Synopsis Introduction History Definition Need for edible vaccine Plants normally used for production of edible vaccine Production Mode of application Advantages Disadvantages Application Conclusion References

1. Edible vaccine
By
KAUSHAL KUMAR SAHU
Assistant Professor (Ad Hoc)
Department of Biotechnology
Govt. Digvijay Autonomous P. G. College
Raj-Nandgaon ( C. G. )

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Edible vaccine
Synopsis
•Introduction
•History
•Definition
•Need for edible vaccine
•Plants normally used for production of
edible vaccine
•Production
•Mode of application
•Advantages
•Disadvantages
•Application
•Conclusion
•References

3. INTRODUCTION
According to WHO, various diseases are responsible for 80%
of illness worldwide and cause more than 20 million deaths
annually.
Vaccines represent an invaluable contribution in the field of
biotechnology as they provide protection against various
diseases
Newer approaches have also been made with regard to the use of
purified antigen vaccines and recombinant vaccines
Edible vaccines are emerging innovations in medical science and
plant biology for the affordable pharmaceuticals.
For production of edible vaccines, it is desirable to select a plant
whose products are consumed raw to avoid degradation during
cooking. Thus, plants like tomato, banana and cucumbers are
generally the plants of choice.
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4. DEFINITION
Those vaccines which can be eaten raw by patient are
called as ediable vaccine.
Edible vaccines are nothing but transgenic plant and
animal based production of or those that contain
agents that trigger an animal’s immune response. In
simple terms,edible vaccines are plant or animal made
pharmaceuticals.
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5. Need for edible vaccine-
In the past few years, agricultural biotechnology has progressed
in leaps and bounds. It started with the commercial success of
“Golden Rice”- a genetically modified crop, aimed to provide
better “Vitamin-A” nutrition to those populations that suffer
from Vitamin- A deficiency.
The other commercial GM crops were namely, “Flavr Savr”
Tomatoes, Bt. Brinjal and many more, each aiming at either
increasing yield or reducing spoilage. It therefore helped in
increasing yield by decreasing the damage.
Biotechnologists in recent years have come up with a new
concept, enhancing the idea behind “Golden Rice”. This new
concept is about Food Vaccines. The difference here lies, that
crops like “golden rice” provided extra nutrition that naturally
didn’t occur in it. But food vaccines are GM crops that would
provide extra added “immunity” from certain diseases.
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6. Food Vaccines or Edible Vaccines have many potential
advantages..
One of the key goals of the edible-vaccine pioneers is to reduce
immunization costs.
It is postulated that edible vaccines would be far cheaper than
current injectable vaccines since they would not have to undergo
the expensive purification and refrigeration of traditional
vaccines, and transportation costs would be much reduced.
Plants normally used for production of edible vaccine
Transgenic plants that express foreign proteins with industrial
or pharmaceutical value represent an economical alternative to
fermentation based production systems.
Specific vaccine have been produced in plants as a result of the
transient or stable expression of foreign genes
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7. Plants/fruits Adventages Dis adventages
1.Tobacco Good model for evaluating
recombinant proteins.
Low cost preserving
system.
Easy purification of
antibodies stored in the
seeds, at an location.
Produces toxic
compounds*
2.Banana
Do not need cooking
Inexpensive
Grown widely in
developing countries
Trees take 2-3 years
to mature
Transformed trees
take about 12 months
to bear fruit
Spoils rapidly after
ripening
Contains very little
protein, so unlikely to
produce large amounts
of recombinant
proteins
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8. 3. Tomato Grow quickly,Cultivated
broadly
High content of vitamin A
may boost immune
response
Overcome the spoilage
problem by freeze-drying
technology
Spoils readily
4.Rice Commonly used in baby
food because of low
allergenic potential
High expression of
proteins/ antigens
Easy
storage/transportation
Expressed protein is
heat-stable
Grows slowly
Requires specialized
glasshouse conditions
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9. Production of edible vaccine-
Plants belongs to the most economical producers of biomass.
They provide an optimal system for the expreesion of
recombinant proteins free of contamination by bacterial toxins
or animal pathogens.
There are two strategies for edible vaccine production
•By stable transformation.
•By plants viruses.
production of
edible vaccine
By stable
transformation
Agrobacterium
mediated
direct DNA
transfer
method
By plants
viruseus
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10. Expression of foreign antigen in plants via stable
transformation
The basic mythology includes identification, selection and
isolation of desirable genes from the pathogen that encodes the
surface antigen proteins. The isolated gene can be then cloned in
a suitable vector for gene transfer.
The selected vector should possess all the unique characteristic
of an ideal vector. The molecular markers present in vectors can
be used for screening transformed host cells form
untransformed.
Transformation is grouped into two broad categories.
•Agrobacterium mediated
•Direct gene transfers
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11. Fig- Development of edible vaccine by A.tumifaciens mediated
transformation
Agrobactrium mediated transformation
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12. Direct transfer
Physical
(Electroporation,
Particle Bombardment,
Microinjection,
Liposome mediated)
Chemical
(PEG ,Calcium
Phosphate ,DEAE-
diehtylaminoethyl)
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13. Selection of transformed cells from untransformed cells
The selection of transformed plant cells from untransformed
cells is an important step in the plant genetic engineering.
For this, a marker gene (e.g. for antibiotic resistance) is
introduced into the plant along with the transgene followed by
the selection of an appropriate selection medium (containing the
antibiotic).
The segregation and stability of the transgene integration and
expression in the subsequent generations can be studied by
genetic and molecular analyses (Northern, Southern, Western
blot, PCR).
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Production of vaccine via plant viruses-
The benefits of virus-based transient RNA and DNA replicons
versus transgenic gene expression include rapid and convenient
engineering coupled with flexibility for expeditious application in
various plant species. These characteristics are especially
advantageous when very high levels of gene expression are
desired within a short time.
The three group of viruses -
•Caulimoviruses
•Germiniviruses
•RNA viruses.
Theses viruses used as vectors for gene transfer in plants.

