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

The Respiratory syncytial virus (RSV) fusion (F) protein is a critical surface glycoprotein that mediates viral entry into host cells by facilitating the fusion of the viral envelope with the host cell membrane [1]. Antigenic site VIII is a highly conserved epitope located on the pre-fusion conformation of the F protein (preF), which is the form of the protein present on the surface of infectious virions [2]. This site is the specific target of clesrovimab (MK-1654), an extended half-life monoclonal antibody developed for the prevention of RSV-associated lower respiratory tract disease in infants [3]. By binding to site VIII, clesrovimab neutralizes the virus and prevents the conformational change from the pre-fusion to the post-fusion state, which is essential for membrane fusion and subsequent infection [4]. Targeting site VIII is advantageous because the epitope is highly conserved across both RSV A and B strains, potentially offering broader protection and a higher barrier to resistance compared to other antigenic sites [5]. This target represents a significant advancement in passive immunization strategies against RSV, particularly for vulnerable pediatric populations [6].

Other names

RSV F protein site 8RSV F protein antigenic site 8Respiratory syncytial virus fusion protein site VIIIRSV F site VIIIMK-1654 epitope

Neutralization of viral fusion by binding to the pre-fusion conformation of the F protein and preventing the transition to the post-fusion state.