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Ferrero DS, Tomás Gilabert O, Verdaguer N. Structural insights on the nucleoprotein C-terminal domain of Měnglà virus. Microbiol Spectr 2023; 11:e0237323. [PMID: 37888996 PMCID: PMC10714759 DOI: 10.1128/spectrum.02373-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE Filoviruses are the causative agents of severe and often fatal hemorrhagic disease in humans. Měnglà virus (MLAV) is a recently reported filovirus, isolated from fruit bats that is capable to replicate in human cells, representing a potential risk for human health. An in-depth structural and functional knowledge of MLAV proteins is an essential step for antiviral research on this virus that can also be extended to other emerging filoviruses. In this study, we determined the first crystal structures of the C-terminal domain (CTD) of the MLAV nucleoprotein (NP), showing important similarities to the equivalent domain in MARV. The structural data also show that the NP CTD has the ability to form large helical oligomers that may participate in the control of cytoplasmic inclusion body formation during viral replication.
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Affiliation(s)
| | | | - Nuria Verdaguer
- Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
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2
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Prado NDR, Brilhante-Da-Silva N, Sousa RMO, Morais MSDS, Roberto SA, Luiz MB, Assis LCD, Marinho ACM, Araujo LFLD, Pontes RDS, Stabeli RG, Fernandes CFC, Pereira SDS. Single-domain antibodies applied as antiviral immunotherapeutics. J Virol Methods 2023; 320:114787. [PMID: 37516366 DOI: 10.1016/j.jviromet.2023.114787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 07/31/2023]
Abstract
Viral infections have been the cause of high mortality rates throughout different periods in history. Over the last two decades, outbreaks caused by zoonotic diseases and transmitted by arboviruses have had a significant impact on human health. The emergence of viral infections in different parts of the world encourages the search for new inputs to fight pathologies of viral origin. Antibodies represent the predominant class of new drugs developed in recent years and approved for the treatment of various human diseases, including cancer, autoimmune and infectious diseases. A promising group of antibodies are single-domain antibodies derived from camelid heavy chain immunoglobulins, or VHHs, are biomolecules with nanometric dimensions and unique pharmaceutical and biophysical properties that can be used in the diagnosis and immunotherapy of viral infections. For viral neutralization to occur, VHHs can act in different stages of the viral cycle, including the actual inhibition of infection, to hindering viral replication or assembly. This review article addresses advances involving the use of VHHs in therapeutic propositions aimed to battle different viruses that affect human health.
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Affiliation(s)
- Nidiane Dantas Reis Prado
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia, Porto Velho, RO, Brazil
| | - Nairo Brilhante-Da-Silva
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia, Porto Velho, RO, Brazil; Programa de Pós-Graduação em Biologia Celular e Molecular, Instituto Oswaldo Cruz, IOC, Rio de Janeiro, RJ, Brazil
| | - Rosa Maria Oliveira Sousa
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia, Porto Velho, RO, Brazil
| | | | - Sibele Andrade Roberto
- Plataforma Bi-institucional de Medicina Translacional, Fundação Oswaldo Cruz-USP, Ribeirão Preto, SP, Brazil
| | - Marcos Barros Luiz
- Instituto Federal de Rondônia Campus Guajará-Mirim, IFRO, Guajará-Mirim, RO, Brazil
| | - Livia Coelho de Assis
- Programa de Pós-Graduação em Biologia Celular e Molecular, Instituto Oswaldo Cruz, IOC, Rio de Janeiro, RJ, Brazil; Laboratório Multiusuário de Pesquisa e Desenvolvimento, Fundação Oswaldo Cruz, Fiocruz unidade Ceará, Eusebio, CE, Brazil
| | - Anna Carolina M Marinho
- Laboratório Multiusuário de Pesquisa e Desenvolvimento, Fundação Oswaldo Cruz, Fiocruz unidade Ceará, Eusebio, CE, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Luiz Felipe Lemes de Araujo
- Plataforma Bi-institucional de Medicina Translacional, Fundação Oswaldo Cruz-USP, Ribeirão Preto, SP, Brazil; Programa de Pós-Graduação em Imunologia Básica e Aplicada, Universidade de São Paulo, USP, Ribeirão Preto, SP, Brazil
