title: Identification of human neutralizing antibodies that bind to complex epitopes on dengue virions.
abstract: Dengue is a mosquito-borne flavivirus that is spreading at an unprecedented rate and has developed into a major health and economic burden in over 50 countries. Even though infected individuals develop potent and long-lasting serotype-specific neutralizing antibodies (Abs), the epitopes engaged by human neutralizing Abs have not been identified. Here, we demonstrate that the dengue virus (DENV)-specific serum Ab response in humans consists of a large fraction of cross-reactive, poorly neutralizing Abs and a small fraction of serotype-specific, potently inhibitory Abs. Although many mouse-generated, strongly neutralizing monoclonal antibodies (mAbs) recognize epitopes that are present on recombinant DENV envelope (E) proteins, unexpectedly, the majority of neutralizing Abs in human immune sera bound to intact virions but not to the ectodomain of purified soluble E proteins. These conclusions with polyclonal Abs were confirmed with newly generated human mAbs derived from DENV-immune individuals. Two of three strongly neutralizing human mAbs bound to E protein epitopes that were preserved on the virion but not on recombinant E (rE) protein. We propose that humans produce Abs that neutralize DENV infection by binding a complex, quaternary structure epitope that is expressed only when E proteins are assembled on a virus particle. Mapping studies indicate that this epitope has a footprint that spans adjacent E protein dimers and includes residues at the hinge between domains I and II of E protein. These results have significant implications for the DENV Ab and vaccine field.
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Ruklanthi
authors.initials: R
authors.lastname: de Alwis
authors.forename: Scott A
authors.initials: SA
authors.lastname: Smith
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Olivarez
authors.forename: William B
authors.initials: WB
authors.lastname: Messer
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Huynh
authors.forename: Wahala M P B
authors.initials: WM
authors.lastname: Wahala
authors.forename: Laura J
authors.initials: LJ
authors.lastname: White
authors.forename: Michael S
authors.initials: MS
authors.lastname: Diamond
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Baric
authors.forename: James E
authors.initials: JE
authors.lastname: Crowe
authors.forename: Aravinda M
authors.initials: AM
authors.lastname: de Silva
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D057134:Antibodies, Neutralizing / Q000276:immunology* / Q000378:metabolism; D000914:Antibodies, Viral / Q000276:immunology* / Q000378:metabolism; D000918:Antibody Specificity / Q000276:immunology; D002522:Chlorocebus aethiops; D003715:Dengue / Q000276:immunology* / Q000821:virology; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D008253:Macaca mulatta; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009500:Neutralization Tests; D011485:Protein Binding / Q000276:immunology; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014771:Virion / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000939:Epitopes; D007106:Immune Sera; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C072281:E protein TH Sman, Dengue virus