Transcriptional Profiling Of Host Gene Expression In IBV-infected Chicken Kidney And Spleen And Mechanism Of Chicken Ifitm1 Inhibiting IBV And NDV Replication

Infectious bronchitis virus(IBV), a prototype of the Coronaviridae family, is an economically important causative agent of infectious bronchitis in chickens and cause acute and highly contagious upper respiratory tract infections that may lead to nephritis. Newcastle disease virus(NDV), a member of the family Paramyxoviridae, is one of the causes of avian highly contagious respiratory, enteric, and neurological diseases and economic losses in the poultry industry.In this study, we conducted global gene expression profiling of chicken kidney tissue after nephropathogenic IBV infection to better understand the interactions between host and virus. IBV infection contributed to differential expression of 1777 genes, of which 876 were up-regulated and 901 down-regulated in the kidney compared to those of control chickens and 103 associated with immune and inflammatory responses may play important roles in the host defense response during IBV infection. Interestingly, chicken IFITM1 was significantly up-regulated expression at kidney during IBV infection. Gene ontology category and KEGG pathway were analyzed. Differentially expressed genes were involved in signal transduction, cell adhesion, immune responses, apoptosis regulation, positive regulation of the I-kappa B kinase/NF-kappa B cascade and response to cytokine stimulus. In this study, a comparative analysis of global gene expression in chicken spleen tissue during IBV infection was performed to better understand the pathogenic mechanisms and host response. The early stage(24 and 48 h postinoculation) and late stage(time of death) of IBV infections in chickens were selected for study. In the early stage, the expression of several innate immune- and inflammatory-response-related genes was significantly upregulated. The inflammation-related genes were significantly more elevated in the late stage than in the early stage of IBV infection. Our results clearly show that the spleen is involved in the immune response to IBV infection, although this response is weaker in the late stage of infection than in the early phage. We present here the first transcription data regarding the chicken splenic and kidney response to IBV infection. This report extends our understanding of the mechanisms of IBV pathogenesis and the IBV-mediated immune responses.Interferon inducible transmembrane(IFITM) proteins are a recently discovered family of cellular anti-viral proteins that restrict the replication of a number of enveloped and nonenveloped viruses. IFITM proteins are located in the plasma membrane and endosomal membranes, the main portals of entry for many viruses. Biochemical and membrane fusion studies suggest IFITM proteins have the ability to inhibit viral entry, possibly by modulating the fluidity of cellular membranes.But little was known about chicken IFITM proteins. We show that the IFITM protein family was conserved during evolutionary history, but ch IFITM1 protein absence of YXX? motifs that promote their internalization into endolysosomes. Chicken IFITM1 was higher expression levels in the gastrointestinal tissue, liver and bursa of Fabricius, but lower expression levels in trachea, kidney, proventriculus, DF1 cell, LMH cell and CEF cell. IBV infection induced chicken IFITM1 up-regulated expression at trachea and kidney. Forthemore different IBV strains infection induced chicken IFITM1 up-regulated expression at kidney. NDV infection also induced chicken IFITM1 up-regulated expression at trachea, kidney and proventriculitis.We found that overexpression of IFITM1 proteins signi?cantly inhibited NDV and reduces viral titer in F48E9 infected DF-1cells. ch IFITM1 reduces IBV viral RNA in Vero cells but p value wasn’t significant difference. In addition, delete N-terminal and C-terminal region of ch IFITM1 influence antiviral activity; both 5’ ectodominant and the 3’ ectodominant are required for the antiviral activity, the 3’ ectodominant but not the 5’ ectodominant are more important for the antiviral activity. Furthermore, confocal microscopy confirmed that ch IFITM1 was diffusely expressed throughout the cytoplasm and didn’t colocalize with the LAMP1, but as we know h IFITM1 being predominantly cell surface expressed. Furthermore, we demonstrate that ch IFITM1 interacted with EIF5A1, which has the ability of inhibiting of NDV. Collectively, these findings first reported that the IFITM protein have the ability of inhibiting Paramyxoviridae virus and IBV replication in vitro, providing a potential candidate for the development of a new class of antiviral compounds to treat NDV infections and these results could facilitate the studies on the antiviral mechanisms of ch IFITM1.