#Monoclonal #antibodies with neutralizing activity and Fc-effector functions against the #Machupo virus glycoprotein (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Monoclonal antibodies with neutralizing activity and Fc-effector functions against the Machupo virus glycoprotein

Fatima Amanat, James Duehr, Cheng Huang, Slobodan Paessler, Gene Tan, Florian Krammer

DOI: 10.1128/JVI.01741-19

 

ABSTRACT

Machupo virus (MACV), the causative agent of Bolivian hemorrhagic fever (BHF), is a New World arenavirus that was first isolated in Bolivia from a human spleen in 1963. Due to the lack of a specific vaccine or therapy, this virus is considered a major risk to public health and is classified as a Category A Priority Pathogen by the US National Institutes of Health. In this study, we used DNA vaccination against the MACV glycoprotein precursor complex (GPC) and murine hybridoma technology to generate 25 mouse monoclonal antibodies (mAbs) against the GPC of MACV. Out of 25, five mAbs were found to have potent neutralization activity in vitro against a recombinant vesicular stomatitis virus expressing MACV GPC (VSV-MACV) as well as authentic MACV. Furthermore, the five neutralizing mAbs exhibited strong antibody-dependent cellular cytotoxicity (ADCC) activity in a reporter assay. When tested in vivo using VSV-MACV in a Stat2-/- mouse model, three mAbs significantly lowered viral loads in the spleen. Our work provides valuable insights into epitopes targeted by neutralizing antibodies that could be potent targets for vaccines and therapeutics, and shed light towards the importance of effector functions in immunity against MACV.

 

Significance

MACV infections are a significant public health concern and lead to high case fatality rates. No specific treatment or vaccine for MACV infections exist. However, cases of Junin virus infection, a related virus, can be treated with convalescent serum. This indicates, that a mAb-based therapy for MACV could be effective. Here, we describe several mAbs that neutralize MACV and could be used for this purpose.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Arenavirus; Machupo virus; Monoclonal antibodies; Bolivian Hemorrhagic Fever.

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Assessing cross-reactivity of #Junín virus-directed neutralizing #antibodies (Antiviral Res., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Antiviral Res. 2019 Jan 19. pii: S0166-3542(18)30591-6. doi: 10.1016/j.antiviral.2019.01.006. [Epub ahead of print]

Assessing cross-reactivity of Junín virus-directed neutralizing antibodies.

Leske A1, Waßmann I2, Schnepel K3, Shifflett K4, Holzerland J5, Bostedt L6, Bohn P7, Mettenleiter TC8, Briggiler AM9, Brignone J10, Enria D11, Cordo SM12, Hoenen T13, Groseth A14.

Author information: 1 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: anne.leske@fli.de. 2 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: iw142102@uni-greifswald.de. 3 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: kevin.schnepel@uni-rostock.de. 4 Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT, USA. Electronic address: kyle.shifflett@umconnect.umt.edu. 5 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: julia.holzerland@fli.de. 6 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: linus.bostedt@fli.de. 7 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: pb132684@uni-greifswald.de. 8 Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: thomasc.mettenleiter@fli.de. 9 Instituto Nacional de Enfermedades Virales Humanas, ANLIS, Pergamino, Argentina. Electronic address: abriggiler@hotmail.com. 10 Instituto Nacional de Enfermedades Virales Humanas, ANLIS, Pergamino, Argentina. Electronic address: jbrignone@anlis.gov.ar. 11 Instituto Nacional de Enfermedades Virales Humanas, ANLIS, Pergamino, Argentina. Electronic address: deliaenria@gmail.com. 12 Laboratory of Virology, IQUIBICEN-Department of Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. Electronic address: scordo@qb.fcen.uba.ar. 13 Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT, USA; Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany. Electronic address: thomas.hoenen@fli.de. 14 Junior Research Group Arenavirus Biology, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany; Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, MT, USA. Electronic address: allison.groseth@fli.de.

 

