title: Expression of an anti-botulinum toxin A neutralizing single-chain Fv recombinant antibody in transgenic tobacco.
abstract: Botulinum neurotoxins (BoNTs) are the most poisonous substances known and are thus classified as high-risk threats for use as bioterror agents. To examine the potential of transgenic plants as bioreactors for the production of BoNT antidotes, we transformed tobacco with an optimized, synthetic gene encoding a botulinum neurotoxin A (BoNT/A) neutralizing single-chain Fv (scFv) recombinant antibody fragment. In vitro mouse muscle twitch assays demonstrated the functional utility of this scFv extracted from tobacco for neutralizing the paralytic effects of BoNT/A at neuromuscular junctions. Based on the efficiency of the scFv capture process and the dose required to antidote a human being, 1-2 ha of this tobacco could yield up to 4 kg of scFv, which would be enough to contribute to the manufacture of 1,000,000 therapeutic doses of a monoclonal antibody (mAb) cocktail capable of neutralizing the effects of BoNT poisoning. Transgenic plants could provide an inexpensive production platform for expression of multiple mAbs toward the creation of polyclonal therapies (i.e. pooled mAbs) as the next improvement in recombinant antibody therapy.
authors.affiliation: Department of Environmental Biology, University of Guelph, Guelph, Ont., Canada N1G 2W1.
authors.forename: Kurt C
authors.initials: KC
authors.lastname: Almquist
authors.forename: Michael D
authors.initials: MD
authors.lastname: McLean
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Niu
authors.forename: Greg
authors.initials: G
authors.lastname: Byrne
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Olea-Popelka
authors.forename: Coral
authors.initials: C
authors.lastname: Murrant
authors.forename: Jack
authors.initials: J
authors.lastname: Barclay
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Hall
mesh_terms: D019274:Botulinum Toxins, Type A / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology*; D003014:Clostridium botulinum / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004364:Pharmaceutical Preparations; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D014026:Nicotiana
chemical_list: D007128:Immunoglobulin Fragments; D004364:Pharmaceutical Preparations; D011993:Recombinant Fusion Proteins; C055966:immunoglobulin Fv; D019274:Botulinum Toxins, Type A