Epstein-Barr virus glycoprotein 42 (gp42) (gp42)

Epstein-Barr virus glycoprotein 42 (gp42) is a critical viral envelope protein essential for the infection of B-lymphocytes (UniProt P0C6Z5). It functions as a co-receptor by binding to Human Leukocyte Antigen (HLA) class II molecules on the surface of B cells, which triggers the viral fusion machinery—comprising gH, gL, and gB—to allow viral entry (NIH, 2024). Interestingly, gp42 also acts as a molecular switch for viral tropism; while it is required for B-cell entry, its presence inhibits the infection of epithelial cells (Wikipedia). Beyond its role in entry, gp42 contributes to immune evasion by sterically hindering the interaction between T-cell receptors and HLA class II-peptide complexes, thereby impairing the host's adaptive immune response (PubMed, 1996). Due to its indispensable role in B-cell infection and its association with EBV-related malignancies like Burkitt's lymphoma and nasopharyngeal carcinoma, gp42 is a primary target for the development of novel vaccines and neutralizing monoclonal antibodies (NIH, 2019). Experimental therapies, such as the monoclonal antibodies A10 and 4C12, have shown promise in neutralizing the virus by blocking gp42's interaction with its receptor or inhibiting the fusion process (Immunity, 2024).

Other names

Glycoprotein 42BZLF2EBV gp42Human herpesvirus 4 gp42gp42

Neutralizing antibodies and vaccines target gp42 to block its binding to HLA class II receptors or to prevent the conformational changes in the gH/gL/gp42 complex required to trigger membrane fusion via gB.