DISSERTATION RESEARCH: Ecologically variable immunity and its consequences for parasite dynamics

预测疾病流行的研究人员的一个重要目标是了解导致疾病流行的寄生虫如何在宿主群体中移动。在对流行病进行预测时，人们会考虑易感宿主和受感染宿主之间如何以及何时接触，但他们通常不会考虑寄生虫进入宿主体内后会发生什么。然而，宿主和寄生虫之间的内部斗争也可能是疾病传播的重要因素。这些寄主内部的战斗之所以发生，是因为寄主的身体不断抵抗和防御寄生虫。在预测疾病动态时，考虑这些动态是很重要的，因为并不是所有的宿主都有同样的能力来抵御寄生虫和疾病。最终，免疫力较低的宿主更有可能允许寄生虫传播。在这个项目中，研究人员将专注于一种生活在湖泊中的无脊椎动物的种群，在这些湖泊中，它们每年都会经历大规模的寄生虫流行。研究人员将通过将关于免疫变化如何影响疾病传播的信息与宿主对宿主的联系信息结合起来，来提高我们对疾病传播的理解。该项目的结果将帮助科学家更好地了解寄生虫感染人类、农场动物和野生动物种群时免疫防御的重要性。它还将使研究生的培训成为可能，并支持旨在鼓励少数族裔、女性和低收入本科生和小学生参与科学的项目。我们对自然人口中生态和免疫因素如何相互作用以确定个人感染概率和随后的总体疾病流行率的了解仍然有限。这项研究利用一个模型宿主-寄生虫系统(水蚤宿主和真菌寄生虫)，研究了免疫功能的潜在机制，以及可变免疫对寄生虫传播的影响。具体地说，研究人员将研究环境应激源(如资源质量和可获得性)如何影响自然水蚤种群免疫功能的平均水平和变异。然后将量化这些人群中高毒力寄生虫的建立和传播，同时跟踪每个人群的暴露水平和随着时间的推移感染成功。这项研究依赖于多个学科的工具，包括生态学、数量生物学、转录学和免疫学。此外，该项目整合了疾病生态学和生态免疫学的理论，以检查跨尺度的疾病过程：从基因组到个人，再到人口和社区。

An important goal of researchers who predict disease epidemics is to know how the parasites that cause them move through a population of hosts. In making predictions about epidemics, people consider how and when susceptible and infected hosts come into contact with one another, but they generally do not consider what happens after the parasite gets inside its host. However, the within-host battles between host and parasite could also be important for disease spread. These within-host battles happen because a host's body is constantly resisting and defending against parasites. It is important to consider these dynamics in predicting disease dynamics because not all hosts are equally equipped to fend off parasites and diseases. Ultimately, hosts that have lower immunity are more likely to allow parasites to spread. In this project, the researcher will focus on populations of an invertebrate that lives in lakes in which they experience large parasite epidemics every year. The researcher will improve our understanding of disease spread by incorporating information about how variability in immunity affects it with host-to-host contact information. The results of this project will help scientists better understand the importance of immune defenses when parasites infect humans, farm animals, and wildlife populations. It will also enable the training of a graduate student, and support projects aimed at encouraging underrepresented minority, female and low-income undergraduate and grade school students to be involved in science.Our understanding of how ecological and immunological factors interact in natural populations to determine both an individual's probability of infection and the subsequent overall disease prevalence remains limited. Working with a model host-parasite system (Daphnia host and fungal parasite), this research examines the mechanisms underlying immune function, as well as the consequences of variable immunity for parasite transmission. Specifically, the researcher will examine how environmental stressors (e.g. resource quality and availability) shape natural Daphnia populations' mean levels of and variation in immune function. The establishment and spread of the highly virulent parasite within these populations will then be quantified, while tracking each population's levels of exposure and infection success through time. The research relies on tools from multiple disciplines, including ecology, quantitative biology, transcriptomics, and immunology. Moreover, the project integrates theories from disease ecology and ecological immunology to examine disease processes across scales: from the genome, to the individual, to the population and community.