Tolerance and resistance responses of African bats to viral antigens: Immunological tradeoffs in zoonotic reservoir hosts.

摘要 该项目的重点是了解蝙蝠独特的生理学在其充当蝙蝠的能力中所发挥的作用。 是可能传染给人类的疾病的宿主。该项目将在现场条件下进行 在乌干达，针对三种蝙蝠进行了研究，这些蝙蝠与埃博拉病毒（EBOV）向人类的传播有不同的联系。由 这项工作比较了这三种蝙蝠应对埃博拉样免疫挑战的能力， 帮助识别导致溢出风险的特征。从长远来看，这项工作将有助于识别宿主 埃博拉病毒和其他对人类构成风险的相关病毒的物种。它还将有助于解释如何不同 不同种类的蝙蝠对不同类型的病毒感染有反应。该项目的主要重点是确定 使储存宿主能够耐受感染的行为和分子途径，提供了重要的见解 成为导致溢出的机制之一。这项工作是由一些蝙蝠物种的假设驱动的 与特定类型的病毒感染共同进化，因此具有适应机制以尽量减少 感染期间的病理。蝙蝠具有全球生物多样性，具有许多独特的生态和生理特性 适应能力，包括飞行以及利用低温和高温体温的能力 监管。该项目重点关注三种蝙蝠物种，因为它们与人类密切接触， 它们的栖息地覆盖了埃博拉病毒暴露风险的范围，并且它们具有不同的共同进化历史 病毒病原体；这三个物种中的两个与埃博拉病毒流行病学有显着联系。该项目地址 通过采取使用埃博拉病毒样病毒的创新方法，在现场自然条件下解决这些问题 颗粒作为生物危害病原体实验感染的代表。该项目有三项具体内容 能够实现其目标的目标。首先，该项目测试了特定非洲蝙蝠的假设 物种将表现出埃博拉病毒疾病耐受性的特征，以应对埃博拉病毒样病毒的挑战 颗粒，因此很可能是天然的储存宿主。这些实验将提供重要的见解 蝙蝠的疾病耐受性和埃博拉病毒储存库的潜在身份。其次，本项目测试 假设蝙蝠表现出不同水平的疾病耐受性，这取决于先天免疫途径 在蝙蝠中经历了独特的进化选择。第三，这个项目探讨了是否容忍 蝙蝠独特的代谢行为促进了对病毒感染的抵抗力，即它们可以 抑制新陈代谢并进入麻木状态以保存能量，并可以提高新陈代谢，从而提高体温 飞行期间。人们对体温变化的作用知之甚少，这些实验将确定 这些生理反应是否有助于重要的免疫耐受和抵抗 疾病储存库。总之，成功完成这些目标将有助于确定是否感染 耐受性赋予非洲蝙蝠物种作为剧毒人畜共患病毒储存宿主的能力 将确定有助于耐受表型的分子、生理和行为机制。

ABSTRACT This project focuses on understanding the role that the unique physiology of bats plays in their ability to act as host reservoirs for diseases that can spill over to humans. The project will be carried out under field conditions in Uganda on three species of bats that have varying links to the spread of Ebola virus (EBOV) to humans. By comparing the ability of these three species of bats to respond to Ebola-like immune challenges, this work will help identify the characteristics that contribute to spillover risk. In the long term, this work will help identify host species for EBOV and other related viruses that present risk to humans. It will also help explain how different species of bats respond to different types of viral infections. The main focus of this project will be to identify behaviors and molecular pathways that enable reservoir hosts to tolerate infections, providing critical insight into one of the mechanisms that leads to spillover. This work is driven by the hypothesis that some bat species have coevolved with particular types of viral infections and, therefore, have adapted mechanisms to minimize pathology during infection. Bats are globally biodiverse and have many unique ecological and physiological adaptations, including flight and the ability to employ both hypo- and hyperthermic body temperature regulation. This project focuses on three bat species chosen because they are in close contact with humans, their habitats cover the range of EBOV exposure risk, and they have divergent coevolutionary histories with viral pathogens; two of the three species have significant ties to EBOV epidemiology. This project addresses these questions under natural conditions in the field by taking the innovative approach of using EBOV virus-like particles as a proxy for experimental infection with biohazardous pathogens. This project has three specific aims that will allow the achievement of its goals. First, the project tests the hypothesis that specific African bat species will display signatures of EBOV disease tolerance in response to challenge with EBOV virus-like particles, and thus are likely to be natural reservoir hosts. These experiments will provide significant insight into disease tolerance in bats and the potential identity of EBOV reservoir(s). Second, this project tests the hypothesis that bats display variable levels of disease tolerance that depend upon innate immune pathways that have undergone unique evolutionary selection in bats. Third, this project explores whether tolerance of and resistance to viral infection are facilitated by the unique metabolic behaviors of bats, namely that they can depress metabolism and enter torpor to conserve energy and can elevate metabolism and thus temperature during flight. The role of changes in body temperature is poorly understood and these experiments will identify whether these physiological responses contribute to immunological tolerance and resistance in important disease reservoirs. Together, the successful completion of these goals will help determine whether infection tolerance confers on African bat species the ability to serve as reservoir hosts for virulent zoonotic viruses and will identify molecular, physiological, and behavioral mechanisms that contribute to tolerance phenotypes.