scholarly journals Functional Analysis of the 60-Nucleotide Duplication in the Respiratory Syncytial Virus Buenos Aires Strain Attachment Glycoprotein

2015 ◽  
Vol 89 (16) ◽  
pp. 8258-8266 ◽  
Author(s):  
Anne L. Hotard ◽  
Elizabeth Laikhter ◽  
Kelsie Brooks ◽  
Tina V. Hartert ◽  
Martin L. Moore

ABSTRACTThere are two subgroups of respiratory syncytial virus (RSV), A and B, and within each subgroup, isolates are further divided into clades. Several years ago, multiple subgroup B isolates which contained a duplication of 60 nucleotides in the glycoprotein (G) gene were described. These isolates were given a new clade designation of BA based on the site of isolation, Buenos Aires, Argentina. BA RSV strains have since become the predominant circulating clade of RSV B viruses. We hypothesized that the duplicated region in G serves to enhance the function of G in the virus life cycle. We generated recombinant viruses that express a consensus BA G gene or a consensus BA G gene lacking the duplication (GΔdup). We determined that the duplicated region functions during virus attachment to cells. Additionally, we showed thatin vitro, the virus containing the duplication has a fitness advantage compared to the virus without the duplication. Our data demonstrate that the duplicated region in the BA strain G protein augments virus attachment and fitness.IMPORTANCERespiratory syncytial virus (RSV) is an important pathogen for infants for which there is no vaccine. Different strains of RSV circulate from year to year, and the predominating strains change over time. Subgroup B RSV strains with a duplication in the attachment glycoprotein (G) emerged and then became the dominant B genotype. We found that a recombinant virus harboring the duplication bound more efficiently to cells and was more fit than a recombinant strain lacking the duplication. Our work advances a mechanism for an important natural RSV mutation.

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 337
Author(s):  
Kristina Borochova ◽  
Katarzyna Niespodziana ◽  
Katarina Stenberg Hammar ◽  
Marianne van Hage ◽  
Gunilla Hedlin ◽  
...  

Respiratory syncytial virus (RSV) infections are a major cause of serious respiratory disease in infants. RSV occurs as two major subgroups A and B, which mainly differ regarding the surface glycoprotein G. The G protein is important for virus attachment and G-specific antibodies can protect against infection. We expressed the surface-exposed part of A2 strain-derived G (A2-G) in baculovirus-infected insect cells and synthesized overlapping peptides spanning complete A2-G. The investigation of the natural IgG response of adult subjects during a period of one year showed that IgG antibodies (i) recognize G significantly stronger than the fusion protein F0, (ii) target mainly non-conformational, sequential peptide epitopes from the exposed conserved region but also buried peptides, and (iii) exhibit a scattered but constant recognition profile during the observation period. The IgG subclass reactivity profile (IgG1 > IgG2 > IgG4 = IgG3) was indicative of a mixed Th1/Th2 response. Two strongly RSV-neutralizing sera including the 1st WHO standard contained high IgG anti-G levels. G-specific IgG increased strongly in children after wheezing attacks suggesting RSV as trigger factor. Our study shows that RSV G and G-derived peptides are useful for serological diagnosis of RSV-triggered exacerbations of respiratory diseases and underlines the importance of G for development of RSV-neutralizing vaccines.


2015 ◽  
Vol 90 (1) ◽  
pp. 245-253 ◽  
Author(s):  
Jia Meng ◽  
Anne L. Hotard ◽  
Michael G. Currier ◽  
Sujin Lee ◽  
Christopher C. Stobart ◽  
...  

