A structural comparison of lipopolysaccharides from two strains of Helicobacter pylori, of which one strain (442) does and the other strain (471) does not stimulate pepsinogen secretion.

Lipopolysaccharides (LPSs) from strains of Helicobacter pylori (442 and 471), which differed in stimulation of pepsinogen secretion, were isolated as water-soluble material of high-M(r), and as water-insoluble gels of low-M(r). Chemical and spectroscopic analyses of soluble LPS and oligosaccharides liberated from the gels led to proposed structures with Lewis (Le) antigen termini connected to N -acetyllacto-saminoglycans of alternating 3-linked beta-D-Gal and 4-linked beta-D-GlcNAc residues with various laterally attached glycosyl substituents. The LPS of H.pylori 442 was similar to previously examined strains (NCTC 11637 and P466) in having partially glycosylated chains with alpha-L-Fuc units attached to O-3 of the majority of GlcNAc residues in Le(x)units, and in chain termination with Le(x)or Le(y)determinants. In contrast, terminal Le(y)units occurred in LPS of H.pylori 471 and glycosaminoglycan chains carried a smaller proportion of alpha-L-Fuc units, but at O-6 of a majority of nonfucosylated GlcNAc residues, there was a novel type of branching with alpha-D-Gal substituents. Evidence for the branched regions was obtained from(1)H-NMR spectra and from characterization of oligosaccharides formed by the action of endo-beta-galactosidase. Examination of oligosaccharides liberated from water-insoluble LPS gels of H.pylori 442 and 471 provided evidence for similar core OS structures to those from other H.pylori strains but interesting differences were observed.

Diversity of lipopolysaccharide structures in Campylobacter jejuni.

Immune blots of electrophoresed lipopolysaccharides extracted from 38 Campylobacter jejuni serostrains suggested the presence of O chains in 16 strains and their absence in 22. Structural analysis confirmed the presence of O chains in serostrains O:19, O:23, and O:36 and the absence of O chains in serostrains O:1, O:2, and O:3. The O:19 strain has O repeat units of beta-D-glucuronic acid amidated with 2-amino-2-deoxyglycerol and N-acetylglucosamine. The 0:36 O chain has four different but closely related repeat units that each consist of N-acetylglucosamine, galactose, and a heptose that is varied in structure from one repeat unit to the next. The O:23 O chain has three different repeat units identical to three of O:36. Except for O:3, core oligosaccharides of strains with or without O chains contain sialic acid (Neu5Ac) in the terminal regions that in many cases mimic the structures of human gangliosides. Three neuropathic isolates were found to have a core terminal trisaccharide (Neu5Ac alpha2-->8Neu5Ac alpha2-->3Galbeta1) that was not found in nonneuropathic strains.

Lipopolysaccharides of Helicobacter pylori serogroups O:3 and O:6--structures of a class of lipopolysaccharides with reference to the location of oligomeric units of D-glycero-alpha-D-manno-heptose residues.

Lipopolysaccharides (LPS) from antigenically different strains assigned to serogroups O:3 and O:6 of Helicobacter pylori were isolated as water-soluble material of high Mr and as water-insoluble gels of low Mr. Chemical and spectroscopic analyses of the soluble LPS and oligosaccharides liberated from the water-insoluble gels led to proposed structures with Lewis (Le) antigen determinants terminating regular repeating units of different types, linked in turn to inner core regions of invariable structure. The O:6 LPS has two populations of related molecules with chains of 3-linked D-glycero-alpha-D-manno-heptose residues similar to those in the MO19 strain, one with and the other without a single terminal Lewis (Le(y)) epitope. In contrast, in the O:3 LPS, Lewis (Le(x) and Le(y)) epitopes terminate a partially fucosylated N-acetyllactosaminoglycan, but a heptan chain similar to that in the O:6 LPS was shown to connect the outer chains to the inner core. These LPS provide examples of the molecular mimicry of cell-surface glycoconjugates. Structural variations of LPS between strains, and differences in some aspects of structure within strains, between high Mr and low Mr LPS indicate a class of LPS whose mechanisms of biosynthesis lead to overall architectures different from those characteristic of most LPS from enteric bacteria.

Lipo-oligosaccharides of Campylobacter jejuni serotype O:10. Structures of core oligosaccharide regions from a bacterial isolate from a patient with the Miller-Fisher syndrome and from the serotype reference strain.

