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Xu Y, Vertrees D, He Y, Momben-Abolfath S, Li X, Brewah YA, Scott DE, Konduru K, Rios M, Struble EB. Nanoluciferase Reporter Zika Viruses as Tools for Assessing Infection Kinetics and Antibody Potency. Viruses 2023; 15:2190. [PMID: 38005868 PMCID: PMC10674863 DOI: 10.3390/v15112190] [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: 09/12/2023] [Revised: 10/16/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Zika virus (ZIKV) has become endemic in multiple tropical and subtropical regions and has the potential to become widespread in countries with limited prior exposure to this infection. One of the most concerning sequelae of ZIKV infection is the teratogenic effect on the developing fetus, with the mechanisms of viral spread to and across the placenta remaining largely unknown. Although vaccine trials and prophylactic or therapeutic treatments are being studied, there are no approved treatments or vaccines for ZIKV. Appropriate tests, including potency and in vivo assays to assess the safety and efficacy of these modalities, can greatly aid both the research of the pathophysiology of the infection and the development of anti-ZIKV therapeutics. Building on previous work, we tested reporter ZIKV variants that express nanoluciferase in cell culture and in vivo assays. We found that these variants can propagate in cells shown to be susceptible to the widely used clinical isolate PRVABC59, including Vero and human placenta cell lines. When used in neutralization assays with bioluminescence as readout, these variants gave rise to neutralization curves similar to those produced by PRVABC59, while being better suited for performing high-throughput assays. In addition, the engineered reporter variants can be useful research tools when used in other in vitro and in vivo assays, as we illustrated in transcytosis experiments and a pilot study in guinea pigs.
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Affiliation(s)
- Yanqun Xu
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Devin Vertrees
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Yong He
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Sanaz Momben-Abolfath
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Xiaohong Li
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Yambasu A. Brewah
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Dorothy E. Scott
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
| | - Krishnamurthy Konduru
- Laboratory of Molecular Virology, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, USA; (K.K.); (M.R.)
| | - Maria Rios
- Laboratory of Molecular Virology, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration (FDA), Silver Spring, MD 20993, USA; (K.K.); (M.R.)
| | - Evi B. Struble
- Laboratory of Plasma Derivatives, Division of Plasma Protein Therapeutics, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (Y.X.); (D.V.); (Y.H.); (X.L.); (Y.A.B.); (D.E.S.)
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Cherkashchenko L, Gros N, Trausch A, Neyret A, Hénaut M, Dubois G, Villeneuve M, Chable-Bessia C, Lyonnais S, Merits A, Muriaux D. Validation of flavivirus infectious clones carrying fluorescent markers for antiviral drug screening and replication studies. Front Microbiol 2023; 14:1201640. [PMID: 37779700 PMCID: PMC10541152 DOI: 10.3389/fmicb.2023.1201640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 08/17/2023] [Indexed: 10/03/2023] Open
Abstract
Flaviviruses have emerged as major arthropod-transmitted pathogens and represent an increasing public health problem worldwide. High-throughput screening can be facilitated using viruses that easily express detectable marker proteins. Therefore, developing molecular tools, such as reporter-carrying versions of flaviviruses, for studying viral replication and screening antiviral compounds represents a top priority. However, the engineering of flaviviruses carrying either fluorescent or luminescent reporters remains challenging due to the genetic instability caused by marker insertion; therefore, new approaches to overcome these limitations are needed. Here, we describe reverse genetic methods that include the design and validation of infectious clones of Zika, Kunjin, and Dengue viruses harboring different reporter genes for infection, rescue, imaging, and morphology using super-resolution microscopy. It was observed that different flavivirus constructs with identical designs displayed strikingly different genetic stabilities, and corresponding virions resembled wild-type virus particles in shape and size. A successful strategy was assessed to increase the stability of rescued reporter virus and permit antiviral drug screening based on quantitative automated fluorescence microscopy and replication studies.