Abstract

Arenaviruses cause several viral hemorrhagic fevers endemic to Africa and South America. The respective causative agents are classified as biosafety level (BSL) 4 pathogens. Unlike for most other BSL4 agents, for the New World arenavirus Junín virus (JUNV) both a highly effective vaccination (Candid#1) and a post-exposure treatment, based on convalescent plasma transfer, are available. In particular, neutralizing antibodies (nAbs) represent a key protective determinant in JUNV infection, which is supported by the correlation between successful passive antibody therapy and the levels of nAbs administered. Unfortunately, comparable resources for the management of other closely related arenavirus infections are not available. Given the significant challenges inherent in studying BSL4 pathogens, our goal was to first assess the suitability of a JUNV transcription and replication-competent virus-like particle (trVLP) system for measuring virus neutralization under BSL1/2 conditions. Indeed, we could show that infection with JUNV trVLPs is glycoprotein (GP) dependent, that trVLP input has a direct correlation to reporter readout, and that these trVLPs can be neutralized by human serum with kinetics similar to those obtained using authentic virus. These properties make trVLPs suitable for use as a proxy for virus in neutralization assays. Using this platform we then evaluated the potential of JUNV nAbs to cross-neutralize entry mediated by GPs from other arenaviruses using JUNV (strain Romero)-based trVLPs bearing GPs either from other JUNV strains, other closely related New World arenaviruses (e.g. Tacaribe, Machupo, Sabiá), or the distantly related Lassa virus. While nAbs against the JUNV vaccine strain are also active against a range of other JUNV strains, they appear to have little or no capacity to neutralize other arenavirus species, suggesting that therapy with whole plasma directed against another species is unlikely to be successful and that the targeted development of cross-specific monoclonal antibody-based resources is likely needed. Such efforts will be supported by the availability of this BSL1/2 screening platform which provides a rapid and easy means to characterize the potency and reactivity of anti-arenavirus neutralizing antibodies against a range of arenavirus species.

Copyright © 2019. Published by Elsevier B.V.

KEYWORDS: Antibody cross-reactivity; Arenavirus; JunÍn virus; Neutralization assay; Neutralizing antibodies; Transcription and replication competent virus-like particle (trVLP) assay

PMID: 30668977 DOI: 10.1016/j.antiviral.2019.01.006

Keywords: Arenavirus; Junin virus; Machupo virus; Sabia virus; Tacaribe virus.

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#Antibodies to the Glycoprotein GP2 Subunit Cross-React between Old and New World #Arenaviruses (mSphere, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

mSphere. 2018 May 2;3(3). pii: e00189-18. doi: 10.1128/mSphere.00189-18. Print 2018 Jun 27.

Antibodies to the Glycoprotein GP2 Subunit Cross-React between Old and New World Arenaviruses.

Amanat F1, Duehr J1,2, Oestereich L3,4, Hastie KM5, Ollmann Saphire E5,6, Krammer F7.

Author information: 1 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA. 2 Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA. 3 Department of Virology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. 4 German Centre for Infection Research (DZIF), Partner Site Hamburg, Hamburg, Germany. 5 Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA. 6 Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, USA. 7 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA florian.krammer@mssm.edu.

 

Abstract

Arenaviruses pose a major public health threat and cause numerous infections in humans each year. Although most viruses belonging to this family do not cause disease in humans, some arenaviruses, such as Lassa virus and Machupo virus, are the etiological agents of lethal hemorrhagic fevers. The absence of a currently licensed vaccine and the highly pathogenic nature of these viruses both make the necessity of developing viable vaccines and therapeutics all the more urgent. Arenaviruses have a single glycoprotein on the surface of virions, the glycoprotein complex (GPC), and this protein can be used as a target for vaccine development. Here, we describe immunization strategies to generate monoclonal antibodies (MAbs) that cross-react between the glycoprotein complexes of both Old World and New World arenaviruses. Several monoclonal antibodies isolated from immunized mice were highly cross-reactive, binding a range of Old World arenavirus glycoproteins, including that of Lassa virus. One such monoclonal antibody, KL-AV-2A1, bound to GPCs of both New World and Old World viruses, including Lassa and Machupo viruses. These cross-reactive antibodies bound to epitopes present on the glycoprotein 2 subunit of the glycoprotein complex, which is relatively conserved among arenaviruses. Monoclonal antibodies binding to these epitopes, however, did not inhibit viral entry as they failed to neutralize a replication-competent vesicular stomatitis virus pseudotyped with the Lassa virus glycoprotein complex in vitro In addition, no protection from virus challenge was observed in in vivo mouse models. Even so, these monoclonal antibodies might still prove to be useful in the development of clinical and diagnostic assays.

 

IMPORTANCE

Several viruses in the Arenaviridae family infect humans and cause severe hemorrhagic fevers which lead to high case fatality rates. Due to their pathogenicity and geographic tropisms, these viruses remain very understudied. As a result, an effective vaccine or therapy is urgently needed. Here, we describe efforts to produce cross-reactive monoclonal antibodies that bind to both New and Old World arenaviruses. All of our MAbs seem to be nonneutralizing and nonprotective and target subunit 2 of the glycoprotein. Due to the lack of reagents such as recombinant glycoproteins and antibodies for rapid detection assays, our MAbs could be beneficial as analytic and diagnostic tools.