Lipo-oligosaccharide (LOSa) was obtained by phenol-water extraction of bacterial cells of an isolate PG 836, identified as Campylobacter jejuni serotype O:10, from a patient who subsequently developed the Miller-Fisher syndrome (MFS). The product was separated into a water-insoluble gel of low Mr and a water-soluble component of high Mr. The structure of the core oligosaccharide region in LOSa is reported herein for comparison with LOSb from the C. jejuni O:10 reference strain, and is based on investigations carried out on: (1) O-deacylated LOSa; (2) the core oligosaccharide (OS 1a) liberated on acetic acid hydrolysis of the ketosidic linkages to lipid A, with accompanying loss of N-acetylneuraminic acid residues; (3) the product of the removal of phosphate residues from OS 1a to give OS 2a; and (4) the Smith degradation of OS 2a to yield a mixture of Os 3a and OS 4a. The results revealed that the core oligosaccharide region in LOSa from the MFS bacterial isolate had chains (1a), of which some were terminated by an N-acetylneuraminobiose [Neu5Ac(alpha 2-8)Neu5Ac] unit in a GD3 [Neu5Ac-Neu5Ac-Gal] epitope, and the inner regions of which were different from those of other C. jejuni serotypes. Similar experiments on LOSb from bacterial cells of the C. jejuni O:10 reference strain showed that the core oligosaccharide unit [1a, R = P (phosphoric monoester)] of LOSa from the MFS isolate was more uniformly complete than that of the O:10 reference strain [1b, R = AEP (2-aminoethylphosphate)] differing in the nature of the phosphate substituent at the inner heptose residue. The close structural relationship of LOSa from the MFS associated bacterium to LOSb from the O:10 reference strain runs parallel to that of the previously studied Guillain-Barré syndrome (GBS) associated bacterium typed as C. jejuni O:19 in comparison with the lipo-oligosaccharide from the reference strain. Preliminary studies on the high Mr components showed that those from the O:10 strains were indistinguishable from each other, but were structurally unrelated to those from the GBS associated C. jejuni serotype O:19 isolates and the O:19 reference strain [G.O. Aspinall, A.G. McDonald, and H. Pang, Biochemistry, 33 (1994) 250-255].

Typing of Helicobacter pylori with monoclonal antibodies against Lewis antigens in lipopolysaccharide.

Recently, it has been shown that the lipopolysaccharide (LPS) O antigen of Helicobacter pylori contains Lewis x (Lex), Lewis y (Ley), or both Lex and Ley antigens. We applied a serotyping method for H. pylori by an enzyme-linked immunosorbent assay with monoclonal antibodies (MAbs) specific for these antigens and the related fucosylated H type 1 (H1) antigen. The selected MAbs recognized the Lex and/or Ley structures in the LPS of H. pylori. The agreement between the results of biochemical compositional analysis and the serological data validated our serotyping system. A total of 152 strains from different geographic origins (The Netherlands, Canada, Poland, Italy, and People's Republic of China) were examined for typeability based on the presence of Lewis antigens. One hundred twenty-nine (84.9%) strains were typeable, and 12 different serotyping patterns were observed; 80.9% of the strains contained Lex and/or Le(y) antigens, and 18.4% reacted with the MAb against the related H1 antigen either alone or in combination with the Lex and/or Ley antigen. Our results show that the Lex and Ley antigens are frequently encountered in the LPS of H. pylori strains from various geographic origins. This typing method is an easy-to-perform technique, which can be used for strain differentiation in epidemiological studies of H. pylori infections.

Miller-Fisher syndrome associated with Campylobacter jejuni bearing lipopolysaccharide molecules that mimic human ganglioside GD3.

A Campylobacter jejuni strain of serotype O:10 was isolated from a patient who had Miller-Fisher syndrome. In its biochemical reactions and cellular morphology, the isolate was characteristic of typical C. jejuni. Antibodies against extracted lipopolysaccharide (LPS) were detected by passive hemagglutination in the acute- and convalescent-phase patient sera. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with the O:10 antiserum, it was demonstrated that the strain possessed both low- and high-molecular-weight molecules. Chemical analysis of the LPS revealed that the core oligosaccharide has a terminal trisaccharide epitope consisting of two molecules of sialic acid linked to galactose, a structure reflecting the terminal region of human ganglioside GD3. As this trisaccharide is also present in LPS cores of serotype O:19 strains from patients with Guillain-Barré syndrome but not in cores of nonneuropathic C. jejuni, a possible role for the trisaccharide in the etiology of neuropathies is indicated, and a difference for distinguishing neuropathic strains from nonneuropathic strains may be the presence of a sialyltransferase required for the synthesis of this trisaccharide.

