EMD-5103
Immature West Nile Virus (WNV) in complex with Fab fragments of the anti-fusion loop antibody E53
EMD-5103
Single-particle15.0 Å
Deposition: 26/02/2009
Map released: 10/09/2009
Last modified: 23/04/2014
Sample: Immature West Nile Virus complexed with E53 Fab
Fitted models: 3ixx (Avg. Q-score: 0.033)
Deposition Authors: Cherrier MV , Kaufmann B, Nybakken GE, Lok SM , Warren JT , Nelson CA, Kostyuchenko VA , Holdaway HA, Chipman PR , Kuhn RJ, Diamond MS, Rossmann MG, Fremont DH
Fitted models: 3ixx (Avg. Q-score: 0.033)
Deposition Authors: Cherrier MV , Kaufmann B, Nybakken GE, Lok SM , Warren JT , Nelson CA, Kostyuchenko VA , Holdaway HA, Chipman PR , Kuhn RJ, Diamond MS, Rossmann MG, Fremont DH
Structural basis for the preferential recognition of immature flaviviruses by a fusion-loop antibody.
Cherrier MV ,
Kaufmann B,
Nybakken GE,
Lok SM ,
Warren JT ,
Chen BR,
Nelson CA,
Kostyuchenko VA ,
Holdaway HA,
Chipman PR ,
Kuhn RJ,
Diamond MS,
Rossmann MG,
Fremont DH
(2009) Embo J. , 28 , 3269 - 3276
(2009) Embo J. , 28 , 3269 - 3276
Abstract:
Flaviviruses are a group of human pathogens causing severe encephalitic or hemorrhagic diseases that include West Nile, dengue and yellow fever viruses. Here, using X-ray crystallography we have defined the structure of the flavivirus cross-reactive antibody E53 that engages the highly conserved fusion loop of the West Nile virus envelope glycoprotein. Using cryo-electron microscopy, we also determined that E53 Fab binds preferentially to spikes in noninfectious, immature flavivirions but is unable to bind significantly to mature virions, consistent with the limited solvent exposure of the epitope. We conclude that the neutralizing impact of E53 and likely similar fusion-loop-specific antibodies depends on its binding to the frequently observed immature component of flavivirus particles. Our results elucidate how fusion-loop antibodies, which comprise a significant fraction of the humoral response against flaviviruses, can function to control infection without appreciably recognizing mature virions. As these highly cross-reactive antibodies are often weakly neutralizing they also may contribute to antibody-dependent enhancement and flavi virus pathogenesis thereby complicating development of safe and effective vaccines.
Flaviviruses are a group of human pathogens causing severe encephalitic or hemorrhagic diseases that include West Nile, dengue and yellow fever viruses. Here, using X-ray crystallography we have defined the structure of the flavivirus cross-reactive antibody E53 that engages the highly conserved fusion loop of the West Nile virus envelope glycoprotein. Using cryo-electron microscopy, we also determined that E53 Fab binds preferentially to spikes in noninfectious, immature flavivirions but is unable to bind significantly to mature virions, consistent with the limited solvent exposure of the epitope. We conclude that the neutralizing impact of E53 and likely similar fusion-loop-specific antibodies depends on its binding to the frequently observed immature component of flavivirus particles. Our results elucidate how fusion-loop antibodies, which comprise a significant fraction of the humoral response against flaviviruses, can function to control infection without appreciably recognizing mature virions. As these highly cross-reactive antibodies are often weakly neutralizing they also may contribute to antibody-dependent enhancement and flavi virus pathogenesis thereby complicating development of safe and effective vaccines.