(Designer Crops)

Plant Biopharming ?

Plant biopharming is defined as the farming of

transgenic plants genetically modified to produce

“humanised” pharmaceutical substances for use in

humans. The growing of crops that have been

genetically modified to produce pharmaceutical

compounds for use by humans: “common crop plants

such as corn and tobacco increasingly being

programmed with recombinant DNA techniques to

produce high-value-added pharmaceuticals, a process

dubbed ‘biopharming’. The plants are harvested and

the drug is then extracted and purified” (Miller 2003:

480).

Conti..

Biopharming is one of several methods that can be used toproduce the class of drugs known as biopharmaceuticals:“these drugs, known as biologics, include any protein, virus,therapeutic serum, vaccine and blood component” (Elbehri2005: 18).

Biopharming is also known as “molecular farming”.Molecular farming is the production of pharmaceuticallyimportant and commercially valuable proteins in plants(Franken et al., 1997).

The most common plants currently being researched forbiopharming include corn, soybeans, rice, tobacco, andpotatoes (see Table 1), modified to produce the substance,usually a protein, vitamins, amino acids in their fruit, leaves,seeds or tubers, etc.

Brief HistoryYear Development Reference

1986 First plant -derived recombinant

therapeutic protein- human GH in

tobacco & sunflower

A. Barta, D. Thompson et al.,

1989 First plant -derived recombinant

antibody –full-sized IgG in

tobacco.

A. Hiatt, K. Bowdish

1990 First native human protein

produced in plants –human serum

albumin in tobacco & potato.

P. C. Sijmons et al.

1992 First plant derived vaccine candidate –hepatitis B virus

surface antigen in tobacco

H. S. Meson, D. M. Lam

1995 Secretory IgA produced in tobacco. J. K. Ma, A. Hiatt, M. Hein et

al.

1996 First plant derived protein polymer-

artificial elastin in tobacco

X. Zhang, D. W. Urry, H.

Daniel

Brief HistoryYear Development Reference

1997 First clinical trial using recombinant

bacterial antigen delivered in a

transgenic potato

C. O. Tacket et al.

1997 Commercial production of avidin

in maize

E. E. Hood et al.

2000 Human GH produced in tobacco

chloroplast

J. M. Staub et al.

2003 Expression and assembly of a

functional antibody

in algae.

S. P. Mayfield, S. E. Franklin

et al.

2003 Commercial production of bovine

trypsin in maize.

S. L. Woodard et al.

Concept of Biopharming

The concept of biopharming is not new. Genetic modification

has been applied to plants for decades in order to improve

their nutritional value and agronomic traits (yield, pest and

drought resistance, etc.).

The production of high value added substances through gene

manipulation is a logical, straight forward extension.

The energy for product synthesis comes from the sun, and

the primary raw materials are water and carbon dioxide and if

it becomes necessary to expand production, it is much easier

to plant a few additional hectares than to build a new bricks

and mortar manufacturing facility.

Conti..

Another major advantage is that vaccines produced in this

way will be designed to be heat stable so that no

refrigeration chain from manufacturer to patient will be

required.

This would have a great application in developing

countries, especially in the tropics and throughout Asia and

Africa.

Globally, several companies are involved in biopharming,

about half have products in clinical trials.

The spectrum of products is broad, ranging from the

prevention of tooth decay and the common cold to

treatments for cancer and cystic fibrosis.

• Biopharming offers tremendous advantages over

traditional methods for producing pharmaceuticals.

There is great potential for reducing the costs of

production.

• Major drivers for the development of biopharming

internationally are its potential to lower the costs of drug

production, the greater ease of upscaling and

downscaling production, an anticipated shortage of

manufacturing capacity using other production methods,

the potential to address some of the limitations of other

production methods, and the desire to strengthen or

evade patent restrictions.

Conti..

Why Plants ?

According to Horn et al., 2004

Significantly lower production costs than with transgenic

animals, fermentation or bioreactors;

Infrastructure and expertise already exists for the planting,

harvesting and processing of plant material;

Plants do not contain known human pathogens (such as

virions, etc.) That could contaminate the final product;

Plant cells can direct proteins to environments that reduce

degradation and therefore increase stability.

