Download - Biopharming
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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 expensivebioreactors (upstream process) by the pharmaceuticalindustry used for producing therapeutic molecules
• These ‘expensive’ molecules can now be expressed inplants through the insertion of the genes that expressthe proteins
• Biopharming may also be cheaper in the process ofextracting (downstream process) the desiredmolecules
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)• VaccinesNeutraceuticals
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 (β-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 vaccinesAdvantages:
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…..