Development of a Human Antibody Cocktail that Deploys Multiple Functions to Confer Pan-Ebolavirus Protection

Wec, Anna Z.; Bornholdt, Zachary A.; He, Shihua; Herbert, Andrew S.; Goodwin, Eileen; Wirchnianski, Ariel S.; Gunn, Bronwyn M.; Zhang, Zirui; Zhu, Wenjun; Liu, Guodong; Abelson, Dafna M.; Moyer, Crystal L.; Jangra, Rohit K.; James, Rebekah M.; Bakken, Russell R.; Bohorova, Natasha; Bohorov, Ognian; Kim, Dowhan; Pauly, Michael; Velasco, Jesús; Bortz, Robert H.; Whaley, Kevin J.; Goldstein, Tracey; Anthony, Simon J.; Alter, Galit; Walker, Laura M.; Dye, John M.; Zeitlin, Larry; Qiu, Xiangguo; Chandran, Kartik

doi:10.1016/j.chom.2018.12.004

Cited by 95 publications

(76 citation statements)

References 52 publications

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“…Many other small molecules have failed to progress beyond guinea pig for EBOV due to a lack of significant efficacy (7, 48–51). While antibodies have been successfully used in this animal model (52, 53), these failures may represent a significant limitation of the guinea pig model to extrapolate small-molecule efficacy against EBOV in humans. We have demonstrated there are substantial metabolic stability differences between mouse, non-human primate, human and guinea pig (25), with the latter having a considerably lower metabolic stability for pyronaridine (Table 2).…”

Section: Discussionmentioning

confidence: 99%

Pyronaridine Tetraphosphate Efficacy Against Ebola Virus Infection in Guinea Pig

Lane

Massey²,

Comer³

et al. 2020

Preprint

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31The recent outbreaks of the Ebola virus (EBOV) in Africa have brought global visibility to 32 the shortage of available therapeutic options to treat patients infected with this or closely 33 related viruses. We have recently computationally identified three molecules which have 34 all demonstrated statistically significant efficacy in the mouse model of infection with 35 mouse adapted Ebola virus (ma-EBOV). One of these molecules is the antimalarial 36 pyronaridine tetraphosphate (IC 50 range of 0.82-1.30 µM against three strains of EBOV 37 and IC 50 range of 1.01-2.72 µM against two strains of Marburg virus (MARV)) which is 38 an approved drug in the European Union and used in combination with artesunate. To 39 date, no small molecule drugs have shown statistically significant efficacy in the guinea 40 pig model of EBOV infection. Pharmacokinetics and range-finding studies in guinea pigs 41 directed us to a single 300mg/kg or 600mg/kg oral dose of pyronaridine 1hr after 42 infection. Pyronaridine resulted in statistically significant survival of 40% at 300mg/kg 43 and protected from a lethal challenge with EBOV. In comparison, oral favipiravir (300 44 mg/kg dosed once a day) had 43.5 % survival. The in vitro metabolism and metabolite 45 identification of pyronaridine and another of our EBOV active molecules, tilorone, which 46 suggests significant species differences which may account for the efficacy or lack 47 thereof, respectively in guinea pig. In summary, our studies with pyronaridine 48 demonstrates its utility for repurposing as an antiviral against EBOV and MARV, 49 providing justification for future testing in non-human primates. 50 51 52 4 Importance 53There is currently no antiviral small molecule drug approved for treating Ebola Virus 54 infection. We have previously used machine learning models to identify new uses for 55 approved drugs and demonstrated their activity against the Ebola virus in vitro and in 56 vivo. We now describe the pharmacokinetic properties of the antimalarial pyronaridine in 57 the guinea pig. In addition, we show that this drug is effective against multiple strains of 58 EBOV and MARV in vitro and in the guinea pig model of Ebola virus infection. These 59 combined efforts indicate the need to further test this molecule in larger animal efficacy 60 studies prior to clinical use in humans. These findings also may be useful for 61 repurposing this drug for use against other viruses in future. 62 63

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Section: Discussionmentioning

confidence: 99%

Pyronaridine Tetraphosphate Efficacy Against Ebola Virus Infection in Guinea Pig

Lane

Massey²,

Comer³

et al. 2020

Preprint

View full text Add to dashboard Cite

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“…This might be attributed to the lower immunogenicity of the S2 than the S1 domain, as is the case for the influenza virus HA2 stalk domain [45]. The practical use of antibody cocktails has been used for Ebola virus [46,47], hepatitis C virus [48], and MERS-CoV [17] to prevent the emergence of escape mutants as well as enhance the neutralization breadth. We suggest that combining RBD mAbs and non-RBD mAbs, targeting multiple antigenic sites on MERS-CoV spike, need to be implemented for treating future MERS-CoV infection.…”

