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Harrison JJ, Nguyen W, Morgan MS, Tang B, Habarugira G, de Malmanche H, Freney ME, Modhiran N, Watterson D, Cox AL, Yan K, Yuen NKY, Bowman DH, Kirkland PD, Bielefeldt-Ohmann H, Suhrbier A, Hall RA, Rawle DJ, Hobson-Peters J. A chimeric vaccine derived from Australian genotype IV Japanese encephalitis virus protects mice from lethal challenge. NPJ Vaccines 2024; 9:134. [PMID: 39085247 PMCID: PMC11291493 DOI: 10.1038/s41541-024-00903-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 05/23/2024] [Indexed: 08/02/2024] Open
Abstract
In 2022, a genotype IV (GIV) strain of Japanese encephalitis virus (JEV) caused an unprecedented and widespread outbreak of disease in pigs and humans in Australia. As no veterinary vaccines against JEV are approved in Australia and all current approved human and veterinary vaccines are derived from genotype (G) III JEV strains, we used the recently described insect-specific Binjari virus (BinJV) chimeric flavivirus vaccine technology to produce a JEV GIV vaccine candidate. Herein we describe the production of a chimeric virus displaying the structural prM and E proteins of a JEV GIV isolate obtained from a stillborn piglet (JEVNSW/22) in the genomic backbone of BinJV (BinJ/JEVNSW/22-prME). BinJ/JEVNSW/22-prME was shown to be antigenically indistinguishable from the JEVNSW/22 parental virus by KD analysis and a panel of JEV-reactive monoclonal antibodies in ELISA. BinJ/JEVNSW/22-prME replicated efficiently in C6/36 cells, reaching titres of >107 infectious units/mL - an important attribute for vaccine manufacture. As expected, BinJ/JEVNSW/22-prME failed to replicate in a variety of vertebrate cells lines. When used to immunise mice, the vaccine induced a potent virus neutralising response against JEVNSW/22 and to GII and GIII JEV strains. The BinJ/JEVNSW/22-prME vaccine provided complete protection against lethal challenge with JEVNSW/22, whilst also providing partial protection against viraemia and disease for the related Murray Valley encephalitis virus. Our results demonstrate that BinJ/JEVNSW/22-prME is a promising vaccine candidate against JEV.
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Affiliation(s)
- Jessica J Harrison
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Wilson Nguyen
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Mahali S Morgan
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Bing Tang
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Gervais Habarugira
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Henry de Malmanche
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Morgan E Freney
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Naphak Modhiran
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Daniel Watterson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Abigail L Cox
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Kexin Yan
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
| | - Nicholas K Y Yuen
- School of Veterinary Science, The University of Queensland, Gatton, QLD, 4343, Australia
| | - Dylan H Bowman
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
| | - Peter D Kirkland
- Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW, 2568, Australia
| | - Helle Bielefeldt-Ohmann
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Andreas Suhrbier
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Roy A Hall
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia
| | - Daniel J Rawle
- QIMR Berghofer Medical Research Institute, Brisbane, 4029, Australia.
| | - Jody Hobson-Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
- Australian Infectious Disease Research Centre, Brisbane, 4072, 4029, Australia.