| | - Rafael de Souza Pontes
- Plataforma Bi-institucional de Medicina Translacional, Fundação Oswaldo Cruz-USP, Ribeirão Preto, SP, Brazil; Programa de Pós-Graduação em Imunologia Básica e Aplicada, Universidade de São Paulo, USP, Ribeirão Preto, SP, Brazil
| | - Rodrigo Guerino Stabeli
- Plataforma Bi-institucional de Medicina Translacional, Fundação Oswaldo Cruz-USP, Ribeirão Preto, SP, Brazil
| | - Carla Freire Celedonio Fernandes
- Programa de Pós-Graduação em Biologia Celular e Molecular, Instituto Oswaldo Cruz, IOC, Rio de Janeiro, RJ, Brazil; Laboratório Multiusuário de Pesquisa e Desenvolvimento, Fundação Oswaldo Cruz, Fiocruz unidade Ceará, Eusebio, CE, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Soraya Dos Santos Pereira
- Laboratório de Engenharia de Anticorpos, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia, Porto Velho, RO, Brazil; Programa de Pós-Graduação em Biologia Celular e Molecular, Instituto Oswaldo Cruz, IOC, Rio de Janeiro, RJ, Brazil; Programa de Pós-graduação em Biologia Experimental, Universidade Federal de Rondônia, UNIR, Porto Velho, RO, Brazil.
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3
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Moliner-Morro A, McInerney GM, Hanke L. Nanobodies in the limelight: Multifunctional tools in the fight against viruses. J Gen Virol 2022; 103. [PMID: 35579613 DOI: 10.1099/jgv.0.001731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antibodies are natural antivirals generated by the vertebrate immune system in response to viral infection or vaccination. Unsurprisingly, they are also key molecules in the virologist's molecular toolbox. With new developments in methods for protein engineering, protein functionalization and application, smaller antibody-derived fragments are moving in focus. Among these, camelid-derived nanobodies play a prominent role. Nanobodies can replace full-sized antibodies in most applications and enable new possible applications for which conventional antibodies are challenging to use. Here we review the versatile nature of nanobodies, discuss their promise as antiviral therapeutics, for diagnostics, and their suitability as research tools to uncover novel aspects of viral infection and disease.
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Affiliation(s)
- Ainhoa Moliner-Morro
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Gerald M McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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4
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Development of High affinity Nanobodies Specific for Na V1.4 and Na V1.5 Voltage-Gated Sodium Channel Isoforms. J Biol Chem 2022; 298:101763. [PMID: 35202650 PMCID: PMC8935509 DOI: 10.1016/j.jbc.2022.101763] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 11/22/2022] Open
Abstract
Voltage-gated sodium channels, NaVs, are responsible for the rapid rise of action potentials in excitable tissues. NaV channel mutations have been implicated in several human genetic diseases, such as hypokalemic periodic paralysis, myotonia, and long-QT and Brugada syndromes. Here, we generated high-affinity anti-NaV nanobodies (Nbs), Nb17 and Nb82, that recognize the NaV1.4 (skeletal muscle) and NaV1.5 (cardiac muscle) channel isoforms. These Nbs were raised in llama (Lama glama) and selected from a phage display library for high affinity to the C-terminal (CT) region of NaV1.4. The Nbs were expressed in Escherichia coli, purified, and biophysically characterized. Development of high-affinity Nbs specifically targeting a given human NaV isoform has been challenging because they usually show undesired crossreactivity for different NaV isoforms. Our results show, however, that Nb17 and Nb82 recognize the CTNaV1.4 or CTNaV1.5 over other CTNav isoforms. Kinetic experiments by biolayer interferometry determined that Nb17 and Nb82 bind to the CTNaV1.4 and CTNaV1.5 with high affinity (KD ∼ 40–60 nM). In addition, as proof of concept, we show that Nb82 could detect NaV1.4 and NaV1.5 channels in mammalian cells and tissues by Western blot. Furthermore, human embryonic kidney cells expressing holo NaV1.5 channels demonstrated a robust FRET-binding efficiency for Nb17 and Nb82. Our work lays the foundation for developing Nbs as anti-NaV reagents to capture NaVs from cell lysates and as molecular visualization agents for NaVs.
