Cytomegalovirus virion surface antigens (CMV surface antigens)

Cytomegalovirus (CMV) virion surface antigens are a group of glycoproteins embedded in the viral envelope of Human Cytomegalovirus (HCMV), a member of the Betaherpesvirinae family (UniProt: P06473, P12824). The most prominent of these antigens include glycoprotein B (gB), the gH/gL/gO trimeric complex, and the gH/gL/UL128/UL130/UL131A pentameric complex (PubMed: 18480438). These proteins are critical for the viral life cycle, mediating the initial attachment to host cells and the subsequent fusion of the viral envelope with the host cell membrane. Specifically, the pentameric complex is essential for entry into epithelial, endothelial, and myeloid cells, while gB is a primary fusogen required for entry into all cell types (PubMed: 19196330). Because these antigens are the primary targets for neutralizing antibodies, they are the focus of therapeutic interventions, including monoclonal antibodies and vaccines like mRNA-1647 (ClinicalTrials.gov: NCT05085301). Drugs and vaccines targeting these surface antigens aim to prevent primary infection, reactivation, or vertical transmission from mother to fetus by blocking the virus's ability to infect new cells.

Other names

HCMV envelope glycoproteinsCMV surface proteinsHCMV virion antigensCMV glycoproteins

The primary mechanism of action involves the binding of antibodies to specific epitopes on the virion surface glycoproteins, such as glycoprotein B (gB) or the pentameric complex (gH/gL/UL128/UL130/UL131A). This binding neutralizes the virus by sterically hindering its ability to attach to host cell receptors or by preventing the conformational changes required for membrane fusion (PubMed: 18480438). Additionally, these antibodies can facilitate the clearance of viral particles through opsonization and induce antibody-dependent cellular cytotoxicity (ADCC) against infected cells (PubMed: 19196330).