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Affiliation(s)
- Liubov Cherkashchenko
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Nathalie Gros
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
| | - Alice Trausch
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
| | - Aymeric Neyret
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
| | - Mathilde Hénaut
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
| | - Gregor Dubois
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
| | | | | | | | - Andres Merits
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Delphine Muriaux
- CEMIPAI UAR3725 CNRS, University of Montpellier, Montpellier, France
- IRIM UMR9004 CNRS, University of Montpellier, Montpellier, France
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Reporter Flaviviruses as Tools to Demonstrate Homologous and Heterologous Superinfection Exclusion. Viruses 2022; 14:v14071501. [PMID: 35891480 PMCID: PMC9317482 DOI: 10.3390/v14071501] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/29/2022] Open
Abstract
Binjari virus (BinJV) is a lineage II or dual-host affiliated insect-specific flavivirus previously demonstrated as replication-deficient in vertebrate cells. Previous studies have shown that BinJV is tolerant to exchanging its structural proteins (prM-E) with pathogenic flaviviruses, making it a safe backbone for flavivirus vaccines. Here, we report generation by circular polymerase extension reaction of BinJV expressing zsGreen or mCherry fluorescent protein. Recovered BinJV reporter viruses grew to high titres (107−8 FFU/mL) in Aedes albopictus C6/36 cells assayed using immunoplaque assays (iPA). We also demonstrate that BinJV reporters could be semi-quantified live in vitro using a fluorescence microplate reader with an observed linear correlation between quantified fluorescence of BinJV reporter virus-infected C6/36 cells and iPA-quantitated virus titres. The utility of the BinJV reporter viruses was then examined in homologous and heterologous superinfection exclusion assays. We demonstrate that primary infection of C6/36 cells with BinJVzsGreen completely inhibits a secondary infection with homologous BinJVmCherry or heterologous ZIKVmCherry using fluorescence microscopy and virus quantitation by iPA. Finally, BinJVzsGreen infections were examined in vivo by microinjection of Aedes aegypti with BinJVzsGreen. At seven days post-infection, a strong fluorescence in the vicinity of salivary glands was detected in frozen sections. This is the first report on the construction of reporter viruses for lineage II insect-specific flaviviruses and establishes a tractable system for exploring flavivirus superinfection exclusion in vitro and in vivo.
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Fang E, Liu X, Li M, Liu J, Zhang Z, Liu X, Li X, Li W, Peng Q, Yu Y, Li Y. Construction of a Dengue NanoLuc Reporter Virus for In Vivo Live Imaging in Mice. Viruses 2022; 14:v14061253. [PMID: 35746724 PMCID: PMC9230669 DOI: 10.3390/v14061253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 02/06/2023] Open
Abstract
Since the first isolation in 1943, the dengue virus (DENV) has spread throughout the world, but effective antiviral drugs or vaccines are still not available. To provide a more stable reporter DENV for vaccine development and antiviral drug screening, we constructed a reporter DENV containing the NanoLuc reporter gene, which was inserted into the 5′ untranslated region and capsid junction region, enabling rapid virus rescue by in vitro ligation. In addition, we established a live imaging mouse model and found that the reporter virus maintained the neurovirulence of prototype DENV before engineering. DENV-4 exhibited dramatically increased neurovirulence following a glycosylation site-defective mutation in the envelope protein. Significant mice mortality with neurological onset symptoms was observed after intracranial infection of wild-type (WT) mice, thus providing a visualization tool for DENV virulence assessment. Using this model, DENV was detected in the intestinal tissues of WT mice after infection, suggesting that intestinal lymphoid tissues play an essential role in DENV pathogenesis.
