Evidence that the amino acid region 124-203 of glycoprotein G from the respiratory syncytial virus (RSV) constitutes a major part of the polypeptide domain that is involved in the protection against RSV infection.

The first 230 residues of the 298-amino acid glycoprotein G of respiratory syncytial virus (RSV) are sufficient to confer complete resistance to challenge with live RSV, whereas the first 180 residues completely failed (Olmsted et al. (1989) J. Virol. 63, 411-420). The characterization of a protective epitope corresponding to the amino acid region 174-187 of the G protein (Trudel et al. (1991) Virology 185, 749-757) suggests that interruption of this region in the 180 residue truncated polypeptide may be responsible for its inability to confer protection and consequently that the 174-187 region may play a major role in the protection effected by the protein G. To support these hypotheses, we examined the ability of the amino acid region 124-203 of glycoprotein G to confer protection. The corresponding peptide was expressed as a non-fusion protein in a recombinant vaccinia virus designated VG27. Immunization of BALB/c mice with this recombinant efficiently induced the production of antibodies capable of recognizing both the parental glycoprotein G and peptide 174-187. Furthermore, upon challenge with RSV, a significant decrease of infectious particles was found in the lungs of mice immunized with VG27 as compared with non-immunized mice. Our results suggest that the 124-203 amino acid region of the RSV G protein constitutes a major part of the domain involved in protection.