title: Characterization of a Prefusion-Specific Antibody That Recognizes a Quaternary, Cleavage-Dependent Epitope on the RSV Fusion Glycoprotein.
abstract: Prevention efforts for respiratory syncytial virus (RSV) have been advanced due to the recent isolation and characterization of antibodies that specifically recognize the prefusion conformation of the RSV fusion (F) glycoprotein. These potently neutralizing antibodies are in clinical development for passive prophylaxis and have also aided the design of vaccine antigens that display prefusion-specific epitopes. To date, prefusion-specific antibodies have been shown to target two antigenic sites on RSV F, but both of these sites are also present on monomeric forms of F. Here we present a structural and functional characterization of human antibody AM14, which potently neutralized laboratory strains and clinical isolates of RSV from both A and B subtypes. The crystal structure and location of escape mutations revealed that AM14 recognizes a quaternary epitope that spans two protomers and includes a region that undergoes extensive conformational changes in the pre- to postfusion F transition. Binding assays demonstrated that AM14 is unique in its specific recognition of trimeric furin-cleaved prefusion F, which is the mature form of F on infectious virions. These results demonstrate that the prefusion F trimer contains potent neutralizing epitopes not present on monomers and that AM14 should be particularly useful for characterizing the conformational state of RSV F-based vaccine antigens.
authors.affiliation: Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America.
authors.forename: Morgan S A
authors.initials: MS
authors.lastname: Gilman
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Syed M
authors.initials: SM
authors.lastname: Moin
authors.affiliation: Centro Nacional de Microbiología and CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Mas
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Man
authors.initials: M
authors.lastname: Chen
authors.affiliation: MedImmune Inc., Gaithersburg, Maryland, United States of America.
authors.forename: Nita K
authors.initials: NK
authors.lastname: Patel
authors.affiliation: MedImmune Inc., Gaithersburg, Maryland, United States of America.
authors.forename: Kari
authors.initials: K
authors.lastname: Kramer
authors.affiliation: MedImmune Inc., Gaithersburg, Maryland, United States of America.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America.
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Kabeche
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Azad
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Centro Nacional de Microbiología and CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Palomo
authors.affiliation: AIMM Therapeutics, Academic Medical Center, Amsterdam, Netherlands.
authors.forename: Tim
authors.initials: T
authors.lastname: Beaumont
authors.affiliation: Electron Microscopy Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Baxa
authors.affiliation: MedImmune Inc., Gaithersburg, Maryland, United States of America.
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Ulbrandt
authors.affiliation: Centro Nacional de Microbiología and CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Melero
authors.affiliation: Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Barney S
authors.initials: BS
authors.lastname: Graham
authors.affiliation: Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America.
authors.forename: Jason S
authors.initials: JS
authors.lastname: McLellan
mesh_terms: D057134:Antibodies, Neutralizing / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure*; D000914:Antibodies, Viral / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure*; D000956:Antigens, Viral / Q000276:immunology; D002460:Cell Line; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure*; D005434:Flow Cytometry; D006023:Glycoproteins / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure; D006801:Humans; D020836:Protein Structure, Quaternary; D012136:Respiratory Syncytial Viruses / Q000276:immunology*; D020349:Surface Plasmon Resonance
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D018985:Epitopes, B-Lymphocyte; D006023:Glycoproteins