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5
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Sherwood LJ, Hayhurst A. Generating Uniformly Cross-Reactive Ebolavirus spp. Anti-nucleoprotein Nanobodies to Facilitate Forward Capable Detection Strategies. ACS Infect Dis 2022; 8:343-359. [PMID: 34994194 DOI: 10.1021/acsinfecdis.1c00478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is often challenging for a single monoclonal antibody to cross-react equally with all species of a particular viral genus that are separated by time and geographies to ensure broad long-term global immunodiagnostic use. Here, we set out to isolate nanobodies or single-domain antibodies (sdAbs) with uniform cross-reactivity to the genus Ebolavirus by immunizing a llama with recombinant nucleoprotein (NP) representing the 5 cultivated species to assemble a phage display repertoire for mining. Screening sdAbs for reactivity against the C-terminal domain of NP guided the isolation of clones that could perform as both captor and tracer for polyvalent antigen in sandwich assays. Two promising sdAbs had equivalent reactivities across all 5 species and greatly enhanced the equilibrium concentration at 50% (EC50) for recombinant NP when compared with a differentially cross-reactive nonimmune sdAb isolated previously. Uniform reactivity and enhanced sensitivity were relayed to live virus titrations, resulting in lower limits of detection of 2-5 pfu for the best sdAbs, representing 10-, 20-, and 100-fold improvements for Zaire, Sudan/Reston, and Taï Forest viruses, respectively. Fusions of the sdAbs with ascorbate peroxidase (APEX2) and mNeonGreen generated one-step immunoreagents useful for colorimetric and fluorescent visualization of cellular NP. Both sdAbs were also able to recognize recombinant NPs from the recently discovered Bombali virus, a putative sixth Ebolavirus species unknown at the start of these experiments, validating the forward capabilities of the sdAbs. The simplicity and modularity of these sdAbs should enable advances in antigen-based diagnostic technologies to be retuned toward filoviral detection relatively easily, thereby proactively safeguarding human health.
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Affiliation(s)
- Laura Jo Sherwood
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, Texas 78227, United States
| | - Andrew Hayhurst
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, Texas 78227, United States
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6
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Sherwood LJ, Hayhurst A. Visualizing Filoviral Nucleoproteins Using Nanobodies Fused to the Ascorbate Peroxidase Derivatives APEX2 and dEAPX. Methods Mol Biol 2022; 2446:427-449. [PMID: 35157287 DOI: 10.1007/978-1-0716-2075-5_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fusions of single-domain antibodies (sdAbs, nanobodies) to enzymatic reporters make convenient molecular probes to detect the presence of an antigen of interest. We have previously fused the monomeric hyperactive ascorbate peroxidase derivative APEX2 to anti-Ebolavirus and anti-Marburgvirus sdAbs to generate immunoreagents useful in detecting nucleoprotein (NP) on western blots, ELISA, and within cells following transfection of NP expression plasmids or following virus infection. Here we present the methods used to overexpress and purify these sdAb-APEX2 fusion proteins, and to employ them as probes in various scenarios with colorimetric and fluorometric signal development. We also introduce a dimeric hyperactive ascorbate peroxidase derivative dEAPX that enables bivalent sdAb probes to be produced while avoiding the need to generate more complex tandem sdAbs, leveraging avidity for improved signal strength. The APEX2 and dEAPX reagents appear interchangeable with any existing detection platform and the methods described here should enable a user to study their antigen of interest by simply swapping out the sdAb for their recombinant affinity reagent of choice.
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Affiliation(s)
- Laura Jo Sherwood
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Andrew Hayhurst
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX, USA.
