Genetic diversity of the attachment protein of subgroup B respiratory syncytial viruses

Abstract

Respiratory syncytial (RS) virus causes repeated infections throughout life. Between the two main antigenic subgroups of RS virus, there is antigenic variation in the attachment protein G. The antigenic differences between the subgroups appear to play a role in allowing repeated infections to occur. Antigenic differences also occur within subgroups; however, neither the extent of these differences nor their contributions to repeat infections are known. We report a molecular analysis of the extent of diversity within the subgroup B RS virus attachment protein genes of viruses isolated from children over a 30-year period. Amino acid sequence differences as high as 12% were observed in the ectodomains of the G proteins among the isolates, whereas the cytoplasmic and transmembrane domains were highly conserved. The changes in the G-protein ectodomain were localized to two areas on either side of a highly conserved region surrounding four cysteine residues. Strikingly, single-amino-acid coding changes generated by substitution mutations were not the only means by which change occurred. Changes also occurred by (i) substitutions that changed the available termination codons, resulting in proteins of various lengths, and (ii) a mutation introduced by a single nucleotide deletion and subsequent nucleotide insertion, which caused a shift in the open reading frame of the protein in comparison to the other G genes analyzed. Fifty-one percent of the G-gene nucleotide changes observed among the isolates resulted in amino acid coding changes in the G protein, indicating a selective pressure for change. Maximum-parsimony analysis demonstrated that distinct evolutionary lineages existed. These data show that sequence diversity exists among the G proteins within the subgroup B RS viruses, and this diversity may be important in the immunobiology of the RS viruses. Respiratory syncytial (RS) virus, a pneumovirus in the family Paramyxoviridae, is the most frequently isolated agent in acute respiratory tract infections of children (27,

Epidemiology of Human Metapneumovirus

“…Overall, there is 32 to 37% amino acid identity of the G protein between the A and B genotypes of hMPV (1,4,92). This is analogous to that observed with G genes of RSV subgroups A and B (77,94,115).…”

Rapid replacement of human respiratory syncytial virus A with the ON1 genotype having 72 nucleotide duplication in G gene

“…In particular, the BA genotype of HRSV-B, which was isolated in Buenos Aires, Argentina during 1999, contains a duplication of 60 nucleotides (nt) in the C-terminal third of the G protein gene and is the predominant strain according to global epidemiological studies (Sullender et al, 1991;Trento et al, 2006;Trento et al, 2010;van Niekert and Venter, 2011;Zhang et al, 2010). More recently, a similar duplication was reported in HRSV-A (ON1) isolates from Canada, Germany, Malaysia, Thailand, Kenya, and South Korea, which was characterized as a 72-nt duplication in the C-terminal third of the G gene (Munywoki et al, 2013;Auksornkitti et al, 2013;Eshaghi et al, 2012;Lee et al, 2012;Prifert et al, 2013).…”

Molecular characteristics and successful management of a respiratory syncytial virus outbreak among pediatric patients with hemato-oncological disease

“…From the total of 8 patients, five of them were infected with a RSV A strain (Case 1, 3, 4, 5, 6), one was tested positive for RSV B (case 8) and two patients were infected with RSV A and B (case 2 and 7) dependent on the time point of sampling. Despite the coexistence of genetically definite genotypic strains with many nucleotide exchanges especially in the C-terminal variable region of RSV-G [25][26][27], we detected the very same nucleotide sequence for the coding region of the RSV-G protein for all patients infected with RSV A (Fig. 3a).…”