Synthesis of an artificial glycoconjugate polymer carrying P k -antigenic trisaccharide and its potent neutralization activity against Shiga-like toxin

Dohi, Hirofumi; Nishida, Yoshihiro; Mizuno, M; Shinkai, Masashige; Kobayashi, Takeshi; Takeda, Tae; Uzawa, Hirotaka; Kobayashi, Kazukiyo

doi:10.1016/s0968-0896(99)00129-7

Cited by 83 publications

(57 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Epidemiological evidence suggests that E. coli strains expressing different subtypes of Stx2 display differences in virulence, including the likelihood of progression to HUS (15,27,36,50). Since different subtypes also display differences in receptor preference (9,14,21,26,27,43), we wanted to determine if any of the amino acid polymorphisms map to the Gb3 binding sites in the Stx2 B subunit. The structure of Stx2a bound to Gb3 has not been determined; however, the structure of a highly homologous form, Stx2e (GT3), with bound Gb3 has been determined (31).…”

Section: Resultsmentioning

confidence: 99%

Shiga Toxin Subtypes Display Dramatic Differences in Potency

et al. 2011

View full text Add to dashboard Cite

Purified Shiga toxin (Stx) alone is capable of producing systemic complications, including hemolytic-uremic syndrome (HUS), in animal models of disease. Stx includes two major antigenic forms (Stx1 and Stx2), with minor variants of Stx2 (Stx2a to -h). Stx2a is more potent than Stx1. Epidemiologic studies suggest that Stx2 subtypes also differ in potency, but these differences have not been well documented for purified toxin. The relative potencies of five purified Stx2 subtypes, Stx2a, Stx2b, Stx2c, Stx2d, and activated (elastase-cleaved) Stx2d, were studied in vitro by examining protein synthesis inhibition using Vero monkey kidney cells and inhibition of metabolic activity (reduction of resazurin to fluorescent resorufin) using primary human renal proximal tubule epithelial cells (RPTECs). In both RPTECs and Vero cells, Stx2a, Stx2d, and elastase-cleaved Stx2d were at least 25 times more potent than Stx2b and Stx2c. In vivo potency in mice was also assessed. Stx2b and Stx2c had potencies similar to that of Stx1, while Stx2a, Stx2d, and elastase-cleaved Stx2d were 40 to 400 times more potent than Stx1.

show abstract

Section: Resultsmentioning

confidence: 99%

Shiga Toxin Subtypes Display Dramatic Differences in Potency

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Highly selective and potent binding of Stx to Gb 3 is mainly attributed to the multiple interaction of the B subunit pentamer with the trisaccharide moiety of Gb 3 . On the basis of these facts, several Stx neutralizers, in which the trisaccharide moiety of Gb 3 is combined with various core structures in multiple ways, have been reported (7)(8)(9)(10). However, no Stx neutralizer has been developed that is capable of detoxifying the toxin present in the circulation.…”

Section: S Higa Toxin (Stx)-producing Escherichia Coli (Stec) Includ-mentioning

confidence: 99%

“…In this study, we used a series of carbosilane dendrimers and identified SUPER TWIG (1)6 as a Stx neutralizer that is active in the circulation. Because of their unique characteristics, carbosilane dendrimers make it feasible to optimize the number and the position of the functional terminal trisaccharides, which resulted in SUPER TWIG (1)6, having the most compact structure among all of the Stx neutralizers that have ever been developed (7)(8)(9)(10). Furthermore, in the physiological scenario SUPER TWIG (1)6 protected mice from challenge with a fatal dose of E. coli O157:H7, even when administered after the establishment of the infection.…”

Section: Super Twigs (1)6 and (1)12 Directly Bind To The Stx B Subunimentioning

confidence: 99%

A therapeutic agent with oriented carbohydrates for treatment of infections by Shiga toxin-producing Escherichia coli O157:H7

Nishikawa

Matsuoka

Kita

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

189

125

View full text Add to dashboard Cite

Infection with Shiga toxin (Stx)-producing Escherichia coli O157:H7, which causes diarrhea and hemorrhagic colitis in humans, often results in fatal systemic complications, such as neurological damage and hemolytic-uremic syndrome. Because Stx circulating in the blood is a major causative factor of these complications, the development of a Stx neutralizer that functions in the circulation holds promise as a viable therapy. Here we developed a series of carbosilane dendrimers, in which trisaccharides of globotriaosyl ceramide, a receptor for Stx, were variously oriented at their termini (referred to as SUPER TWIG), and identified a SUPER TWIG with six trisaccharides as a Stx neutralizer functioning in the circulation. This SUPER TWIG specifically bound to Stx with high affinity (Kd ‫؍‬ 1.1 ؋ 10 ؊6 M) and inhibited the incorporation of the toxin into target cells. Intravenous administration of the SUPER TWIG along with Stx to mice substantially reduced the fatal brain damage and completely suppressed the lethal effect of Stx. Moreover, the SUPER TWIG protected mice from challenge with a fatal dose of E. coli O157:H7, even when administered after the establishment of the infection. The SUPER TWIG neutralized Stx in vivo by a mechanism in which the accumulation and immediate degradation of Stx by phagocytic macrophages present in the reticuloendothelial system were induced. Taken together, our findings indicate that this SUPER TWIG is therapeutic agent against infections by Stx-producing E. coli.

