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Santoni M, Gutierrez-Valdes N, Pivotto D, Zanichelli E, Rosa A, Sobrino-Mengual G, Balieu J, Lerouge P, Bardor M, Cecchetto R, Compri M, Mazzariol A, Ritala A, Avesani L. Performance of plant-produced RBDs as SARS-CoV-2 diagnostic reagents: a tale of two plant platforms. FRONTIERS IN PLANT SCIENCE 2024; 14:1325162. [PMID: 38239207 PMCID: PMC10794598 DOI: 10.3389/fpls.2023.1325162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/04/2023] [Indexed: 01/22/2024]
Abstract
The COVID-19 pandemic has underscored the need for rapid and cost-effective diagnostic tools. Serological tests, particularly those measuring antibodies targeting the receptor-binding domain (RBD) of the virus, play a pivotal role in tracking infection dynamics and vaccine effectiveness. In this study, we aimed to develop a simple enzyme-linked immunosorbent assay (ELISA) for measuring RBD-specific antibodies, comparing two plant-based platforms for diagnostic reagent production. We chose to retain RBD in the endoplasmic reticulum (ER) to prevent potential immunoreactivity issues associated with plant-specific glycans. We produced ER-retained RBD in two plant systems: a stable transformation of BY-2 plant cell culture (BY2-RBD) and a transient transformation in Nicotiana benthamiana using the MagnICON system (NB-RBD). Both systems demonstrated their suitability, with varying yields and production timelines. The plant-made proteins revealed unexpected differences in N-glycan profiles, with BY2-RBD displaying oligo-mannosidic N-glycans and NB-RBD exhibiting a more complex glycan profile. This difference may be attributed to higher recombinant protein synthesis in the N. benthamiana system, potentially overloading the ER retention signal, causing some proteins to traffic to the Golgi apparatus. When used as diagnostic reagents in ELISA, BY2-RBD outperformed NB-RBD in terms of sensitivity, specificity, and correlation with a commercial kit. This discrepancy may be due to the distinct glycan profiles, as complex glycans on NB-RBD may impact immunoreactivity. In conclusion, our study highlights the potential of plant-based systems for rapid diagnostic reagent production during emergencies. However, transient expression systems, while offering shorter timelines, introduce higher heterogeneity in recombinant protein forms, necessitating careful consideration in serological test development.
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Affiliation(s)
| | | | - Denise Pivotto
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Elena Zanichelli
- Department of Biotechnology, University of Verona, Verona, Italy
| | | | - Guillermo Sobrino-Mengual
- Université de Rouen Normandie, Normandie Univ, GlycoMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, GDR CNRS Chemobiologie, RMT BESTIM, Rouen, France
- Applied Plant Biotechnology Group, Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Lleida, Spain
| | - Juliette Balieu
- Université de Rouen Normandie, Normandie Univ, GlycoMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, GDR CNRS Chemobiologie, RMT BESTIM, Rouen, France
| | - Patrice Lerouge
- Université de Rouen Normandie, Normandie Univ, GlycoMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, GDR CNRS Chemobiologie, RMT BESTIM, Rouen, France
| | - Muriel Bardor
- Université de Rouen Normandie, Normandie Univ, GlycoMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, GDR CNRS Chemobiologie, RMT BESTIM, Rouen, France
| | - Riccardo Cecchetto
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, Verona, Italy
| | - Monica Compri
- Azienda Ospedaliera Universitaria, UOC Microbiologia e Virologia, Verona, Italy
| | - Annarita Mazzariol
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, Verona, Italy
| | - Anneli Ritala
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | - Linda Avesani
- Department of Biotechnology, University of Verona, Verona, Italy
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2
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Song L, Wang Q, Wen Y, Tan R, Cui Y, Xiong D, Jiao X, Pan Z. Enhanced immunogenicity elicited by a novel DNA vaccine encoding the SARS-CoV-2 S1 protein fused to the optimized flagellin of Salmonella typhimurium in mice. Microbiol Spectr 2023; 11:e0254923. [PMID: 37909745 PMCID: PMC10714832 DOI: 10.1128/spectrum.02549-23] [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: 06/18/2023] [Accepted: 09/08/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE The development of safe and effective vaccines is needed to control the transmission of coronavirus disease 2019 (COVID-19). Synthetic DNA vaccines represent a promising platform in response to such outbreaks. Here, DNA vaccine candidates were developed using an optimized antibiotic-resistance gene-free asd-pVAX1 vector. An optimized flagellin (FliC) adjuvant was designed by fusion expression to increase the immunogenicity of the S1 antigen. S1 and S1-FliCΔD2D3 proteins were strongly expressed in mammalian cells. The FliCΔD2D3-adjuvanted DNA vaccine induced Th1/Th2-mixed immune responses and high titers of neutralizing antibodies. This study provides crucial information regarding the selection of a safer DNA vector and adjuvant for vaccine development. Our FliCΔD2D3-adjuvanted S1 DNA vaccine is more potent at inducing both humoral and cellular immune responses than S1 alone. This finding provides a new idea for the development of novel DNA vaccines against COVID-19 and could be further applied for the development of other vaccines.