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Puarattana-aroonkorn S, Tharakaraman K, Suriyawipada D, Ruchirawat M, Fuangthong M, Sasisekharan R, Artpradit C. Rapid and Scalable Production of Functional SARS-CoV-2 Virus-like Particles (VLPs) by a Stable HEK293 Cell Pool. Vaccines (Basel) 2024; 12:561. [PMID: 38932290 PMCID: PMC11209123 DOI: 10.3390/vaccines12060561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 06/28/2024] Open
Abstract
At times of pandemics, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the situation demands rapid development and production timelines of safe and effective vaccines for delivering life-saving medications quickly to patients. Typical biologics production relies on using the lengthy and arduous approach of stable single-cell clones. Here, we used an alternative approach, a stable cell pool that takes only weeks to generate compared to a stable single-cell clone that needs several months to complete. We employed the membrane, envelope, and highly immunogenic spike proteins of SARS-CoV-2 to produce virus-like particles (VLPs) using the HEK293-F cell line as a host system with an economical transfection reagent. The cell pool showed the stability of protein expression for more than one month. We demonstrated that the production of SARS-CoV-2 VLPs using this cell pool was scalable up to a stirred-tank 2 L bioreactor in fed-batch mode. The purified VLPs were properly assembled, and their size was consistent with the authentic virus. Our particles were functional as they specifically entered the cell that naturally expresses ACE-2. Notably, this work reports a practical and cost-effective manufacturing platform for scalable SARS-CoV-2 VLPs production and chromatographic purification.
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Affiliation(s)
| | - Kannan Tharakaraman
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Disapan Suriyawipada
- Translational Research Unit, Chulabhorn Research Institute, Bangkok 10210, Thailand (M.F.)
| | - Mathuros Ruchirawat
- Translational Research Unit, Chulabhorn Research Institute, Bangkok 10210, Thailand (M.F.)
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok 10400, Thailand
| | - Mayuree Fuangthong
- Translational Research Unit, Chulabhorn Research Institute, Bangkok 10210, Thailand (M.F.)
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok 10400, Thailand
- Program in Applied Biological Sciences, Chulabhorn Graduate Institute, Bangkok 10210, Thailand
| | - Ram Sasisekharan
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Charlermchai Artpradit
- Translational Research Unit, Chulabhorn Research Institute, Bangkok 10210, Thailand (M.F.)
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3
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Dong HL, Chen ZL, He MJ, Cui JZ, Cheng H, Wang QY, Xiong XH, Liu G, Chen HP. The Chimeric Chaoyang-Zika Vaccine Candidate Is Safe and Protective in Mice. Vaccines (Basel) 2024; 12:215. [PMID: 38400198 PMCID: PMC10893063 DOI: 10.3390/vaccines12020215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 02/06/2024] [Accepted: 02/17/2024] [Indexed: 02/25/2024] Open
Abstract
Zika virus (ZIKV) is an emerging flavivirus that causes congenital syndromes including microcephaly and fetal demise in pregnant women. No commercial vaccines against ZIKV are currently available. We previously generated a chimeric ZIKV (ChinZIKV) based on the Chaoyang virus (CYV) by replacing the prME protein of CYV with that of a contemporary ZIKV strain GZ01. Herein, we evaluated this vaccine candidate in a mouse model and showed that ChinZIKV was totally safe in both adult and suckling immunodeficient mice. No viral RNA was detected in the serum of mice inoculated with ChinZIKV. All of the mice inoculated with ChinZIKV survived, while mice inoculated with ZIKV succumbed to infection in 8 days. A single dose of ChinZIKV partially protected mice against lethal ZIKV challenge. In contrast, all the control PBS-immunized mice succumbed to infection after ZIKV challenge. Our results warrant further development of ChinZIKV as a vaccine candidate in clinical trials.
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Affiliation(s)
| | | | | | | | | | | | | | - Gang Liu
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Hui-Peng Chen
- Academy of Military Medical Sciences, Beijing 100071, China
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Zhang HQ, Li N, Zhang ZR, Deng CL, Xia H, Ye HQ, Yuan ZM, Zhang B. A Chimeric Classical Insect-Specific Flavivirus Provides Complete Protection Against West Nile Virus Lethal Challenge in Mice. J Infect Dis 2024; 229:43-53. [PMID: 37368353 DOI: 10.1093/infdis/jiad238] [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: 02/15/2023] [Revised: 06/15/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023] Open
Abstract
West Nile virus (WNV), an arthropod-borne flavivirus, can cause severe symptoms, including encephalitis, and death, posing a threat to public health and the economy. However, there is still no approved treatment or vaccine available for humans. Here, we developed a novel vaccine platform based on a classical insect-specific flavivirus (cISF) YN15-283-02, which was derived from Culicoides. The cISF-WNV chimera was constructed by replacing prME structural genes of the infectious YN15-283-02 cDNA clone with those of WNV and successfully rescued in Aedes albopictus cells. cISF-WNV was nonreplicable in vertebrate cells and nonpathogenic in type I interferon receptor (IFNAR)-deficient mice. A single-dose immunization of cISF-WNV elicited considerable Th1-biased antibody responses in C57BL/6 mice, which was sufficient to offer complete protection against lethal WNV challenge with no symptoms. Our studies demonstrated the potential of the insect-specific cISF-WNV as a prophylactic vaccine candidate to prevent infection with WNV.
