The Epstein-Barr virus-encoded G protein-coupled receptor BILF1 upregulates ICAM-1 through a mechanism involving the NF-&x49b;B pathway

Although the Epstein-Barr virus (EBV) infection is usually asymptomatic, a primary encounter with the virus can cause mononucleosis. EBV infection is also strongly associated with lymphoma and epithelial cancers. The structure and infection mechanism of EBV have been well studied, but the EBV-encoded G protein-coupled receptor, BILF1, is not fully understood. Here, it was found that the EBVBILF1was expressed early in the viral lytic cycle and its ectopic expression strikingly upregulated the ICAM-1 expression in Raji cells. The positive effect of BILF1 on theICAM-1promoter was observed and the BILF1 deficiency attenuatedICAM-1promoter activity. Moreover, NF-kappa B binding sites were important for the regulation ofICAM-1promoter by BILF1. Furthermore, BILF1 reduced the constitutive level of the I & x49b;B-a protein and increased the amount of nuclear NF-& x49b;B in Raji cells. In conclusion, this study determined that BILF1 upregulated ICAM-1 in a mechanism involving NF-& x49b;B.