Potential role of molecular mimicry between Helicobacter pylori lipopolysaccharide and host Lewis blood group antigens in autoimmunity.

Helicobacter pylori is involved in gastritis, gastric and duodenal ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. Earlier studies already suggested a role for autoimmune phenomena in H. pylori-linked disease. We now report that lipopolysaccharides (LPS) of H. pylori express Lewis y, Lewis x, and H type I blood group structures similar to those commonly occurring in gastric mucosa. Immunization of mice and rabbits with H. pylori cells or purified LPS induced an anti-Lewis x or y or anti-H type I response, yielding antibodies that bound human and murine gastric glandular tissue, granulocytes, adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma cells. Experimental oral infections in mice or natural infection in humans yielded anti-Lewis antibodies also. The beta chain of gastric (H+,K+)-ATPase, the parietal cell proton pump involved in acid secretion, contained Lewis y epitopes; gastric mucin contained Lewis x and y antigenic determinants. Growth in mice of a hybridoma that secretes H. pylori-induced anti-Lewis y monoclonal antibodies resulted in histopathological evidence of gastritis, which indicates a direct pathogenic role for anti-Lewis antibodies. In conclusion, our observations demonstrate that molecular mimicry between H. pylori LPS and the host, based on Lewis antigens, and provide understanding of an autoimmune mechanism for H. pylori-associated type B gastritis.

Lipopolysaccharide of the Helicobacter pylori type strain NCTC 11637 (ATCC 43504): structure of the O antigen chain and core oligosaccharide regions.

Smooth- and rough-form lipopolysaccharides from phenol-water extraction of cells from Helicobacter pylori type strain NCTC 11637 were isolated as the water-soluble component of high-M(r) and water-insoluble low-M(r) gel. Structural investigations were performed on the intact water-soluble smooth-form lipopolysaccharide, various oligosaccharides formed as chemical and enzymic degradation products, and three oligosaccharide fractions liberated by acetic acid hydrolysis from the water-insoluble rough-form lipopolysaccharide. A structure is proposed for the complete polysaccharide component of the smooth-form lipopolysaccharide comprising the O antigen chain, an intervening region, and the inner core oligosaccharide on the basis of 1H and 13C NMR experiments, fast atom bombardment/mass spectrometry, and methylation linkage analysis of permethylated oligo- and polysaccharide derivatives. The most striking feature of the O antigen region in the lipopolysaccharide is the presence of extended chains with fucosylated and nonfucosylated N-acetyllactosamine (LacNAc) units that mimic human cell surface glycoconjugates in normal human granulocytes. The chains are terminated by di- or trimeric Lewis(x) (Le(x)) determinants, which are also found in tumor-associated carbohydrate antigens in many adenocarcinomas.

Lipopolysaccharides of Helicobacter pylori strains P466 and MO19: structures of the O antigen and core oligosaccharide regions.

Lipopolysaccharides (LPS) from phenol-water extraction of dyspeptic (P466) and asymptomatic (MO19) strains of Helicobacter pylori were each isolated as water-soluble material of high relative molecular mass (high M(r)) and as water-insoluble gels of low M(r). Chemical and spectroscopic analyses of the soluble LPS and oligosaccharides liberated from the water-insoluble gels led to proposed structures for chains comprising the O antigen, intervening, and core regions. As in the LPS from the type strain NCTC 11637 [Aspinall, G. O., et al. (1996) Biochemistry 35, 2489-2497], the O antigen region of the P466 LPS is characterized by the presence of extended chains with fucosylated and nonfucosylated N-acetyllactosamine units, the former carrying alpha-L-fucopyranose units at O-3 of beta-D-GlcNAc residues. This structure differs from that of the type strain in termination of the O chain by a Lewis(y) (Le(y)) antigenic determinant [alpha-L-Fuc(1-->2)beta-D-Gal(1-->4)[alpha-L-Fuc(1-->3)]beta-D-GlcNAc] but also has internal Lewis(x) (Le(x)) units. The inner core region of the P466 LPS is indistinguishable from that in the type strain. In contrast, the O antigen region of the LPS from strain MO19 consists of a single Le(y) epitope linked via a 3-linked beta-D-Gal to an intervening region on the basis of a sequence of 3-linked D-glycero-alpha-D-manno-heptose residues which is in turn linked to an inner core identical to that in the type strain and the P466 strain. Results in this and the preceding paper show that LPS from the three H. pylori strains display molecular mimicry of human cell surface glycoconjugates but may vary in the expression of Le(x) or Le(y) determinants, the degree of O antigen chain extension, or in the presence of an additional region between the inner core and the O antigen.

