Effects Of Chicken CIS Gene On ALV-J Replication

Avian leukosis(AL)is avian infectious disease caused by avian leucosis virus(ALV).Among them,subgroup J avian leukosis virus ALV-J mainly causes the infection of chickens through horizontal and vertical transmission,which can cause immunosuppression of infected chickens,leading to increased mortality,tumor occurrence and reduced production performance.Feng Min had analyzed the transcriptomic data of ALV-J-invading MDM cells and found that the cytokine inducible SH2 containing protein may be associated with ALV-J infection.To explore the relationship between CIS protein and ALV-J,we used the ALV-J SCAU-HN06 strain as the experimental strain in this study.We analyzed the transcription level of the CIS gene in DF-1 cells with or without ALV-J infection.Results showed that the CIS gene transcriptional levels of infected DF-1 cells were significantly upregulated at 6,36,96,120 and 144 h post compared to the not infected cells.This result showed that ALV-J infection can significantly promote the transcription of the CIS gene,suggesting that this gene is associated with the infection and replication of ALV-J in DF-1 cells.The effect of the gene on ALV-J replication in the case of overexpression or knockdown was further investigated by constructing a CIS gene overexpression plasmid and specific si RNA.It was found that overexpression of the CIS gene promoted the virus replication in DF-1 cells.In contrast,the replication of ALV-J in DF-1 cells was inhibited when the expression of the CIS gene was knocked down.The CIS protein was a member of SOCS protein family.SOCS proteins are often used as negative regulators of the JAK-STAT pathway,subsequently affected the antiviral effects of interferon(IFN).Therefore,we further explore whether CIS proteins promote viral replication by affecting the expression of IFN and interferon-stimulated genes ISGs(ZAP,PKR and CH25H).Results showed that overexpression of CIS protein significantly down-regulated the expression of ch IFN-α/β and inhibited the transcription of ISGs.In contrast,expression of ch IFN-α/β and ISGs were significantly upregulated when the expression of the CIS gene was knocked down.For the first time,we discovered that ALV-J affects the antiviral effect of IFN by hijacking the expression of CIS gene in DF-1 cells,which is conducive to the continuous replication and infection of the virus itself in DF-1 cells.Further research is needed for how ALV-J affect the expression of CIS proteins.We also found that ALV-J infection can cause an increase trend of CIS transcription in chicken immune organ.Based on this study,we hypothesis that the abnormal expression of CIS gene in chicken caused by ALV-J infection may be associated with host immunosuppression.The mechanism remains to be further studied.