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7
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Tung Yep A, Takeuchi Y, Engelhardt OG, Hufton SE. Broad Reactivity Single Domain Antibodies against Influenza Virus and Their Applications to Vaccine Potency Testing and Immunotherapy. Biomolecules 2021; 11:biom11030407. [PMID: 33802072 PMCID: PMC8001348 DOI: 10.3390/biom11030407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/05/2021] [Accepted: 03/06/2021] [Indexed: 12/11/2022] Open
Abstract
The antigenic variability of influenza presents many challenges to the development of vaccines and immunotherapeutics. However, it is apparent that there are epitopes on the virus that have evolved to remain largely constant due to their functional importance. These more conserved regions are often hidden and difficult to access by the human immune system but recent efforts have shown that these may be the Achilles heel of the virus through development and delivery of appropriate biological drugs. Amongst these, single domain antibodies (sdAbs) are equipped to target these vulnerabilities of the influenza virus due to their preference for concave epitopes on protein surfaces, their small size, flexible reformatting and high stability. Single domain antibodies are well placed to provide a new generation of robust analytical reagents and therapeutics to support the constant efforts to keep influenza in check.
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Affiliation(s)
- Andrew Tung Yep
- Biotherapeutics Division, National Institute for Biological Standards and Control (NIBSC), Potters Bar, Hertfordshire EN6 3QG, UK;
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK;
| | - Yasu Takeuchi
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK;
- Advanced Therapies Division, NIBSC, Potters Bar, Hertfordshire EN6 3QG, UK
| | | | - Simon E. Hufton
- Biotherapeutics Division, National Institute for Biological Standards and Control (NIBSC), Potters Bar, Hertfordshire EN6 3QG, UK;
- Correspondence:
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8
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Sherwood LJ, Hayhurst A. Toolkit for Quickly Generating and Characterizing Molecular Probes Specific for SARS-CoV-2 Nucleocapsid as a Primer for Future Coronavirus Pandemic Preparedness. ACS Synth Biol 2021; 10:379-390. [PMID: 33534552 PMCID: PMC7875338 DOI: 10.1021/acssynbio.0c00566] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Indexed: 12/31/2022]
Abstract
Generating and characterizing immunoreagents to enable studies of novel emerging viruses is an area where ensembles of synthetic genes, recombinant antibody pipelines, and modular antibody-reporter fusion proteins can respond rapidly. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread through the global population causing widespread morbidity, mortality, and socioeconomic chaos. Using SARS-CoV-2 as our model and starting with a gBlocks encoded nucleocapsid (N) gene, we purified recombinant protein from E. coli, to serve as bait for selecting semisynthetic nanobodies from our Nomad single-pot library. Clones were isolated in days and first fused to Gaussia luciferase to determine EC50 in the tens of nM range, and second fused to the ascorbate peroxidase derivative APEX2 for sensitive detection of SARS-CoV-2 infected cells. To generate inherently fluorescent immunoreagents, we introduce novel periplasmic sdAb fusions made with mNeonGreen and mScarlet-I, which were produced at milligram amounts. The fluorescent fusion proteins enabled concise visualization of SARS-CoV-2 N in the cytoplasm but not in the nucleus 24 h post infection, akin to the distribution of SARS-CoV N, thereby validating these useful imaging tools. SdAb reactivity appeared specific to SARS-CoV-2 with very much weaker binding to SARS-CoV, and no noticeable cross-reactivity to a panel of overexpressed human codon optimized N proteins from other CoV. High periplasmic expression levels and in silico immortalization of the nanobody constructs guarantees a cost-effective and reliable source of SARS-CoV-2 immunoreagents. Our proof-of-principle study should be applicable to known and newly emerging CoV to broaden the tools available for their analysis and help safeguard human health in a more proactive than reactive manner.
