Characterization of two antigenic sites recognized by neutralizing monoclonal antibodies directed against the fusion glycoprotein of human respiratory syncytial virus

Abstract

Two antigenic sites recognized by neutralizing monoclonal antibodies (MAbs) directed against the fusion (F) glycoprotein of human respiratory syncytial virus were mapped on the primary structure of the protein by (i) the identification of amino acid substitutions selected in antibody-escape mutants and (ii) the reactivity of synthetic peptides with MAbs. The first site contained several overlapping epitopes which were located within the trypsin-resistant amino-terminal third of the large F1 subunit. Only one of these epitopes was faithfully reproduced by a short synthetic peptide; the others might require specific local conformations to react with MAbs. The second antigenic site was located in a trypsin-sensitive domain of the F1 subunit towards the carboxy-terminal end of the cysteine-rich region. One of these epitopes was reproduced by synthetic peptides. In addition, mutagenized F protein with a substitution of serine for arginine at position 429 did not bind MAbs to the second site. These results are discussed in terms of F protein structure and the mechanisms of virus neutralization.

Influence of bovine respiratory syncytial virus F glycoprotein N-linked glycans on in vitro expression and on antibody responses in BALB/c mice☆

“…Several of these regions, which were recognized by the CD4+ T cells from calves, are adjacent to previously identified B cell epitopes [25]. The antigenic sites for neutralizing MAbs to the HRSV F protein have also been mapped, primarily to the F 1 subunit [26][27][28]. One region is near the C terminal-end of the cysteine-rich region and not far from the heptad repeat [27].…”

Characteristic Differences in Reverse Transcription-Polymerase Chain Reaction Products of Ovine, Bovine, and Human Respiratory Syncytial Viruses

“…4,8,32 This portion of the F protein has recently been described as a major protective antigenic region (region B 8 or region II 4 ). Coincidentally, in studies involving HRSV antibody escape mutants, 4 most amino acid changes in mutant viruses were clustered in a small segment of the F protein (amino acids 262-272) within the same antigenic region (B or II) as the BRSV primer-specific RT-PCR. Similarly, nucleic acid sequences amplified with HRSV-specific primers code for what has been suggested to be a protective epitope (HRSV amino acids 212-232).…”

“…Similarly, nucleic acid sequences amplified with HRSV-specific primers code for what has been suggested to be a protective epitope (HRSV amino acids 212-232). 33,34 Sequence analysis and immunologic characterization with monoclonal antibodies as described elsewhere 4,8 will be required to completely assess the significance of these findings.…”

Conformational constraints of conserved neutralizing epitopes from a major antigenic area of human respiratory syncytial virus fusion glycoprotein

“…Thus, monoclonal antibodies (MAbs) (Taylor et al, 1984;Walsh et al, 1984) and polyclonal antisera raised against the F protein (Walsh et al, 1987) ) is shown in boldface. Amino acid changes found in the antibody escape mutants described by Arbiza et al (1992) are shown in italic underlined typeface. The predicted secondary structure for the protein is presented: (r---I) e-helix, (,v~,) p-sheet and (1) random coil.…”

“…Other peptides are shown above the sequence. (b) Examples of antibody binding of selected escape mutants, as described by Arbiza et al (1992). or sera from animals inoculated with vaccinia virus recombinants expressing this antigen (Olmsted et al, 1986;Stott et al, 1987;Portela et al, 1989) neutralized RS virus. In addition, passive administration of anti-F antibodies to experimental animals (Taylor et aI., 1984;Walsh et al, 1984) or immunization with either purified F protein (Walsh et al, 1987;Routledge et al, 1988) or vaccinia virus recombinants (Olmsted et al, 1986;Wertz et al, 1987;Portela et al, 1989) confer protection against a challenge with human RS virus of the two antigenic subgroups (A and B).…”