Host-driven temperature dependence of deformed wing virus infection in honey bee pupae

Authors: PALMER-YOUNG, EVANS - Department Of Agriculture Government Of Sri Lanka; MARKOWITZ, LINDSEY - University Of Maryland; Evans, Jay

Submitted to: Communications Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2023
Publication Date: 3/27/2023
Citation: Palmer-Young, E.C., Markowitz, L.M., Evans, J.D. 2023. Host-driven temperature dependence of deformed wing virus infection in honey bee pupae. Communications Biology. 6(333):Article e333. https://doi.org/10.1038/s42003-023-04704-6.
DOI: https://doi.org/10.1038/s42003-023-04704-6

Interpretive Summary: Honey bees are able to manipulate the temperatures in their hives in response to the outside climate. There is some evidence that honey bees can also increase hove temperatures as a form of ‘social fever’ to reduce disease impacts. We tested this with viral infections in bees. We first described the temperature limits of a key protein for the widespread bee pathogen deformed wing virus. We then tested virus levels in infected bees raised at different temperatures. Surprisingly, virus infections were strong in bees across a wide range of tempeartures and only decreased at temperatures that were harmful to the bees thrmselves. Temperature extremes in honey bee hives can be used to treat disease, but do not show such promise for controlling honey bee viruses.

Technical Abstract: Temperature affects growth, metabolism, and interspecific interactions in microbial communities. Within animal hosts, gut bacterial symbionts can provide resistance to parasitic infections. Infection can also be shaped by host body temperature. However, the effects of temperature on the antiparasitic activities of gut symbionts have seldom been explored. The Lactobacillus-rich gut microbiota of facultatively endothermic honey bees is subject to seasonal and ontogenetic changes in host temperature that could alter the effects of symbionts against parasites. We used cell cultures of a Lactobacillus symbiont and an important trypanosomatid gut parasite of honey bees to test the potential for temperature to shape parasite-symbiont interactions. We found that symbionts showed greater heat tolerance than parasites and chemically inhibited parasite growth via production of acids. Acceleration of symbiont growth and acid production at high temperatures resulted in progressively stronger antiparasitic effects across a temperature range typical of bee colonies. Consequently, the presence of symbionts reduced both peak growth rate and heat tolerance of parasites. Results suggest that the endothermic behavior of honey bees could potentiate the effectiveness of gut symbionts that limit parasites’ ability to withstand high temperature, implicating thermoregulation as a reinforcer of core symbioses and possibly microbiome-mediated antiparasitic defense.