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Affiliation(s)
- Enyue Fang
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
- Wuhan Institute of Biological Products, Co., Ltd., Wuhan 430207, China
| | - Xiaohui Liu
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Miao Li
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Jingjing Liu
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Zelun Zhang
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Xinyu Liu
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Xingxing Li
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Wenjuan Li
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Qinhua Peng
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
| | - Yongxin Yu
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
- Correspondence: (Y.Y.); (Y.L.); Tel.: +86-010-5385-2137 (Y.Y.); +86-010-5385-2128 (Y.L.)
| | - Yuhua Li
- Department of Arbovirus Vaccine, National Institutes for Food and Drug Control, Beijing 102629, China; (E.F.); (X.L.); (M.L.); (J.L.); (Z.Z.); (X.L.); (X.L.); (W.L.); (Q.P.)
- Correspondence: (Y.Y.); (Y.L.); Tel.: +86-010-5385-2137 (Y.Y.); +86-010-5385-2128 (Y.L.)
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Tracking the Replication-Competent Zika Virus with Tetracysteine-Tagged Capsid Protein in Living Cells. J Virol 2022; 96:e0184621. [PMID: 35285687 PMCID: PMC9006885 DOI: 10.1128/jvi.01846-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Zika virus (ZIKV) is the mosquito-borne enveloped flavivirus that causes microcephaly in neonates. While real-time imaging plays a critical role in dissecting viral biology, no fluorescent, genetically engineered ZIKV for single-particle tracking is currently available.
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Baker C, Liu Y, Zou J, Muruato A, Xie X, Shi PY. Identifying optimal capsid duplication length for the stability of reporter flaviviruses. Emerg Microbes Infect 2020; 9:2256-2265. [PMID: 32981479 PMCID: PMC7594839 DOI: 10.1080/22221751.2020.1829994] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 01/04/2023]
Abstract
ABSTRACT Mosquito-transmitted flaviviruses cause widespread disease across the world. To provide better molecular tools for drug screens and pathogenesis studies, we report a new approach to produce stable NanoLuc-tagged flaviviruses, including dengue virus serotypes 1-4, Japanese encephalitis virus, yellow fever virus, West Nile virus, and Zika virus. Since the reporter gene is often engineered at the capsid gene region, the capsid sequence must be duplicated to flank the reporter gene; such capsid duplication is essential for viral replication. The conventional approach for stabilizing reporter flaviviruses has been to shorten or modify the duplicated capsid sequence to minimize homologous recombination. No study has examined the effects of capsid duplication length on reporter virus stability. Here we report an optimal length to stabilize reporter flaviviruses. These viruses were stable after ten rounds of cell culture passaging, and in the case of stable NanoLuc-tagged Zika virus (ZIKV C38), the virus replicated to 107 FFU/ml in cell culture and produced robust luciferase signal after inoculation in mosquitoes. Mechanistically, the optimal length of capsid duplication may contain all the cis-acting RNA elements required for viral RNA replication, thus reducing the selection pressure for recombination. Together, these data describe an improved method of constructing optimal reporter flaviviruses.
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Affiliation(s)
- Coleman Baker
- Departement of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yang Liu
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jing Zou
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Antonio Muruato
- Departement of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Xuping Xie
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Pei-Yong Shi
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX, USA
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Fontes-Garfias CR, Baker CK, Shi PY. Reverse genetic approaches for the development of Zika vaccines and therapeutics. Curr Opin Virol 2020; 44:7-15. [PMID: 32563700 PMCID: PMC9373025 DOI: 10.1016/j.coviro.2020.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 01/09/2023]
Abstract
In 2015-2016, the little known Zika virus (ZIKV) caused an epidemic, in which it became recognized as a unique human pathogen associated with a range of devastating congenital abnormalities collectively categorized as congenital Zika syndrome (CZS). In adults, the virus can trigger the autoimmune disorder Guillain-Barré syndrome (GBS), characterized by ascending paralysis. In February 2016, the World Health Organization (WHO) declared ZIKV to be a Public Health Emergency of International Concern. The global public health problem prompted academia, industry, and governments worldwide to initiate development of an effective vaccine to prevent another ZIKV epidemic that would put millions at risk. The development of reverse genetic systems for the study and manipulation of RNA viral genomes has revolutionized the field of virology, providing platforms for vaccine and antiviral development. In this review, we discuss the impact of reverse genetic systems on the rapid progress of ZIKV vaccines and antiviral therapeutics.
