#Marburg virus #RNA #synthesis is inhibited by a synthetic anti-VP35 #antibody (ACS Infect Dis., abstract)

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

ACS Infect Dis. 2019 May 23. doi: 10.1021/acsinfecdis.9b00091. [Epub ahead of print]

Marburg virus RNA synthesis is inhibited by a synthetic anti-VP35 antibody.

Amatya P, Wagner N, Chen G, Luthra P, Shi L, Borek D, Pavlenco A, Rohrs HW, Basler CF, Sidhu SS, Gross ML, Leung DW.

 

Abstract

Marburg virus causes sporadic outbreaks of severe hemorrhagic fever with high case fatality rates. Approved, effective, and safe therapeutic or prophylactic countermeasures are lacking. To address this, we used phage display to engineer a synthetic antibody, sFab H3, which binds the Marburg virus VP35 protein (mVP35). mVP35 is a critical cofactor of the viral replication complex and a viral immune antagonist. sFab H3 displayed high specificity for mVP35 and not for the closely related Ebola virus VP35. sFab H3 inhibited viral RNA synthesis in a minigenome assay, suggesting its potential use as an antiviral. We characterized sFab H3 by a combination of biophysical and biochemical methods, and a crystal structure of the complex solved to 1.7 Å resolution defined the molecular interface between sFab H3 and mVP35 interferon inhibitory domain. Our study identifies mVP35 as a therapeutic target using an approach that provides a framework for generating engineered Fabs targeting other viral proteins.

PMID: 31120240 DOI: 10.1021/acsinfecdis.9b00091

Keywords: Marburg virus; Monoclonal antibodies.

——

Advertisements

Longitudinal #Analysis of the #Human B Cell Response to #Ebola Virus #Infection (Cell, abstract)

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

Cell. 2019 May 10. pii: S0092-8674(19)30455-6. doi: 10.1016/j.cell.2019.04.036. [Epub ahead of print]

Longitudinal Analysis of the Human B Cell Response to Ebola Virus Infection.

Davis CW1, Jackson KJL2, McElroy AK3, Halfmann P4, Huang J1, Chennareddy C1, Piper AE5, Leung Y6, Albariño CG7, Crozier I8, Ellebedy AH9, Sidney J10, Sette A11, Yu T12, Nielsen SCA13, Goff AJ5, Spiropoulou CF7, Saphire EO14, Cavet G6, Kawaoka Y15, Mehta AK16, Glass PJ5, Boyd SD13, Ahmed R17.

Author information: 1 Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA. 2 Department of Pathology, Stanford University, Stanford, CA, USA; Immunology Division, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia. 3 Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA; Division of Pediatric Infectious Disease, Emory University, Atlanta, GA, USA; Division of Pediatric Infectious Disease, University of Pittsburgh, Pittsburgh, PA, USA. 4 Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA. 5 Virology Division, United States Army Medical Research Institute for Infectious Diseases, Fort Detrick, MD, USA. 6 Atreca, Redwood City, CA, USA. 7 Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA. 8 Integrated Research Facility at Fort Detrick, Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institutes, Frederick, MD, USA. 9 Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA; Division of Immunobiology, Department of Pathology and Immunology Washington University School of Medicine, St. Louis, MO, USA. 10 Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA. 11 Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA; Department of Medicine, University of California San Diego, La Jolla, CA, USA. 12 Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, USA. 13 Department of Pathology, Stanford University, Stanford, CA, USA. 14 Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA, USA; La Jolla Institute for Immunology, La Jolla, CA, USA. 15 Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI, USA; Division of Virology, Department of Microbiology and Immunology, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan. 16 Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA, USA. 17 Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA. Electronic address: rahmed@emory.edu.

 

Abstract

Ebola virus (EBOV) remains a public health threat. We performed a longitudinal study of B cell responses to EBOV in four survivors of the 2014 West African outbreak. Infection induced lasting EBOV-specific immunoglobulin G (IgG) antibodies, but their subclass composition changed over time, with IgG1 persisting, IgG3 rapidly declining, and IgG4 appearing late. Striking changes occurred in the immunoglobulin repertoire, with massive recruitment of naive B cells that subsequently underwent hypermutation. We characterized a large panel of EBOV glycoprotein-specific monoclonal antibodies (mAbs). Only a small subset of mAbs that bound glycoprotein by ELISA recognized cell-surface glycoprotein. However, this subset contained all neutralizing mAbs. Several mAbs protected against EBOV disease in animals, including one mAb that targeted an epitope under evolutionary selection during the 2014 outbreak. Convergent antibody evolution was seen across multiple donors, particularly among VH3-13 neutralizing antibodies specific for the GP1 core. Our study provides a benchmark for assessing EBOV vaccine-induced immunity.

