Biopharming 12

1

Presentation on

BIOPHARMING

Ms. Varsha Gaitonde. PG:14042

Department of Genetics and Plant Breeding

IAS, BHU Varanasi

Presentation Outline • What is biopharming?

• History

• Strategies for Biopharming

• Why use plants?

• Industrial importance

• Risks and Concerns

• Current and evolving regulation

• What are the risks and concerns?

• Current challenges

• Future directions

• The use of agricultural plants for the production of useful

molecules for non food, feed or fiber applications. (also

called molecular farming, pharming, or biopharming)

• Biopharming is different because the plants are

genetically engineered (GE) to produce the molecules we

want them to.( Plant or animal)

• Biopharming started about 20 years ago with the

promise to produce therapuetic molecules for a fraction

of their current costs

• Some therapeutic molecules are very expensive to

produce (e.g. glucerobrosidase enzyme)

What is biopharming?

How will biopharming do that?

Biopharming aims to replace very expensive

bioreactors (upstream process) by the pharmaceutical

industry used for producing therapeutic molecules

• These ‘expensive’ molecules can now be expressed in

plants through the insertion of the genes that express

the proteins

• Biopharming may also be cheaper in the process of

extracting (downstream process) the desired

molecules

History

– 1990 – Human serum albumin produced in

genetically engineered tobacco and potato

plants

– In development

• Recombinant subunit vaccines against Norwalk

and rabies viruses

• Recombinant monoclonal antibodies against tooth

decay-causing bacteria

Industrial products

• proteins

• enzymes

• modified starches

• fats

• oils

• waxes

• plastics

Pharmaceuticals

• recombinant human proteins

• therapeutic proteins and

pharmaceutical intermediates

• antibodies (plantibodies)

• Vaccines

Neutraceuticals

2. Plant-made pharmaceuticals (PMPs) and

industrial products (PMIP) (GE)

1.Plant-derived pharmaceuticals (non-GE)

Plant Products

Over 120 pharmaceutical products currently in use are derived from

plants. Mainly from tropical forest species (e.g. Taxol from Yew trees)

Why biopharming?

Heralded by biotech industry and associated scientists as:

– Moneymaker (get some of those pharma $)

– Overcoming public resistance to GM crops • Belief that resistance is due to ‘no consumer

benefit’ of ‘first-generation’ GM crops

• Belief that ‘cheaper’ drug production will be seen as consumer benefit

Strategies for Biopharming

1.Plant gene expression strategies

• Transient transformation

• adv. – quick and easy production

• disadv. – small amount of product, processing problems

• Stable transformation • adv. – use for producing large quantities of protein, stability and

storage

• disadv – gene flow - outcrossing w/native species

• Chloroplast transformation • adv. – reduce gene flow through pollen

• disadv. – protein not stable for long periods of time therefore

complications extraction/processing times

Agrobacterium mediated gene transformation

1. Plant gene expression strategies

Protein quantity and preservation

• Whole plant • adv. - an obtain large amts of protein

• disadv. - problems w/preservation • examples - tobacco, alfalfa, duckweed

• Target specific tissues (e.g. seed, root) • adv. - high amts of protein in seed/root, long-term

storage capability.

• examples: soy, corn, rice, barley

2. Location of transgene expression

Strategies for Biopharming

1. Plant gene expression system

2. Location of trans-gene expression

3. Selection of plant species and characteristics

• Mode of reproduction – self/outcrossing

• Yield, harvest, production, processing

Strategies for Biopharming

Advantages

Cost reduction

- scalability (e.g. Enbrel® )

- low/no inputs

- low capital cost

Stability - storage

Safety

- eukaroytic production system

- free of animal viruses (e.g.

BSE)

Why use plants?