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Affiliation(s)
- Laura Jo Sherwood
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | - Andrew Hayhurst
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
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9
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Zimmermann I, Egloff P, Hutter CAJ, Kuhn BT, Bräuer P, Newstead S, Dawson RJP, Geertsma ER, Seeger MA. Generation of synthetic nanobodies against delicate proteins. Nat Protoc 2020; 15:1707-1741. [PMID: 32269381 DOI: 10.1038/s41596-020-0304-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/16/2020] [Indexed: 12/21/2022]
Abstract
Here, we provide a protocol to generate synthetic nanobodies, known as sybodies, against any purified protein or protein complex within a 3-week period. Unlike methods that require animals for antibody generation, sybody selections are carried out entirely in vitro under controlled experimental conditions. This is particularly relevant for the generation of conformation-specific binders against labile membrane proteins or protein complexes and allows selections in the presence of non-covalent ligands. Sybodies are especially suited for cases where binder generation via immune libraries fails due to high sequence conservation, toxicity or insufficient stability of the target protein. The procedure entails a single round of ribosome display using the sybody libraries encoded by mRNA, followed by two rounds of phage display and binder identification by ELISA. The protocol is optimized to avoid undesired reduction in binder diversity and enrichment of non-specific binders to ensure the best possible selection outcome. Using the efficient fragment exchange (FX) cloning method, the sybody sequences are transferred from the phagemid to different expression vectors without the need to amplify them by PCR, which avoids unintentional shuffling of complementary determining regions. Using quantitative PCR (qPCR), the efficiency of each selection round is monitored to provide immediate feedback and guide troubleshooting. Our protocol can be carried out by any trained biochemist or molecular biologist using commercially available reagents and typically gives rise to 10-30 unique sybodies exhibiting binding affinities in the range of 500 pM-500 nM.
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Affiliation(s)
- Iwan Zimmermann
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.,Linkster Therapeutics AG, Zurich, Switzerland
| | - Pascal Egloff
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.,Linkster Therapeutics AG, Zurich, Switzerland
| | - Cedric A J Hutter
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Benedikt T Kuhn
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Philipp Bräuer
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Roger J P Dawson
- Linkster Therapeutics AG, Zurich, Switzerland.,Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Eric R Geertsma
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.
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10
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Structural and thermodynamic basis for the recognition of the substrate-binding cleft on hen egg lysozyme by a single-domain antibody. Sci Rep 2019; 9:15481. [PMID: 31664051 PMCID: PMC6820745 DOI: 10.1038/s41598-019-50722-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 09/10/2019] [Indexed: 01/06/2023] Open
Abstract
Single-domain antibodies (VHHs or nanobodies), developed from heavy chain-only antibodies of camelids, are gaining attention as next-generation therapeutic agents. Despite their small size, the high affinity and specificity displayed by VHHs for antigen molecules rival those of IgGs. How such small antibodies achieve that level of performance? Structural studies have revealed that VHHs tend to recognize concave surfaces of their antigens with high shape-complementarity. However, the energetic contribution of individual residues located at the binding interface has not been addressed in detail, obscuring the actual mechanism by which VHHs target the concave surfaces of proteins. Herein, we show that a VHH specific for hen egg lysozyme, D3-L11, not only displayed the characteristic binding of VHHs to a concave region of the surface of the antigen, but also exhibited a distribution of energetic hot-spots like those of IgGs and conventional protein-protein complexes. The highly preorganized and energetically compact interface of D3-L11 recognizes the concave epitope with high shape complementarity by the classical lock-and-key mechanism. Our results shed light on the fundamental basis by which a particular VHH accommodate to the concave surface of an antigens with high affinity in a specific manner, enriching the mechanistic landscape of VHHs.
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11
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Sherwood LJ, Taylor AB, Hart PJ, Hayhurst A. Paratope Duality and Gullying are Among the Atypical Recognition Mechanisms Used by a Trio of Nanobodies to Differentiate Ebolavirus Nucleoproteins. J Mol Biol 2019; 431:4848-4867. [PMID: 31626803 PMCID: PMC6990103 DOI: 10.1016/j.jmb.2019.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/28/2019] [Accepted: 10/07/2019] [Indexed: 02/08/2023]
Abstract
We had previously shown that three anti–Marburg virus nanobodies (VHH or single-domain antibody [sdAb]) targeted a cryptotope within an alpha-helical assembly at the nucleoprotein (NP) C-terminus that was conserved through half a century of viral evolution. Here, we wished to determine whether an anti–Ebola virus sdAb, that was cross-reactive within the Ebolavirus genus, recognized a similar structural feature upstream of the ebolavirus NP C-terminus. In addition, we sought to determine whether the specificities of a less cross-reactive anti–Zaire ebolavirus sdAb and a totally specific anti–Sudan ebolavirus sdAb were the result of exclusion from this region. Binding and X-ray crystallographic studies revealed that the primary determinant of cross-reactivity did indeed appear to be a preference for the helical feature. Specificity, in the case of the Zaire ebolavirus–specific sdAb, arose from the footprint shifting away from the helices to engage more variable residues. While both sdAbs used CDRs, they also had atypical side-on approaches, with framework 2 helping to accommodate parts of the epitope in sizeable paratope gullies. The Sudan ebolavirus–specific sdAb was more remarkable and appeared to bind two C-terminal domains simultaneously via nonoverlapping epitopes—“paratope duality.” One mode involved paratope gullying, whereas the other involved only CDRs, with CDR3 restructuring to wedge in between opposing walls of an interdomain crevice. The varied routes used by sdAbs to engage antigens discovered here deepen our appreciation of the small scaffold’s architectural versatility and also reveal lucrative opportunities within the ebolavirus NP C-termini that might be leveraged for diagnostics and novel therapeutic targeting.
