Despite great concern about the current global health threat of worms (helminths) in humans and domestic animals, we still don’t have a clear understanding about how ecological heterogeneity determines burdens, disease, or how to successfully control infections in variable populations. Most drug treatments are selected using data from laboratory animal systems such as inbred mice. While these models are essential for understanding the molecular and cellular responses to infection, they do not capture the variability inherent in natural populations, humans and animals alike. Our over- reliance on highly controlled, laboratory models may underlie some of our failures to adequately manage and assess the impact of infectious diseases in real-world settings, where individuals compete for food, mates and space; endure seasonal and spatial environmental variability, including regular bouts of food limitation; and are exposed to a vast array of parasites and pathogens. These sources of variation affect the dynamics of infection, host response and disease, and yet are missing in laboratory studies.
Over the past 10 years, we have established a wild mouse – parasite community system and developed the appropriate immunological tools to study the dynamics and consequences of parasite infection for host health, fitness and population dynamics under natural conditions. Furthermore, we have recently developed a wild-derived colony of wood mice and their naturally-infecting parasites, with which we can pair infection/coinfection experiments and varying experimental diets with the wild studies, allowing us to measure and compare immune responses in controlled settings with those in the wild. The aim of this interdisciplinary studentship is to use this ecologically-relevant mammalian model system, both in the field and in the lab, to understand how ecological and demographic heterogeneities affect the success or failure of disease control strategies.
Specifically, the student will aim to bridge the current divide between laboratory models and real-world systems by testing how ecological heterogeneity drives infection burdens, immunity and treatment success in (1) a wild mouse-parasite model that has been brought into the laboratory to conduct mechanistic experiments, paired with (2) the same species in their natural setting, bringing the vast laboratory immunological toolbox into the wild. Together this pairing in both the lab and natural setting provides a unique and powerful opportunity to understand the causes and consequences of ecological heterogeneity on infection, immunity and control.
The key questions of this interdisciplinary studentship are:
(1) How do ecological heterogeneities (e.g. sex, age, coinfection) affect infection dynamics in the wild versus controlled conditions?
(2) Does variation in demography and parasite exposure/infection determine the expression and efficacy of the immune response?
(3) Can an ecologically relevant model system improve our ability to design successful parasite control?
For publications and a broader perspective on the research, please see supervisors’ websites:
Amy Pedersen, http://www.biology.ed.ac.uk/research/groups/apedersen/index.html
Andy Fenton, https://www.liv.ac.uk/integrative-biology/staff/andrew-fenton/
Knowles, S.L., Fenton, A., Petchey, O, & Pedersen, A.B. (2013) Stability of within
host parasite communities in a wild mammal system. Proceedings of the Royal Society B. 280: 1762.
Pedersen, A.B. & Fenton, A. (2015). The role of antiparasite treatment experiments in
assessing the impact of parasites on wildlife. Trends in Parasitology, 31(5): 200-211.
Babayan, S. A., Liu, W., Hamilton, G., Kilbride, E., Rynkiewicz, E. C., Clerc, M., & Pedersen, A. B. (2018). The Immune and Non-Immune Pathways That Drive Chronic Gastrointestinal Helminth Burdens in the Wild. Front Immunol, 9, 56. doi:10.3389/fimmu.2018.00056