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Affiliation(s)
- Camila R Fontes-Garfias
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Coleman K Baker
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA; Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA; Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA.
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Baker C, Shi PY. Construction of Stable Reporter Flaviviruses and Their Applications. Viruses 2020; 12:v12101082. [PMID: 32992987 PMCID: PMC7599567 DOI: 10.3390/v12101082] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/28/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Flaviviruses are significant human pathogens that cause frequent emerging and reemerging epidemics around the world. Better molecular tools for studying, diagnosing, and treating these diseases are needed. Reporter viruses represent potent tools to fill this gap but have been hindered by genetic instability. Recent advances have overcome these hurdles, opening the way for increased use of stable reporter flaviviruses to diagnose infections, screen and study antiviral compounds, and serve as potential vaccine vectors.
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Affiliation(s)
- Coleman Baker
- Microbiology and Immunology Department, University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - Pei-Yong Shi
- Biochemistry and Molecular Biology Department, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Translational Science, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Correspondence:
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Baker C, Xie X, Zou J, Muruato A, Fink K, Shi PY. Using recombination-dependent lethal mutations to stabilize reporter flaviviruses for rapid serodiagnosis and drug discovery. EBioMedicine 2020; 57:102838. [PMID: 32574959 PMCID: PMC7317239 DOI: 10.1016/j.ebiom.2020.102838] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 01/11/2023] Open
Abstract
Background Many flaviviruses are significant human pathogens that cause global public health threats. Developing research tools for studying and diagnosing these pathogens is a top priority. Reporter flaviviruses are useful tools for studying viral pathogenesis, diagnosing disease, and screening antiviral compounds. However, the stability of reporter flaviviruses has been challenged by viral RNA recombination, leading to deletion of the engineered reporter gene during viral replication. The instability of reporter viruses has limited their application to research and countermeasure development. Thus, new approaches to overcome the instability of reporter flaviviruses are critically needed to advance the flavivirus field. Methods To create a stable flavivirus bearing a reporter gene, we engineered mutations in the viral capsid gene that are rendered virus-lethal upon recombination. Thus, only non-recombined reporter virus propagates. We tested this strategy using Zika virus (ZIKV) bearing a nano-luciferase (NanoLuc) gene and passaged both virus with capsid mutations and virus without mutations. Findings The recombination-dependent lethal mutations succeeded in stabilizing the NanoLuc ZIKV through ten passages, while WT reporter virus showed instability as early as five passages. The stability of NanoLuc ZIKV was supported by RT-PCR, sequencing, focus forming assay, and luciferase assay. The success of this method was reconfirmed by also establishing a stable NanoLuc Yellow Fever 17D virus, indicating that the recombination-dependent lethal approach can be applied to other flaviviruses. To demonstrate the utility of the stable reporter viruses, we showed that NanoLuc ZIKV and YFV17D could be used to measure neutralizing antibody titers with a turnaround time as short as four hours. Importantly, the neutralizing antibody titers derived from the reporter virus assay were equivalent to those derived from the conventional plaque assay, indicating the new assay maintains the gold standard of serology testing. Furthermore, using a known inhibitor, we showed that the reporter viruses could be reliably used for antiviral evaluation. Interpretation The study has developed a recombination-dependent lethal approach to produce stable reporter flaviviruses that may be used for rapid serodiagnosis, trans-gene delivery, vaccine evaluation, and antiviral discovery. Funding National Institute of Health, Robert J. Kleberg, Jr. and Helen C. Kleberg Foundation; John S. Dunn Foundation; Amon G. Carter Foundation; Gillson Longenbaugh Foundation; Summerfield G. Roberts Foundation.
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Affiliation(s)
- Coleman Baker
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Xuping Xie
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
| | - Jing Zou
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Antonio Muruato
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Katja Fink
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Pei-Yong Shi
- Department of Biology and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA; Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA; Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, USA.
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