Targeted Transcriptome Analysis of Beef Cattle Persistently Infected with Bovine Viral Diarrhea Virus

Bovine viral diarrhea virus (BVDV) is an endemic virus of North American cattle populations with significant economic and animal health impacts. While BVDV infection has a myriad of clinical manifestations, a unique and problematic outcome is the establishment of a persistently infected (PI) animal following in utero viral infection. While it is well established that PI animals serve as a constant reservoir of BVDV, the mechanism for the maintained infection remains unknown despite multiple theories.

The purpose of this study was to use transcriptome analysis to investigate the long-term immune status of adult PI cattle and offer insight into the potential mechanistic establishment of persistent BVDV infection.

Peripheral blood mononuclear cells were collected from PI beef cattle (N = 6) and controls (N = 6) for targeted RNAseq analysis using 54 immune-related genes followed by pathway enrichment analysis.

Analysis revealed 29 differentially expressed genes (FDR < 0.05, fold change ≥ 2), representing 14 significant KEGG pathways between groups (FDR < 0.05). Transcriptome changes indicated chronic upregulation of interferon-gamma (IFNG) with an unexpected expression of related genes.

These results provide novel insight into understanding the adult PI immune system and indicate maintained stimulation resulting from virus-mediated dysregulation.