Effect Of Host Factor IFI44 And IFI35 On Replication Of Vesicular Stomatitis Virus

Vesicular stomatitis(VS)is a highly contagious disease caused by the infection of vesicular stomatitis virus.It infects human beings and animals such as pigs,horses and cattle.VS is listed as one of 13 foreign animal diseases that are mainly prevented in the National Medium-and Long-Term Animal Disease Prevention and Control Program(2012-2020).Although VSV infection rarely leads to animal death directly,the decline of animal resistance,secondary infection and group transmission have brought great economic losses to livestock husbandry.VSV belongs to the family of rhabviridae and genus of vesicular viruses,its genome is single-stranded negative stranded RNA without segment.VSV mainly infects livestock and rodents through arthropod as a transmission medium,and could also infect human beings.After the livestock such as pigs and cattle are infected by VSV,blisters and ulcerations in the lips,tongue,nipples,hoofs are common symptoms.Because its clinical symptoms are similar to foot-and-mouth disease and vesicular stomatitis of pigs,careful identification is needed when the disease occurs.When an adult is infected with VSV,it will lead to subclinical or mild influenza like symptoms such as dizziness,nausea,muscle paralysis,etc.While children will induce serious encephalitis when they are infected with VSV.VSV has a wide range of cell tropism and can infect many types of cells.After infection,it displays complex interaction with host factors in the cell.It is reported that host cells would harness many mechanisms to fight against the invading virus through its factors.While VSV can also resist and escape from immune response of host cells by specific host factors after infection,so as to achieve survival and replication.Therefore,in-depth study on the disease from the perspective of interaction between host factors and viruses can not only help to reveal the pathogenesis of VSV,but also provide technical support for the healthy development of animal husbandry,and also has important significance for public health and safety.Interferon production is an effective way for host cells to fight against virus invasion.Previous studies have found that interferon-induced protein 44 is one of the protein products induced by interferon,which can be induced by IFN-? and ? type,and is located in the protein coding region of 1p31.Initially,it was found that ifi44 could affect the formation of microtubules in cells infected with hepatitis C virus(HCV).IFI44 is a cytoplasmic protein that contains a GTP binding domain,although it has no homology with GTPases or G protein.It was confirmed that when host cells were infected with H1N1 virus(a SSRNA virus),IFI44 could impair host antiviral response and promote viral replication by interacting with cellular FK506-binding protein 5(FKBP5).The above report firstly suggests that IFI44 can negatively regulate the antiviral response induced by the virus,suggesting that IFI44 may play an important role in balancing the excessive immune response and controlling the extent of IFN response.Therefore,this study aims to explore the role of IFI44 in the antiviral process of innate immune cells by studying the effect of IFI44 on VSV replication in macrophages.And also explore the potential role of VSV in the application as an oncolytic virus by studying the effect of IFI44 on VSV replication in tumor cells.Interferon-induced protein 35 is another protein product induced by interferon-?.IFI35 was initially identified by screening the c DNA library of He La cells stimulated by IFN-?,and it was found to be involved in the regulation of infection,innate immunity,inflammatory response and other pathological processes.It is reported that IFI35 has a negative regulatory effect on the anti-virus response of IFN in the process of VSV infection into He La and HEK293 cells,which inhibits the activity of retinoic acid induced gene I(RIG-I),impairs its role as RNA sensor in antiviral response,and inhibits IFN production and promotes VSV replication.Functional study of IFI35 opens up a new research field for the regulation of RIG-I antiviral signaling,and also proposes the importance of the negative regulation mechanism of cellular antiviral response.Therefore,this study aims to explore the role of IFI35 in the antiviral process of innate immune cells by studying the effect of IFI35 on VSV replication in macrophage.In the present study,we established Ifi44 silencing and overexpression cell lines by constructing the silencing and overexpression vectors of Ifi44 gene,packaging lentivirus and infecting macrophages and tumor cells respectively.Ifi35 silencing and overexpression cell lines were also established by constructing the silencing and overexpression vectors of Ifi35 gene,packaging lentivirus and infect macrophage.Real-time PCR and Western Blot were performed to investigate the effects of host factors Ifi44 and Ifi35 on VSV replication.The results showed that both IFI44 and IFI35 play a supporting role in the process of VSV replication.This study not only provides a basic theoretical basis for revealing the pathogenic mechanism of VSV,but also provides a new idea for exploring VS disease prevention and control.