Structural basis of broad ebolavirus neutralization by a human survivor antibody

West, Brandyn R.; Wec, Anna Z.; Moyer, Crystal L.; Fusco, Marnie L.; Ilinykh, P.A.; Huang, Kai; Wirchnianski, Ariel S.; James, Rebekah M.; Herbert, Andrew S.; Hui, Sean; Goodwin, Eileen; Howell, Katie A.; Kailasan, Shweta; Aman, M. Javad; Walker, Lauren M.; Dye, John M.; Bukreyev, Alexander; Chandran, Kartik; Saphire, Erica Ollmann

doi:10.1038/s41594-019-0191-4

Cited by 35 publications

(55 citation statements)

References 49 publications

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“…The base-binding antibodies c2G4 and c4G7 [31,32] also stabilized the low-FRET state, to a greater extent than KZ52 (Figure 5a). In contrast, ADI-15946, an antibody that competes with KZ52 but bridges the GP1 core and glycan cap [33][34][35], modestly stabilized the high-FRET state. We also tested nAbs ADI-15878 and ADI-15742, which contact the GP2 fusion loop and adjacent GP1 protomer [33,34,36].…”

Section: Neutralizing Antibodies Mediate Gp Conformationmentioning

confidence: 86%

Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics

Durham

Howard

Govindan

et al. 2020

Viruses

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The Ebola virus (EBOV) envelope glycoprotein (GP) mediates the fusion of the virion membrane with the membrane of susceptible target cells during infection. While proteolytic cleavage of GP by endosomal cathepsins and binding of the cellular receptor Niemann-Pick C1 protein (NPC1) are essential steps for virus entry, the detailed mechanisms by which these events promote membrane fusion remain unknown. Here, we applied single-molecule Förster resonance energy transfer (smFRET) imaging to investigate the structural dynamics of the EBOV GP trimeric ectodomain, and the functional transmembrane protein on the surface of pseudovirions. We show that in both contexts, pre-fusion GP is dynamic and samples multiple conformations. Removal of the glycan cap and NPC1 binding shift the conformational equilibrium, suggesting stabilization of conformations relevant to viral fusion. Furthermore, several neutralizing antibodies enrich alternative conformational states. This suggests that these antibodies neutralize EBOV by restricting access to GP conformations relevant to fusion. This work demonstrates previously unobserved dynamics of pre-fusion EBOV GP and presents a platform with heightened sensitivity to conformational changes for the study of GP function and antibody-mediated neutralization.

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Section: Neutralizing Antibodies Mediate Gp Conformationmentioning

confidence: 86%

Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics

Durham

Howard

Govindan

et al. 2020

Viruses

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“…Cleavage removes the glycan cap with the b17-b18 loop and exposes the pocket, which explained enhanced binding of rEBOV-520 to GP CL ( Figure 1C) and enhanced neutralization potency of this mAb against virions bearing the GP CL compared with intact GP . Previous work suggested that binding of the non-neutralizing macaque mAb FVM09 to the b17-b18 loop itself displaces the loop causing unmasking of the neutralizing epitopes for mAbs 2G4 and ADI-15946 on the GP base (Howell et al, 2017;West et al, 2019). However, unlike with FVM09, Figure 4.…”

Section: Identification and Functional Properties Of Candidate Cocktamentioning

confidence: 94%

“…base of each protomer of GP CL , and the constant domains were oriented upward from the viral membrane ( Figure 3C). The rE-BOV-520 footprint includes relatively conserved regions including the internal fusion loop (IFL) stem of the GP2 subunit and the hydrophobic pocket formed by five residues of the GP1 subunit and termed previously the ''3 10 '' pocket (Zhao et al, 2016;West et al, 2019). The footprint of rEBOV-520 is distinct from that of the previously described broad human base-specific mAb ADI-15878 West et al, 2018) but is similar to the footprint of the potent human-base-specific mAb ADI-15946 ( Figure 3D), which fully neutralizes EBOV and BDBV but not SUDV (Wec et al, 2017;West et al, 2019).…”