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Affiliation(s)
- Li Song
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Qiaoju Wang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Yaya Wen
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Ruimeng Tan
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Yaodan Cui
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Dan Xiong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
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3
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Margolin E, Schäfer G, Allen JD, Gers S, Woodward J, Sutherland AD, Blumenthal M, Meyers A, Shaw ML, Preiser W, Strasser R, Crispin M, Williamson AL, Rybicki EP, Chapman R. A plant-produced SARS-CoV-2 spike protein elicits heterologous immunity in hamsters. FRONTIERS IN PLANT SCIENCE 2023; 14:1146234. [PMID: 36959936 PMCID: PMC10028082 DOI: 10.3389/fpls.2023.1146234] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/17/2023] [Indexed: 06/16/2023]
Abstract
Molecular farming of vaccines has been heralded as a cheap, safe and scalable production platform. In reality, however, differences in the plant biosynthetic machinery, compared to mammalian cells, can complicate the production of viral glycoproteins. Remodelling the secretory pathway presents an opportunity to support key post-translational modifications, and to tailor aspects of glycosylation and glycosylation-directed folding. In this study, we applied an integrated host and glyco-engineering approach, NXS/T Generation™, to produce a SARS-CoV-2 prefusion spike trimer in Nicotiana benthamiana as a model antigen from an emerging virus. The size exclusion-purified protein exhibited a characteristic prefusion structure when viewed by transmission electron microscopy, and this was indistinguishable from the equivalent mammalian cell-produced antigen. The plant-produced protein was decorated with under-processed oligomannose N-glycans and exhibited a site occupancy that was comparable to the equivalent protein produced in mammalian cell culture. Complex-type glycans were almost entirely absent from the plant-derived material, which contrasted against the predominantly mature, complex glycans that were observed on the mammalian cell culture-derived protein. The plant-derived antigen elicited neutralizing antibodies against both the matched Wuhan and heterologous Delta SARS-CoV-2 variants in immunized hamsters, although titres were lower than those induced by the comparator mammalian antigen. Animals vaccinated with the plant-derived antigen exhibited reduced viral loads following challenge, as well as significant protection from SARS-CoV-2 disease as evidenced by reduced lung pathology, lower viral loads and protection from weight loss. Nonetheless, animals immunized with the mammalian cell-culture-derived protein were better protected in this challenge model suggesting that more faithfully reproducing the native glycoprotein structure and associated glycosylation of the antigen may be desirable.
