title: Neutralizing activity of polyvalent Gb3, Gb2 and galacto-trehalose models against Shiga toxins.
abstract: Shiga toxin (Stx) is one of the most critical factors in the development of hemolytic uremic syndrome and other systemic complications following enterohemorrhagic Escherichia coli (EHEC) infection. Substances neutralizing Stx by interfering with toxin-receptor binding have been explored as therapeutic candidates for EHEC infection. In this study, we examined globotriaosyl (Gb3), galabiosyl (Gb2) and galacto-trehalose, each of which was synthetically conjugated with a polyacrylamide backbone, for Stxneutralizing activity. Galacto-trehalose was designed as a Gb2 mimicking, unnatural Stx-ligand that was expected to show tolerance to enzymatic degradation in vivo. Galacto-trehalose copolymer showed neutralizing activity against Stx-1 but not Stx-2 in a HeLa cell cytotoxicity assay. It was thought that galactotrehalose copolymer could be a lead compound for the treatment of Stx-mediated diseases, although it requires modification to show neutralizing activity to Stx-2. The Gb3 copolymer with high sugar unit density showed stronger neutralizing activity against Stx-2 than those with lower density. However, the density-dependency of the neutralizing activity was less obvious against Stx-1. Intravenous administration of the Gb3 copolymer prevented death in mice lethally infected with Stx-1- and Stx-2-producing E. coli O157:H7. Thus, we demonstrated that the artificial Gb3 copolymer could neutralize Stx-1 and the more clinically relevant Stx-2 in vitro and effectively inhibit Stx toxicity in vivo.
authors.affiliation: Laboratory of Microbiology, Department of Public Health Pharmacy, Gifu Pharmaceutical University, Japan.
authors.forename: Paola
authors.initials: P
authors.lastname: Neri
authors.forename: Saori Itoh
authors.initials: SI
authors.lastname: Nagano
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Dohi
authors.forename: Kazukiyo
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Miura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Inazu
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mori
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology; D019453:Escherichia coli O157 / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D005260:Female; D005690:Galactose / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D022622:Shiga Toxin 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D022641:Shiga Toxin 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms; D014199:Trehalose / Q000494:pharmacology*
chemical_list: D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D014199:Trehalose; D005690:Galactose