PLANT AS BIOREACTOR, USE

FOR THE PRODUCTION OF

EDIBLE VACCINES

PRESENTED BY

EKE, ERIC PAUL. SID: 10509537

2Plant as Bioreactor

• A Bioreactor is a device in which a substrate of low value is utilized by living cells to generate products of higher value.

• Plants used as bioreactors, also known as transgenic plants, are plants in which foreign genes of desired characters have been inserted into and are expressed.

• However, the use of transgenic plants as “BIOREACTORS” is relatively new in bioscience and is gaining momentum

Introduction

3Plant as Bioreactor

• Types of plant bioreactors are: Seed-based plant bioreactors Plant Suspension Cultures Hairy Root System Bioreactor Chloroplast bioreactor

• The products that are currently being produced in plants include bioactive peptides, vaccine antigens, antibodies, diagnostic proteins, nutritional supplements, enzymes and biodegradable plastics.

4Plant as Bioreactor

Tree depicting biotechnological advances using plants as bioreactorsSource: www.plantbioreactor.co.in/images/00_112.jpg

5Plant as Bioreactor

• Vaccines are non-pathogenic antigen strains of disease- causing microorganisms (bacteria and viruses) responsible for the stimulation of protective antibody and other immune mechanisms to the host organism (s).

• The vaccines can be made from live attenuated or killed (inactivated) organisms.

Streatfield SJ et al., 2003

What are vaccines?

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• A vaccine in which an antigenic protein is engineered into an edible plant; after ingestion, the protein is released and recognized by the immune system is known as an EDIBLE VACCINE

7Plant as Bioreactor

• Two ways ……

• In one case , the entire structural gene is inserted into plant transformation vector between 5’ and 3’ regulatory element.

• In the second case , epitope within the antigen are identified ,DNA fragment encoding these can be used to construct gene by fusion with a coat protein gene from plant virus e.g. TMV or CMV .

Developing edible vaccines

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Developing edible vaccines cont’d

9Plant as Bioreactor

Protein purification

Direct feeding

Antibodies production: Western blotting ELISA

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Plasmid vector carrier system :

• Agrobacterium tumefaciens method.

• Micro projectile bombardment method.

• Electroporation method.

Methods for transformation of DNA/gene into plant

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Production of edible cholera vaccine using A.tumefaciens in potato plant

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Micro projectile

13Plant as Bioreactor

Administering oral vaccines would require little or no training at all.

Cost effective as no sophisticated equipment is required

Oral vaccines provide “mucosal immunity” at various sites by secreting antibodies.

Don’t need to worry about re-use, misuse and lack of sterilization. Thus, low risk of infection.

Needle free

Cheap

Why edible vaccine?

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Plant pathogens do not infects infect humans and animals

Needs no purification.

Edible vaccine activates both mucosal and systemic immunity

Heat-stable; do not require cold-chain maintenance. Hence, does not require refrigeration.

Proteins can easily be stored indefinitely in seeds ` ` with less reduction in biological activities

Storage

Safe

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• Selection of best plant is difficult.

• Consistency of dosage from fruit to fruit, plant-to-plant, and generation-to-generation is not similar.

• Possible allergic reaction to plant components is yet another remote concern.

• Effect of GM crops on biodiversity and environment

• There is a risk of “gene pollution” .

• Religious issues ……..vegetarian people and some ethnic groups.

Limitations and Concerns

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• Edible plant-derived vaccines may lead to a future of safer and more effective immunization. Resulting therapeutic products would overcome some of the difficulties associated with traditional vaccines, like costly production, distribution and delivery.

Conclusion

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THANK YOU!