Bovine Mx1 enables resistance against foot-and-mouth disease virus in naturally susceptible cells by inhibiting the replication of viral RNA

Abstract

Innate immunity, especially the anti-viral genes, exerts an important barrier function in preventing viral infections. Myxovirus-resistant (Mx) gene take an anti-viral role, whereas its eff ects on foot-andmouth disease virus (FMDV) in naturally susceptible cells are still unclear. Th e bovine primary fetal tracheal epithelial cell line BPTE-siMx1, in which bovine Mx1 gene was silenced, was established and treated with IFN alpha for 6 hr before FMDV infection. Th e copy numbers of the negative and positive strand viral RNA were determined by strand-specific real-time fluorescence quantitative RT-PCR. Th e TCID50 of BPTE-siMx1 cells increased at least 17-fold as compared to control cells BPTE-LacZ at 8 hr post infection, thus silencing of bovine Mx1 could promote the replication of FMDV. Th e amount of both the negative and positive strand viral RNA in BPTE-siMx1 cells significantly increased as compared to BPTE-LacZ cells, indicating that the replication levels of viral RNA were promoted by silencing bovine Mx1. Th e bovine Mx1 gene could provide resistance against FMDV in the bovine primary fetal tracheal epithelial cells via suppressing the replication of viral RNA.