Long-term persistent infection with equine arteritis virus is associated with the upregulation of specific CD8+ T lymphocyte transcription factors, inhibitory receptors, and the CXCL16/CXCR6 axis in the ampullae of the stallion reproductive tract

We performed whole transcriptome analysis of the ampullae, the primary site of EAV persistence, derived from long-term carrier stallions to understand the molecular signature of persistent infection. We demonstrated that long-term persistence is characterized by a local CD8+ T lymphocyte response predominantly driven by the transcription factors EOMES and NFATC2.We showed that EAV persistence is associated with an enhanced expression of CXCL16/CXCR6 in infiltrating lymphocytes. Furthermore, we established a link between the CXCL16 genotype and the gene expression profile at the site of persistence following EAV infection. Co-expression network analysis identified CXCL16 as a “hub” gene, likely driving a specific transcriptional network. Overall design: We have perfomed whole transcriptome sequencing (RNAseq) on 12 ampulla samples derived from naïve stallions (n=3), short-term equine arteritis virus carrier (n=6) and long-term equine arteritis virus carrier stallions (n=3). Findings were further confirmed by RT-qPCR and other experiments were performed to characterize the inflammatory response and the involvement of the chemokine CXCL16 and its receptor CXCR6. Gene expression was also analyzed based on the CXCL16 genotype (CXCL16S or CXCL16R).