PSXV-21 - Transcriptome analysis of chicken reveals the impact of Herpesvirus of Turkeys on bursa RNA expression in Marek’s disease virus infections

Marek’s disease virus (MDV) is an oncogenic herpesvirus that causes various clinical syndromes in chicken. MDV early infection induces a transient immunosuppression and harbored in B cells of the bursa during the cytolysis phase of its replication cycle. One of the most commonly used commercial vaccines is Herpesvirus of Turkeys (HVT), which is a nonpathogenic virus of domestic turkey and may influence the expression of RNA. The aim of this study is to characterize the regulation of bursa gene in MDV infections and the impact of HVT vaccination on RNA expression in MDV-infected chickens. We used RNA-seq on the bursa samples to compare the transcriptome differences among MDV-infected chickens, HVT-infected chickens, co-infected chickens and uninfected control groups at 4, 7, 14 and 21 days post infection. Meanwhile, we also compared the expression at three different time points to examine alterations in the expression pattern. The result of differential gene expression showed that 14 days post infection might be the point in time when HVT worked. At false discovery (FDR) < 0.05 and fold change (FC) ≥2, we found 745, 218 and 76 genes in MDV-infected chickens, HVT-infected chickens and co-infected chickens respectively as differentially expressed compared with control group and 713 genes between MDV-infected chickens and co-infected chickens at 14 dpi. KEGG and GO enrichment analysis showed that these genes were highly enriched for Lysosome, immune response, inflammatory response, plasma membrane and so on. Overall, these findings help to better understand host-pathogen interaction in the bursa and elucidate the mechanism how HVT contribute to resist MDV. Further investigation of the roles of these candidate genes and signaling pathways in the regulation of MDV-HVT interaction may lead new directions for the development of drugs or cultivation of highly MDV resistant chickens.