Respiratory syncytial virus fusion protein and human metapneumovirus fusion protein (RSV F / hMPV F)

The Respiratory Syncytial Virus (RSV) and Human Metapneumovirus (hMPV) fusion (F) proteins are critical Class I viral fusion glycoproteins that facilitate the entry of these viruses into host respiratory epithelial cells [10, 14]. These proteins are synthesized as inactive precursors (F0) that undergo proteolytic cleavage into disulfide-linked F1 and F2 subunits, which then assemble into metastable prefusion trimers on the viral surface [7, 10]. Upon triggering, the F protein undergoes a dramatic conformational rearrangement into a highly stable postfusion state, a process that drives the fusion of the viral envelope with the host cell membrane [1, 18]. Because the F protein is the primary target of the neutralizing antibody response and is highly conserved, it is the central focus for the development of vaccines and monoclonal antibody therapies [3, 19]. While several products are now approved for RSV—including the monoclonal antibodies palivizumab and nirsevimab, and prefusion-stabilized vaccines such as Arexvy and Abrysvo—hMPV remains a significant unmet medical need with no approved specific therapies [9, 15]. However, the structural homology between RSV F and hMPV F has enabled the identification of cross-neutralizing antibodies, such as MPE8 and RSV-199, which target conserved epitopes like antigenic site III [1, 6, 8]. These cross-reactive agents represent a promising strategy for providing broad protection against both viruses, which are major causes of severe respiratory disease, including bronchiolitis and pneumonia, in infants, the elderly, and immunocompromised populations [5, 12, 25].

Other names

RSV fusion proteinhMPV fusion proteinPneumovirus fusion proteinFusion glycoprotein F0RSV-FhMPV-FRespiratory syncytial virus F proteinHuman metapneumovirus F protein

Fusion inhibition, Viral neutralization, Viral entry inhibition