Section: Plos Onementioning

confidence: 99%

Characterization of a human monoclonal antibody generated from a B-cell specific for a prefusion-stabilized spike protein of Middle East respiratory syndrome coronavirus

et al. 2020

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Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory infection and continues to infect humans, thereby contributing to a high mortality rate (34.3% in 2019). In the absence of an available licensed vaccine and antiviral agent, therapeutic human antibodies have been suggested as candidates for treatment. In this study, human monoclonal antibodies were isolated by sorting B cells from patient's PBMC cells with prefusion stabilized spike (S) probes and a direct immunoglobulin cloning strategy. We identified six receptor-binding domain (RBD)-specific and five S1 (non-RBD)-specific antibodies, among which, only the RBD-specific antibodies showed high neutralizing potency (IC 50 0.006-1.787 μg/ml) as well as high affinity to RBD. Notably, passive immunization using a highly potent antibody (KNIH90-F1) at a relatively low dose (2 mg/kg) completely protected transgenic mice expressing human DPP4 against MERS-CoV lethal challenge. These results suggested that human monoclonal antibodies isolated by using the rationally designed prefusion MERS-CoV S probe could be considered potential candidates for the development of therapeutic and/or prophylactic antiviral agents for MERS-CoV human infection.

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“…Because GP→GP CL cleavage is a prerequisite for cell entry by all filoviruses that have been evaluated to date (22,24,47), we postulated that this cleavage also destabilizes GPs from divergent ebolaviruses. Accordingly, we used the pan-ebolavirus base-binding mAb ADI-15878 to probe the thermal stability of GPs from the divergent ebolaviruses Sudan virus (SUDV) and the recently discovered Bombali virus (BOMV) in the epitope-loss ELISA (48)(49)(50)(51). THL cleavage of SUDV GP and BOMV GP was verified by western blot ( Fig 3A).…”

Section: The Gp Proteins Of Other Ebolaviruses Are Also Destabilized mentioning

confidence: 99%

A virion-based assay for glycoprotein thermostability reveals key determinants of filovirus entry and its inhibition

Bortz

Wong

Grodus

et al. 2020

Preprint

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Ebola virus (EBOV) entry into cells is mediated by its spike glycoprotein (GP). Following attachment and internalization, virions traffic to late endosomes where GP is cleaved by host cysteine proteases.Cleaved GP then binds its cellular receptor, Niemann-Pick C1. In response to an unknown cellular trigger, GP undergoes conformational rearrangements that drive fusion of viral and endosomal membranes . The temperature-dependent stability (thermostability) of the pre-fusion conformers of 'Class I' viral fusion glycoproteins, including those of filovirus GPs, has provided insights into their propensity to undergo fusion-related rearrangements. However, previously described assays have relied on soluble glycoprotein ectodomains. Here, we developed a simple ELISA-based assay that uses the temperature-dependent loss of conformational epitopes to measure thermostability of GP embedded in viral membranes. The base and glycan cap subdomains of all filovirus GPs tested suffered a concerted loss of pre-fusion conformation at elevated temperatures, but did so at different temperature ranges, indicating virus-specific differences in thermostability. Despite these differences, all of these GPs displayed reduced thermostability upon cleavage to GP CL . Surprisingly, acid pH enhanced, rather than decreased, GP thermostability, suggesting it could enhance viral survival in hostile endo/lysosomal compartments. Finally, we confirmed and extended previous findings that some small-molecule inhibitors of filovirus entry destabilize EBOV GP and uncovered evidence that the most potent inhibitors act through multiple mechanisms. We establish the epitope-loss ELISA as a useful tool for studies of filovirus entry, engineering of GP variants with enhanced stability for use in vaccine development, and discovery of new stability-modulating antivirals. ImportanceThough a vaccine for Ebola virus has been approved by the FDA within the past year, no FDA-approved therapeutics are available to treat infections by Ebola virus or other filoviruses. The development of such countermeasures is challenged by our limited understanding of the mechanism by which Ebola virus enters cells, especially at the final step of membrane fusion. The sole surface-exposed viral protein, GP, mediates key steps in virus entry, including membrane fusion, and undergoes major structural rearrangements during this process. The stability of GP at elevated temperatures (thermostability) can provide insights into its capacity to undergo these structural rearrangements.Here, we describe a new assay that uses GP-specific antibodies to measure GP thermostability under a variety of conditions relevant to viral entry. We show that proteolytic cleavage and acid pH have significant effects on GP thermostability that shed light on their respective roles in viral entry. We also show that the assay can be used to study how small-molecule entry inhibitors affect GP stability. This work provides a simple and readily accessible assay to engineer forms of GP with enhanced stability that cou...

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Development of a Human Antibody Cocktail that Deploys Multiple Functions to Confer Pan-Ebolavirus Protection

Cited by 95 publications

References 52 publications

Pyronaridine Tetraphosphate Efficacy Against Ebola Virus Infection in Guinea Pig

Pyronaridine Tetraphosphate Efficacy Against Ebola Virus Infection in Guinea Pig

Characterization of a human monoclonal antibody generated from a B-cell specific for a prefusion-stabilized spike protein of Middle East respiratory syndrome coronavirus

A virion-based assay for glycoprotein thermostability reveals key determinants of filovirus entry and its inhibition

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