PLANTIBODIES :UNRAVELLING THE MYSTERY

PRIYANKA PARKAR ROLL NO:23

A plantibody is an antibody produced by genetically modified plants.

Antibodies are part of animal immune systems, and are produced in plants by transforming them with antibody genes from animals.

This was first done in 1989, with a mouse antibody made by tobacco plants.

Although plants do not naturally make antibodies, plantibodies have been shown to function in the same way as normal antibodies.

The term plantibody as well as the concept is trademarked by the company Biolex.

WHAT ARE PLANTIBODIES?

Plants are being used as antibody factories, using their endomembrane and secretory systems to produce large amounts of clinically viable proteins.

Antibodies can be expressed in plants as either full-length molecules or as smaller fragments.

Antibodies are produced in plants for both humans therapeutic purposes and for protection for plants against diseases.

ANTIBODY FACTORIES

Full-size monoclonal antibodies recently produced in transgenic

plants PLANT ANTIBODY TYPE (TARGET)

PURPOSE

TOBACCO IgG (NEMATODE) Plant pathogen resistance

TOBACCO sIgG/A (steptococcus mutans)

Therapeutic (topical)

SOYABEAN, RICE IgG ( herpes simplex virus)

Therapeutic (topical)

TOBACCO IgG (colon cancer) Therapeutic (systemic injection)

ALFALFA IgG ( human IgG) Diagnostic

TOBACCO IgG (rabies virus) Therapeutic (systemic injection)

TOBACCO IgG (hepatitis B virus) Therapeutic

TOBACCO IgG ( low mol. wt. phosphonate ester)

Catalytic antibodies

Using transformation and transient expression to introduce new genes into a host cell.

Targeting to the APOPLASM by the tagging with a small peptide sequence.

Signal molecules added to target the protein to the Endoplasmic Reticulum (E.R); to ensures correct folding of the protein.

Higher protein levels obtained in the E.R and the apoplasm as compared to the cytosol.

METHODS FOR PLANTIBODY PRODUCTION

TRANSFORMATION TARGETING APOPLASM

Glycosylation refers to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules.

It occurs in all higher eukaryotes in the golgi complex.

Glycans serve a variety of structural and functional roles in membrane and secreted proteins.

Glycosylation by plants differs to that found in mammalian cells. Plant glycans are smaller and have different terminal sugar residues.

It is thought this may have an immunogenic effect and have low antigen-binding affinity.

GLYCOSYLATION

Plantibodies can be purified cheaply in large quantities.

Transgenic seeds assure excellent storage properties and due to limited range of endogenous proteins in seeds, separation of plantibody is less complicated.

There is no risk of spreading animal diseases to humans as the antibodies are produced by plants

The production of large amounts of clinically viable protein especially IgA has many applications in medicine.

PURIFICATION OF PLANTIBODIES

Filtration Immunofluoresence Chromatography Diafiltration Polymer fusionEvaluation techniques for the Plantibodies RIA(Radioimmunoassay)

Northern blot analysis ELISA (Enzyme linked

immuno-sorbent assay) Western blot analysis

Immunofluorescence Southern blot analysis

Techniques for purification of Plantibodies

Nematodes cause huge crop damage.

Plants engineered to express ScFv’s against nematode cellulases have been shown to inactivate the pests.

This technology could eradicate the need for toxic nematicides and fumigants that are currently in use.

Protection against Nematodes

Plants provide a cheap, efficient and safe system for the production of antibodies.

The progression of transgenic plant technology now has allowed for the progression of human life and other medicinal advancements.

It is projected that in the near future, many of the necessary human antibodies will have an origin as a plantibody.

CONCLUSION

Larrick J.W., Yu L., Chen J., et. al.Production of antibodies in transgenic plants.Res. in Immuno. 1998; 149: 603-8.

ENCYLOPEDIA OF APPLIED PLANT SCIENCES – Volume 1 A. Edited by – Thomas, Murphy, Murray

PLANT BIOTECHNOLOGY- JOURNAL 6(4) 623-631 Mason H.S., Arntzen C.J. Transgenic plants as vaccine

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Schillberg S., Zimmermann S., Zhang M.Y.,Fischer R. Antibody-based resistance to plant pathogens. Transgenic Res. 2001; 10:1-12.

De Jaeger G., De Wilde C., Eeckhout D.,Fiers E., Depicker A. The plantibody approach:expression of antibody genes in plants to modulate plant metabolism or to obtain pathogen resistance. Plant Mol. Biol. 2000; 43;419-428.

REFERENCES