Dissertation Research: Within-host seasonal drivers of pathogen dynamics in a fruit bat reservoir

疾病往往遵循一定的规律：例如，通常会有一个流感季节，麻疹和水痘的发生周期也是众所周知的。解释通常涉及宿主（人类）运动和接触的模式。该项目将审查其他因素，如宿主状况（例如营养或生殖状况）的季节性变化如何影响疾病的传播。这项研究的重点是蝙蝠，它们是许多疾病已知或疑似的宿主和宿主。更多地了解宿主对疾病的耐受性将对预测和预防新的传染病至关重要。研究结果将增进对疾病风险和传播的了解，对人类健康产生直接影响。这些研究人员将继续与马达加斯加的科学家合作，为该国的人类和野生动物健康和保护作出贡献。该奖项将促进博士生的教育和培训，支持她开发一种新的宿主状况测量方法和改进的疾病动态模型。博士生将开设一门疾病动力学建模课程，并将继续与本科生进行研究。研究人员假设，脂肪组织的季节性波动是宿主对多种病毒、细菌和原生动物感染的病原体耐受与抵抗策略的基础。脂肪组织可能通过调节细胞内自噬过程介导病原体诱导的细胞内损伤并促进修复。这种调节将促进宿主对感染的耐受性。在资源匮乏的冬季，肥胖的减少可能导致自噬过程功能的下降，从而导致细胞内病原体诱导的损伤积累，从而需要免疫抵抗。研究人员将使用在对马达加斯加三种地方性果蝠进行为期18个月的病原体动态实地研究期间收集的血清样本来检验这些假设。他们将对数据集中每只蝙蝠的血清样本进行瘦素（一种由脂肪组织分泌的神经内分泌信号激素）的酶免疫测定，以量化肥胖。关于肥胖的数据将用于参数化一个新的宿主内模型，探索脂肪组织对病原体损伤控制的贡献。虽然季节性接触模式往往反映了人类感染的流行动态，但它们不足以解释病原体的持久性，以及在包括蝙蝠在内的一些重要野生动物宿主中观察到的疾病传播的季节性。

Diseases often follow regular patterns: there is commonly a flu season, for example, and regular cycles in the occurrence of measles and chicken pox are well known. Explanations usually involve patterns of host (human) movement and contact. This project will examine how other factors such as seasonal changes in host status (nutritional or reproductive status, for example) influence the spread of disease. The research focuses on bats, which are known or suspected hosts and reservoirs for a number of diseases. Understanding more about host tolerance to disease will be critical to predicting and preventing new infectious diseases. Results will improve understanding of disease risk and spread, with direct consequences for human health. The researchers will continue to work with scientists in Madagascar, contributing to human and wildlife health and conservation in that country. The award will advance the education and training of a doctoral student, supporting her to develop a new measure of host condition and improved models for disease dynamics. The doctoral student will develop a course in modeling disease dynamics and will continue to engage undergraduate students in the research. The researchers hypothesize that seasonal fluctuations in adipose tissue underlie a host's strategy of pathogen tolerance versus resistance for a diverse suite of viral, bacterial, and protozoan infections. Adipose tissues may mediate pathogen-induced intracellular damage and promote repair by regulating processes of intracellular autophagy. This regulation would promote host tolerance to infection. During resource-scarce winters, reductions in adiposity could lead to declining function in autophagic processes, allowing for accumulation of intracellular pathogen-induced damage that necessitates immune resistance. The researchers will test these hypotheses using serum samples collected during an 18-month field study of pathogen dynamics in three endemic fruit bats in Madagascar. They will conduct enzyme-immunoassays for leptin, a neuroendocrine signaling hormone secreted by adipose tissue, in serum samples of each individual bat in the dataset to quantify adiposity. Data on adiposity will be used to parameterize a new, within-host model exploring adipose tissue contributions to pathogen damage control. Although seasonal contact patterns often capture epidemic dynamics in human infections, they are insufficient to explain pathogen persistence, and the observed seasonality of disease transmission, in a number of important wildlife hosts, including bats.