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Affiliation(s)
- Emmanuel Margolin
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Trust Centre for Infectious Disease Research in Africa, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Georgia Schäfer
- Wellcome Trust Centre for Infectious Disease Research in Africa, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Observatory, Cape Town, Cape Town, South Africa
| | - Joel D Allen
- School of Biological Sciences and Institute of Life Sciences, University of Southampton, Southampton, United Kingdom
| | | | - Jeremy Woodward
- Electron Microscope Unit, University of Cape Town, Cape Town, South Africa
| | - Andrew D Sutherland
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University Tygerberg Campus, Cape Town, South Africa
| | - Melissa Blumenthal
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology, Observatory, Cape Town, Cape Town, South Africa
| | - Ann Meyers
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Megan L Shaw
- Department of Medical Biosciences, University of the Western Cape, Cape Town, South Africa
| | - Wolfgang Preiser
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University Tygerberg Campus, Cape Town, South Africa
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Max Crispin
- School of Biological Sciences and Institute of Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Anna-Lise Williamson
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Edward P Rybicki
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
| | - Ros Chapman
- Division of Medical Virology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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4
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England C, TrejoMartinez J, PerezSanchez P, Karki U, Xu J. Plants as Biofactories for Therapeutic Proteins and Antiviral Compounds to Combat COVID-19. Life (Basel) 2023; 13:617. [PMID: 36983772 PMCID: PMC10054913 DOI: 10.3390/life13030617] [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: 01/17/2023] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had a profound impact on the world's health and economy. Although the end of the pandemic may come in 2023, it is generally believed that the virus will not be completely eradicated. Most likely, the disease will become an endemicity. The rapid development of vaccines of different types (mRNA, subunit protein, inactivated virus, etc.) and some other antiviral drugs (Remdesivir, Olumiant, Paxlovid, etc.) has provided effectiveness in reducing COVID-19's impact worldwide. However, the circulating SARS-CoV-2 virus has been constantly mutating with the emergence of multiple variants, which makes control of COVID-19 difficult. There is still a pressing need for developing more effective antiviral drugs to fight against the disease. Plants have provided a promising production platform for both bioactive chemical compounds (small molecules) and recombinant therapeutics (big molecules). Plants naturally produce a diverse range of bioactive compounds as secondary metabolites, such as alkaloids, terpenoids/terpenes and polyphenols, which are a rich source of countless antiviral compounds. Plants can also be genetically engineered to produce valuable recombinant therapeutics. This molecular farming in plants has an unprecedented opportunity for developing vaccines, antibodies, and other biologics for pandemic diseases because of its potential advantages, such as low cost, safety, and high production volume. This review summarizes the latest advancements in plant-derived drugs used to combat COVID-19 and discusses the prospects and challenges of the plant-based production platform for antiviral agents.
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Affiliation(s)
- Corbin England
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA
- Molecular Biosciences Program, Arkansas State University, Jonesboro, AR 72401, USA
| | | | - Paula PerezSanchez
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR 72401, USA
| | - Uddhab Karki
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA
- Molecular Biosciences Program, Arkansas State University, Jonesboro, AR 72401, USA
| | - Jianfeng Xu
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA
- College of Agriculture, Arkansas State University, Jonesboro, AR 72401, USA
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5
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Guan X, Yang Y, Du L. Advances in SARS-CoV-2 receptor-binding domain-based COVID-19 vaccines. Expert Rev Vaccines 2023; 22:422-439. [PMID: 37161869 PMCID: PMC10355161 DOI: 10.1080/14760584.2023.2211153] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/03/2023] [Indexed: 05/11/2023]
Abstract
INTRODUCTION The Coronavirus Disease 2019 (COVID-19) pandemic has caused devastating human and economic costs. Vaccination is an important step in controlling the pandemic. Severe acute respiratory coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, infects cells by binding a cellular receptor through the receptor-binding domain (RBD) within the S1 subunit of the spike (S) protein. Viral entry and membrane fusion are mediated by the S2 subunit. AREAS COVERED SARS-CoV-2 S protein, particularly RBD, serves as an important target for vaccines. Here we review the structure and function of SARS-CoV-2 S protein and its RBD, summarize current COVID-19 vaccines targeting the RBD, and outline potential strategies for improving RBD-based vaccines. Overall, this review provides important information that will facilitate rational design and development of safer and more effective COVID-19 vaccines. EXPERT OPINION The S protein of SARS-CoV-2 harbors numerous mutations, mostly in the RBD, resulting in multiple variant strains. Although many COVID-19 vaccines targeting the RBD of original virus strain (and previous variants) can prevent infection of these strains, their ability against recent dominant variants, particularly Omicron and its offspring, is significantly reduced. Collective efforts are needed to develop effective broad-spectrum vaccines to control current and future variants that have pandemic potential.
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Affiliation(s)
- Xiaoqing Guan
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
| | - Yang Yang
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Lanying Du
- Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, USA
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6
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Pitino M, Fleites LA, Shrum L, Heck M, Shatters RG. Plant production of high affinity nanobodies that block SARS-CoV-2 spike protein binding with its receptor, human angiotensin converting enzyme. Front Bioeng Biotechnol 2022; 10:1045337. [PMID: 36619377 PMCID: PMC9822723 DOI: 10.3389/fbioe.2022.1045337] [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: 09/15/2022] [Accepted: 12/05/2022] [Indexed: 12/25/2022] Open
Abstract
Nanobodies® (VHH antibodies), are small peptides that represent the antigen binding domain, VHH of unique single domain antibodies (heavy chain only antibodies, HcAb) derived from camelids. Here, we demonstrate production of VHH nanobodies against the SARS-CoV-2 spike proteins in the solanaceous plant Nicotiana benthamiana through transient expression and their subsequent detection verified through western blot. We demonstrate that these nanobodies competitively inhibit binding between the SARS-CoV-2 spike protein receptor binding domain and its human receptor protein, angiotensin converting enzyme 2. There has been significant interest and a number of publications on the use of plants as biofactories and even some reports of producing nanobodies in plants. Our data demonstrate that functional nanobodies blocking a process necessary to initiate SARS-CoV-2 infection into mammalian cells can be produced in plants. This opens the alternative of using plants in a scheme to rapidly respond to therapeutic needs for emerging pathogens in human medicine and agriculture.
