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| Article Authors: | Jason S McLellan; Bruno E Correia; Man Chen; Yongping Yang; Barney S Graham; William R Schief; Peter D Kwong |
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| Article Title: | Design and characterization of epitope-scaffold immunogens that present the motavizumab epitope from respiratory syncytial virus. |
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| Reference ID: | 1022078 |
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| Abstract: | Respiratory syncytial virus (RSV) is a major cause of respiratory tract infections in infants, but an effective vaccine has not yet been developed. An ideal vaccine would elicit protective antibodies while avoiding virus-specific T-cell responses, which have been implicated in vaccine-enhanced disease with previous RSV vaccines. We propose that heterologous proteins designed to present RSV-neutralizing antibody epitopes and to elicit cognate antibodies have the potential to fulfill these vaccine requirements, as they can be fashioned to be free of viral T-cell epitopes. Here we present the design and characterization of three epitope-scaffolds that present the epitope of motavizumab, a potent neutralizing antibody that binds to a helix-loop-helix motif in the RSV fusion glycoprotein. Two of the epitope-scaffolds could be purified, and one epitope-scaffold based on a Staphylococcus aureus protein A domain bound motavizumab with kinetic and thermodynamic properties consistent with the free epitope-scaffold being stabilized in a conformation that closely resembled the motavizumab-bound state. This epitope-scaffold was well folded as assessed by circular dichroism and isothermal titration calorimetry, and its crystal structure (determined in complex with motavizumab to 1.9 Å resolution) was similar to the computationally designed model, with all hydrogen-bond interactions critical for binding to motavizumab preserved. Immunization of mice with this epitope-scaffold failed to elicit neutralizing antibodies but did elicit sera with F binding activity. The elicitation of F binding antibodies suggests that some of the design criteria for eliciting protective antibodies without virus-specific T-cell responses are being met, but additional optimization of these novel immunogens is required. |
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| Affiliations: | Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. mclellanja@mail.nih.gov |
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| Date: | 2011 |
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| Reference Type: | Literature |
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| PubMed ID: | 21549714 |
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| Journal: | J Mol Biol |
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| Journal Volume: | 409 |
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| Article Pages: | 853-66 |
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| Journal ISSN: | 1089-8638 |
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| Article Chemical List: | Antibodies, Monoclonal;Epitopes;Staphylococcal Protein A;motavizumab |
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| Article MeSH List: | Amino Acid Sequence; Antibodies, Monoclonal(immunology); Calorimetry; Cell Line; Circular Dichroism; Epitopes(chemistry; immunology); Humans; Models, Molecular; Molecular Sequence Data; Respiratory Syncytial Viruses(immunology); Staphylococcal Protein A(chemistry) |
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| Curation Last Updated: | 2012-05-31 20:50:17 |
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