Bluetongue virus is an arbovirus that seriously harms ruminants such as sheep,this study aims to investigate the molecular mechanism of bluetongue virus infection and host cell interferon antiviral immune response.The study was conducted to characterize the mRNA expression of inter-feron pathway genes by real-time fluorescence quantitative PCR,as well as Western blot analysis of MDA5,TRAF3,RIG-Ⅰ,and TBK1 protein expression in BHK-21 cells induced by BTV with a multiplicity of infections(MOI)of 1 for 18,24,and 36 h.The results showed that the most pro-nounced changes in the expression of interferon signaling pathway genes were observed at 24 h of induction,the gene mRNA expression levels of the IFN-α,IFN-β,RIG-Ⅰ,TBK1,MDA5,VISA,and TRAF3 genes were upregulated.However,the mRNA expression levels of IKKε and TRAF6 genes were downregulated.At the protein level,MDA5 and TBK1 proteins were upregulated while RIG-1 and TRAF3 proteins were downregulated,which showed that BTV infection induces a typeⅠ interferon immune response in BHK-21 cells.This study lays the foundation for further exploring the antiviral immunity mechanism of IFN-Ⅰ signaling pathway regulatory genes in host cells infected with BTV infection.

Bluetongue virus (BTV) usually infects sheep, cattle, deer and other domesticated and wild ruminants through the bite of the vector insects, Culicoide, causing bluetongue (BT). BT in subtropical and even temperate regions poses a serious threat to the development and international trade of the livestock industry. This article introduced the structure and cellular invasion, and summarized the mechanisms of anti-BTV immune response of host cells and antagonism of host cell innate immune response by the non-structural proteins (e.g., NS3 and NS4) and structural proteins (e.g., VP3 and VP4) of BTV. This review provided a basis for understanding the antagonism mechanisms of BTV against the interferon (IFN) immune response in the host cell and the pathogenesis of BTV as well as for developing novel vaccines against this virus.
Bluetongue virus/immunology* ; Animals ; Bluetongue/prevention & control* ; Immunity, Innate ; Interferons/immunology* ; Sheep ; Viral Nonstructural Proteins/immunology* ; Cattle