ABSTRACTHuman respiratory syncytial virus (RSV) is an important pathogen causing acute lower respiratory tract disease in children. The RSV attachment glycoprotein (G) is not required for infection, as G-null RSV replicates efficiently in several cell lines. Our laboratory previously reported that the viral fusion (F) protein is a determinant of strain-dependent pathogenesis. Here, we hypothesized that virus dependence on G is determined by the strain specificity of F. We generated recombinant viruses expressing G and F, or null for G, from the laboratory A2 strain (Katushka RSV-A2GA2F [kRSV-A2GA2F] and kRSV-GstopA2F) or the clinical isolate A2001/2-20 (kRSV-2-20G2-20F and kRSV-Gstop2-20F). We quantified the virus cell binding, entry kinetics, infectivity, and growth kinetics of these four recombinant virusesin vitro. RSV expressing the 2-20 G protein exhibited the greatest binding activity. Compared to the parental viruses expressing G and F, removal of 2-20 G had more deleterious effects on binding, entry, infectivity, and growth than removal of A2 G. Overall, RSV expressing 2-20 F had a high dependence on G for binding, entry, and infection.IMPORTANCERSV is the leading cause of childhood acute respiratory disease requiring hospitalization. As with other paramyxoviruses, two major RSV surface viral glycoproteins, the G attachment protein and the F fusion protein, mediate virus binding and subsequent membrane fusion, respectively. Previous work on the RSV A2 prototypical strain demonstrated that the G protein is functionally dispensable forin vitroreplication. This is in contrast to other paramyxoviruses that require attachment protein function as a prerequisite for fusion. We reevaluated this requirement for RSV using G and F proteins from clinical isolate 2-20. Compared to the laboratory A2 strain, the G protein from 2-20 had greater contributions to virus binding, entry, infectivity, andin vitrogrowth kinetics. Thus, the clinical isolate 2-20 F protein function depended more on its G protein, suggesting that RSV has a higher dependence on G than previously thought.


REVISTA FIMCA ◽  
2017 ◽  
Vol 4 (1) ◽  
pp. 17-30
Author(s):  
Jackson Alves da Silva Queiroz ◽  
Luciane Soares Alves ◽  
Deusilene Souza Vieira Dall’acqua ◽  
Luan Felipo Botelho Souza

Introdução: O desenvolvimento de primers é extremamente importante para pesquisas moleculares. Objetivos: O presente estudo objetivou desenhar e validar primers in silico para detecção do vírus sincicial respiratório humano (RSVH). Materiais e Métodos: Foi construído um banco de 100 sequências de genoma completo do Vírus Sincicial Respiratório Humano (RSVH) depositadas no Genbank (NCBI). Realizado um alinhamento múltiplo global utilizando o algoritimo Clustal W, mapeadas as regiões conservadas e selecionado os primers. Posteriormente submetidos a análise dos parâmetros especificidade, pela ferramenta BLAST, concentração de GC%, TMelting, comprimento, formação de dímeros e hairpin utilizando o software Oligo Analyser, validando-os para uso in vitro. Para discussão dos resultados, foram selecionados 14 primers de estudos realizados, submetidos à metodologia proposta neste estudo, comparando os dados obtidos. A região alvo escolhida foi o gene da Glicoproteína G, pela presença de sítios conservados. Resultados: Os primers amplificam um fragmento de 381pb, que submetido a uma segunda PCR, resulta em 109 pb correspondente ao tipo A do vírus e 168 pb para o tipo B, permitindo a detecção viral e a distinção de genótipos. Os primers possuem tamanho de 21 a 24 pb, com uma temperatura de melting entre 48,9 oC e 55,3 oC. A concentração de GC% varia de 33,3% a 52,4%. O número de bases complementares na análise de dímeros e hairpin manteve-se abaixo de 5 bases. A Energia Livre de Gibbs (Delta G) acima de -9 kcal.moles(-1) como desejado. Conclusão: Os valores obtidos na validação dos primers estão em concordância com os já utilizados em estudos de referência, validando assim o seu uso in vitro. Introduction: Developing primers is extremely important to molecular researches. Objectives: This study aims to drawing and validate in silico primers for detection of Human Respiratory Syncytial Virus (RSVH). Materials and Methods: It was built a database of 100 complete genome sequences of Human Respiratory Syncytial Virus (RSVH) deposited in the Genbank (NCBI), carried out a global multiple alignment using the algoritm Clustal W, thus mapping the conserved regions, and selecting primers, subsequently submitted to analysis of parameters such as specificity, by the BLAST tool, concentration of GC% TMelting, length, and formation of dimers and hairpins using the software Oligo Analyser, validating them to use in vitro. For discussion of the results, we selected 14 primers of studies already carried out and submitted the methodology proposed in this study, comparing the data obtained. The selected target region was the gene encoding the Glycoprotein G, by the presence of conserved sites. Results: The primers selected amplifies a fragment of 381 bp in the 1st PCR, which subjected to a second PCR results in 109 bp corresponding to the type A of the virus and 168 base pairs for the type Bwhat allows not only viral detection, as the distinction of the type to which it belongs. The primers have size from 21 to 24 base pairs, having a melting temperature (Tmelting) between 48,9o C and 55,3o C and GC% concentration ranging from 33.3% to 52.4%. The number of complementary bases in the dimers and hairpins analysis was maintained below 5 bases, while the Gibbs free energy (Delta G) was kept above kcal.mole -9(-1) as desired. Conclusion: All values obtained in the validation of the primers are in agreement with the ones already used in the reference studies, thereby validating its use in vitro.


