A Therapeutic Antibody against West Nile Virus Neutralizes Infection by Blocking Fusion within Endosomes

Thompson, Bruce S.; Moesker, Bastiaan; Smit, Jolanda M.; Wilschut, Jan; Diamond, Michael S.; Fremont, Daved H.

doi:10.1371/journal.ppat.1000453

Cited by 94 publications

(97 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the high degree of aggregation prevented detailed structural analysis. The reduction of particle aggregation at low pH in the presence of Fab is consistent with the hypothesis that E16 blocks the fusion process prior to exposure of the fusion loop [13][14][15].…”

Section: Resultssupporting

confidence: 86%

“…The E glycoprotein is the principal antigen that elicits neutralizing antibodies against flaviviruses [11]. The monoclonal antibody (mAb) E16 neutralizes WNV primarily at a postattachment stage, probably by interfering with the pH-induced reorganization of E prior to fusion [12][13][14][15]. In the present study, cryo-electron microscopy (cryoEM) was used to examine WNV complexes with E16 antigen binding fragments (Fab) after exposure to low pH.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Capturing a Flavivirus Pre-Fusion Intermediate

Kaufmann¹,

Chipman²,

Holdaway³

et al. 2014

Selected Papers of Michael G Rossmann With Commentaries

Self Cite

View full text Add to dashboard Cite

During cell entry of flaviviruses, low endosomal pH triggers the rearrangement of the viral surface glycoproteins to a fusionactive state that allows the release of the infectious RNA into the cytoplasm. In this work, West Nile virus was complexed with Fab fragments of the neutralizing mAb E16 and was subsequently exposed to low pH, trapping the virions in a prefusion intermediate state. The structure of the complex was studied by cryo-electron microscopy and provides the first structural glimpse of a flavivirus fusion intermediate near physiological conditions. A radial expansion of the outer protein layer of the virion was observed compared to the structure at pH 8. The resulting ,60 Å -wide shell of low density between lipid bilayer and outer protein layer is likely traversed by the stem region of the E glycoprotein. By using antibody fragments, we have captured a structural intermediate of a virus that likely occurs during cell entry. The trapping of structural transition states by antibody fragments will be applicable for other processes in the flavivirus life cycle and delineating other cellular events that involve conformational rearrangements.

show abstract

Section: Resultssupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Capturing a Flavivirus Pre-Fusion Intermediate

Kaufmann¹,

Chipman²,

Holdaway³

et al. 2014

Selected Papers of Michael G Rossmann With Commentaries

Self Cite

View full text Add to dashboard Cite

show abstract

“…Hu-E16 derived from mammalian cells is highly potent against almost all WNV strains because it binds a conserved epitope and blocks viral fusion (11). Compared to the parent mHu-E16, pHu-E16 showed equivalent binding kinetics and neutralization activity in vitro.…”

Section: Discussionmentioning

confidence: 99%

“…This mAb is highly inhibitory because it blocks viral fusion at concentrations that result in low occupancy of accessible sites on the virion (10,11). Hu-E16 has therapeutic activity in rodents even after WNV has entered the central nervous system (9,12), in part because it can directly disrupt virus transmission between neurons (13).…”

mentioning

confidence: 99%

Monoclonal antibody produced in plants efficiently treats West Nile virus infection in mice

Lai

Engle²,

Fuchs³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

106

178

View full text Add to dashboard Cite

Over the past decade, West Nile virus (WNV) has spread to all 48 of the lower United States as well as to parts of Canada, Mexico, the Caribbean, and South America, with outbreaks of neuroinvasive disease occurring annually. At present, no therapeutic or vaccine is available for human use. Epidemics of WNV and other emerging infectious disease threats demand cost-efficient and scalable production technologies that can rapidly transfer effective therapeutics into the clinical setting. We have previously reported that Hu-E16, a humanized anti-WNV mAb, binds to a highly conserved epitope on the envelope protein, blocks viral fusion, and shows promising postexposure therapeutic activity. Herein, we generated a plant-derived Hu-E16 mAb that can be rapidly scaled up for commercial production. Plant Hu-E16 was expressed at high levels within 8 days of infiltration in Nicotiana benthamiana plants and retained high-affinity binding and potent neutralizing activity in vitro against WNV. A single dose of plant Hu-E16 protected mice against WNV-induced mortality even 4 days after infection at rates that were indistinguishable from mammalian-cell-produced Hu-E16. This study demonstrates the efficacy of a plant-produced mAb against a potentially lethal infection several days after exposure in an animal challenge model and provides a proof of principle for the development of plant-derived mAbs as therapy against emerging infectious diseases.

show abstract

“…Some clinical cases of arboviral encephalitis can be mitigated successfully if medication is started as soon as possible. A number of therapeutic drugs specific to arboviral infections are under investigation for their potential antiviral and neuroprotective effects: minocycline and curcumin for JEV and other arboviruses [87][88][89], ribavirin for LACV [90], interferon (Omr-IgG-aM) and humanized monoclonal antibody (Mab E16) as a potential candidate for WNV treatment [61,91,92]. However, currently there is limited information available on the effectiveness of these therapeutic modalities in the clinical setting.…”

Section: Treatment Of Arboviral Infectionsmentioning

confidence: 99%