Torpor effects on host response to pathogen

Hibernation, the use of prolonged torpor to depress metabolism, is employed by mammals to conserve resources during extended periods of extreme temperatures and/or resource limitation. Mammalian hibernators arouse to euthermy periodically during torpor for reasons that are not well understood but that may be related to immune processes. To determine if arousals facilitate host responses to pathogens, we used dual RNA-Seq to examine gene expression in a hibernating bat, the little brown myotis (Myotis lucifugus). During torpor, gene expression differed little between uninfected wing tissues and tissues infected with Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome. Upon arousal to euthermy, however, large changes in gene expression were observed, particularly in genes involved in host responses to fungal pathogens. These results support the view that torpor is a period of relative immune dormancy and suggest that periodic euthermic arousals partly exist to enable hosts to enhance responses to pathogens.