Some of Plants Used for Biopharmaceutical

ProductionSr. No. Category Plants used

1 Model plant Arabidopsis thaliana

2 Leafy crops Tobacco, lettuce, alfalfa, clover

3 Cereals Maize, rice, wheat, barley

4 Legumes Soybean, pea, pigeon pea

5 Fruits and vegetables Potato, carrot, tomato, banana

6 Oil crops Oilseed Rape Seed, Camelina sativa

7 Simple plants Lemna sp. Physcomitrella patens,

Marchantia polymorpha, Chlamidomonas

reinhardtii

Sibila Jelaska et al. 2005

Bio-pharmed crops

Drug/Chemical Use Test Crop

Laccase Textiles, Adhesives Corn

Folic acid Vitamin Tomatoes

Erythropoeitin Anemia Tobacco

Essential fatty acids Cell membrane production Soybeans

SARS vaccine Immunization Tomato

Vaccine against pollen allergies Immunization Rice

Traveler’s and other Diarrheas Immunization/

Drug

Rice, Potatoes

and Corn

Insulin Treatment of Diabetes Safflower

Insulin-like Growth Factors Diabetes, Growth,

Carcinogen

Rice

Recombinant Proteins Expressed in Plants

According to Horn et al., 2004

Parental Therapeutics and Pharmaceutical

Intermediates

Antibody in plants

Edible Vaccines

Industrial proteins

Edible vaccine

• Concept of edible vaccine got impetus after expression of

hepatitis B surface antigen in tobacco plants (Mason et

al., 1992)

• The first reported edible vaccine was a surface protein

from streptococcus expressed in tobacco leaves. (Mason

and Arntzen, 1995)

Why to Choose Plants for Vaccines?

No Ethical Issues

Ability to Express Combined

Transgenes

By Sexual Crossing

Flexible Production Size,

Low Cost

Large Scale Production in

Biotech-Corps / Agriculture

Easy to Taken, No Phobia to

Injection

Easy Transport

as Fruits, Leaves and

Seeds, More Viability

Correct Folding and

Modification of Proteins in ER

Low Contamination

Risk by Bacterial Enzymes, Toxins,

Fungus and Viruses

Examples of edible vaccinesVaccines Vector used Disease /conditions

for which it is used

Hepatitis B Virus Tobacco, Potato,

Lettuce

Hepatitis B

Norwalk virus Tobacco, Potato Diarrhoea, Nausea,

Rabies virus Tabacco Rabies

Transmissible

gastroenteritis

Corona virus

Tobacco, Maize Gastroenteritis

Rabbit hemorrhagic

disease virus

Potato Hemorrhage

HIV virus Tomato AIDS

Vibrio cholerae Potato Cholera

Neeraj et al. (2008)

TRANSGENIC TOMATO

See I lost my

shelf life how can

I improve my

shelf life ?

Look at me they are

making transgenic

tomato so that I can

improve my shelf life.

WOW!!! So excited

Table 1: Currently Transgenic Plants in Commercial Development

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Golden Rice

Purported to be the solution to the problem of Vitamin A

deficiency in developing countries

Developed in 1999 by Swiss and German scientists, led by

Ingo Potrykus

-Potrykus has accused GM opponents of “crimes against humanity”

Produced by splicing two daffodil and one bacterial gene

into japonica rice, a variety adapted for temperate climates

In 2011, First time plantings in India with Philippines and

Vietnam

But crop not yet adapted to local climates in developing

countries

Produces β-carotene, which the body converts into Vitamin

A (in the absence of other nutritional deficiencies - such as

zinc, protein, and fats - and in individuals not suffering from

diarrhea)

Β-carotene is a pro-oxidant, which may be carcinogenic

The latest…

• Syngenta Golden Rice - II (20 times more provitamin A)

and GM potatoes recently developed

• Third generation Golden Rice using indica rice being

tested (japonica variety used in other iterations

unpalatable, produced much less vitamin A)

• GE soybeans with omega-3 fatty acids (fish oil) in final

stages of FDA approval (2010)

Lowering production costs

A major advantage claimed for producing drugs through plant

biopharming is lower production costs for pharmaceuticals.

Current production methods (fermentation and cell cultures) are

characterised as inefficient, expensive and time-consuming

processes, while biopharming promises significantly lower

infrastructure and operating costs (Elbehri 2005).

Capacity shortage and flexible supply

The increased demand for protein-based drugs; manufacturing

capacity is said to be a major constraint on future supply (Elbehri

2005; Nevitt et al. 2006; Fernandez et al. 2002). According to

Nevitt et al. (2006: 104), “demand for affordable protein-based

therapies has already outpaced production capacity”, and this

pressure on capacity is expected to increase.

Advantage

Potential for new and better drugs

biopharming is its potential to produce biopharmaceuticals that cannot be

produced in other ways (Thiel 2004). Dyck et al. (2003: 395) note

problems with other production platforms (bacteria, yeast, and insect,

metazoan and mammalian cells) and suggest that transgenic plants (and

animals) may avoid these problems, thus presumably enabling successful

production of drugs that could not (or would not) otherwise be produced.

According to Ma et al. (2005).

Opportunities for patent-enhancing and patent-busting

producing new medicines, biopharming may be seen instead as a way to

undermine or reinforce patents on existing medicines. Biopharming may

enable companies to “bust” the existing patents of other companies by

developing a new process to produce a substance whose patent is

associated with another method of production. Conversely, biopharming

may enable a company to extend patent protection for a drug by acquiring

a new patent for it based on a new production method.

Conti..

