Plant-derived vaccines (PDVs) include edible vaccines which are used to immunize humans and animals orally through feeding or production of antigens in plants, and purification of them to be used in subunit vaccines. The utilization of plants in vaccine development offers many advantages because vast amounts of low-cost recombinant proteins can be produced in plants. Moreover, antigens are protected from proteases in the gastrointestinal tract due to the strong cell walls of these hosts, making plants useful for oral vaccination strategies. Plant-derived antigens are safer compared to methods using mammalian cells/tissues which may contain viruses or prions. Additionally, genetic engineering of plants is relatively easy, and they possess the machinery for the post-translational modification of proteins.
An efficient way to obtain plant-based vaccines is the production of virus-like particles (VLPs) in plants. VLPs are formed by the self-assembly of viral structural proteins. The organization of a VLP mimics the native virus except for its genome. Highly potent VLPs can be obtained by eliminating the immunosuppressive proteins of native viruses. Additionally, possible modification of the epitopes during the inactivation of the live virus does not occur in VLPs. Moreover, VLPs are safe, scalable, and relatively stable molecules that do not require viral replication, and potentially induce humoral and cellular immune responses. Transient expression systems can be used for the production of VLPs in plants which provide posttranslational modification of the proteins, such as glycosylation.
Purification of recombinant proteins in plants such as tobacco is challenging due to the high amount of secondary metabolites (e.g. polyphenols and alkaloids) which need clarification prior to chromatography. This step extends the purification process and generally results in the loss of antigens. Therefore, efficient strategies are required to overcome this problem. For instance, antigens can be produced in seeds as storage proteins, where the number of endogenous proteins is limited. Thus, purification of native antigens is easier, and batch production is flexible.
The utilization of plants in vaccine research is a hot topic in recent years. If the antigens are not purified from the plants or not produced as VLPs, plants are applied via different feeding strategies. This Research Topic is open to quality original research and review articles on plant-based antigen production and vaccine research.
Areas of research to be covered are, but are not limited to:
• Expression of antigen-coding genes in plants, determination of antigen yield in the transgenic plants, and immunogenicity of the plant-derived antigen;
• New methods for better expression or purification of antigens in plants;
• Production of virus-like particles (VLPs) in plants, and their characterization;
• Preclinical and clinical studies using plant-derived vaccines;
• Oral vaccination with plant-based vaccines and immune responses to edible vaccines;
• Discovery of new antigens using plants;
• Adjuvant research for increased plant-based vaccine efficacy.
Plant-derived vaccines (PDVs) include edible vaccines which are used to immunize humans and animals orally through feeding or production of antigens in plants, and purification of them to be used in subunit vaccines. The utilization of plants in vaccine development offers many advantages because vast amounts of low-cost recombinant proteins can be produced in plants. Moreover, antigens are protected from proteases in the gastrointestinal tract due to the strong cell walls of these hosts, making plants useful for oral vaccination strategies. Plant-derived antigens are safer compared to methods using mammalian cells/tissues which may contain viruses or prions. Additionally, genetic engineering of plants is relatively easy, and they possess the machinery for the post-translational modification of proteins.
An efficient way to obtain plant-based vaccines is the production of virus-like particles (VLPs) in plants. VLPs are formed by the self-assembly of viral structural proteins. The organization of a VLP mimics the native virus except for its genome. Highly potent VLPs can be obtained by eliminating the immunosuppressive proteins of native viruses. Additionally, possible modification of the epitopes during the inactivation of the live virus does not occur in VLPs. Moreover, VLPs are safe, scalable, and relatively stable molecules that do not require viral replication, and potentially induce humoral and cellular immune responses. Transient expression systems can be used for the production of VLPs in plants which provide posttranslational modification of the proteins, such as glycosylation.
Purification of recombinant proteins in plants such as tobacco is challenging due to the high amount of secondary metabolites (e.g. polyphenols and alkaloids) which need clarification prior to chromatography. This step extends the purification process and generally results in the loss of antigens. Therefore, efficient strategies are required to overcome this problem. For instance, antigens can be produced in seeds as storage proteins, where the number of endogenous proteins is limited. Thus, purification of native antigens is easier, and batch production is flexible.
The utilization of plants in vaccine research is a hot topic in recent years. If the antigens are not purified from the plants or not produced as VLPs, plants are applied via different feeding strategies. This Research Topic is open to quality original research and review articles on plant-based antigen production and vaccine research.
Areas of research to be covered are, but are not limited to:
• Expression of antigen-coding genes in plants, determination of antigen yield in the transgenic plants, and immunogenicity of the plant-derived antigen;
• New methods for better expression or purification of antigens in plants;
• Production of virus-like particles (VLPs) in plants, and their characterization;
• Preclinical and clinical studies using plant-derived vaccines;
• Oral vaccination with plant-based vaccines and immune responses to edible vaccines;
• Discovery of new antigens using plants;
• Adjuvant research for increased plant-based vaccine efficacy.