Synthetic Oligosaccharides as Tools to Demonstrate Cross-Reactivity between Polysaccharide Antigens

Abstract

Escherichia coli O148 is a nonencapsulated enterotoxigenic (ETEC) Gram negative bacterium that can cause diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome in humans. The surface-exposed O-specific polysaccharide (O-SP) of the lipopolysaccharide of this bacterium is considered both a virulence factor and a protective antigen. It is built up of the linear tetrasaccharide repeating unit [3)-α-L-Rhap-(1→2)-α-D-Glcp-(1→3)-α-D-GlcNAcp-(1→3)-α-L-Rhap-(1→] differing from that of the O-SP of Shigella dysenteriae type 1 (SD) only in that the latter contains a D-Galp residue in place of the glucose moiety of the former. The close similarity of the O-SPs of these bacteria indicated a possible cross-reactivity. To answer this question we synthesized several oligosaccharide fragments of E. coli O148 O-SP, up to a dodecasaccharide, as well as their bovine serum albumin or recombinant diphtheria toxin conjugates. Immunization of mice with these conjugates induced anti-O-SP-specific serum IgG antibody responses. The antisera reacted equally well with the LPSs of both bacteria, indicating cross-reactivity between the SD and E. coli O148 O-SPs that was further supported by Westernblot and dot-blot analyses, as well as by inhibition of binding between the antisera and the O-SPs of both bacteria.

Remote Electronic Effects by Ether Protecting Groups Fine-Tune Glycosyl Donor Reactivity

“…for C 41 H 42 O 6 SNH 4 + 680.3040; found 680.3053. Spectral values were in accordance with those reported in ref and .…”

Intracellular and membrane-damaging activities of methyl gallate isolated from Terminalia chebula against multidrug-resistant Shigella spp.

“…mg species below the detection limit within 20 h. Amongst four species and many subtypes of Shigella, S. dysenteriae 1 is the only Shigella that causes epidemics and pandemics, distinguished by high fever, cramps, seizures, bloody diarrhoea and dysentery, and haemolytic uraemic syndrome, and shows enormously high fatality rates amongst children and adults (Sur et al, 2004;Pozsgay et al, 2007;McKenzie et al, 2008;Barman et al, 2011). S. dysenteriae 1 causes recurrent disease in Asian countries such as India and Bangladesh (Dutta et al, 2003;von Seidlein et al, 2006;Emch et al, 2008).…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

“…As vaccine antigens (Mannose) 6 Human acid -glucosidase TOF Comparison of various synthetic methods 6-O-Me-D-glycero-- (Pozsgay et al, 2012) Per-OMe--cyclodextrin BSA TOF (CHCA)…”