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Affiliation(s)
- Hong-Qing Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Na Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Zhe-Rui Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Cheng-Lin Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Han Xia
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
- Hubei Jiangxia Laboratory, Wuhan, China
| | - Han-Qing Ye
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhi-Ming Yuan
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
- Hubei Jiangxia Laboratory, Wuhan, China
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5
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Koh C, Saleh MC. Translating mosquito viromes into vector management strategies. Trends Parasitol 2024; 40:10-20. [PMID: 38065789 DOI: 10.1016/j.pt.2023.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 01/06/2024]
Abstract
Mosquitoes are best known for transmitting human and animal viruses. However, they also harbour mosquito-specific viruses (MSVs) as part of their microbiota. These are a group of viruses whose diversity and prevalence overshadow their medically relevant counterparts. Although metagenomics sequencing has remarkably accelerated the discovery of these viruses, what we know about them is often limited to sequence information, leaving much of their fundamental biology to be explored. Understanding the biology and ecology of MSVs can enlighten our knowledge of virus-virus interactions and lead to new innovations in the management of mosquito-borne viral diseases. We retrace the history of their discovery and discuss research milestones that would line the path from mosquito virome knowledge to vector management strategies.
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Affiliation(s)
- Cassandra Koh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France.
| | - Maria-Carla Saleh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
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Dong HL, He MJ, Wang QY, Cui JZ, Chen ZL, Xiong XH, Zhang LC, Cheng H, Xiong GQ, Hu A, Lu YY, Cheng CL, Meng ZX, Zhu C, Zhao G, Liu G, Chen HP. Rapid Generation of Recombinant Flaviviruses Using Circular Polymerase Extension Reaction. Vaccines (Basel) 2023; 11:1250. [PMID: 37515065 PMCID: PMC10383701 DOI: 10.3390/vaccines11071250] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
The genus Flavivirus is a group of arthropod-borne single-stranded RNA viruses, which includes important human and animal pathogens such as Japanese encephalitis virus (JEV), Zika virus (ZIKV), Dengue virus (DENV), yellow fever virus (YFV), West Nile virus (WNV), and Tick-borne encephalitis virus (TBEV). Reverse genetics has been a useful tool for understanding biological properties and the pathogenesis of flaviviruses. However, the conventional construction of full-length infectious clones for flavivirus is time-consuming and difficult due to the toxicity of the flavivirus genome to E. coli. Herein, we applied a simple, rapid, and bacterium-free circular polymerase extension reaction (CPER) method to synthesize recombinant flaviviruses in vertebrate cells as well as insect cells. We started with the de novo synthesis of the JEV vaccine strain SA-14-14-2 in Vero cells using CPER, and then modified the CPER method to recover insect-specific flaviviruses (ISFs) in mosquito C6/36 cells. Chimeric Zika virus (ChinZIKV) based on the Chaoyang virus (CYV) backbone and the Culex flavivirus reporter virus expressing green fluorescent protein (CxFV-GFP) were subsequently rescued in C6/36 cells. CPER is a simple method for the rapid generation of flaviviruses and other potential RNA viruses. A CPER-based recovery system for flaviviruses of different host ranges was established, which would facilitate the development of countermeasures against flavivirus outbreaks in the future.
