Evaluation of subgroup‐specific peptides of the G protein of respiratory syncytial virus for characterization of the immune response

Abstract

Two synthetic peptides, designated peptides 12G(A) and 12G(B), representing amino acids 174-188 of the G glycoprotein of respiratory syncytial virus (RSV) subgroup A (strain A2) and subgroup B (strain CH18537) were evaluated for their properties as subgroup-specific antigens for enzyme immunoassay (ELISA). These peptides were used to characterize the immune response of children with naturally occurring RSV infection during six annual epidemics in the Huntington area, West Virginia, USA; viz. 1978-1979, 1979-1980, 1980-1981, 1983-1984, 1989-1990, and 1990-1991. The study group comprised 43 paired sera from 42 infants and children, who ranged in age between 1 month and 5.5 years of age (median age 16 months). The inclusion criteria were subgroup identification of RSV, respiratory tract illness requiring admission to hospital, and the availability of paired sera. Five of 30 children with subgroup A and 3 of 13 children with subgroup B infections developed homologous or dual fourfold or greater antibody responses to peptides 12G(A) and 12G(B) during convalescence; six of these eight children also developed antibody rises to whole virus antigens. Twenty children (14 subgroup A and 6 subgroup B) developed such responses in antibody only to whole virus (not to the peptides), and 15 children (11 subgroup A and 4 subgroup B) failed to develop a rise in antibody. Children who developed rises in antibody to the peptides were usually less than 9 months of age, suggesting that a response to peptides was more likely to occur during primary infection. Peptides 12G(A) and 12G(B) of RSV G protein lacked sufficient sensitivity and specificity to serve as antigens for ELISA for characterizing the subgroup-specific immune responses to RSV infection in infants and children.

Antiviral Activity and Structural Characteristics of the Nonglycosylated Central Subdomain of Human Respiratory Syncytial Virus Attachment (G) Glycoprotein

“…Cold passage-derived RSV, with the attachment glycoprotein deleted, was not viable in vivo (58), and syncytium formation by cells expressing the RSV fusion glycoprotein was enhanced by co-expression of the attachment glycoprotein (61,62). Furthermore, antibodies that map to the nonglycosylated central subdomain of the attachment glycoprotein neutralize RSV (33)(34)(35)(36)(37), and antigen preparations containing this portion of the attachment glycoprotein elicit a protective immune response when used as vaccines (38 -43). Thus, interaction of the RSV attachment glycoprotein with receptor(s) would appear to be important to the infectious process of RSV.…”

“…Immunological observations support this contention. For example, neutralizing monoclonal antibodies (33)(34)(35)(36), polyclonal antibodies (33,37), and antibodies from convalescent sera (33,34) map to the nonglycosylated central subdomain. In addition, a protective antigenic response is elicited upon vaccination of mice with synthetic peptides containing a portion of this sequence (38,39), recombinant proteins containing the subdomain (40,41), recombinant bacteriophage displaying a portion of this subdomain (42), and recombinant vaccinia viruses expressing the RSV attachment glycoprotein (43).…”

Respiratory Syncytial Virus Genetic and Antigenic Diversity

“…Preliminary work with a limited number of sera had suggested that these peptides might be useful for the detection of antibodies (3). However, the peptides were found to lack sufficient sensitivity and specificity to allow the group-specific detection of RSV antibodies in children (4). Peptides were also synthesized for bovine, ovine, and human RSV G proteins (amino acids 158 to 189) and used to detect antibodies against RSV (72).…”

Surface display on staphylococci: a comparative study

“…The choice of fragment was based on deletion mutant analyses of the RSV G protein [37] and identification of protective and neutralizing epitopes [38]. The selected segment of the G protein contains four cysteine residues, of which Cys-176 and Cys-182 have been suggested to form a disulfide bridge essential for the reaction with monoclonal antibodies which are able to confer passive protection upon RSV challenge [38,39]. Four synthetic gene fragments were assembled, encoding variants of the described region of the G protein, all with codons selected to be suitable for bacterial production [12,32,33].…”