Abstract
Chemical and enzymic cleavages of the F1 subunit of the fusion (F) protein of respiratory syncytial (RS) virus showed that the sequence 184-Gly to 314-Trp reacted with neutralizing monoclonal antibodies (MAbs). Twelve synthetic peptides covering a part of this sequence were analysed for their immunoreactivity with neutralizing MAbs and anti-RS virus rabbit serum. Two sequential antigenic domains corresponding to amino acids 200 to 225 and 255 to 278 were defined with anti-RS virus rabbit serum. The peptides 205225 and 259278, belonging to these antigenic domains, inhibited binding to the F protein and the neutralizing activity of the anti-RS virus rabbit serum. One MAb (RS-348) reacted with peptides containing amino acids 200 to 225. Moreover, the peptide 205225 induced an anti-peptide rabbit serum neutralizing RS virus in vitro. These results indicate that the sequence from residues 200 to 225 was present in one of the immunodominant sites of the F protein.