Using Caenorhabditis viruses to identify the ecological role of spillover outcome on the evolution of disease emergence

新的传染病的出现可能对许多生物体的健康产生重要影响。大多数新出现的疾病是当一个宿主物种的病原体感染一个新的宿主物种，然后进化出在宿主内良好复制和在宿主之间良好传播的能力。当病原体传播得足够好以无限期地留在新的宿主物种中时，这被称为疾病出现事件。这种现象也被称为“宿主跳跃”。防止宿主跳跃的关键在于识别与疾病出现相关的特征，以便及早采取行动阻止疾病的传播。然而，知识的因素，促进或防止主机跳转是有限的。这项研究旨在确定暴露后决定出现风险的条件。 这项研究的结果将与保护工作、粮食安全和人类健康直接相关。研究人员也将向公众广泛传播从这项工作中获得的知识。病原体可以根据溢出潜力进行分类。SP1病原体不能感染新的宿主。SP2病原体可以感染新的宿主，但不传播。SP3病原体可以感染新的宿主并传播，但不足以持续存在。这三类病原体中的任何一种，在适当的环境下，都可能进化成为成熟的病原体。目前的理论假设，SP3病原体的出现风险最高，其次是SP2，然后是SP1病原体。尽管有这些理论预测，但很少有实证研究探讨溢出类的出现风险如何变化。本研究将使用实验和理论方法来挑战这一理论。它将使用一种新的实验系统（小杆线虫宿主和原生于小杆线虫的病毒）来确定解释羽化成功率变化的潜在机制。elegans和C. briggsae）。 小杆线虫-病毒系统允许病原体在大的复制宿主群体中传播。此外，初步数据表明，宿主-病毒组合跨越SP1、SP2和SP3病原体的范围。 具体而言，该研究将首先描述小杆线虫宿主暴露于其非原生病毒后的病毒动态。第二，这项工作将描述小杆线虫宿主暴露于其非原生病毒后病原体的演变。最后，这项工作将开发连接病毒动力学和宿主跳跃成功的数学模型。（进化过程群）与整合有机体系统的划分（共生，感染和免疫计划）该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

The emergence of new infectious diseases can have important consequences for the health of many organisms. Most emerging diseases arise when a pathogen of one host species infects a new host species and then evolves the ability to replicate well within hosts and transmit well between hosts. When the pathogen transmits itself well enough to remain in the new host species indefinitely, this is referred to as a disease emergence event. This phenomenon is also known as a "host jump". Preventing host jumps depends critically on identifying traits associated with disease emergence so that actions can be taken early to stop the spread of the disease. However, knowledge of the factors that facilitate or prevent host jumps is limited. This research seeks to identify the conditions following exposure that determine risk of emergence. The findings of this research will have direct relevance for conservation efforts, food security and human health. The researcher will also widely disseminate the knowledge gained from this work to the public.Pathogens can be classified by spillover potential. SP1 pathogens are incapable of infecting new hosts. SP2 pathogens can infect new hosts but not transmit. SP3 pathogens can infect new hosts and transmit but not well enough to persist. Pathogens in any of these three categories could presumably, under the right circumstances, evolve to become established pathogens. Current theory assumes that emergence risk is highest for SP3, followed by SP2, followed by SP1 pathogens. Despite these theoretical predictions, little empirical work has explored how emergence risk varies by spillover class. This research will use experimental and theoretical approaches to challenge this theory. It will identify the underlying mechanisms that explain variation in emergence success using a novel experimental system (Caenorhabditis hosts and viruses native to C. elegans and C. briggsae). The Caenorhabditis-virus system allows for pathogen transmission in large, replicate host populations. Furthermore, preliminary data has shown that host-virus combinations span the range of SP1, SP2, and SP3 pathogens. Specifically, the research will first characterize virus dynamics following exposure of Caenorhabditis hosts to their non-native viruses. Second, the work will characterize the evolution of pathogens following exposure of Caenorhabditis hosts to their non-native viruses. Finally, the work will develop mathematical models connecting virus dynamics to host jump success.This project is jointly funded by the Division of Environmental Biology (Evolutionary Processes Cluster) and the Division of Integrative Organismal Systems (Symbiosis, Infection and Immunity Program).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.