Alterations in Host Metabolism After Avian Reovirus Inoculation In Vitro and In Ovo

Abstract

Avian reovirus (ARV) is a virus that causes substantial concern for the poultry industry. This double-stranded RNA virus is ubiquitous worldwide and can cause diseases such as arthritis, tenosynovitis, runting-stunting syndrome, and enteritis. Increasing knowledge of host-pathogen interactions following ARV infection is a current priority for better controlling and preventing this disease. Metabolomics can improve the understanding of these interactions by assessing the metabolites present in infected samples and the changes in host metabolism induced by the infection. This study used ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to profile the metabolome of distinct chicken cell types and embryo organs after inoculation with ARV strain S1133 across various inoculation doses at different timepoint. An in vitro experiment was conducted using three different chicken cell types, i.e., primary chicken embryo liver (CELi) cells, chicken embryo kidney (CEK) cells, and leghorn male hepatoma (LMH) cells, inoculated with ARV S1133 at with either 10^3 or 10^5 tissue culture infectious dose 50 (TCID50) and a mock-inoculated group. Cells were collected at three timepoints at 12, 24, and 36 hours post-inoculation (hpi). For the in ovo experiment, embryonated specific-pathogen-free (SPF) eggs were inoculated at 18 days of embryonation with ARV S113 at the same two doses, along with a control group. Embryos were euthanized, and jejunum and liver samples were harvested at 24 and 48 hpi. Untargeted metabolomics analyses were performed on all samples. Results show that ARV inoculation reprograms host metabolism by altering metabolite concentrations and regulating pathways across samples. Pathway enrichment analysis identified purine metabolism as the most affected pathway across the sample types, showing significant enrichment (padj < 0.05) in LMH, jejunum, and liver samples. Several metabolites within this pathway, such as adenosine, inosine, hypoxanthine, guanosine, and guanine, were significantly altered, suggesting changes in nucleotide synthesis to support viral replication and host immune cells recruitment. Additionally, metabolism of pyrimidine, sphingolipid, and riboflavin also showed significance. Overall, these findings demonstrate that ARV reprograms host metabolism across different chicken models, highlighting purine metabolism as a key component of host-virus interactions and a potential target for further investigations into ARV pathogenicity and for improvements in control and prevention.