Application of rDNA Technology .pdf

Biotechnology

1. Application of rDNA
Technology and Genetic
Engineering in Medicine

2. 1. Vaccines
rDNAtechnologyisusedforproducingvaccinesagainstdiseaseby
isolatingantigenorproteinpresentonthesurfaceofviralparticles.
Vaccinescontainingaformofaninfectiousorganismthatdoesnotcause
butallowthebodyimmunesystemtoformantibodiesagainsttheinfective
organism.
Whenanindividualreceivesvaccinationagainstanyviraldisease,the
antigensproduceantibodiestoactagainstandinactivatetheviral
proteins.
ThescientistswiththehelpofrDNAtechnologyhavetransferredthegenes
forsomeviralsheathproteinstovacciniaviruswhichwasusedagainstsmall
pox.

3. Vaccinesproducedbygenecloningarenoncontaminatedandsafeas
theycontainonlycoatproteinsagainstwhichantibodiesareproduced.
Vaccinesagainstviralhepatitisinfluenza,herpessimplexvirus,virusinduced
footandmouthdiseaseinanimalsarebeingproducedbygenecloning.

4. 2. Hormones
Insulinwascommerciallyproducedin1982throughbiogeneticorrDNA
technology.
Itsmedicinalusewasapprovedbyfoodanddrugadministration(FDA)of
theUSAinthesameyear.
ThehumaninsulingenehasbeenclonedinlargequantitiesinE.coli
bacteriumthatcanbeusedforsynthesisinginsulin.
Humilinisthecommerciallyavailablegeneticallyengineeredinsulin.

5. 3. Lymphokines
Theyareproteinsregulatingtheimmunesysteminhumanbody.
α-interferonisanexampleoflymphokinesthatisusedtofightviraldiseases
(suchashepatitis,herpesandcommoncold)andcancer.Suchdrugscan
bemanufacturedinlargequantitiesinbacterialcell.
LymphokinesarealsohelpfulinAIDS.
Interleukin-llisacommerciallyavailablegeneticallyengineeredsubstance
thatstimulatesthemultiplicationoflymphocytes.

6. 4. Somatostatin
Itisusedinsomeofthegrowthrelatedabnormalities.Thisdrugappearsto
bespeciesandthepolypeptideobtainedfromothermammalshasno
effectonhuman,henceitisextractedfromthehypothalamusofcadavers.
Geneticengineeringhashelpedinthechemicalsynthesisofgenewhichis
joinedtothepBR322plasmidDNAandclonedintoabacterium.This
trasnformedbacteriumisconvertedintosomatostatinsynthesisingfactory.

7. 5. Production of Blood Clotting Factors
Blockageofcoronaryarteriesbycholesterolorbloodclotscausesheart
attack.Plasminogenisasubstancefoundinbloodclots.
GeneticallyengineeredtissueplasminogenActivator(tPA)enzymeisused
todissolvetheseclotsinindividualswhohavesufferedheartattacks.

8. 6. Cancer
Antibodiesclonedfromasinglesourceandtargetedforaspecificantigen
(monoclonalantibodies)haveprovedusefulinthetreatmentofcancer.
Monoclonalantibodieshavebeentargetedwithradioactiveelementsor
cytotoxins(eg.Ricinfromcastorseed)tomakethemmoredeadly.
Suchantibodiesseekcancercellsandkillthemwiththeirradioactiveityor
toxins.