In vitro inhibition of vesicular stomatitis virus replication by purified porcine Mx1 protein fused to HIV-1 Tat protein transduction domain (PTD)

• It is firstly reported the feasibility of recombinant pig Mx1 protein against VSV.
• This protein was performed in pCold prokaryotic expression system.
• This protein was fused to HIV-1 Tat PTD and could entry into VSV-infected cells.
• PTD-poMx1 could reduce viral titers in VSV-infected cells.
• PTD-poMx1 will be applicable to virus inhibition as a clinical therapeutic drug.

Vesicular stomatitis virus (VSV) is the causative agent of Vesicular stomatitis (VS), a highly contagious fatal disease of human and pigs. Few effective antiviral drugs are currently available against VSV infection. Mx proteins are interferon (IFN)-induced dynamin-like GTPases present in all vertebrates with a range of antiviral activities. Previous studies have shown that the transfected cell lines expressing either porcine Mx1 or human MxA acquired a high degree of resistance to VSV. To explore the feasibility of taking porcine Mx1 protein expressed in Escherichia coli as an antiviral agent, we applied the pCold system to express this fusion protein (PTD-poMx1), which consisted of an N-terminal HIV-1 Tat protein transduction domain (PTD) and the full-length porcine Mx1, and investigated its effects on the replication of VSV in Vero cells. The results demonstrated that the purified PTD-poMx1 fusion proteins could transduct into cells after incubated for 5 h and had no cytotoxic. Furthermore, plaque reduction assay, determination of TCID50, real-time PCR and Western blot analyses were carried out to confirm the antiviral activity of purified fusion proteins in VSV-infected Vero cells. Altogether, these data suggested that PTD-poMx1 fusion proteins might be applicable to inhibit VSV replication as a novel antiviral therapeutic agent.