Characterization of seasonal CoV immunity and operationalization of a novel controlled human infection model for the betacoronavirus OC43

项目摘要 冠状病毒（CoV）是一种大型RNA病毒，具有很好的跳跃宿主物种的潜力。的 新出现的CoV的持续威胁需要对CoV免疫力进行彻底的了解， 为应对疫情做好准备。四种冠状病毒季节性传播，SARS-CoV-2进一步 证明了冠状病毒在一生中多次重新感染同一个体的能力。 冠状病毒再感染的发生是否由于病毒表位的进化或免疫记忆的减弱，以及 在宿主免疫中选择新的变异体仍然是理解CoV免疫的关键差距。 我的长期职业目标是成为一名独立和富有成效的CoV和流感研究人员 疫苗学，重点是受控人类感染模型（CHIM）。使用季节性CoV的CHIM OC 43具有低致病性和与严重CoV的结构相似性，将促进我们对 CoV免疫学研究，为泛CoV疫苗和治疗药物的研制提供基础 以备将来爆发。 在冠状病毒专家弗里曼博士和疫苗专家诺伊齐尔博士的指导下 开发和控制人类感染模型，我将追求这一目标，开发一个CHIM与 季节性冠状病毒OC 43。OC 43的2022分离株正在进行用于CHIM的开发。然而，在这方面， 评价对季节性CoV如OC 43的免疫力的测定历来受到相对 在细胞培养物中生长不良和缺乏结合测定的特异性。因此，在目标1中我将使用 假病毒开发功能性中和试验，以评估对季节性CoV的免疫力， 过去四十年的血清中和最近和较旧的OC 43假型病毒的能力。 这将提供一种机制，以更高的准确性快速评估季节性CoV中和， 抗体单独结合。在目标2中，我将以最近在马里兰州大学进行的流感CHIM为基础 探索受控制感染后个体内发生的流感突变的多样性， 对影响病毒多样性的宿主因素的新探索。病毒基因组分析平台， 目标2中的病毒多样性对于评估OC 43 CHIM期间病毒多样性的发展至关重要。在Aim中 3我将制定季节性CoV CHIM的方案，并仔细考虑安全性和终点， 将使我们能够评估预先存在的免疫力对有症状的感染，病毒脱落， 免疫反应的持续时间。 季节性CoV CHIM已经有40多年没有进行了，今天将使我们能够描述 保护的细胞和体液相关性，定义易感性的宿主介质，并直接评估 免疫力的持久性。该模型系统将成为评估防变异泛冠状病毒的重要工具 这些措施将为未来新型冠状病毒的出现做好准备。

Project Summary Coronaviruses (CoVs) are large RNA viruses with a well-demonstrated potential for jumping host species. The persistent threat of novel emergent CoVs necessitates a thorough understanding of CoV immunity and preparedness for outbreak response. Four CoVs circulate seasonally, and SARS-CoV-2 has further demonstrated the ability of coronaviruses to re-infect the same individual multiple times over a lifetime. Whether CoV reinfections occur due to evolving viral epitopes or waning immunologic memory, and the role of within host immunity for selection of novel variants remains a critical gap in understanding CoV immunity. My long-term career goal is to become an independent and productive investigator in CoV and influenza vaccinology, with a focus on controlled human infection models (CHIMs). A CHIM using the seasonal CoV OC43, with low pathogenicity and structural similarity to the severe CoVs, will advance our understanding of CoV immunology and provide a foundation for pan-CoV vaccine and therapeutic development in preparation for future outbreaks. Under the mentorship of Dr. Frieman, an expert in coronaviruses, and Dr. Neuzil, an expert in vaccine development and controlled human infection models, I will pursue this goal of developing a CHIM with the seasonal CoV OC43. A 2022 isolate of OC43 is undergoing ongoing development for use in a CHIM. However, the assays to evaluate immunity to seasonal CoVs such as OC43 have historically been limited by relatively poor growth in cell culture and lack of specificity by binding assays. Therefore, in Aim 1 I will use pseudoviruses to develop a functional neutralization assay to assess immunity to seasonal CoVs, evaluating the ability of sera from the past four decades to neutralize both recent and older OC43 pseudotyped viruses. This will provide a mechanism to rapidly evaluate seasonal CoV neutralization with greater accuracy than antibody binding alone. In Aim 2 I will build on a recent influenza CHIM conducted at the University of Maryland to explore the diversity of influenza mutations occurring within individuals after a controlled infection, providing novel explorations of the host factors that affect viral diversity. The viral genome analysis platform that we develop in aim 2 will be essential for evaluating the viral diversity that develops during an OC43 CHIM. In Aim 3 I will develop the protocol for a seasonal CoV CHIM, with careful consideration for safety and endpoints that will allow us to evaluate the effect of pre-existing immunity on symptomatic infection, viral shedding, and duration of immune response. A seasonal CoV CHIM has not been conducted for over 40 years, and today would allow us to characterize the cellular and humoral correlates of protection, define host mediators of susceptibility, and directly assess durability of immunity. This model system will be an essential tool for assessing variant-proof pan-coronavirus interventions and will provide preparedness for the emergence of future novel coronaviruses.