PLANTIBODIES :UNRAVELLING THE MYSTERY PRIYANKA PARKAR ROLL NO:23
WHAT ARE PLANTIBODIES?A plantibody is an antibody produced bygenetically modified plants.Antibodies are part of animal immunesystems, and are produced in plants bytransforming them with antibody genesfrom animals.This was first done in 1989, with amouse antibody made by tobacco plants.Although plants do not naturally makeantibodies, plantibodies have beenshown to function in the same way asnormal antibodies.The term plantibody as well as theconcept is trademarked by the companyBiolex.
ANTIBODY FACTORIES 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.
METHODS FOR PLANTIBODY PRODUCTIONUsing transformation and transientexpression to introduce new genesinto a host cell. Targeting to the APOPLASM by thetagging with a small peptidesequence.Signal molecules added to target theprotein to the Endoplasmic Reticulum(E.R); to ensures correct folding of theprotein.Higher protein levels obtained in theE.R and the apoplasm as compared tothe cytosol.
GLYCOSYLATIONGlycosylation refers to theenzymatic process that attachesglycans to proteins, lipids, or otherorganic molecules.It occurs in all higher eukaryotes inthe golgi complex.Glycans serve a variety of structuraland functional roles in membraneand secreted proteins.Glycosylation by plants differs tothat found in mammalian cells.Plant glycans are smaller and havedifferent terminal sugar residues.It is thought this may have animmunogenic effect and have lowantigen-binding affinity.
PURIFICATION OF PLANTIBODIES 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.
Techniques for purification of Plantibodies Filtration Immunofluoresence Chromatography Diafiltration Polymer fusionEvaluation techniques for thePlantibodies RIA(Radioimmunoassay) Northern blot analysis ELISA (Enzyme linked immuno- sorbent assay) Western blot analysis Immunofluorescence Southern blot analysis
Protection against NematodesNematodes cause huge cropdamage.Plants engineered to expressScFv’s against nematodecellulases have been shown toinactivate the pests.This technology could eradicatethe need for toxic nematicidesand fumigants that arecurrently in use.
CONCLUSION 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.
REFERENCESLarrick J.W., Yu L., Chen J., et. al.Production of antibodies intransgenic plants.Res. in Immuno. 1998; 149: 603-8.ENCYLOPEDIA OF APPLIED PLANT SCIENCES – Volume 1 A.Edited by – Thomas, Murphy, MurrayPLANT BIOTECHNOLOGY- JOURNAL 6(4) 623-631Mason H.S., Arntzen C.J. Transgenic plants as vaccineproduction systems. Trends in Biotechnology. 1995; 13: 388-92.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 inplants to modulate plant metabolism or to obtain pathogenresistance. Plant Mol. Biol. 2000; 43;419-428.