Expression of an anti-botulinum toxin A neutralizing single-chain Fv recombinant antibody in transgenic tobacco.
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.
Almquist
Kurt C
KC
Department of Environmental Biology, University of Guelph, Guelph, Ont., Canada N1G 2W1.
McLean
Michael D
MD
Niu
Yongqing
Y
Byrne
Greg
G
Olea-Popelka
Fernando C
FC
Murrant
Coral
C
Barclay
Jack
J
Hall
J Christopher
JC
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
D007128:Immunoglobulin Fragments; D004364:Pharmaceutical Preparations; D011993:Recombinant Fusion Proteins; C055966:immunoglobulin Fv; D019274:Botulinum Toxins, Type A