Risks, Concerns and Issues

Potential gene flow to weeds or related crops through

pollination or seed contamination (horn et al., 2004).

Pdms accidentally entering the food chain and being

consumed by non-target organisms (breyer et al., 2012).

A major concern for many developing countries is the lack

of bio-safety legislation for genetically modified plants

(salehi, 2012).

Health and Environmental Risks of GE Foods

• Allergies and toxicities from new proteins entering the food supply• Eosinophilia Myalgia Syndrome from Showa Denko’s GE-L-tryptophan

supplements in 1980s

FDA covered up• Bt corn increases sensitivity of mammals to other allergens, increases

levels of cytokines and interleukins involved in various autoimmune diseases

• Bt corn toxic to caddisflies, a food resource for fish and amphibians

• Bt toxin can affect bee learning, may contribute to colony collapse disorder

• Bt found in blood of 69% of non-pregnant women, 93% of pregnant women, and 80% of fetuses

• GM peas (with bean gene) cause lung inflammation in mice – trial stopped

• New, allergenic proteins in GE soy in South Korea

Secret Monsanto report found that rats fed a diet rich in GM cornhad smaller kidneys and unusually high white blood cell counts

Monsanto’s MON 863 YieldGard Rootworm (GM) Maize damagesrats’ livers and kidneys

-Bt eggplant shows similar damage

Russian Academy of Sciences report found up to six-fold increasein death and severe underweight in infants of mothers fed GM soy

Austrian study shows impaired fertility in mice fed GM maize

Bt-cotton reported to cause skin and respiratory illnesses/allergiesin workers in Philippines

Altered nutritional value of foodstuffs

Transfer of antibiotic resistance genes into intestinal bacteria or other organisms, contributing to antibiotic resistance in human pathogens

Horizontal gene transfer of gene inserted into GM soy to DNA of human gut bacteria-Soy allergies increased by 50% after introduction of GM soy into the UK

Allergenicity in India

In India, hundreds of laborers picking cotton and working in cotton ginning

factories developed allergic reactions when handling the BT cotton. This didn’t

happen with the non-Bt varieties. [Ashish Gupta et. al., “Impact of Bt Cotton on

Farmers’ Health (in Barwani and Dhar District of Madhya Pradesh),”

Investigation Report, Oct–Dec 2005]

Hospital records: “ Show that victims of itching have increased massively this

year, and all of them are related to BT cotton farming.” [The Sunday Indian,

10/26/08]

Itching all over the body,

eruptions, wounds,

discoloration

• Pests now becoming resistant to Bt

• Meta-analysis of Bt corn and cotton (2013):

• 5/13 major pests resistant (compared with 1 in 2005)

• Bt cotton destroyed by mealy bug; harvests in India

decline dramatically, contributing to suicides among

farmers

Animal data suggest DNA can be taken up intact bylymphocytes through Peyer’s patches of small intestine

Animal studies show adverse effects on multiple organs,including tumors, multiple organ damage, and prematuredeath

Micro RNA and short interfering RNA not destroyed duringdigestion, absorbed, can affect gene expression in animalsand humans

Herbicide resistance improved crop Weeds related to crop(Same Spp)

Resistance gene transfer to weeds

Super weeds

Can’t destroy using weedicide

Pollination

X

Genetic transfer to Non target species

Super weeds ?

Super Pest ?

ReferencesBreyer, D, De Schrin, Gossens, M., Pauwels, K., Heeman, P. (2012) Biosafety of

molecular farming in GM plants. Springer. 259-274.

Franken, E., Teuschel, U. And Hain, R. (1997) Recombinant Proteins from trangenicplants. Curr. Opin. Biotech. Vol. 7 : 171-181.

Horn, M. E., Woodard, S. L and Howard J. A (2004). Plant molecular farming: systemsand products. Plant Cell. Rep. Vol. 22: 711-720.

Jelaska S, Mihaljeric S and Bauer N. (2005). Production of biopharmaceuticals,antibodies and edible vaccines in transgenic plants. Current studies of biotechnology.Vol. 4.

Mason H. S., and Arntzen, C. J. (1995). Transgenic plants as vaccine production systems. Trends Biotechnol. Vol. 13. 388-392.

Mason H. S., Lam D. M. K., and Arntzen C. J. (1992). Expression of Hepatitis B surface antigen in transgenic plants. Proc. Wall. Acad. Sci. USA. Vol. 89, 11747-11749.

Neeraj M., Prem N. G., Kapil K, Amit K. G., and Suresh P. V., (2008). Edible vaccines: A new approach to oral immunization. Ind. Jor. Of Biotech. Vol. 7. 283-294.

Rishi A. S, Nelson N. D, Goyal A. (2001) Molecular Farming in plants: A current perspective. Journal of plant biotechnology and biochemistry. Vol. 10(1). p. 1-12.

Salehi J. G., (2012) Risk assessment of GM crops; regulation and science. Boisafety. 113.