Peripheral transcriptional responses to experimental SARS-CoV-2 inoculation in North American Elk cows and calves

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a health risk for humans and other domestic and wildlife species. Recently, North American elk has been identified as seropositive for SARS-CoV-2, thus posing a potential threat to humans and other mammals. In this work, we characterized the peripheral transcriptomic response to experimental SARS-CoV-2 infection in calves and adult elk. Results Significantly differentially expressed genes were identified at 2, 5, and 14 days post inoculation (dpi) for both age groups. Adult elk presented the greatest number of differentially expressed (DE) genes at all time points, including many genes associated with the viral response, immune activation, and antibody production, those associated with coronavirus disease (COVID-19), and coronavirus GO terms and KEGG pathways. Calves presented DE genes associated with viral responses at 5 dpi as well as neurodegenerative-associated genes at 14 dpi. Both adults and calves showed predicted activation of the ISGF3 and IFN type I pathways at 2 dpi and, globally, increased activity related to the coronavirus pathway disease at 5 and 14 dpi. Conclusions Collectively, this work provides valuable data characterizing the immune response of elk to viral diseases as well as the response of wildlife to SARS-CoV-2 infection.