Effect of exportin 1/XPO1 nuclear export pathway inhibition on coronavirus replication.

Nucleocytoplasmic transport of proteins using XPO1 (exportin 1) plays a vital role in cell proliferation and survival. Many viruses also exploit this pathway to promote infection and replication. Thus, inhibiting the XPO1-mediated nuclear export pathway with selective inhibitors has a diverse effect on virus replication by regulating antiviral, proviral, and anti-inflammatory pathways. The XPO1 inhibitor, Selinexor, is an FDA-approved anticancer drug predicted to have antiviral or proviral functions against viruses. Here, we observed that pretreatment of cultured cell lines from human or mouse origin with nuclear export inhibitor Selinexor significantly enhanced protein expression and replication of Mouse Hepatitis Virus (MHV), a mouse coronavirus. Knockdown of cellular XPO1 protein expression also significantly enhanced the replication of MHV in human cells. However, for SARS-CoV-2, selinexor treatment had diverse effects on virus replication in different cell lines. These results indicate that XPO1-mediated nuclear export pathway inhibition might affect coronavirus replication depending on cell types and virus origin.