title: Clostridium botulinum serotype D neurotoxin and toxin complex bind to bovine aortic endothelial cells via sialic acid.
abstract: Botulinum neurotoxin (BoNT) is produced as a large toxin complex (L-TC) associated with nontoxic nonhemagglutinin (NTNHA) and three hemagglutinin subcomponents (HA-70, -33 and -17). The binding properties of BoNT to neurons and L-TC to intestinal epithelial cells are well documented, while those to other tissues are largely unknown. Here, to obtain novel insights into the pathogenesis of foodborne botulism, we examine whether botulinum toxins bind to vascular endothelial cells. BoNT and 750 kDa L-TC (a complex of BoNT, NTNHA and HAs) of Clostridium botulinum serotype D were incubated with bovine aortic endothelial cells (BAECs), and binding to the cells was assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot. Both BoNT and L-TC bound to BAECs, with L-TC showing stronger binding. Binding of BoNT and L-TC to BAECs was significantly inhibited by N-acetyl neuraminic acid in the cell culture medium or by treatment of the cells with neuraminidase. However, galactose, lactose or N-acetyl galactosamine did not significantly inhibit toxin binding to the cells. This is the first report demonstrating that BoNT and L-TC bind to BAECs via sialic acid, and this mechanism may be important in the trafficking pathway of BoNT in foodborne botulism.
authors.affiliation: Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Yoneyama
authors.forename: Keita
authors.initials: K
authors.lastname: Miyata
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Chikai
authors.forename: Akifumi
authors.initials: A
authors.lastname: Mikami
authors.forename: Tomonori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kimiko
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ikeda
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tohru
authors.initials: T
authors.lastname: Ohyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Niwa
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001905:Botulinum Toxins / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D047969:Clostridium botulinum type D / Q000378:metabolism / Q000472:pathogenicity*; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D006388:Hemagglutinins / Q000737:chemistry / Q000378:metabolism; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D009498:Neurotoxins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006388:Hemagglutinins; D009498:Neurotoxins; D001905:Botulinum Toxins; D019158:N-Acetylneuraminic Acid