show abstract

“…12) In light of these findings, many synthetic compounds mimicking the natural receptors have been investigated for eliminating Stxs from the intestine and/or neutralizing Stxs in the circulation, as a therapeutic strategy for protecting patients from serious Stx-mediated diseases. 9,10,[13][14][15][16][17][18][19][20][21][22] All of these previously reported compounds possess repeated Gb 3 mimic structures in a molecule with various backbones on expecting clustering effect of the saccharide moiety, although there was one exception of adamantyl-Gb 3 , 10) a Gb 3 monovalent derivative, that was speculated to assemble into small aggregates for activity.In the present study, we synthesized novel Gb 3 -and Gb 2 -conjugated derivatives with a phosphatidyl residue, a sugar unit monomer in the chemical structure, which would be expected to form liposomes and clusters of the sugar unit to neutralize Stx-1 and Stx-2. These compounds showed strong neutralizing activity against not only Stx-1 but also Stx-2.…”

mentioning

confidence: 99%

Monovalent Gb3-/Gb2-Derivatives Conjugated with a Phosphatidyl Residue: A Novel Class of Shiga Toxin-Neutralizing Agent

Neri

Tokoro

Yokoyama

et al. 2007

Biological & Pharmaceutical Bulletin

Self Cite

View full text Add to dashboard Cite

Shiga toxin (Stx)-1 and Stx-2 are involved in the pathogenesis of hemolytic uremic syndrome (HUS) and severe systemic complications following enterohemorrhagic Escherichia coli (EHEC) infection in humans. [1][2][3][4] Stxs have an AB 5 structure, in which a single catalytic A subunit is associated with five identical B subunits. The B pentamer is responsible for the toxin binding to eukaryotic cell-surface glycolipid receptors such as galabiosyl (Gb 2 )-ceramide and globotriaosyl (Gb 3 )-ceramide. The susceptibility of target cells to Stxs is dependent on the presence of the functional glycolipid receptors. 5,6) After binding, Stxs are internalized into the cells, and then the A subunit exerts RNA N-glycosidase activity, resulting in inhibition of protein synthesis by catalytic inactivation of 28S rRNA. 7,8) Thus, the binding of Stxs to the receptor is the primary event causing Stx-mediated diseases.The binding of Stxs to the receptors is attributed to the interaction of the B pentamer with the saccharide moiety of the receptors. However, the Stxs do not strongly bind to the Gb 3 monomer.9,10) It has been shown that Gb 3 molecules are clustered and localized in lipid rafts on the cell membranes. 11)The clustering of Gb 3 molecules is important for strong binding to Stxs. 12) In light of these findings, many synthetic compounds mimicking the natural receptors have been investigated for eliminating Stxs from the intestine and/or neutralizing Stxs in the circulation, as a therapeutic strategy for protecting patients from serious Stx-mediated diseases. 9,10,[13][14][15][16][17][18][19][20][21][22] All of these previously reported compounds possess repeated Gb 3 mimic structures in a molecule with various backbones on expecting clustering effect of the saccharide moiety, although there was one exception of adamantyl-Gb 3 , 10) a Gb 3 monovalent derivative, that was speculated to assemble into small aggregates for activity.In the present study, we synthesized novel Gb 3 -and Gb 2 -conjugated derivatives with a phosphatidyl residue, a sugar unit monomer in the chemical structure, which would be expected to form liposomes and clusters of the sugar unit to neutralize Stx-1 and Stx-2. These compounds showed strong neutralizing activity against not only Stx-1 but also Stx-2. In the present paper, we propose monovalent Gb 3 -/Gb 2 -derivatives conjugated with phosphatidyl residue as a new type of Stx-neutralizing agent. MATERIALS AND METHODS CompoundsThe structures of the compounds used in this study are shown in Fig. 1. Gb 3 and Gb 2 conjugated with phosphatidylethanolamine dipalmitoyl (PEDP) residue are referred to as Gb 3 -PEDP and Gb 2 -PEDP, respectively. Gb 3 conjugated with dipalmitoyl phosphatidyl hexyl (DPPA) residue is referred to as Gb 3 -DPPA. These compounds were dissolved in dimethyl sulfoxide at a concentration of 2 mM, then diluted 10 times in phosphate-buffered saline (PBS, pH 7.4) and stored at 4°C. The stock solutions were diluted with culture medium just before use, and sonicated for 10 min in a water ...

show abstract

Synthesis of an artificial glycoconjugate polymer carrying P k -antigenic trisaccharide and its potent neutralization activity against Shiga-like toxin

Cited by 83 publications

References 24 publications

Shiga Toxin Subtypes Display Dramatic Differences in Potency

Shiga Toxin Subtypes Display Dramatic Differences in Potency

A therapeutic agent with oriented carbohydrates for treatment of infections by Shiga toxin-producing Escherichia coli O157:H7

Monovalent Gb3-/Gb2-Derivatives Conjugated with a Phosphatidyl Residue: A Novel Class of Shiga Toxin-Neutralizing Agent

Contact Info

Product

Resources

About