Plantibodies are antibodies or proteins produced in genetically modified crops. They can be used as edible vaccines, diagnostic or therapeutic monoclonal antibodies, or to confer disease resistance in plants. There are three main types - expression of full-length antibodies, antibody fragments, or single chain or single domain genes. Plants are an attractive production system due to low contamination risk, flexible and low-cost production, and no ethical issues. The plantibody approach involves constructing genes containing antibody sequences with effective promoters, then transforming plants and propagating through breeding or tissue culture. Applications include therapeutic antibodies for various diseases and oral vaccines delivered through edible plants. While plant-produced antibodies have identical peptide sequences and functions to mammalian ones, they have different post-

1. Plantibodies
By,
Himani Dey,
Pondicherry Uiversity

2. What are they???
• A plantibody is an antibody/proteins produced by genetically
modified crops.
• Uses: as edible vaccines, diagnostic/ therapeutic monoclonal
antibodies, for disease resistance in plants.
Expression
of full-length
antibody
TYPES
Expression
of antibody
fragments
(Fab)
Expression of
single chain
scFv or single
domain (VL)
genes.

3. LARGE –SCALE
PRODUCTION IN
LOW CONTAMINATION
RISK BY BACTERIAL
ENZYMES,TOXINS
AND VIRUSES
BIOTECORS/AGRICULTURE
FLEXIBLE
PRODUCTION
SIZE, LOW COST
WHY TO
CHOOSE
PLANTS?
ABILITY TO EXPRESS
COMBINED TRANGENES
BY SEXUAL CROSSING
NO ETHICAL
ISSUES
EASY TRANSPORT
AS SEEDS,
MORE VIABILITY
CORRECT FOLDING
AND MODIFICATION
OF PROTEINS IN ER

4. The Plantibody Approach
- form Plant Molecular Biology (2000), 43, 419–428

5. COMPONENTS OF A PLANTIBODY GENE
• Plantibodies gene construct can contain sequence for fragment
(Fab, scFv, whole length antibody).
• Effective promoters for increased expression of proteins attached
upstream of the genes. Eg. Hsp70 promoter is more effective the
35S promoter.
• Signal peptide sequence – needed for targeting of antibody into
ER for proper folding of protein.
• C-terminal peptide- usually KDEL added to C-terminal of the
peptide that can increase expression and retention of the protein in
cell.

6. PLANTIBODY PRODUCTION
Plant Cell Transformation
Agrobacterium Mediated
Transfer Of Antibody Genes
Direct Gene Transfer By
Gene Gun , Liposomes etc.
Insertion Of Transformed Cell Into Plant Embryo
Plant development and propagation in fields

7. Ti- PLASMID GENE CONSTRUCT

8. PLANT BREEDING BY SEXUAL CROSS
Plant
transformed
with gene for
kappa chain of
light/heavy
chain
Plant
transformed
with gene for
gamma chain
of light/heavy
chain
Plant with genes
for kappa
&gamma chain
Advantages:
 New antibody combinations
can be produced.
 Dual purpose vaccines can be
made.
 Properties like enhanced
expression, stability, binding
affinity can be achieved using
different promoters, signal
sequences.
 Mutations in CDRs of Vregions can enhance binding
affinity of antibodies.

9. PLANT TISSUE CULTURE
Differentiated plant cells states are grown in bioreactors and
foreign proteins harvested from either the biomass or culture
liquid.
ADVANTAGES:
Cell cultures contain fewer biological proteins or molecules
which may contaminate the product.
 Large amounts of proteins obtained in short time & less
purification steps.
Sexual reproduction is not needed to ensure the lifespan of the
species. Transgene stability is also increased.
DISADVANTAGE:
Cannot be used for edible vaccines.

10. APPLICATIONS
THERAPEUTIC APPLICATIONS
Treatment of infectious disease, inflammation, autoimmune
disease or cancer.
Tobacco produced mAb is more viable alternative to mAb
produced in mouse ascites fluid for the large amounts needed for
purification of hepatitis B vaccine.
 World's first clinically tested plantibody, CaroRx binds
specifically to Streptococcus mutans, the bacteria that cause tooth
decay, and prevents the bacteria from adhering to teeth.
CaroRx is intended for regular topical preventative administration
by both dental hygienists and patients allowing a thorough cleaning
and intervention for any existing decay.

11. IMMUNIZATION
 Potential proteins produced are
cytokines, hormones, enzymes, epidermal growth
factors, interferons,, and pharmaceutical foodstuff which are
considered for oral immunization.
 Transgenic plants expressing antigens are
used as an inexpensive oral-vaccine production
and delivery system so immunization through
consumption of an "edible vaccine" to provide
passive immunity. Eg. Transgenic banana that
eaten,are like subunit preparations in that are
engineered to contain antigens subunit but bear
no genes that would enable whole pathogens
to form.

12. • One of these is a full-length IgG specific for EpCAM (a
marker of colorectal cancer) developed as the drug
Avicidin by NeoRx and Monsanto.It is under pre clinical
trial phase II.
• Other antibodies are CaroRx,scFvT84.66, AntiHSV, 38C13 and PIPP (antihCG).
• Oral cholera vaccine developed in potato .

13. Production Costs for Antibodies
Production costs
cost in $ /gram
hybridomas
1000
transgenic animals
transgenic plants
100
10
Source: Daniell et al. (2001) TIPS 6, 219-226
E. coli & yeast
Tr. animals and
animal cells
Transgenic
plants

14. Functional antibodies need:
• Need to be properly folded and assembled.
• Need disulfide bond formation and glycosylation.
• Glycosylation is different in plants.
• Only mannose is attached-shorter half-life of Ab.

15. Glycosylation in Golgi

16. Comparison of Mammalian and Plant-produced
Antibodies

Peptide sequence: identical

Correct cleavage of Ig-derived signal peptides

Kinetics & affinity: identical

Stability in seeds > 30 months

Antibody types: plant system more versatile (sIgA)
•
Post-translational processing: different

core glycan identical, terminal sugar different plus xylose & fucose

antigenicity & clearance: apparently identical (shorter half-life)

17. FULL-SIZE MONOCLONAL ANTIBODIES RECENTLY
PRODUCED IN TRANSGENIC PLANTS

18. REFERENCES
Monoclonal antibody engineering in plants
•Andrew Hiatt , Julian K-C. Ma
•Department of Cell Biology, The Scripps Rcsearch Institute, La Jolla, CA 92037, USA
Plantibodies: applications, advantages and bottlenecks
Molecular Biotechnology Unit, John Innes Centre, Norwich Research Park, Norwich
NR4 7UH, UK
b Department for Molecular Biotechnology, RWTH Aachen, Worringerweg 1, 52074
Aachen, Germany
PLANTIBODY: AN OVERVIEW(Asian journal of Pharmacy and Life Science, Vol. 1
(1), Jan-Mar, 2011)
Priya Jain*, Prasoon Pandey, Dheeraj Jain, Pankaj Dwivedi
College of pharmacy, IPS academy, rajendra nagar, Indore, India. 452012