Section: Identification and Functional Properties Of Candidate Cocktamentioning

confidence: 99%

“…The rE-BOV-520 footprint includes relatively conserved regions including the internal fusion loop (IFL) stem of the GP2 subunit and the hydrophobic pocket formed by five residues of the GP1 subunit and termed previously the ''3 10 '' pocket (Zhao et al, 2016;West et al, 2019). The footprint of rEBOV-520 is distinct from that of the previously described broad human base-specific mAb ADI-15878 West et al, 2018) but is similar to the footprint of the potent human-base-specific mAb ADI-15946 ( Figure 3D), which fully neutralizes EBOV and BDBV but not SUDV (Wec et al, 2017;West et al, 2019). Both ADI-15946 and rEBOV-520 bound to the 3 10 pocket and IFL stem regions of the fusion loop, unlike human mAb ADI-15878, which binds to the hydrophobic loop end of the structure and bridges to a neighboring GP protomer (King et al, 2019).…”

Section: Identification and Functional Properties Of Candidate Cocktamentioning

confidence: 99%

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Analysis of a Therapeutic Antibody Cocktail Reveals Determinants for Cooperative and Broad Ebolavirus Neutralization

et al. 2020

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Graphical AbstractHighlights d Human mAbs of two epitope specificities bind cooperatively to the ebolavirus GP d Cooperativity is mediated by a mAb that enhances binding to a vulnerable GP epitope d A two-mAb cocktail exhibits enhanced potency against heterologous ebolaviruses d Two 30 mg/kg doses of the cocktail fully protected nonhuman primates (NHPs) challenged with EBOV SUMMARY Structural principles underlying the composition of protective antiviral monoclonal antibody (mAb) cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic mAb cocktail against Ebola virus. We systematically analyzed the antibody repertoire in human survivors and identified a pair of potently neutralizing mAbs that cooperatively bound to the ebolavirus glycoprotein (GP). High-resolution structures revealed that in a twoantibody cocktail, molecular mimicry was a major feature of mAb-GP interactions. Broadly neutralizing mAb rEBOV-520 targeted a conserved epitope on the GP base region. mAb rEBOV-548 bound to a glycan cap epitope, possessed neutralizing and Fc-mediated effector function activities, and potentiated neutralization by rEBOV-520. Remodeling of the glycan cap structures by the cocktail enabled enhanced GP binding and virus neutralization. The cocktail demonstrated resistance to virus escape and protected non-human primates (NHPs) against Ebola virus disease. These data illuminate structural principles of antibody cooperativity with implications for development of antiviral immunotherapeutics.

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“…Nine solved structures for EBOV glycoproteins are found in the Protein Data Bank (Berman et al 2003) with the following codes: 5JQ3, 6QD7, 6QD8, 6MAM, 6EA7, 5KEL, 5KEN, 6EA5, and 5KEM with a resolution of 2. 23, 3.10, 3.30, 4.10, 4.25, 4.30, 4.30, 4.75, and 5.50 Å, respectively (Ehrhardt et al 2019;Pallesen et al 2016;West et al 2018West et al , 2019. Four of these structures are solved by x-ray crystallography (5JQ3, 6MAM, 6EA7, and 6EA5), while the rest are solved by cryo-electron microscopy.…”

Section: Methodsmentioning

confidence: 99%

Ebola virus glycoprotein GP1—host cell-surface HSPA5 binding site prediction

Elfiky

2020

Cell Stress and Chaperones

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Ebola virus (EBOV) infection is a widespread infection that has created a bad memory in Africa. In the 2014 and 2015 outbreak, more than 28,000 infections were reported by the World Health Organization, with about 11,300 deaths in Guinea, Liberia, and Sierra Leone. Heat shock protein A5 (HSPA5), termed also GRP78, is a host cell chaperone protein responsible for the unfolded protein response in the endoplasmic reticulum. Under stress, HSPA5 is upregulated and becomes cell-surface exposed. Recent studies report the association of cell-surface HSPA5 with EBOV glycoproteins GP1 and GP2. In this study, structural and sequence analysis and molecular docking are used to predict the possible binding site between the cell-surface HSPA5 and EBOV GP1. The results show a promising binding site that supports the hypothesis of HSPA5 selectivity for binding to a specific peptide sequence (pep42). This study paves the way to suggest possible inhibitors to stop viral association with cell-surface receptors and subsequently reduce viral infection.

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Structural basis of broad ebolavirus neutralization by a human survivor antibody

Cited by 35 publications

References 49 publications

Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics

Real-Time Analysis of Individual Ebola Virus Glycoproteins Reveals Pre-Fusion, Entry-Relevant Conformational Dynamics

Analysis of a Therapeutic Antibody Cocktail Reveals Determinants for Cooperative and Broad Ebolavirus Neutralization

Ebola virus glycoprotein GP1—host cell-surface HSPA5 binding site prediction

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