Copyright © 2019 Elsevier Inc. All rights reserved.

KEYWORDS: B cell repertoire; Ebola; IgG subclass; antibody evolution; public clonotype

PMID: 31104840 DOI: 10.1016/j.cell.2019.04.036

Keywords: Ebola; Immunology; Immunoglobulins; Serology.

——

A Site of #Vulnerability on the #Influenza Virus #Hemagglutinin Head Domain Trimer Interface (Cell, abstract)

[Source: Cell, full page: (LINK). Abstract, edited.]

Cell. 2019 May 16;177(5):1136-1152.e18. doi: 10.1016/j.cell.2019.04.011.

A Site of Vulnerability on the Influenza Virus Hemagglutinin Head Domain Trimer Interface.

Bangaru S1, Lang S2, Schotsaert M3, Vanderven HA4, Zhu X2, Kose N5, Bombardi R5, Finn JA1, Kent SJ4, Gilchuk P5, Gilchuk I5, Turner HL2, García-Sastre A6, Li S7, Ward AB2, Wilson IA8, Crowe JE Jr9.

Author information: 1 Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA. 2 Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. 3 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. 4 Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia. 5 The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA. 6 Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. 7 Department of Medicine and Biomedical Sciences, School of Medicine, University of California, San Diego, CA 92093, USA. 8 Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: wilson@scripps.edu. 9 Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA. Electronic address: james.crowe@vanderbilt.edu.

 

Abstract

Here, we describe the discovery of a naturally occurring human antibody (Ab), FluA-20, that recognizes a new site of vulnerability on the hemagglutinin (HA) head domain and reacts with most influenza A viruses. Structural characterization of FluA-20 with H1 and H3 head domains revealed a novel epitope in the HA trimer interface, suggesting previously unrecognized dynamic features of the trimeric HA protein. The critical HA residues recognized by FluA-20 remain conserved across most subtypes of influenza A viruses, which explains the Ab’s extraordinary breadth. The Ab rapidly disrupted the integrity of HA protein trimers, inhibited cell-to-cell spread of virus in culture, and protected mice against challenge with viruses of H1N1, H3N2, H5N1, or H7N9 subtypes when used as prophylaxis or therapy. The FluA-20 Ab has uncovered an exceedingly conserved protective determinant in the influenza HA head domain trimer interface that is an unexpected new target for anti-influenza therapeutics and vaccines.

Copyright © 2019 Elsevier Inc. All rights reserved.

KEYWORDS: B-lymphocytes; antibodies; antibody-dependent cell cytotoxicity; antigen-antibody reactions; hemagglutinin glycoproteins; influenza A virus; influenza virus; monoclonal; viral

PMID: 31100268 DOI: 10.1016/j.cell.2019.04.011

Keywords: Influenza A; H1N1; H3N2; H5N1; H7N9; Monoclonal antibodies; Animal models.

——-

#Human #monoclonal #antibodies potently neutralize #Zika virus and select for escape mutations on the lateral ridge of the envelope protein (J Virol., abstract)

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

Human monoclonal antibodies potently neutralize Zika virus and select for escape mutations on the lateral ridge of the envelope protein

Mark J. Bailey, Felix Broecker, Alec Freyn, Angela Choi, Julia A. Brown, Nadia Fedorova, Viviana Simon, Jean K. Lim, Matthew J. Evans, Adolfo García-Sastre, Peter Palese, Gene S. Tan

DOI: 10.1128/JVI.00405-19

 