Lipo-oligosaccharide of Campylobacter lari strain PC 637. Structure of the liberated oligosaccharide and an associated extracellular polysaccharide.

Lipo-oligosaccharide from phenol-water extraction of cells of Campylobacter lari strain PC 637 was separated as a water-insoluble gel of low relative molecular mass (M(r)) from a water-soluble extracellular polysaccharide of high M(r). Structural investigations were performed on the lipo-oligosaccharide and the extracellular polysaccharide, variously using 1H, 13C, and 31P NMR spectroscopy, linkage analysis, and fast atom bombardment-mass spectrometry of permethylated derivatives of the glycans and their products of chemical and enzymic degradation. The following structures are proposed for the highly branched oligosaccharide region: [formula: see text] and for the tetraglycosyl phosphate repeating unit of the extracellular polysaccharide: [formula; see text]

Lipo-oligosaccharide of the Campylobacter lari type strain ATCC 35221. Structure of the liberated oligosaccharide and an associated extracellular polysaccharide.

Lipo-oligosaccharide (LOS) from phenol-water extraction of cells of the Campylobacter lari type strain (ATCC 35221) was separated as a water-insoluble gel of low relative molecular mass (M(r)) from a water-soluble extracellular polysaccharide of high M(r). Structural investigations were performed on the liberated oligosaccharide and the extracellular polysaccharide, variously using 1H, 13C, and 31P NMR spectroscopy, linkage analysis, and fast atom bombardment-mass spectrometry of permethylated derivatives of the glycans and their products of chemical and enzymic degradation. The following structures are proposed for the highly branched region of the LOS: [formula: see text] and for the tetraglycosyl phosphate repeating unit of the extracellular polysaccharide: [-(PO3-)-->3)-beta-D-GlcpNAc-(1-->2)-6-d-alpha-L-gul-Hepp -(1-->2)-3-d-beta-D-threo-Penp-(1-->3)-6-d-alpha-L-gul-He pp-]n

Chemical structures of the core region of Campylobacter jejuni O:3 lipopolysaccharide and an associated polysaccharide.

The complete structure for the core oligosaccharide region of the water-insoluble low-M(r) lipopolysaccharide of Campylobacter jejuni serotype O:3 from phenol/water extraction of bacterial cells was assigned through studies on derivatives of the liberated oligosaccharide. Structure determinations were performed using 1H-NMR and 31P-NMR spectroscopies, methylation analysis supported by fast-atom-bombardment mass spectrometry, and Smith degradation experiments. It was concluded that the complete chains in the core oligosaccharide had the following structure in which a proportion of the terminal residues were phosphorylated: [formula: see text] From a similar series of experiments, it was concluded that an associated polysaccharide, which was isolated from the water phase of the phenol/water extracts, had the following repeating unit in which a proportion of the previously unknown L-glycero-D-ido-heptose (L-alpha-D-ido-Hep) residues were present as 3-hydroxypropanoyl esters, and were not covalently linked to the lipopolysaccharide: [formula see: text]

Lipopolysaccharides from Campylobacter jejuni associated with Guillain-Barré syndrome patients mimic human gangliosides in structure.

