Multi-omics profiling reveals infectious bursal disease virus-induced alterations in gene expression and metabolism in chicken bursa of fabricius.

Abstract

Infectious Bursal Disease (IBD) is an acute, highly contagious disease caused by IBDV, characterized by inflammation, atrophy of the Bursa of Fabricius, and immunosuppression. This study infected 21-day-old SPF chickens with three IBDV strains (classical YZ, very virulent AH, and variant SD). On day 7 post-infection, bursa samples were collected for transcriptomic and metabolomic analyses. Metabolite profiles were analyzed using multivariate statistics, and KEGG enrichment analysis was used to identify dysregulated pathways, elucidating the transcriptional and metabolic responses in IBDV-infected bursa tissue. Transcriptomic analysis identified 1733 DEGs in the YZ group, 5731 in the AH group, and 84 in the SD group. Gene Ontology clustering of common SDE genes between virus-infected and control groups focused on cellular components, molecular functions, and biological processes；KEGG enrichment showed they were mainly involved in lipid-related metabolic pathways for the three IBDV subtypes. Metabolomic analysis detected 460 significantly changed metabolites per subtype after IBDV infection. Lipid metabolism disorders were associated with IBDV, involving L-carnitine and other substances；KEGG analysis indicated the main pathways were lipid-related, like arachidonic acid (AA) metabolism. Moreover, this study verified mRNA levels of cytokines, NLRP3 protein level, and AA content. IBDV infection induces differential gene expression related to host immune response and metabolic regulation at the transcriptomic level, with metabolomic changes mainly involving lipid metabolism. Integrating transcriptomics and metabolomics provides a comprehensive understanding of the host's response to IBDV infection.