Respiratory syncytial virus prefusion fusion glycoprotein (RSV preF glycoprotein)

The respiratory syncytial virus prefusion fusion glycoprotein (RSV preF) is a class I viral surface fusion protein and the principal mediator of RSV entry into host respiratory epithelial cells. The F protein is synthesized as an inactive precursor, F0, which is cleaved by host proteases into two subunits (F1 and F2) and assembled into a metastable trimeric prefusion state on the viral surface[1][4]. On encountering a host cell, RSV F undergoes dramatic conformational changes exposing a hydrophobic fusion peptide that enables viral and cellular membrane fusion[1][4]. The prefusion conformation is structurally and antigenically distinct from the postfusion form, revealing unique epitopes—especially "Site Ø" and "Site V"—that are the primary targets of highly potent neutralizing antibodies in natural infection and vaccine responses[6][7]. Stabilized forms of prefusion RSV F are the basis for the most advanced RSV vaccines and innovative monoclonal antibody therapies now approved or in late-stage clinical trials, with improved immunogenicity and protection compared to postfusion-based or whole-virus vaccines[5][6][7].

Other names

RSV F glycoprotein (prefusion form)RSV F protein (preF)RSV preFRSV prefusion F

Neutralizing antibodies bind RSV prefusion F and block the conformational change required for viral membrane fusion, preventing entry into host cells[6][7] Vaccine-induced immune response generates neutralizing antibodies, especially against preF-specific sites, preventing infection[6][7]