Avian Interferon-Inducible Transmembrane Protein Family Effectively Restricts Avian Tembusu Virus Infection

Chen, Shilong; Wang, Long; Chen, Jieying; Zhang, Lanlan; Wang, Song; Goraya, Mohsan U.; Chi, Xiaojuan; Na, Yang; Shao, Wenhan; Yang, Zhou; Zeng, Xiancheng; Chen, Shaoying; Chen, Ji-Long

In the present study, we examined the expression of key IFNs and IFITMs in host cells after ATMUV infection in vitro and in vivo. Interestingly, we observed that ATMUV infection could trigger duck innate immune response including robust expression of particular type I and type III IFNs and IFITM family proteins. Using DF-1 cell system, we found that knockdown of endogenous IFITM1 and IFITM3 by short hairpin RNA (shRNA) markedly enhanced ATMUV infection in host. However, silencing IFITM2 had no significant effect on ATMUV replication. Furthermore, overexpression of chicken or duck IFITM1 and IFITM3 could strongly inhibit the replication of ATMUV. These results reveal that avian IFITM1 and IFITM3 but not IFITM2 serve as the critical components of host innate immune defense against ATMUV infection.