R9AP is a functional receptor for Epstein-Barr virus infection in both epithelial cells and B cells

Epstein-Barr virus (EBV), also known as the first human tumor virus, is linked to nearly 200,000 new cancer cases and millions of non-malignant diseases per year. EBV infects both human epithelial cells and B cells, several virally encoded glycoproteins define tropism and mediate a complicated entry process. Here, we showed that R9AP silencing, genetic knockout or antibody blocking significantly inhibits EBV infection in both epithelial and B cells, while R9AP overexpression promoted EBV infection, establishing this protein as a previously unidentified, essential entry receptor for EBV. Mechanistically, R9AP directly binds to EBV glycoprotein gH/gL to mediate membrane fusion. Importantly, the interaction of R9AP with gH/gL was inhibited by the competition of AMMO1, a highly potent anti-gH/gL neutralizing antibody blocking EBV infection of both Epithelial cells and B cells. Further, treatment with an R9AP peptide encompassing the gH/gL binding site inhibited EBV infection in vitro and reduced viral loads in EBV infected humanized mice. Altogether, we proposed R9AP as the first characterized common cellular receptor for EBV infection of the major cell types and could serve as a potential target for novel interventional strategies. Gene expression in NPEC1-BMI and NPEC2-BMI2 cell lines.Each cell line was harvested as MLCs, SLCs or SLCs infected EBV respectively.