Intragroup antigenic diversity of human respiratory syncytial virus (group A) isolated in Argentina and Chile

Abstract

The intragroup antigenic diversity of the G glycoprotein of 226 human respiratory syncytial virus (HRSV) strains isolated in Buenos Aires (Argentina) and Santiago (Chile) between 1995 and 2002 was evaluated by ELISA with a panel of 14 anti-G monoclonal antibodies (MAbs). Out of 226 strains characterized, 172 (76%) belonged to group A and 54 (24%) to group B. Strains from both groups cocirculated throughout the study period in both countries, except in 1996, 2000, and 2002 when only group A strains were isolated. Within group A 23 different antigenic patterns were found as defined by the combination of reactivities with eight strain-specific anti-G MAbs. These antigenic patterns showed different behavior regarding their circulation. Some major patterns were observed in most years with variable proportions; other minor patterns were present in low proportions during 1 or 2 years and then were apparently replaced by new patterns. Some antigenic patterns occurred both in Argentina and Chile during the same epidemics. Since no strain-specific MAbs were available for group B, we could not evidence the antigenic variability within group B. These are the first data on antigenic characterization of HRSV strains isolated in Argentina and Chile. It is shown that the ELISA with MAbs directed against the G protein of RSV is a valuable tool. These results will also provide useful information for further studies to evaluate the antigenic variability of HRSV strains in relation with genetic characteristics.

Conservation of G-Protein Epitopes in Respiratory Syncytial Virus (Group A) Despite Broad Genetic Diversity: Is Antibody Selection Involved in Virus Evolution?

“…3 and 5 are globally examined, no obvious correspondence between genotype genetic relatedness and MAb reactivity pattern is observed. These results are generally in agreement with previous reports that detected sporadic antigenic changes in viruses circulating in Argentina and Chile (35,41) or in Germany (36) with the MAbs used in this study but without any distinctive trend.…”

“…Therefore, the NA1, NA2, NA4, and ON1 genotypes were regrouped within the GA2 genotype in Table 2. hRSV strains collected through relatively short time periods (15,35,36). Hence, a set of hRSV group A viruses, covering the entire recorded history of this antigenic group and representing all genotypes shown in Table 2 except GA4 and GA6 (for which viruses were not available), was used to reevaluate reactivity with the strain-variable MAbs.…”

Subgroup Prevalence and Genotype Circulation Patterns of Human Respiratory Syncytial Virus in Belgium during Ten Successive Epidemic Seasons

“…Interestingly, GB13 strains with different predicted G protein lengths were prevalent during these 2 seasons. Previous investigations have reported that a replacement of the predominating HRSV genotype occurs each year (5,11,33). However, we did not identify such an annual shift of the prevailing genotype among hospitalized patients in Belgium.…”

Human respiratory syncytial virus genomic and antigenic variants isolated in two hospitals during one epidemic, in Santiago, Chile

“…RSV can be divided into two groups, A and B, using monoclonal antibodies (Mab) directed against gpF and gpG (Cane, 2001). RSV strains have also been further assigned to different antigenic subgroups according to reactivity patterns with Mab panels directed against gpG (Galiano et al, 2005a). The analysis of RSV genes by restriction endonuclease digestion (RFLP) and nucleotide sequencing have demonstrated the occurrence of evolutionary intragroup lineages or genotypes, which have worldwide distribution (Cane and Pringle, 1992;Cane, 2001).…”