2002 ◽  
Vol 76 (23) ◽  
pp. 12355-12359 ◽  
Author(s):  
Ulrike Schmidt ◽  
Jörg Beyer ◽  
Ulf Polster ◽  
Laurel J. Gershwin ◽  
Ursula J. Buchholz

ABSTRACT Recombinant bovine respiratory syncytial virus (rBRSV) and an rBRSV deletion mutant lacking the G gene (rBRSVΔG) were characterized in calves with respect to replication competence, attenuation, and protective efficacy as live-attenuated BRSV vaccines. Both recombinant viruses were safe and induced protection against a BRSV challenge infection. rBRSV replicated efficiently in the upper respiratory tract. Intranasal immunization with rBRSVΔG led to infection but not to mucosal virus replication. Neutralizing antibodies were induced by rBRSV and rBRSVΔG. Thus, the BRSV attachment glycoprotein G seems to be dispensable in vaccinating calves against BRSV.


2001 ◽  
Vol 82 (3) ◽  
pp. 631-640 ◽  
Author(s):  
Axel Karger ◽  
Ulrike Schmidt ◽  
Ursula J. Buchholz

Bovine respiratory syncytial virus (BRSV) encodes three transmembrane envelope glycoproteins, namely the small hydrophobic (SH) protein, the attachment glycoprotein (G) and the fusion glycoprotein (F). The BRSV reverse genetics system has been used to generate viable recombinant BRSV lacking either the G gene or the SH gene or both genes. The deletion mutants were fully competent for multicycle growth in cell culture, proving that, of the BRSV glycoprotein genes, the SH and G genes are non-essential. Virus morphogenesis was not impaired by either of the deletions. The deletion mutants were used to study the role of the F glycoprotein and the contributions of SH and G with respect to virus attachment. Attachment mediated by the F protein alone could be blocked by soluble heparin, but not by chondroitin sulphate. Heparin affinity chromatography revealed that both the BRSV G and F glycoproteins have heparin-binding activity, with the affinity of the F glycoprotein being significantly lower than that of G. Therefore, the roles of the BRSV glycoproteins in virus attachment and receptor binding have to be reconsidered.


2008 ◽  
Vol 89 (3) ◽  
pp. 741-750 ◽  
Author(s):  
Toby M. Ward ◽  
Vicki Traina-Dorge ◽  
Kara A. Davis ◽  
Wayne L. Gray

Recombinant simian varicella viruses (rSVVs) were engineered to express respiratory syncytial virus (RSV) antigens. The RSV surface glycoprotein G and second matrix protein M2 (22k) genes were cloned into the SVV genome, and recombinant viruses were characterized in vitro and in vivo. rSVVs were also engineered to express the membrane-anchored or secreted forms of the RSV-G protein as well as an RSV G lacking its chemokine mimicry motif (CX3C), which may have different effects on priming the host immune response. The RSV genes were efficiently expressed in rSVV/RSV-infected Vero cells as RSV-G and -M2 transcripts were detected by RT-PCR, and RSV antigens were detected by immunofluorescence and immunoblot assays. The rSVVs replicated efficiently in Vero cell culture. Rhesus macaques immunized with rSVV/RSV-G and rSVV/RSV-M2 vaccines produced antibody responses to SVV and RSV antigens. The results demonstrate that recombinant varicella viruses are suitable vectors for the expression of RSV antigens and may represent a novel vaccine strategy for immunization against both pathogens.


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