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Affiliation(s)
- Laura Jo Sherwood
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX, 78227, USA
| | - Alexander Bryan Taylor
- X-ray Crystallography Core Laboratory, Institutional Research Cores and Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Peter John Hart
- X-ray Crystallography Core Laboratory, Institutional Research Cores and Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA; Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, TX, 78229, USA
| | - Andrew Hayhurst
- Disease Intervention and Prevention, Texas Biomedical Research Institute, San Antonio, TX, 78227, USA. http://
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12
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Periplasmic Nanobody-APEX2 Fusions Enable Facile Visualization of Ebola, Marburg, and Mĕnglà virus Nucleoproteins, Alluding to Similar Antigenic Landscapes among Marburgvirus and Dianlovirus. Viruses 2019; 11:v11040364. [PMID: 31010013 PMCID: PMC6521291 DOI: 10.3390/v11040364] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 11/26/2022] Open
Abstract
We explore evolved soybean ascorbate peroxidase (APEX2) as a reporter when fused to the C-termini of llama nanobodies (single-domain antibodies, sdAb; variable domains of heavy chain-only antibodies, VHH) targeted to the E. coli periplasm. Periplasmic expression preserves authentic antibody N-termini, intra-domain disulphide bond(s), and capitalizes on efficient haem loading through the porous E. coli outer membrane. Using monomeric and dimeric anti-nucleoprotein (NP) sdAb cross-reactive within the Marburgvirus genus and cross-reactive within the Ebolavirus genus, we show that periplasmic sdAb–APEX2 fusion proteins are easily purified at multi-mg amounts. The fusions were used in Western blotting, ELISA, and microscopy to visualize NPs using colorimetric and fluorescent imaging. Dimeric sdAb–APEX2 fusions were superior at binding NPs from viruses that were evolutionarily distant to that originally used to select the sdAb. Partial conservation of the anti-Marburgvirus sdAb epitope enabled the recognition of a novel NP encoded by the recently discovered Mĕnglà virus genome. Antibody–antigen interactions were rationalized using monovalent nanoluciferase titrations and contact mapping analysis of existing crystal structures, while molecular modelling was used to reveal the potential landscape of the Mĕnglà NP C-terminal domain. The sdAb–APEX2 fusions also enabled live Marburgvirus and Ebolavirus detection 24 h post-infection of Vero E6 cells within a BSL-4 laboratory setting. The simple and inexpensive mining of large amounts of periplasmic sdAb–APEX2 fusion proteins should help advance studies of past, contemporary, and perhaps Filovirus species yet to be discovered.
