A 0）与RSV严重程度的相关性。的 这一建议的重点是调查这些协会使用人性化的潜在机制， 携带SFTPA 2 - 1A 0变体的RSV转基因新生小鼠模型。核心假设是SP- 遗传变异和男性聚集在新生儿AM中导致SP-A/SP-R210通路失调 RSV清除延迟和过度炎症。将通过以下方式检验中心假设 具体目的：1）确定SFTPA 2 - 1A 0如何在体内调节雄性和雌性中AM对RSV的差异应答。 2）阐明SFTPA 2 - 1A 0介导的SP-A/SP-R210功能障碍的机制 在RSV清除途径中的作用，并确定外源性SP-A在新生儿RSV感染中的体内治疗作用。 这些研究将产生关于SP-A/SP-R210信号传导作为RSV中的新途径的重要信息 严重程度，也将确定是否SP-A，其受体，SP-R210，或SP-A/SP-R210的调节， 可能是RSV感染的未来治疗靶点。在颁奖期间，甘地博士将继续 发展他在免疫学、分子生物学和遗传学方面的专业知识。此外，甘地博士将开发 流式细胞术和显微镜方法研究病毒动力学的技能。多学科指导 为了确保该项目的成功，已经组建了一个团队，其中包括病毒生物学方面的专业知识， 发病机制和新型抗病毒药物的开发（Lukacher博士）;肺细胞纯化，培养 协议和先进的生命成像技术（Chroneos博士）;和性别差异的机制， 新生儿肺部疾病（Lingappan博士）。导师团队将指导甘地博士满足他的 通过直接研究经验、正式教学和参与职业生涯实现培训目标 发展机遇。本提案中所述的研究具有创新性，将是一项实质性的研究。 除了知识差距，并将帮助甘地博士成为一个独立的R 01资助的调查员。

Project summary: This K08 proposal describes a 5-year research and training plan that will facilitate the transition of Chintan Gandhi, MD to an independent researcher in the field of lung innate immunity and host defense. Dr. Gandhi is establishing himself as a basic and translational researcher focusing on innate immune responses to respiratory infections with a focus on the respiratory syncytial virus (RSV). Although RSV is the leading cause of mortality due to viral respiratory illnesses in children worldwide, there are no virus-specific treatments or vaccines currently available. This is partly due to an incomplete understanding of the interaction between the virus and the immature host immune system. Age at initial infection and male sex are independent risk factors for RSV severity. Surfactant protein A (SP-A), an innate immune protein, regulates phagocytic and inflammatory functions of alveolar macrophages (AMs) through the surfactant protein-A-receptor 210 (SP- R210). SP-A genetic variants and low levels of SP-A are associated with RSV severity. Dr. Gandhi reported associations of young age and the 1A0 variant of SFTPA2 (SFTPA2-1A0) with RSV severity in children. The focus of this proposal is to investigate the underlying mechanisms of those associations using a humanized transgenic neonatal mouse model of RSV carrying the SFTPA2-1A0 variant. The central hypothesis is that SP- A genetic variants and male sex converge to dysregulate the SP-A/SP-R210 pathway in neonatal AMs leading to delayed RSV clearance and excessive inflammation. The central hypothesis will be tested via the following Specific Aims: 1) determine how SFTPA2-1A0 regulates in vivo AM differential responses to RSV in male and female pups, and 2) elucidate mechanisms of the SFTPA2-1A0 mediated dysfunction of SP-A/SP-R210 pathway in RSV clearance and define in vivo therapeutic effects of exogenous SP-A in neonatal RSV infection. These studies will yield important information about the SP-A/SP-R210 signaling as a novel pathway in RSV severity and will also determine if SP-A, its receptor, SP-R210, or the modulation of the SP-A/SP-R210 pathway may be future therapeutic targets for RSV infection. During the award period, Dr. Gandhi will continue to develop his expertise in immunology, molecular biology, and genetics. In addition, Dr. Gandhi will develop skills in flow cytometry and microscopic approaches to study viral dynamics. A multidisciplinary mentorship team has been assembled to ensure the success of this project, and includes expertise in virus biology, pathogenesis, and development of novel antiviral agents (Dr. Lukacher); lung cell purification, culture protocols, and advanced life imaging techniques (Dr. Chroneos); and mechanisms of sex differences in neonatal pulmonary diseases (Dr. Lingappan). The mentorship team will guide Dr. Gandhi in meeting his training objectives through direct research experience, formal didactics, and participation in career development opportunities. The research described in this proposal is innovative and will be a substantive addition to the knowledge gap and will help Dr. Gandhi to become an independent R01-funded investigator.