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Affiliation(s)
| | | | | | - Michelle Heck
- Emerging Pests and Pathogens Research Unit, USDA Agricultural Research Service, Ithaca, NY, United States
| | - Robert G. Shatters
- U.S. Horticultural Research Laboratory, Subtropical Insects and Horticulture Research Unit, USDA Agricultural Research Service, Fort Pierce, FL, United States,*Correspondence: Robert G. Shatters Jr,
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7
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High-Yield Production of Chimeric Hepatitis E Virus-Like Particles Bearing the M2e Influenza Epitope and Receptor Binding Domain of SARS-CoV-2 in Plants Using Viral Vectors. Int J Mol Sci 2022; 23:ijms232415684. [PMID: 36555326 PMCID: PMC9779006 DOI: 10.3390/ijms232415684] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Capsid protein of Hepatitis E virus (HEV) is capable of self-assembly into virus-like particles (VLPs) when expressed in Nicotiana benthamiana plants. Such VLPs could be used as carriers of antigens for vaccine development. In this study, we obtained VLPs based on truncated coat protein of HEV bearing the M2e peptide of Influenza A virus or receptor-binding domain of SARS-CoV-2 spike glycoprotein (RBD). We optimized the immunogenic epitopes' presentation by inserting them into the protruding domain of HEV ORF2 at position Tyr485. The fusion proteins were expressed in Nicotiana benthamiana plants using self-replicating potato virus X (PVX)-based vector. The fusion protein HEV/M2, targeted to the cytosol, was expressed at the level of about 300-400 μg per gram of fresh leaf tissue and appeared to be soluble. The fusion protein was purified using metal affinity chromatography under native conditions with the final yield about 200 μg per gram of fresh leaf tissue. The fusion protein HEV/RBD, targeted to the endoplasmic reticulum, was expressed at about 80-100 μg per gram of fresh leaf tissue; the yield after purification was up to 20 μg per gram of fresh leaf tissue. The recombinant proteins HEV/M2 and HEV/RBD formed nanosized virus-like particles that could be recognized by antibodies against inserted epitopes. The ELISA assay showed that antibodies of COVID-19 patients can bind plant-produced HEV/RBD virus-like particles. This study shows that HEV capsid protein is a promising carrier for presentation of foreign antigen.
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8
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Mardanova ES, Kotlyarov RY, Ravin NV. Rapid Transient Expression of Receptor-Binding Domain of SARS-CoV-2 and the Conserved M2e Peptide of Influenza A Virus Linked to Flagellin in Nicotiana benthamiana Plants Using Self-Replicating Viral Vector. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11243425. [PMID: 36559537 PMCID: PMC9785242 DOI: 10.3390/plants11243425] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 11/30/2022] [Accepted: 12/04/2022] [Indexed: 06/12/2023]
Abstract
The development of recombinant vaccines against SARS-CoV-2 and influenza A is an important task. The combination of the conserved influenza A antigen, the extracellular domain of the transmembrane protein M2 (M2e), and the receptor-binding domain of the SARS-CoV-2 spike glycoprotein (RBD) provides the opportunity to develop a bivalent vaccine against these infections. The fusion of antigens with bacterial flagellin, the ligand for Toll-like receptor 5 and potent mucosal adjuvant, may increase the immunogenicity of the candidate vaccines and enable intranasal immunization. In this study, we report the transient expression of RBD alone, RBD coupled with four copies of M2e, and fusions of RBD and RBD-4M2e with flagellin in Nicotiana benthamiana plants using the self-replicating potato virus X-based vector pEff. The yields of purified recombinant proteins per gram of fresh leaf tissue were about 20 µg for RBD, 50-60 µg for RBD-4M2e and the fusion of RBD with flagellin, and about 90 µg for RBD-4M2e fused to flagellin. Targeting to the endoplasmic reticulum enabled the production of glycosylated recombinant proteins comprising RBD. Our results show that plant-produced RBD and RBD-4M2e could be further used for the development of subunit vaccines against COVID-19 and a bivalent vaccine against COVID-19 and influenza A, while flagellin fusions could be used for the development of intranasal vaccines.
