A bioenergetic approach to understanding how natural selection shapes strategies for host defense and pathogen evolution
Hosts deploy numerous mechanisms to defend themselves against pathogens — ranging from behavioral changes and immune cells to cultivating beneficial microbes. Because each defense targets various processes of the host-pathogen interaction (e.g., infection vs. pathogen growth vs. transmission), they carry critical implications for evolutionary epidemiology. Indeed, many common interventions (e.g., vaccines) directly target or mimic different host defenses (e.g., by blocking transmission). However, the net costs, benefits, and fitness consequences of these defenses (or interventions that target them) remains poorly resolved.
To address this challenge, my work takes a bioenergetic approach, examining the tension that arises from nutritional resources that fuel host defenses and pathogen growth and development. My work indicates that while ample resources can improve the recovery of individual hosts, population-level processes can override these individual-level benefits; higher resources can increase reproduction and total host density, increasing total transmission [Hite et al., 2018, in press, Hite and Cressler 2019, Hite et al., in prep]. This cross-scale approach offers key insights into how pathogens alter their host populations (and vice versa) and identifies key biology missing from classical theory, which typically focuses on either within-host or between-host processes and examines the effect of resources or immune functions, but not their interactive effects.
Dr. Sarah duRant (University of Arkansas)
Dr. Clay Cressler (University of Nebraska)
Dr. Kristi Montooth (University of Nebraska)
Alaina Pfenning (University of Nebraska)
Dr. Justin Buchanan (Vanderbilt University)
1. Hite J.L., A. Pfenning, and C.E. Cressler. In press. Starving the Enemy? Feeding behavior shapes host-parasite interactions. Trends in Ecology and Evolution.
2. Hite J.L. and C.E. Cressler. In press. Parasite-mediated anorexia, dietary context, and the evolution of virulence. Integrated and Comparative Biology.
3. Strauss, A.T., Hite, J.L., Civitello, D.J., Shocket, M.S., Cáceres, C.E., and S.R. Hall. Genotypic covariation in mechanistic, non-nonlinear components of parasite transmission. In revision at Proc B.
4. C.E. Cressler, Hite J.L., S.R. Hall, M.A. Duffy, and C. Searle. In prep. Dynamic energy-budget models illustrate how pathogen-mediated anorexia shapes host and pathogen fitness.
5. J.L. Hite, C.E. Cressler, and S.A. duRant. In prep. Resources shape host strategies for resistance and tolerance and drive pathogen virulence: A case study in avian conjunctivitis.