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13
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Bekker GJ, Ma B, Kamiya N. Thermal stability of single-domain antibodies estimated by molecular dynamics simulations. Protein Sci 2018; 28:429-438. [PMID: 30394618 PMCID: PMC6319760 DOI: 10.1002/pro.3546] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/03/2018] [Accepted: 10/28/2018] [Indexed: 12/20/2022]
Abstract
Single‐domain antibodies (sdAbs) function like regular antibodies, however, consist of only one domain. Because of their low molecular weight, sdAbs have advantages with respect to production and delivery to their targets and for applications such as antibody drugs and biosensors. Thus, sdAbs with high thermal stability are required. In this work, we chose seven sdAbs, which have a wide range of melting temperature (Tm) values and known structures. We applied molecular dynamics (MD) simulations to estimate their relative stability and compared them with the experimental data. High‐temperature MD simulations at 400 K and 500 K were executed with simulations at 300 K as a control. The fraction of native atomic contacts, Q, measured for the 400 K simulations showed a fairly good correlation with the Tm values. Interestingly, when the residues were classified by their hydrophobicity and size, the Q values of hydrophilic residues exhibited an even better correlation, suggesting that stabilization is correlated with favorable interactions of hydrophilic residues. Measuring the Q value on a per‐residue level enabled us to identify residues that contribute significantly to the instability and thus demonstrating how our analysis can be used in a mutant case study.
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Affiliation(s)
- Gert-Jan Bekker
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Benson Ma
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332
| | - Narutoshi Kamiya
- Graduate School of Simulation Studies, University of Hyogo, Kobe, Hyogo, Japan
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14
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Human transbodies that interfere with the functions of Ebola virus VP35 protein in genome replication and transcription and innate immune antagonism. Emerg Microbes Infect 2018; 7:41. [PMID: 29568066 PMCID: PMC5864874 DOI: 10.1038/s41426-018-0031-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/29/2017] [Accepted: 01/08/2018] [Indexed: 01/10/2023]
Abstract
Small molecular inhibitors and passive immunization against Ebola virus disease (EVD) have been tested in animal models, including rodents and non-human primates, as well as in clinical trials. Nevertheless, there is currently no Food and Drug Administration (FDA)-approved therapy, and alternative strategies must be pursued. The aim of this study was to produce cell-penetrable human single-chain antibodies (transbodies) that are able to interfere with the activities of interferon inhibitory domain (IID) of the VP35 protein, a multifunctional virulence factor of Ebola virus (EBOV). We speculated that effective VP35-IID-specific transbodies could inspire further studies to identify an alternative to conventional antibody therapies. Phage display technology was used to generate Escherichia coli-derived human single-chain antibodies (HuscFvs) that bind to IID. HuscFvs were linked to nona-arginine (R9) to make them cell penetrable. Transbodies of transformed E. coli clones 13 and 3, which were predicted to interact with first basic patch residues (R9-HuscFv13), central basic patch, and end-cap residues (R9-HuscFv3), effectively inhibited EBOV minigenome activity. Transbodies of E. coli clones 3 and 8 antagonized VP35-mediated interferon suppression in VP35-transduced cells. We postulate that these transbodies formed an interface contact with the IID central basic patch, end-cap, and/or residues that are important for IID multimeric formation for dsRNA binding. These transbodies should be evaluated further in vitro using authentic EBOV and in vivo in animal models of EVD before their therapeutic/prophylactic effectiveness is clinically evaluated.
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15
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Wu Y, Jiang S, Ying T. Single-Domain Antibodies As Therapeutics against Human Viral Diseases. Front Immunol 2017; 8:1802. [PMID: 29326699 PMCID: PMC5733491 DOI: 10.3389/fimmu.2017.01802] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/30/2017] [Indexed: 12/12/2022] Open
Abstract
In full-size formats, monoclonal antibodies have been highly successful as therapeutics against cancer and immune diseases. However, their large size leads to inaccessibility of some epitopes and relatively high production costs. As an alternative, single-domain antibodies (sdAbs) offer special advantages compared to full-size antibodies, including smaller size, larger number of accessible epitopes, relatively low production costs and improved robustness. Currently, sdAbs are being developed against a number of viruses, including human immunodeficiency virus-1 (HIV-1), influenza viruses, hepatitis C virus (HCV), respiratory syncytial virus (RSV), and enteric viruses. Although sdAbs are very potent inhibitors of viral infections, no sdAbs have been approved for clinical use against virial infection or any other diseases. In this review, we discuss the current state of research on sdAbs against viruses and their potential as therapeutics against human viral diseases.
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Affiliation(s)
- Yanling Wu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Tianlei Ying
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai, China
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