Inhibitors of phosphatidylinositol 3-kinase and mTOR but not Akt enhance replication of bovine ephemeral fever virus

Non-segmented, negative-sense RNA viruses (NNSVs) depend on Akt (protein kinase B) for efficient replication. Infection with bovine ephemeral fever virus (BEFV) increases Akt phosphorylation. This study examined the effect of inhibition of phosphatidylinositol 3-kinase (PI3K)–Akt signalling on BEFV replication, since PI3K is the major upstream regulator of Akt. Treatment of BEFV-infected cells with two specific PI3K inhibitors (wortmannin and LY294002) enhanced replication of BEFV when compared to the effects of Akt inhibitors III and IV. BEFV antagonised the effects of PI3K inhibitors on Akt dephosphorylation. Inhibition of mTOR by rapamycin also enhanced replication of BEFV. The results provide evidences that inhibition of PI3K and mTOR has positive effects on replication of BEFV.