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Affiliation(s)
- Hao-Long Dong
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Mei-Juan He
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Qing-Yang Wang
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Jia-Zhen Cui
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Zhi-Li Chen
- Academy of Military Medical Sciences, Beijing 100071, China
| | | | | | - Hao Cheng
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Guo-Qing Xiong
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Ao Hu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Yuan-Yuan Lu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Chun-Lin Cheng
- School of Life Science, Hebei University, Baoding 071000, China
| | - Zhi-Xin Meng
- School of Life Science, Hebei University, Baoding 071000, China
| | - Chen Zhu
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Guang Zhao
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Gang Liu
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Hui-Peng Chen
- Academy of Military Medical Sciences, Beijing 100071, China
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Adam A, Lee C, Wang T. Rational Development of Live-Attenuated Zika Virus Vaccines. Pathogens 2023; 12:194. [PMID: 36839466 PMCID: PMC9963317 DOI: 10.3390/pathogens12020194] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 02/03/2023] Open
Abstract
Zika virus (ZIKV), a re-emerging mosquito-borne flavivirus, has caused outbreaks in Africa, Asia, the Pacific, and, more recently, in the Americas. ZIKV has been associated with the neurological autoimmune disorder Guillain-Barre syndrome in adults and congenital Zika syndrome in fetuses and infants, including microcephaly, spontaneous abortion, and intrauterine growth restriction. It is considered to be a major threat to global public health due to its unprecedented clinical impact on humans. Currently, there are no specific prophylactics or therapeutics available to prevent or treat ZIKV infection. The development of a safe and efficacious ZIKV vaccine remains a global health priority. Since the recent outbreak, multiple platforms have been used in the development of candidate ZIKV vaccines. The candidate vaccines have been shown to elicit strong T cell and neutralization antibody responses and protect against ZIKV infection in animal models. Some candidates have progressed successfully to clinical trials. Live-attenuated vaccines, which induce rapid and durable protective immunity, are one of the most important strategies for controlling flavivirus diseases. In this review, we discuss recent progress in the development of candidate live-attenuated ZIKV vaccines.
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Affiliation(s)
- Awadalkareem Adam
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Christy Lee
- John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Tian Wang
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
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TGF-β1 Promotes Zika Virus Infection in Immortalized Human First-Trimester Trophoblasts via the Smad Pathway. Cells 2022; 11:cells11193026. [PMID: 36230987 PMCID: PMC9562857 DOI: 10.3390/cells11193026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 12/05/2022] Open
Abstract
The Zika virus (ZIKV) is well known for causing congenital Zika syndrome if the infection occurs during pregnancy; however, the mechanism by which the virus infects and crosses the placenta barrier has not been completely understood. In pregnancy, TGF-β1 is abundant at the maternal–fetal interface. TGF-β1 has been reported to enhance rubella virus binding and infection in human lung epithelial cells. Therefore, in this study, we investigate the role of TGF-β1 in ZIKV infection in the immortalized human first-trimester trophoblasts, i.e., Swan.71. The cells were treated with TGF-β1 (10 ng/mL) for two days before being inoculated with the virus (American strain PRVABC59) at a multiplicity of infection of five. The results showed an enhancement of ZIKV infection, as demonstrated by the immunofluorescent assay and flow cytometry analysis. Such enhanced infection effects were abolished using SB431542 or SB525334, inhibitors of the TGF-β/Smad signaling pathway. An approximately 2-fold increase in the virus binding to the studied trophoblasts was found. In the presence of the Smad inhibitors, virus replication was significantly suppressed. An enhancement in Tyro3 and AXL (receptors for ZIKV) expression induced by TGF-β1 was also noted. The results suggest that TGF-β1 promotes the virus infection via the Smad pathway. Further studies should be carried out to clarify the underlying mechanisms of these findings.
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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: 7] [Impact Index Per Article: 3.5] [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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