Mc. Sanz et al., GENETIC-HETEROGENEITY OF THE ATTACHMENT GLYCOPROTEIN-G AMONG GROUP-A RESPIRATORY SYNCYTIAL VIRUSES, Virus research, 33(3), 1994, pp. 203-217
Fifteen independent group A respiratory syncytial virus (RSV) isolates
were compared by sequencing a 300-nucleotide interval encoding a vari
able region of the attachment glycoprotein G. The viruses compared inc
luded the reference strains Long (USA 1956), A2 (Australia 1961), and
669 (Sweden 1959), along with 13 clinical isolates obtained at differe
nt times and locations throughout the United States. Representatives o
f all six antigenic subgroups, recognized by reactivity patterns with
monoclonal antibodies, were compared. The maximum sequence heterogenei
ty within the G glycoprotein region compared was 15.7% of nucleotide s
equences and 26% of amino acid sequences, more than twice the differen
ce observed between Long and A2. Half of the nucleotide changes encode
d amino acid substitutions, possibly indicating that the protein inter
val compared was subject to immune selection. Because the ratio of nuc
leotide to amino acid substitutions was nearly constant for all degree
s of genetic divergence, the potential range of sequence divergence am
ong group A RSV has probably not yet been attained. There was little c
orrelation between the patterns of reactivity against a panel of monoc
lonal antibodies and sequence relationships among the 15 isolates. The
sequence information showed multiple genotypes circulating simultaneo
usly in the same community and very similar genotypes circulating in w
idely separated communities and during different years. Genetic analys
es of RSV strains can provide important information about the relation
ships between RSV infections.