Activity of botulinum neurotoxin type D (strain 1873) in human neurons.
Botulinum Neurotoxin type D (BoNT/D) causes periodic outbreaks of botulism in cattle and horses, but is rarely associated with human botulism. Previous studies have shown that humans responded poorly to peripheral injection of up to 10U of BoNT/D. Isolated human pyramidalis muscle preparations were resistant to BoNT/D, whereas isolated human intercostal muscle preparations responded to BoNT/D similarly as to other BoNT serotypes. In vitro data indicate that BoNT/D does not cleave human VAMP1 efficiently, and differential expression of the VAMP 1 and 2 isoforms may be responsible for the above observations. Here we examined sensitivity of cultured human neurons derived from human induced pluripotent stem cells to BoNT/D. Our data indicate that BoNT/D can enter and cleave VAMP 2 in human neurons, but at significantly lower efficiency than other BoNT serotypes. In addition, BoNT/D had a short duration of action in the cultured neurons, similar to that of BoNT/E. In vivo analyses indicated a slower time to death in mice, as well as a later onset and shorter duration of action than BoNT/A1. Finally, examination of BoNT/D activity in various rodent and human cell models resulted in dramatic differences in sensitivity, indicating a unique cell entry mechanism of BoNT/D.
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA. Electronic address: sludwig@wisc.edu.
Sabine
S
Pellett
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
William H
WH
Tepp
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
Jacob M
JM
Scherf
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
Christina L
CL
Pier
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
Eric A
EA
Johnson
D000818:Animals; D001905:Botulinum Toxins / Q000633:toxicity*; D001906:Botulism / Q000175:diagnosis*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D050987:Vesicle-Associated Membrane Protein 1 / Q000235:genetics / Q000378:metabolism; D050988:Vesicle-Associated Membrane Protein 2 / Q000235:genetics / Q000378:metabolism
C494704:VAMP1 protein, human; C494807:VAMP2 protein, human; D050987:Vesicle-Associated Membrane Protein 1; D050988:Vesicle-Associated Membrane Protein 2; C096325:botulinum toxin type D; D001905:Botulinum Toxins
BoNT/D; Botulinum neurotoxin; Botulinum neurotoxin D; Clostridium botulinum type D