Antigenic structure of the human respiratory syncytial virus G glycoprotein and relevance of hypermutation events for the generation of antigenic variants.

Abstract

A set of monoclonal antibodies (MAbs) specific for the attachment (G) glycoprotein of a recently isolated strain of human respiratory syncytial virus (HRSV) is described. Antibody reactivity with a series of HRSV isolates belonging to antigenic groups A and B identified three epitope categories : (i) strainspecific or variable epitopes that were present in a limited set of viruses from the same antigenic group, (ii) group-specific epitopes shared by viruses from the same antigenic group and (iii) conserved epitopes present in all HRSV isolates. Sequence analysis of escape mutants was used to map relevant antigenic sites of the G glycoprotein. Strain-specific epitopes were located preferentially in the variable C-terminal third of the G polypeptide, in agreement with previous studies of the Long strain. However, a

Major changes in the G protein of human respiratory syncytial virus isolates introduced by a duplication of 60 nucleotides

“…3A). However, when the infected cells were treated with tunicamycin to visualize the unglycosylated precursor (Palomo et al, 1991;Martínez et al, 1997), a clear difference in size was observed between the G protein precursor of Mon/15/90 and BA viruses (Fig. 3B).…”

“…Besides single amino acid substitutions, some escape mutants had: (i) frame-shift mutations that altered the C-terminal one-third of the G protein (García-Barreno et al, 1990); (ii) premature stop codons that shortened the length of the G polypeptide by between 1 and 42 amino acids (Rueda et al, 1991(Rueda et al, , 1995; and (iii) ARG hypermutations that were translated into several amino acid changes, some of them involving a conserved cluster of cysteines found in the middle of the G protein ectodomain (Rueda et al, 1994;Martínez et al, 1997;Walsh et al, 1998).…”

The antigenic and genetic variability of bovine respiratory syncytial virus with emphasis on the G protein

“…It was assumed that the four cystein residues (Cys 173, Cys 176, Cys 182, Cys 186) are present in all human and bovine respiratory viruses. The culture of human viruses in the presence of monoclonal antibodies against glycoprotein G resulted in the selection of mutants with one cystein replaced by arginine (Rueda et al, 1994;Martinez et al, 1997). These mutant viruses were stable in further nonselective passages and grew with unchanged intensity in a mixed viral culture with the original virus.…”

“…Antigenic epitopes of glycoprotein G can be divided by means of monoclonal antibodies into conserved present in all HRSV isolates, group-specific shared by viruses from the same antigenic group and strain-specific or variable epitopes present in a limited set of viruses from the same antigenic group. The strain specific epitopes are localized mainly in variable regions compared to the conserved and group specific epitopes which are localized in the central region of glycoprotein G ectodomain (Akerlind-Stopner et al, 1990;Martinez et al, 1997;Jones et al, 2002).…”

Bovine parainfluenza virus type 3 (PIV3) expressing the respiratory syncytial virus (RSV) attachment and fusion proteins protects hamsters from challenge with human PIV3 and RSV

“…At 48 h p.i., proteins were extracted with lysis buffer. The cell lysate was fractionated on a 10 % protein gel, transferred onto a nylon membrane and probed with RSV G68 mAb (Martinez et al, 1997). Protein-antibody complexes were visualized by chemiluminescence (Amersham).…”