Host antiviral protein IFITM2 restricts pseudorabies virus replication.

Pseudorabies virus (PRV) is one of the most destructive swine pathogens and leads to huge economic losses to the global pig industry. Type I interferons (IFNs) plays a pivotal role in the innate immune response to virus infection via induction of a series of interferon-stimulated genes (ISGs) expression. IFN-induced transmembrane (IFITM) proteins, a group of ISGs, are important host self-restriction factors, possessing a broad spectrum of antiviral effects. They are known confer resistance to a variety of RNA and DNA viruses. However, little is known about the role of IFITMs in PRV infection. In this study, we show that IFITM is crucial for controlling PRV infection and that IFITM proteins can interfere with PRV cell binding and entry. Furthermore, we showed that IFITM2-mediated inhibition of PRV entry requires the cholesterol pathway. Collectively, these results provide insight into the anti-PRV role of IFITM proteins and this inhibition possible associated with the change of cholesterol in the endosome, further underlying the importance of cholesterol in virus infection.