ABSTRACT

The mosquito-borne Zika virus has been causing epidemic outbreaks on a global scale. Virus infection can result in severe disease in humans including microcephaly in newborns and Guillain-Barré syndrome in adults. Here, we characterized monoclonal antibodies isolated from a patient with an active Zika virus infection that potently neutralized virus infection in Vero cells at the nanogram per milliliter range. In addition, these antibodies enhanced internalization of virions into human leukemia K562 cells in vitro, indicating their possible ability to cause antibody-dependent enhancement of disease. Escape variants of the ZIKV MR766 strain to a potently neutralizing antibody, AC10, exhibited an amino acid substitution at residue S368 in the lateral ridge region of the envelope protein. Analysis of publicly availably ZIKV sequences revealed the S368 site to be conserved among the vast majority (97.6%) of circulating strains. We validated the importance of this residue by engineering a recombinant virus with an S368R point mutation that was unable to be fully neutralized by AC10. Four out of the twelve monoclonal antibodies tested were also unable to neutralize the virus with the S368R mutation, suggesting this region to be an important immunogenic epitope during human infection. Lastly, a time of addition infection assay further validated the escape variant and showed that all monoclonal antibodies inhibited virus binding to the cell surface. Thus, the present study demonstrates that the lateral ridge region of the envelope protein is likely an immunodominant, neutralizing epitope.

 

IMPORTANCE

Zika virus (ZIKV) is a global health threat causing severe disease in humans including microcephaly in newborns and Guillain-Barré syndrome in adults. Here, we analyzed the human monoclonal antibody response to acute ZIKV infection and found that neutralizing antibodies could not elicit Fc-mediated immune effector functions but could potentiate antibody-dependent enhancement of disease. We further identified critical epitopes involved with neutralization by generating and characterizing escape variants by whole genome sequencing. We demonstrate the lateral ridge region, particularly the S368 amino acid site, is critical for neutralization by domain III specific antibodies.

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

Keywords: Zika Virus; Monoclonal antibodies.

——

Development of Neutralizing #Antibodies against #Zika Virus Based on Its #Envelope #Protein Structure (Virol Sin., abstract)

[Source: Virologica Sinica, full page: (LINK). Abstract, edited.]

Development of Neutralizing Antibodies against Zika Virus Based on Its Envelope Protein Structure

Authors: Chunpeng Yang, Rui Gong, Natalia de Val

Open Access / Review / First Online: 24 April 2019

 

Abstract

As we know more about Zika virus (ZIKV), as well as its linkage to birth defects (microcephaly) and autoimmune neurological syndromes, we realize the importance of developing an efficient vaccine against it. Zika virus disease has affected many countries and is becoming a major public health concern. To deal with the infection of ZIKV, plenty of experiments have been done on selection of neutralizing antibodies that can target the envelope (E) protein on the surface of the virion. However, the existence of antibody-dependent enhancement (ADE) effect might limit the use of them as therapeutic candidates. In this review, we classify the neutralizing antibodies against ZIKV based on the epitopes and summarize the resolved structural information on antibody/antigen complex from X-ray crystallography and cryo-electron microscopy (cryo-EM), which might be useful for further development of potent neutralizing antibodies and vaccines toward clinical use.

Keywords: Zika virus (ZIKV) – Envelope protein – Neutralizing antibody – X-ray crystallography – Cryo-electron microscopy (cryo-EM)

Keywords: Zika Virus; Monoclonal antibodies; A.D.E.

——

Localization #Analysis of Heterophilic #Antigen Epitopes of #H1N1 #Influenza Virus #Hemagglutinin (Virol Sin., abstract)

[Source: Virologica Sinica, full page: (LINK). Abstract, edited.]

Localization Analysis of Heterophilic Antigen Epitopes of H1N1 Influenza Virus Hemagglutinin

Authors: Chun-Yan Guo, Hai-Xiang Zhang, Jun-Jun Zhang, Li-Jun Sun, Hui-Jin Li, Dao-Yan Liang, Qing Feng, Yan Li, Yang-Meng Feng, Xin Xie, Jun Hu

Research Article / First Online: 24 April 2019

 

