scholarly journals Trivalency of a Nanobody Specific for the Human Respiratory Syncytial Virus Fusion Glycoprotein Drastically Enhances Virus Neutralization and Impacts Escape Mutant Selection

2016 ◽  
Vol 60 (11) ◽  
pp. 6498-6509 ◽  
Author(s):  
Concepción Palomo ◽  
Vicente Mas ◽  
Laurent Detalle ◽  
Erik Depla ◽  
Olga Cano ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Antigenic Site ◽  
Serial Passage ◽  
Human Respiratory Syncytial Virus ◽  
Escape Mutant ◽  
Comprehensive Description ◽  
Mutant Selection ◽  
Fusion Glycoprotein ◽  
Escape Mutants ◽  
Syncytial Virus

ABSTRACTALX-0171 is a trivalent Nanobody derived from monovalent Nb017 that binds to antigenic site II of the human respiratory syncytial virus (hRSV) fusion (F) glycoprotein. ALX-0171 is about 6,000 to 10,000 times more potent than Nb017 in neutralization tests with strains of hRSV antigenic groups A and B. To explore the effect of this enhanced neutralization on escape mutant selection, viruses resistant to either ALX-0171 or Nb017 were isolated after serial passage of the hRSV Long strain in the presence of suboptimal concentrations of the respective Nanobodies. Resistant viruses emerged notably faster with Nb017 than with ALX-0171 and in both cases contained amino acid changes in antigenic site II of hRSV F. Detailed binding and neutralization analyses of these escape mutants as well as previously described mutants resistant to certain monoclonal antibodies (MAbs) offered a comprehensive description of site II mutations which are relevant for neutralization by MAbs and Nanobodies. Notably, ALX-0171 showed a sizeable neutralization potency with most escape mutants, even with some of those selected with the Nanobody, and these findings make ALX-0171 an attractive antiviral for treatment of hRSV infections.

scholarly journals Antigenic Structure of Human Respiratory Syncytial Virus Fusion Glycoprotein

1998 ◽  
Vol 72 (8) ◽  
pp. 6922-6928 ◽  
Author(s):  
Juan A. López ◽  
Regla Bustos ◽  
Claes Örvell ◽  
Mabel Berois ◽  
Juan Arbiza ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Protein Sequence ◽  
Neutralizing Antibodies ◽  
Human Respiratory Syncytial Virus ◽  
Antigenic Structure ◽  
Antigenic Sites ◽  
Fusion Glycoprotein ◽  
Escape Mutants ◽  
Syncytial Virus ◽  
Prediction Of Secondary Structure

ABSTRACT New series of escape mutants of human respiratory syncytial virus were prepared with monoclonal antibodies specific for the fusion (F) protein. Sequence changes selected in the escape mutants identified two new antigenic sites (V and VI) recognized by neutralizing antibodies and a group-specific site (I) in the F1 chain of the F molecule. The new epitopes, and previously identified antigenic sites, were incorporated into a refined prediction of secondary-structure motifs to generate a detailed antigenic map of the F glycoprotein.

scholarly journals Fatty Acid Acylation of the Fusion Glycoprotein of Human Respiratory Syncytial Virus

1989 ◽  
Vol 264 (18) ◽  
pp. 10339-10342
Author(s):  
R G Arumugham ◽  
R C Seid ◽  
S Doyle ◽  
S W Hildreth ◽  
P R Paradiso
Keyword(s):  
Fatty Acid ◽  
Respiratory Syncytial Virus ◽  
Human Respiratory Syncytial Virus ◽  
Fusion Glycoprotein ◽  
Syncytial Virus

scholarly journals Genotyping of Type A Human Respiratory Syncytial Virus Based on Direct F Gene Sequencing

Medicina ◽  
2019 ◽  
Vol 55 (5) ◽  
pp. 169 ◽  
Author(s):  
Daifullah Al Aboud ◽  
Nora M. Al Aboud ◽  
Mater I. R. Al-Malky ◽  
Ahmed S. Abdel-Moneim
Keyword(s):  
Respiratory Syncytial Virus ◽  
Mutational Analysis ◽  
Gene Sequencing ◽  
Human Respiratory Syncytial Virus ◽  
Clinical Samples ◽  
Escape Mutant ◽  
Respiratory Pathogens ◽  
Virus Genotype ◽  
F Gene ◽  
Syncytial Virus