Disadvantages

Environment

contamination - gene flow

- wildlife exposure

Food supply

contamination

- mistaken/intentional mixing

w/human food

Health safety

concerns - Variable, case-specific

Avidin by Sigma • transgenic corn

• traditionally isolated from chicken egg whites

• used in medical diagnostics

GUS (b-glycuronidase) by Sigma • transgenic corn

• traditionally isolated from bacterial

sources (E.Coli)

• used as visual marker in research labs

Trypsin by Sigma • transgenic corn

• traditionally isolated from bovine pancreas

• variety of applications, including biopharmaceutical

processing

• first large scale transgenic plant product

• Worldwide market = US$280 million in 2014 (Promo pharma

Industrial products on the market

Industrial products close to market

• Plant- made vaccines (edible vaccines)

• Plant-made antibodies (plantibodies)

• Plant-made therapeutic proteins and

intermediates

Plant-made Pharmaceuticals (PMPs)

Edible vaccines

Advantages:

Administered directly

• no purification required

• no hazards assoc. w/injections

Production

• may be grown locally, where needed most

• no transportation costs

Naturally stored

• no need for refrigeration or special storage

Plant-made Vaccines

Examples of edible vaccines under development:

• pig vaccine in corn

• HIV-suppressing protein in spinach

• human vaccine for hepatitis B in potato

Plant-made Vaccines

• Plantibodies - monoclonal antibodies produced in

plants

• Plants used include tobacco, corn, potatoes, soy,

alfalfa, and rice

• Free from potential contamination of mammalian

viruses

• Examples: cancer, dental caries, herpes simplex virus,

respiratory syncytial virus

- **GE Corn can produce up to 1 kg antibody/acre and

can be stored at RT for up to 5 years. Curr Opin Drug Discover Dev

2010

Plantibodies

Therapeutic proteins and intermediates

• Blood substitutes – human hemoglobin

• Proteins to treat diseases such as HIV,

Hypertension, Hepatitis B…..many others

Plant made Pharmaceuticals

**To date, there are no plant-produced

pharmaceuticals commercially available

Current ‘Pharm’ Companies

•LEX System™

•Lemna (duckweed) •trangenic tobacco

•PMPs and non-protein substances (flavors

and fragrances, medicinals, and natural

insecticides)

Kentucky Tobacco

Research and

Development Center

Controlled Pharming

Ventures •collaboration w/Purdue

•transgenic corn

•biomass biorefinery

•based on switchgrass.

•used to produce PHAs in

green tissue plants for fuel

generation.

• Genetically engineered Arabidopsis plants can

sequester arsenic from the soil. (Dhankher et al. 2012

Nature Biotechnology)

• Immunogenicity in human of an edible vaccine for

hepatitis B (Thanavala et al., 2010. PNAS)

Examples of Current Research

• Expression of single-chain antibodies in transgenic

plants. (Galeffi et al., 2005 Vaccine)

• Plant based HIV-1 vaccine candidate: Tat

protein produced in spinach. (Karasev et al. 2005

Vaccine)

• Plant-derived vaccines against diarrheal diseases. (Tacket. 2005 Vaccine)

Well known examples of biopharming • Herbicide resistance

• Bt gene incorporation: corn and cotton

• Stacked crops

• Golden rice

Environment contamination

• Gene flow via pollen

• Non-target species near field sites

e.g. butterflies, bees, etc

Food supply contamination

• Accident, intentional, gene flow

Health safety concerns

• Non-target organ responses

• Side-effects

• Allergenicity

Risks and Concerns

Main concern is containment.

Opponents want:

• a guarantee of 0% contamination

of the food supply.

• full disclosure of field trials, crop,

gene, location, etc.

• an extensive regulatory framework

Biopharm opposition

1. Physical differences

• e.g. “purple” maize

2. Sterility

• male sterile plants

• terminator technology

3. Easily detectable by addition of 'reporter

genes‘

• e.g. PCR markers

Suggested Safeguards for

biopharm operations

4.Use chloroplast expression system

• will help increase yield

• will eliminate potential gene flow via pollen

• disadv. = technically difficult (Chlorogen

Company)

5. Complete disclosure of DNA sequences

6. Legislate for administration

Suggested Safeguards for

biopharm operations

Improve the yield of the therapeutic molecules

Increase the stability of the molecules

Improve the downstream process

Improve and establish a more reliable biosafety

system

Current challenges

Future directions for

agricultural biotechnology?

Public perception

of risk Regulation

Science has developed genetically enhanced crops and

has/can develop plant-made industrial and

pharmaceuticals crops.

The extent to which these crops will be further developed

for commercial and/or humanitarian use will ultimately

depend on…..