Lipopolysaccharides extracted from Campylobacter jejuni serostrains (serotype reference strains) for serotypes O:4 and O:19 were found to have core oligosaccharides with terminal structures resembling human gangliosides GM1 and GD1a. High-molecular-weight molecules that reflected the presence of O chains were shown in immunoblots to be immunologically specific for each serostrain. The O:19 antiserum also reacted strongly with core oligosaccharides of two isolates from patients with Guillain-Barré syndrome (GBS), but the banding patterns and molecular structures were different from those of the O:19 serostrain. A neuraminobiose disaccharide unit is attached to the terminal Gal residue in one isolate, and the other isolate lacked terminal N-acetyl glucosamine and galactose with attached sialic acid so that the sialic acid residues were present in a neuraminobiose unit linked to the only remaining galactose. Analysis of the high-M(r) lipopolysaccharides of the O:19 serostrain and the two isolates from GBS patients revealed the presence of a hyaluronic acid-like polymer with disaccharide-repeating units consisting of beta-D-glucuronic acid amidated with 2-amino-2-deoxyglycerol and N-acetyl glucosamine. The results confirm a potential role for the core oligosaccharides in the etiology of GBS but also suggest that the O-chain polysaccharide may be a contributing factor.

Lipopolysaccharides of Campylobacter jejuni serotype O:19: structures of core oligosaccharide regions from the serostrain and two bacterial isolates from patients with the Guillain-Barré syndrome.

Lipopolysaccharides from phenol-water extraction of cells of Campylobacter jejuni serotype O:19 were separated into a water-soluble gel of low M(r) and a water-soluble component of high M(r). Acetic acid hydrolysis of the ketosidic linkages to lipid A furnished respectively a core oligosaccharide, the structure of which is reported herein, and an O antigenic polysaccharide. Structural investigations were performed on the O-deacetylated lipopolysaccharide of low M(r), the liberated core oligosaccharide and the various products from removal of neuraminic acid and phosphate residues, and from the Smith degradation. It is concluded that the lipopolysaccharide from the serostrain has a core region with two types of closely related oligosaccharide chains showing striking homologies with gangliosides, the first with a single N-acetylneuraminic acid residue in an outer chain resembling GM1 and the second with two N-acetyl-neuraminic acid residues with a terminal region resembling GD1a. Similar experiments were carried out on lipopolysaccharides of low M(r) from bacterial isolates OH 4384 and OH 4382 serotyped as O:19 that had been obtained from two patients who subsequently developed the Guillain-Barré syndrome. The core oligosaccharide region of lipopolysaccharide from the former isolate differed only slightly from that of the serostrain, whereas that from the latter isolate was distinctly shorter.

Lipopolysaccharides of Campylobacter jejuni serotype O:19: structures of O antigen chains from the serostrain and two bacterial isolates from patients with the Guillain-Barré syndrome.

An O antigenic polysaccharide was liberated from the lipopolysaccharide of high M(r) from Campylobacter jejuni serotype O:19 by acetic acid hydrolysis of the ketosidic linkage to lipid A. The structure of the polysaccharide was established in several one- and two-dimensional 1H and 13C NMR experiments, fast atom bombardment mass spectrometry and methylation linkage analysis of the permethylated glycan and its degradation products. It is concluded that the glycan is a derivative of hyaluronic acid in which the beta-D-glucuronic acid residues in the alternating sequence [-4)-beta-D-GlcA-(1-->3)-beta-D-GlcNAc-(1]n are present as amides of 2-amino-2-deoxyglycerol. Parallel experiments were performed on O antigens liberated from lipopolysaccharides of high M(r) from bacterial isolates that had been obtained from two patients who subsequently developed the Guillain-Barré syndrome. Within the limits of structural analysis by NMR spectroscopy and methylation linkage analysis, both these O antigens were identical to that from the serostrain.

An antigenic polysaccharide from Campylobacter coli serotype O:30. Structure of a teichoic acid-like antigenic polysaccharide associated with the lipopolysaccharide.

A water-soluble antigenic polysaccharide of high M(r) associated with the lipopolysaccharide has been isolated from phenol-water extraction of cells of Campylobacter coli serotype O:30. The polysaccharide and oligosaccharide degradation products formed on O-dephosphorylation and by periodate oxidation followed by reduction have been investigated by one- and two-dimensional 1H, 13C, and 31P NMR. It is concluded that the antigenic polysaccharide has a teichoic acid-like structure with a poly-Ribitol phosphate, [5-Ribitol-1-P]n, backbone with side chains at O-2 of O-(6-deoxy-beta-D-talo-heptopyranosyl)-(1-->4)-(2-acetylamino-2-deoxy-beta-D- glucopyranosyl) units. The structure is unusual in Gram-negative bacteria and is unique in possessing 6-deoxy-D-talo-heptose as a constituent sugar. Evidence for the relationship of the antigenic polysaccharide to the lipopolysaccharide of low M(r) is discussed.