Abstract

Previous studies have indicated that two monoclonal antibodies (mAbs; A1-10 and H1-84) of the hemagglutinin (HA) antigen on the H1N1 influenza virus cross-react with human brain tissue. It has been proposed that there are heterophilic epitopes between the HA protein and human brain tissue (Guo et al. in Immunobiology 220:941–946, 2015). However, characterisation of the two mAbs recognising the heterophilic epitope on HA has not yet been performed. In the present study, the common antigens of influenza virus HA were confirmed using indirect enzyme-linked immunosorbent assays and analysed with DNAMAN software. The epitopes were localized to nine peptides in the influenza virus HA sequence and the distribution of the peptides in the three-dimensional structure of HA was determined using PyMOL software. Key amino acids and variable sequences of the antibodies were identified using abYsis software. The results demonstrated that there were a number of common antigens among the five influenza viruses studied that were recognised by the mAbs. One of the peptides, P2 (LVLWGIHHP191–199), bound both of the mAbs and was located in the head region of HA. The key amino acids of this epitope and the variable regions in the heavy and light chain sequences of the mAbs that recognised the epitope are described. A heterophilic epitope on H1N1 influenza virus HA was also introduced. The existence of this epitope provides a novel perspective for the occurrence of nervous system diseases that could be caused by influenza virus infection, which might aid in influenza prevention and control.

Keywords: H1N1 – influenza virus – HA – antigen – Monoclonal antibody – Localization – Heterophilic epitope

___

Chun-Yan Guo and Hai-Xiang Zhang have contributed equally to this work.

Electronic supplementary material

The online version of this article ( https://doi.org/10.1007/s12250-019-00100-9) contains supplementary material, which is available to authorized users.

 

Notes

Acknowledgements

This work was supported by The National Key Research and Development Program of China (Grant No. 2016YFD0500700), The Natural Science Basic Research Program of Shaanxi Province (Grant No. 2016JM8065) and Shaanxi Provincial People’s Hospital Incubation Fund Program (Grant No. 2015YX-4).

Author Contributions

CG, XX and LS designed the experiments. CG, JZ, HL, DL, QF, YL and YF conducted the experiments. CG and JH analyzed the data. CG and HZ wrote the paper. All authors approved the final manuscript.

 

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no competing interests.

Animal and Human Rights Statement

This article does not include any experiments that involve human or animal subjects.

Keywords: Influenza A; H1N1; Neurotropism; Viral pathogenesis; Monoclonal antibodies.

——

Cross-reactive neutralizing #human #survivor monoclonal #antibody BDBV223 targets the #ebolavirus stalk (Nat Commun., abstract)

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

Nat Commun. 2019 Apr 17;10(1):1788. doi: 10.1038/s41467-019-09732-7.

Cross-reactive neutralizing human survivor monoclonal antibody BDBV223 targets the ebolavirus stalk.

King LB1, West BR1, Moyer CL1, Gilchuk P2, Flyak A3, Ilinykh PA4,5, Bombardi R2, Hui S1, Huang K4,5, Bukreyev A4,5,6, Crowe JE Jr2,3, Saphire EO7,8,9.

Author information: 1 Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA. 2 Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA. 3 Departments of Pediatrics, Pathology, and Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA. 4 Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA. 5 Galveston National Laboratory, Galveston, TX, 77555, USA. 6 Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, 77555, USA. 7 Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA. erica@lji.org. 8 Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA. erica@lji.org. 9 La Jolla Institute for Immunology La Jolla, CA, 92037, USA. erica@lji.org.

 

Abstract

Three Ebolavirus genus viruses cause lethal disease and lack targeted therapeutics: Ebola virus, Sudan virus and Bundibugyo virus. Monoclonal antibody (mAb) cocktails against the surface glycoprotein (GP) present a potential therapeutic strategy. Here we report two crystal structures of the antibody BDBV223, alone and complexed with its GP2 stalk epitope, an interesting site for therapeutic/vaccine design due to its high sequence conservation among ebolaviruses. BDBV223, identified in a human survivor of Bundibugyo virus disease, neutralizes both Bundibugyo virus and Ebola virus, but not Sudan virus. Importantly, the structure suggests that BDBV223 binding interferes with both the trimeric bundle assembly of GP and the viral membrane by stabilizing a conformation in which the monomers are separated by GP lifting or bending. Targeted mutagenesis of BDBV223 to enhance SUDV GP recognition indicates that additional determinants of antibody binding likely lie outside the visualized interactions, and perhaps involve quaternary assembly or membrane-interacting regions.

PMID: 30996276 DOI: 10.1038/s41467-019-09732-7

Keywords: Ebola; Monoclonal antibodies.

——