Plant-Based Vaccines: Antigen Design, Diversity, and Strategies for High Level Production

Vaccines for human use have conventionally been developed by the production of (1) microbial pathogens in eggs or mammalian cells that are then inactivated, or (2) by the production of pathogen proteins in mammalian and insect cells that are purified for vaccine formulation, as well as, more recently, (3) by using RNA or DNA fragments from pathogens. Another approach for recombinant antigen production in the last three decades has been the use of plants as biofactories. Only have few plant-produced vaccines been evaluated in clinical trials to fight against diseases, of which COVID-19 vaccines are the most recent to be FDA approved. In silico tools have accelerated vaccine design, which, combined with transitory antigen expression in plants, has led to the testing of promising prototypes in pre-clinical and clinical trials. Therefore, this review deals with a description of immunoinformatic tools and plant genetic engineering technologies used for antigen design (virus-like particles (VLP), subunit vaccines, VLP chimeras) and the main strategies for high antigen production levels. These key topics for plant-made vaccine development are discussed and perspectives are provided.

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High Level Production of Proteins in Mammalian Cells

Genetic Engineering ◽

10.1007/978-1-4684-5377-5_10 ◽

1987 ◽

pp. 155-198 ◽

Cited By ~ 5

Author(s):

Randal J. Kaufman

Keyword(s):

Mammalian Cells ◽

High Level ◽

Level Production

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The Proposed EU-regulation on Clinical Trials on Medicinal Products: An Unethical Proposal?

European Journal of Health Law ◽

10.1163/15718093-12341284 ◽

2013 ◽

Vol 20 (4) ◽

pp. 347-362 ◽

Cited By ~ 4

Author(s):

Jilles Heringa ◽

Joseph Dute

Keyword(s):

Clinical Trials ◽

Human Subjects ◽

The European Union ◽

Medicinal Products ◽

Member States ◽

Legal Documents ◽

Human Use ◽

Proposed Regulation ◽

High Level ◽

Force Member

Abstract The Commission has proposed a regulation ‘on clinical trials on medicinal products for human use’ to introduce one regulatory framework for clinical trials in the European Union. This regulation should replace the current clinical trials directive (2001/20/EC). In this article we describe and critically review the main provisions of the proposed regulation. We assess the consequences for a sound authorisation procedure of clinical trials and the level of protection for human subjects. We note that the proposed regulation is inconsistent with applicable international legal documents, such as the Biomedicine Convention and the Declaration of Helsinki. We conclude that the proposed regulation does not ensure a “high level of human health protection” — required by its legal basis in the TFEU — because it may force Member States concerned to accept a reporting Member States’ approval of — in their estimation — an unethical clinical trial.

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High-level production and purification of biologically active proteins from bacterial and mammalian cells using the tandem pGFLEX expression system

Gene ◽

10.1016/s0378-1119(97)00126-1 ◽

1997 ◽

Vol 193 (2) ◽

pp. 229-237 ◽

Cited By ~ 5

Author(s):

Herbert T. Manoharan ◽

Jean Gallo ◽

Andrew M. Gulick ◽

William E. Fahl

Keyword(s):

Mammalian Cells ◽

Expression System ◽

Biologically Active ◽

High Level ◽

Level Production

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Evaluation of Extracellular Subviral Particles of Dengue Virus Type 2 and Japanese Encephalitis Virus Produced by Spodoptera frugiperda Cells for Use as Vaccine and Diagnostic Antigens

Clinical and Vaccine Immunology ◽

10.1128/cvi.00087-10 ◽

2010 ◽

Vol 17 (10) ◽

pp. 1560-1566 ◽

Cited By ~ 28

Author(s):

Miwa Kuwahara ◽

Eiji Konishi

Keyword(s):

Dengue Virus ◽

Japanese Encephalitis Virus ◽

Japanese Encephalitis ◽

Spodoptera Frugiperda ◽

Mammalian Cells ◽

Encephalitis Virus ◽

Commercial Application ◽

Sf9 Cells ◽

High Level ◽

Level Production

ABSTRACT New or improved vaccines against dengue virus types 1 to 4 (DENV1 to DENV4) and Japanese encephalitis virus (JEV), the causative agents of dengue fever and Japanese encephalitis (JE), respectively, are urgently required. The use of noninfectious subviral extracellular particles (EPs) is an inexpensive and safe strategy for the production of protein-based flavivirus vaccines. Although coexpression of premembrane (prM) and envelope (E) proteins has been demonstrated to produce EPs in mammalian cells, low yields have hindered their commercial application. Therefore, we used an insect cell expression system with Spodoptera frugiperda-derived Sf9 cells to investigate high-level production of DENV2 and JEV EPs. Sf9 cells transfected with the prM and E genes of DENV2 or JEV secreted corresponding viral antigens in a particulate form that were biochemically and biophysically equivalent to the authentic antigens obtained from infected C6/36 mosquito cells. Additionally, equivalent neutralizing antibody titers were induced in mice immunized either with EPs produced by transfected Sf9 cells or with EPs produced by transfected mammalian cells, in the context of coimmunization with a DNA vaccine that expresses EPs. Furthermore, the results of an enzyme-linked immunosorbent assay (ELISA) using an EP antigen derived from Sf9 cells correlated significantly with the results obtained by a neutralization test and an ELISA using an EP antigen derived from mammalian cells. Finally, Sf9 cells could produce 10- to 100-fold larger amounts of E antigen than mammalian cells. These results indicate the potential of Sf9 cells for high-level production of flavivirus protein vaccines and diagnostic antigens.

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