Respiratory syncytial virus fusion protein (antigenic site IV) (RSV F protein (site IV))

The Respiratory syncytial virus (RSV) fusion (F) protein is a type I integral membrane glycoprotein essential for viral entry and syncytia formation (McLellan et al., 2013, Science). It facilitates the fusion of the viral envelope with the host cell plasma membrane through a dramatic conformational change from a metastable pre-fusion state to a stable post-fusion state. Antigenic site IV is a specific, highly conserved epitope located on the head of the F protein that is accessible in both the pre-fusion and post-fusion conformations (McLellan et al., 2010, Nature Structural & Molecular Biology). Monoclonal antibodies targeting site IV, such as suptavumab, bind to this region to neutralize the virus and prevent infection. Although site IV is generally conserved across RSV A and B strains, specific mutations can confer resistance, as seen in clinical trials where certain strains were not neutralized (Simões et al., 2021, NEJM). This target remains a focal point for passive immunization strategies and vaccine design aimed at providing broad protection against RSV-related respiratory diseases. The structural stability of site IV makes it an attractive target for therapeutic antibodies, though its efficacy depends on the circulating viral genotypes.

Other names

RSV F protein site IVAntigenic site IV of RSV fusion glycoproteinRSV-F site IVFusion protein antigenic site IV

Neutralization of viral infectivity by binding to the F protein and inhibiting the membrane fusion process required for viral entry into host cells.