15. Mode of action-
Many pathogens enter the body through the nose,
mouth or other openings. Hence, the first defenses
they encounter are those in the mucous membrane.
These membranes constitute the biggest pathogen-
deterring surface in the body. When the mucosal
immune response is effective, it generates molecules
known as secretary antibodies that neutralizing any
pathogens they find.
Injected vaccines initially bypass mucous membranes
and typically do a poor job of stimulating mucosal
immune responses.
But edible vaccines come into contact with the lining of
the digestive tract. In theory, then, they would activate
both mucosal and systemic immunity. That dual effect
should, in turn, help improve protection against many
dangerous microorganism.
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16. Edible vaccine when enters orally undergoes mastication process and the
majority of plant cell degradation occurs in the intestine as a result of
bacterial or digestive enzymatic actions and thus small intestine is the
site of action of edible vaccine.
Breakdown of edible vaccine near payer patches releases vaccine
contains where as payer’s patches act as mucosal immune effectors
sites.
Payer patches consists of 30-40 lymphoid nodules on outer surface of
intestine and contain follicles from which germinal center developes
upon antigenic stimulation and these follicles act as the site from which
antigen penetrates the intestinal epithelium. Thus facillating
accumulation of antigen within organized lymphoid structure. The
antigen comes in contact with M-cells.
It contacts with lumen which is filled with clusters of B-cells,T-cells
and macrophage.
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17. As a result of interaction with M-cell, a helper T-cells produces cytokines.
These cytokines activate B-cell within these lymphoid follicles. The
activated B-cell leave lymphoid follicle and migrate to diffuse mucosal
associated lymphoid tissue where they diffrentiate and proliferate into
plasma cell and memory cell.
Plasma cell secrete IgA class of antibodies. These IgA antibody
transported across the epithelial cell into secretion of lumen where they
can interact with antigen present in lumen.
Memory cell remain in the body indefinite, ready to differentiate into
plasma cell. If the antigen is ever detected gain in the body.
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18. How does it work?
Fig – mode of action of edible vaccine.
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19. Application
Currently researchers are seeking to develop genetically altered
plants that could provide immunity to infectious diseases.
1.Vaccines against diarrhea
.
An oral plant-based delivery system would be especially useful to
prevent diarrheal diseases for which mucosal immune responses
at the site of colonization are likely to be protective.
Two important diarrheal pathogens have been targets of vaccine
development in recent years—enterotoxigenic E. coli (ETEC) and
norovirus (NV).
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20. The B subunit of the ETEC toxin (LT-B) binds epithelial cell GM1
gangliosides and is a potent stimulator of mucosal immune
responses when given orally, but is not itself diarrheagenic.
Norovirus with a single capsid protein that can assemble
spontaneously into virus-like particles (VLP) and stimulate immune
responses .
Both LT-B and the capsid protein of norovirus were successfully
expressed in plants and induced immune responses in mice after
ingestion of transgenic plant material .
Antibody to LTB induced by vaccine could interfere with binding
of the toxin to its target thereby protecting against diarrhea,
and in fact, immune responses to LT-B offer short-term
protection against infection with LTproducing E.coli.
2. Vaccine against cholera
ETEC diarrhea is mediated by its heat labile enterotoxin,
designated LT E
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22. •Edible vaccine using GM maize in hepatitis B:
Fig.: Edible vaccine using GM maize
Maize plants to produce a protein used to make the hepatitis B
virus vaccine.
More than 2 billion people are infected with hepatitis B, and
about 350 million of these are at high risk of serious illness and
death from liver damage and liver cancer.
A vaccine against the disease is already available, but the
researchers say that edible vaccines produced by GM plants
would be cheaper and would not need to be refrigerated.
GM maize plants that produce the protein known as HbsAg, which
elicits an immune response against the hepatitis B virus and could
be used as a vaccine.
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23. •potato vaccine could fight stomach virus:
Fig- production of potato vaccine
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24. Vaccine Development have successfully tested a potato-based
vaccine to combat the Norwalk Virus, which is spread by
contaminated food and water. The virus causes severe abdominal
pain and diarrhea.
Researchers demonstrated that the edible vaccine is safe and
stimulates antibodies, or germ-fighting proteins in the
volunteers tested.
To be immunized, people would need to eat a raw vegetable that
contains the gene for the vaccine protein.
severe spread of the Norwalk Virus is a leading cause of infant
mortality.
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•”planr biotechnology” by H.S.Chawla.
•“Biotechnology” by U.Satyanarayan.
Websites-
•Scientific American.com
•Pharmainfo.net

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