KEYWORDS: GP2; GPC; Junin; Lassa; Machupo; arenaviruses

PMID: 29720525 DOI: 10.1128/mSphere.00189-18

Keywords: Arenavirus; Monoclonal Antibodies; Machupo Virus; Lassa Fever.

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The #Ectodomain of #Glycoprotein from the Candid#1 #Vaccine Strain of #Junin Virus Rendered #Machupo Virus Partially Attenuated in Mice Lacking IFN-αβ/γ Receptor (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]

OPEN ACCESS / PEER-REVIEWED / RESEARCH ARTICLE

The Ectodomain of Glycoprotein from the Candid#1 Vaccine Strain of Junin Virus Rendered Machupo Virus Partially Attenuated in Mice Lacking IFN-αβ/γ Receptor

Takaaki Koma, Cheng Huang, Judith F. Aronson, Aida G. Walker, Milagros Miller, Jeanon N. Smith, Michael Patterson, Slobodan Paessler

Published: August 31, 2016 / http://dx.doi.org/10.1371/journal.pntd.0004969

 

Abstract

Machupo virus (MACV), a New World arenavirus, is the etiological agent of Bolivian hemorrhagic fever (BHF). Junin virus (JUNV), a close relative, causes Argentine hemorrhagic fever (AHF). Previously, we reported that a recombinant, chimeric MACV (rMACV/Cd#1-GPC) expressing glycoprotein from the Candid#1 (Cd#1) vaccine strain of JUNV is completely attenuated in a murine model and protects animals from lethal challenge with MACV. A rMACV with a single F438I substitution in the transmembrane domain (TMD) of GPC, which is equivalent to the F427I attenuating mutation in Cd#1 GPC, was attenuated in a murine model but genetically unstable. In addition, the TMD mutation alone was not sufficient to fully attenuate JUNV, indicating that other domains of the GPC may also contribute to the attenuation. To investigate the requirement of different domains of Cd#1 GPC for successful attenuation of MACV, we rescued several rMACVs expressing the ectodomain of GPC from Cd#1 either alone (MCg1), along with the TMD F438I substitution (MCg2), or with the TMD of Cd#1 (MCg3). All rMACVs exhibited similar growth curves in cultured cells. In mice, the MCg1 displayed significant reduction in lethality as compared with rMACV. The MCg1 was detected in brains and spleens of MCg1-infected mice and the infection was associated with tissue inflammation. On the other hand, all animals survived MCg2 and MCg3 infection without detectable levels of virus in various organs while producing neutralizing antibody against Cd#1. Overall our data suggest the indispensable role of each GPC domain in the full attenuation and immunogenicity of rMACV/Cd#1 GPC.

 

Author Summary

Machupo virus (MACV), a member of Arenaviridae family, causes Bolivian hemorrhagic fever (BHF) in humans. No approved vaccine or treatment are available to date despite the high case fatality rate of BHF. rMACV/Cd#1-GPC is fully attenuated and protects mice from lethal MACV challenge. Although one virulence determinant was found in the transmembrane domain of GPC (F438), other virulence determinants in GPC are very likely. Our new data indicated that the ectodomain of Cd#1 GPC is necessary, but not sufficient, for complete attenuation of the rMACV/Cd#1-GPC. This new finding may help generate highly attenuated MACVs for vaccine development and/or for drug screening purpose.

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Citation: Koma T, Huang C, Aronson JF, Walker AG, Miller M, Smith JN, et al. (2016) The Ectodomain of Glycoprotein from the Candid#1 Vaccine Strain of Junin Virus Rendered Machupo Virus Partially Attenuated in Mice Lacking IFN-αβ/γ Receptor. PLoS Negl Trop Dis 10(8): e0004969. doi:10.1371/journal.pntd.0004969

Editor: Gregory D. Ebel, Colorado State University, UNITED STATES

Received: April 28, 2016; Accepted: August 10, 2016; Published: August 31, 2016

Copyright: © 2016 Koma et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All sequence files are available from the DDBJ/EMBL/GenBank (accession number: LC123592, LC123593 and LC123594). The sequence data are available in S1 File, too.

Funding: This work was supported by Public Health Service grant R01AI093445/The National Institute of Allergy and Infectious Diseases/The National Institutes of Health to SP (https://www.niaid.nih.gov/researchfunding/grant/Pages/default.aspx). TK was supported in part by a JSPS Postdoctoral Fellowship for Research Abroad/The Japan Society for the Promotion of Science (https://www.jsps.go.jp/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Research; Abstracts; Arenavirus; Junin Virus; Machupo Virus.

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