Early transcriptome profile of goat peripheral blood mononuclear cells (PBMCs) infected with peste des petits ruminant's vaccine virus (Sungri/96) revealed induction of antiviral response in an interferon independent manner

Abstract

Sungri/96 vaccine strain is considered the most potent vaccine providing long-term immunity against peste des petits ruminants (PPR) in India. Previous studies in our laboratory highlighted induction of robust antiviral response in an interferon independent manner at 48 h and 120 h post infection (p.i.). However, immune response at the earliest time point 6 h p.i. (time taken to complete one PPRV life cycle), in PBMCs infected with Sungri/96 vaccine virus has not been investigated. This study was taken up to understand the global gene expression profiling of goat PBMCs after Sungri/96 PPRV vaccine strain infection at 6 h post infection (p.i.). A total of 1926 differentially expressed genes (DEGs) were identified with 616 - upregulated and 1310 - downregulated. TLR7/TLR3, IRF7/IRF1, ISG20, IFIT1/IFIT2, IFITM3, IL27 and TREX1 were identified as key immune sensors and antiviral candidate genes. Interestingly, type I interferons (IFNα/β) were not differentially expressed at this time point as well. TREX1, an exonuclease which inhibits type I interferons at the early stage of virus infection was found to be highly upregulated. IL27, an important antiviral host immune factor was significantly upregulated. ISG20, an antiviral interferon induced gene with exonuclease activity specific to ssRNA viruses was highly expressed. Functional profiling of DEGs showed significant enrichment of immune system processes with 233 genes indicating initiation of immune defense response in host cells. Protein interaction network showed important innate immune molecules in the immune network with high connectivity. The study highlights important immune and antiviral genes at the earliest time point.