IFITM1 is a host restriction factor that inhibits porcine epidemic diarrhea virus infection

Abstract

Abstract Interferon-induced transmembrane proteins (IFITMs) play an important role in the innate immune response triggered by viral infection. Porcine epidemic diarrhea virus (PEDV) is a pathogen causing intestinal infectious diseases in pigs. The current study provided overexpression of IFITM1 could suppress the proliferation of PEDV in IPEC-J2, while knockdown of it had opposite effect. Furthermore, co-localization of IFITM1 with PEDV virions could be observed, with the former mainly residing in the cytoplasm surrounding the nucleus, as revealed by IFA. Intriguingly, a phenomenon of IFITM protein embedded on the surface of virions was revealed by immunocolloidal gold electron microscopy. Moreover, we identified that the IFITM1 binds to the N protein of PEDV via CO-IP. Notably, Further investigations revealed that the CTD mutations of IFITM1 greatly compromised its inhibitory function on PEDV proliferation, with the amino acid residues 113 to 117 in this domain of it having a pronounced effect. Collectively, these findings suggest that IFTIM1 exerts an inhibitory function in PEDV infection, with the residues and structural motifs in the CTD of IFITM1 having fundamental effect on this modulatory actio.