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9
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Rebelo BA, Folgado A, Ferreira AC, Abranches R. Production of the SARS-CoV-2 Spike protein and its Receptor Binding Domain in plant cell suspension cultures. FRONTIERS IN PLANT SCIENCE 2022; 13:995429. [PMID: 36340353 PMCID: PMC9634662 DOI: 10.3389/fpls.2022.995429] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/20/2022] [Indexed: 05/29/2023]
Abstract
The COVID-19 pandemic, caused by the worldwide spread of SARS-CoV-2, has prompted the scientific community to rapidly develop efficient and specific diagnostics and therapeutics. A number of avenues have been explored, including the manufacture of COVID-related proteins to be used as reagents for diagnostics or treatment. The production of RBD and Spike proteins was previously achieved in eukaryotic cells, mainly mammalian cell cultures, while the production in microbial systems has been unsuccessful until now. Here we report the effective production of SARS-CoV-2 proteins in two plant model systems. We established transgenic tobacco BY-2 and Medicago truncatula A17 cell suspension cultures stably producing the full-length Spike and RBD recombinant proteins. For both proteins, various glycoforms were obtained, with higher yields in Medicago cultures than BY-2. This work highlights that RBD and Spike can be secreted into the culture medium, which will impact subsequent purification and downstream processing costs. Analysis of the culture media indicated the presence of the high molecular weight Spike protein of SARS-CoV-2. Although the production yields still need improvement to compete with mammalian systems, this is the first report showing that plant cell suspension cultures are able to produce the high molecular weight Spike protein. This finding strengthens the potential of plant cell cultures as production platforms for large complex proteins.
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Plchová H, Moravec T, Čeřovská N, Pobořilová Z, Dušek J, Kratochvílová K, Navrátil O, Kundu JK. A GoldenBraid-Compatible Virus-Based Vector System for Transient Expression of Heterologous Proteins in Plants. Viruses 2022; 14:1099. [PMID: 35632840 PMCID: PMC9146717 DOI: 10.3390/v14051099] [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: 03/26/2022] [Revised: 05/09/2022] [Accepted: 05/19/2022] [Indexed: 12/10/2022] Open
Abstract
We have developed a Potato virus X (PVX)-based vector system compatible with the GoldenBraid 2.0 (GB) cloning strategy to transiently express heterologous proteins or peptides in plants for biotechnological purposes. This vector system consists of three domestication vectors carrying three GB parts-the cauliflower mosaic virus (CaMV) 35S promoter with PVX upstream of the second subgenomic promoter of the PVX coat protein (PVX CP SGP), nopaline synthase (NOS) terminator with PVX downstream of the first PVX CP SGP and the gene of interest (GOI). The full-length PVX clone carrying the sequence encoding a green fluorescent protein (GFP) as GOI was incorporated into the binary GB vector in a one-step reaction of three GB parts using the four-nucleotide GB standard syntax. We investigated whether the obtained vector named GFP/pGBX enables systemic PVX infection and expression of GFP in Nicotiana benthamiana plants. We show that this GB-compatible vector system can be used for simple and efficient assembly of PVX-based expression constructs and that it meets the current need for interchange of standard biological parts used in different expression systems.
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Affiliation(s)
- Helena Plchová
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
| | - Tomáš Moravec
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
| | - Noemi Čeřovská
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
| | - Zuzana Pobořilová
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
| | - Jakub Dušek
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
- Department of Plant Protection, Czech University of Life Sciences, 16500 Prague, Czech Republic
| | - Kateřina Kratochvílová
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
- Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 12843 Prague, Czech Republic
| | - Oldřich Navrátil
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
| | - Jiban Kumar Kundu
- Laboratory of Virology, Centre for Plant Virus Research, Institute of Experimental Botany of the Czech Academy of Sciences, 16500 Prague, Czech Republic; (H.P.); (N.Č.); (Z.P.); (J.D.); (K.K.); (O.N.)
- Plant Virus and Vector Interactions, Centre for Plant Virus Research, Crop Research Institute, 16106 Prague, Czech Republic
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