Respiratory syncytial virus fusion glycoprotein, antigenic site IV (RSV F site IV)

Antigenic site IV is a major neutralizing epitope located on the Respiratory Syncytial Virus (RSV) fusion (F) glycoprotein. It is a relatively conserved, linear epitope (residues 422-438) found in domain II of the F protein, and it remains accessible in both the pre-fusion and post-fusion conformations [1, 2, 5]. Antibodies targeting this site, such as the monoclonal antibody 101F and the clinical candidate clesrovimab (MK-1654), neutralize the virus by inhibiting the fusion of the viral envelope with the host cell membrane [2, 15, 21]. Because site IV is highly conserved across RSV subtypes (A and B) and even some other pneumoviruses like human metapneumovirus (hMPV), it is a key target for the development of broad-spectrum prophylactic and therapeutic agents [5, 22, 27]. Clesrovimab, a long-acting monoclonal antibody targeting this site, has shown significant efficacy in Phase 3 clinical trials for preventing RSV-associated lower respiratory tract disease in infants [15, 22].

Other names

Site IVSite CRSV F antigenic site IVRSV F site CAntigenic site IV of RSV F proteinRSHZ19 epitope

Neutralization of RSV by binding to the F protein and blocking the fusion of the viral envelope with the host cell membrane.