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

Five IFITM proteins have been identified in duck and chicken species including IFITM1, IFITM2, IFITM3, IFITM5, and IFITM10. IFITM1, IFITM2, and IFITM3 belong to the immunerelated clade, whereas non-immune IFITM5 and IFITM10 make up the two remaining clades (Blyth et al., 2015) . In this study, we observed that IFITM1 increase fold was much higher than those of IFITM2 and IFITM3 by in vivo and in vitro assays. This may be due to high basal expression of IFITM2 and IFITM3 in the cells tested. In addition, we cloned and characterized chicken and duck species of IFITM1 and IFITM3 genes. Despite sharing low amino acid identity between chicken IFITM1 and duck IFITM1 (45.11%) and high amino acid identity between chicken IFITM3 and duck IFITM3 (75.18%), both chicken and duck origin IFITM1 and IFITM3 could effectively restrict ATMUV replication. Certain key amino acids in IMD and CIL domain are conserved in chicken and duck IFITMs, suggesting their importance for functioning of the IFITMs (Smith et al., 2013) .