IntBIO: Collaborative Research: Integrated mechanisms of environment-host-virome interactions

In nature, encounters between humans and wildlife correlate with greater viral burdens in wildlife and therefore with higher risk of new viral pathogens spilling over into human populations. Yet, the factors contributing to this risk remain poorly understood, especially among highly mobile, but tightly packed populations of animals, such as cave-dwelling bats. Using the Egyptian fruitbat as a study system, this project seeks to understand how factors such as access to food, overall animal health, and responses to immune challenges influence each other in the wild to control the degree of viral infection in populations experiencing variable exposure to humans. The project will use highly integrative approaches to illuminate the fundamental biology of disease risk and to enhance the capacity to predict risks of viral spillover from bats to other wildlife or to humans. The project will also have broader impact on education and training by implementing an innovative active-learning experience, called “From the Bat Cave – Integrative Disease Research for Undergraduates”, in which postdoctoral researchers will learn to apply integrative research and mentoring methods to involve cohorts of undergraduate students in research and peer-peer mentoring through GBatNet, a NSF-funded international network of bat research groups. Human disruption of the environment is thought to play a central role in disease emergence in wildlife populations by reducing the availability of foods and refuge that animals rely upon, thereby stressing the animals and making them more susceptible to viruses. However, the mechanisms governing relationships among the environment, the wildlife host, and the viral communities they support are poorly known. To address this problem, the project will take advantage of a single cohesive wild system of Egyptian fruit bats (Rousettus aegyptiacus) to sample animals of different sex, age, and reproductive condition from caves that support different numbers of bats, are subject to variable levels of hunting, and are surrounded by different qualities of foraging habitat and hence food resources. Using each individual bat as the unit of observation, analyses will aim to relate landscape resources, and individual condition and immunity to viral profiles, thus answering three key questions: (1) how do host abundance, reproduction, age, and condition differentially or interactively influence viral diversity; (2) how do molecular immune mechanisms respond to environmental and physiological stressors in wild populations; and (3) how do gene expression profiles and viral infection influence one another in the wild? The results should allow links to be discerned that connect environmental gradients of human disturbance to virome diversity via organismal conditions, thereby providing essential new information for understanding disease dynamics in the wild, modeling risks, and thus preventing the next pandemic. Moreover, the project’s integrated and mechanistic systems approach to studying fundamental processes in disease emergence is expected to be generalizable across taxa at the human-wildlife disease interface.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.