Background and objectives: The human respiratory syncytial virus (hRSV) is among the important respiratory pathogens affecting children. Genotype-specific attachment (G) gene sequencing is usually used to determine the virus genotype. The reliability of the fusion (F) gene vs. G gene genotype-specific sequencing was screened. Materials and Methods: Archival RNA from Saudi children who tested positive for hRSV-A were used. Samples were subjected to a conventional one-step RT-PCR for both F and G genes and direct gene sequencing of the amplicons using the same primer sets. Phylogeny and mutational analysis of the obtained sequences were conducted. Results: The generic primer set succeeded to amplify target gene sequences. The phylogenetic tree based on partial F gene sequencing resulted in an efficient genotyping of hRSV-A strains equivalent to the partial G gene genotyping method. NA1, ON1, and GA5 genotypes were detected in the clinical samples. The latter was detected for the first time in Saudi Arabia. Different mutations in both conserved and escape-mutant domains were detected in both F and G. Conclusion: It was concluded that a partial F gene sequence can be used efficiently for hRSV-A genotyping.

scholarly journals Characterization of the epitope for anti-human respiratory syncytial virus F protein monoclonal antibody 101F using synthetic peptides and genetic approaches

2007 ◽  
Vol 88 (10) ◽  
pp. 2719-2723 ◽  
Author(s):  
Sheng-Jiun Wu ◽  
Albert Schmidt ◽  
Eric J. Beil ◽  
Nicole D. Day ◽  
Patrick J. Branigan ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Antigenic Site ◽  
Neutralizing Antibody ◽  
Human Respiratory Syncytial Virus ◽  
Peptide Sequence ◽  
F Protein ◽  
Syncytial Virus ◽  
A Minor ◽  
Key Residues

Chimeric 101F (ch101F) is a mouse–human chimeric anti-human respiratory syncytial virus (HRSV) neutralizing antibody that recognizes residues within antigenic site IV, V, VI of the fusion (F) glycoprotein. The binding of ch101F to a series of peptides overlapping aa 422–438 spanning antigenic site IV, V, VI was analysed. Residues 423–436 comprise the minimal peptide sequence for ch101F binding. Substitution analysis revealed that R429 and K433 are critical for ch101F binding, whilst K427 makes a minor contribution. Binding of ch101F to a series of single mutations at positions 427, 429 and 433 in the F protein expressed recombinantly on the cell surface confirmed the peptide results. Sequence analysis of viruses selected for resistance to neutralization by ch101F indicated that a single change (K433T) in the F protein allowed ch101F escape. The results confirm that ch101F and palivizumab have different epitope specificity and define key residues for ch101F recognition.

scholarly journals Structure of a Major Antigenic Site on the Respiratory Syncytial Virus Fusion Glycoprotein in Complex with Neutralizing Antibody 101F

2010 ◽  
Vol 84 (23) ◽  
pp. 12236-12244 ◽  
Author(s):  
Jason S. McLellan ◽  
Man Chen ◽  
Jung-San Chang ◽  
Yongping Yang ◽  
Albert Kim ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Effective Vaccine ◽  
Linear Epitope ◽  
Peptide Epitope ◽  
Fusion Glycoprotein ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in infants and elderly people. Currently there is no effective vaccine against RSV, but passive prophylaxis with neutralizing antibodies reduces hospitalizations. To investigate the mechanism of antibody-mediated RSV neutralization, we undertook structure-function studies of monoclonal antibody 101F, which binds a linear epitope in the RSV fusion glycoprotein. Crystal structures of the 101F antigen-binding fragment in complex with peptides from the fusion glycoprotein defined both the extent of the linear epitope and the interactions of residues that are mutated in antibody escape variants. The structure allowed for modeling of 101F in complex with trimers of the fusion glycoprotein, and the resulting models suggested that 101F may contact additional surfaces located outside the linear epitope. This hypothesis was supported by surface plasmon resonance experiments that demonstrated 101F bound the peptide epitope ∼16,000-fold more weakly than the fusion glycoprotein. The modeling also showed no substantial clashes between 101F and the fusion glycoprotein in either the pre- or postfusion state, and cell-based assays indicated that 101F neutralization was not associated with blocking virus attachment. Collectively, these results provide a structural basis for RSV neutralization by antibodies that target a major antigenic site on the fusion glycoprotein.

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