Broadly Neutralizing Alphavirus Antibodies Bind an Epitope on E2 and Inhibit Entry and Egress

Cell. 2015 Nov 19;163(5):1095-1107. doi: 10.1016/j.cell.2015.10.050. Epub 2015 Nov 6.


We screened a panel of mouse and human monoclonal antibodies (MAbs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. Passive transfer of broadly neutralizing MAbs protected mice against infection by chikungunya, Mayaro, and O'nyong'nyong alphaviruses. Using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing MAbs block multiple steps in the viral lifecycle, including entry and egress, and bind to a conserved epitope on the B domain of the E2 glycoprotein. A 16 Å resolution cryo-electron microscopy structure of a Fab fragment bound to CHIKV E2 B domain provided an explanation for its neutralizing activity. Binding to the B domain was associated with repositioning of the A domain of E2 that enabled cross-linking of neighboring spikes. Our results suggest that B domain antigenic determinants could be targeted for vaccine or antibody therapeutic development against multiple alphaviruses of global concern.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alphavirus / classification
  • Alphavirus / immunology*
  • Alphavirus / metabolism
  • Alphavirus Infections / immunology*
  • Alphavirus Infections / prevention & control
  • Alphavirus Infections / therapy
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Neutralizing / immunology*
  • Antibodies, Viral / immunology*
  • Chikungunya virus / chemistry
  • Chikungunya virus / immunology
  • Cryoelectron Microscopy
  • Epitopes*
  • Glycoproteins / chemistry
  • Glycoproteins / immunology
  • Humans
  • Immunoglobulin Fab Fragments / immunology
  • Immunoglobulin Fab Fragments / ultrastructure
  • Mice
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / immunology*
  • Viral Vaccines / immunology
  • Virus Internalization


  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Epitopes
  • Glycoproteins
  • Immunoglobulin Fab Fragments
  • Viral Envelope Proteins
  • Viral Vaccines

Associated data

  • PDB/5ANY