| 1. |
- Barone, Angela, et al.
(författare)
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Glycosphingolipids of porcine, bovine, and equine pericardia as potential immune targets in bioprosthetic heart valve grafts
- 2018
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X. ; 25:5
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPericardial tissue from various animal species is utilized for the production of the bioprosthetic heart valves (BHV) used clinically. Experimental data show that the eventual breakdown of BHV is partly due to immunological interactions with carbohydrate tissue antigens. To understand these processes, we have examined the glycolipid-based carbohydrate antigens in naive porcine, bovine, and equine pericardia. ExperimentalTotal non-acid and acid glycosphingolipid fractions were isolated from porcine, bovine, and equine pericardia, and individual glycolipid compounds were characterized by thin-layer chromatography, mass spectrometry, and binding of monoclonal antibodies, lectins and bacteria in chromatogram binding assays. ResultsThe non-acid glycolipid fractions from all species contained glycosphingolipids based on the globo- and neolacto-series, including pentaglycosylceramides with terminal Gal3 determinants. Terminal blood group A and H (O) structures based on type 2 core chains were present in porcine pericardium, while the Forssman pentaosylceramide was found in equine pericardium. All acid glycolipid fractions contained sulfatide and several gangliosides with both N-acetyl- and N-glycolyl-neuraminic acid as terminal saccharide chain determinants. ConclusionSeveral carbohydrate antigens which are potential targets for the human immune system have been identified in the animal pericardial tissues used for the production of BHV. Which of these antigens are left in the tissues after industrial BHV production processes, as well as their potential role in eventual BHV degradation, remains to be elucidated.
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| 2. |
- Benktander, John, et al.
(författare)
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Helicobacter pylori SabA binding gangliosides of human stomach
- 2018
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Ingår i: Virulence. - : Informa UK Limited. - 2150-5594 .- 2150-5608. ; 9:1, s. 738-751
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Tidskriftsartikel (refereegranskat)abstract
- Adhesion of Helicobacter pylori to the gastric mucosa is a prerequisite for the pathogenesis of H. pylori related diseases. In this study, we investigated the ganglioside composition of human stomach as the target for attachment mediated by H. pylori SabA (sialic acid binding adhesin). Acid glycosphingolipids were isolated from human stomach and separated into subfractions, which were characterized by mass spectrometry and by binding of antibodies, bacteria, and Solanum tuberosum lectin. H. pylori SabA binding gangliosides were characterized as Neu5Ac alpha 3-neolactohexaosylceramide and Neu5Ac alpha 3-neolactooctaosylceramide, while the other acid human stomach glycosphingolipids characterized (sulfatide and the gangliosides GM3, GD3, GM1, Neu5Ac alpha 3-neolactotetraosylceramide, GD1a and GD1b) were not recognized by the bacteria. Defining H. pylori binding glycosphingolipids of the human gastric mucosa will be useful to specifically target this microbe-host interaction for therapeutic intervention.
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| 3. |
- Breimer, Michael, 1951, et al.
(författare)
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Glycosphingolipids of human embryonic stem cells.
- 2017
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Ingår i: Glycoconjugate journal. - : Springer Science and Business Media LLC. - 1573-4986 .- 0282-0080. ; 34:6, s. 713-723
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Forskningsöversikt (refereegranskat)abstract
- The application of human stem cell technology offers theoretically a great potential to treat various human diseases. However, to achieve this goal a large number of scientific issues remain to be solved. Cell surface carbohydrate antigens are involved in a number of biomedical phenomena that are important in clinical applications of stem cells, such as cell differentiation and immune reactivity. Due to their cell surface localization, carbohydrate epitopes are ideally suited for characterization of human pluripotent stem cells. Amongst the most commonly used markers to identify human pluripotent stem cells are the globo-series glycosphingolipids SSEA-3 and SSEA-4. However, our knowledge regarding human pluripotent stem cell glycosphingolipid expression was until recently mainly based on immunological assays of intact cells due to the very limited amounts of cell material available. In recent years the knowledge regarding glycosphingolipids in human embryonic stem cells has been extended by biochemical studies, which is the focus of this review. In addition, the distribution of the human pluripotent stem cell glycosphingolipids in human tissues, and glycosphingolipid changes during human stem cell differentiation, are discussed.
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| 4. |
- Cervin, Jakob, et al.
(författare)
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GM1 ganglioside-independent intoxication by Cholera toxin
- 2018
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors via its B subunit (CTB). We have recently shown that in addition to the previously described binding partner ganglioside GM1, CTB binds to fucosylated proteins. Using flow cytometric analysis of primary human jejunal epithelial cells and granulocytes, we now show that CTB binding correlates with expression of the fucosylated Lewis X (LeX) glycan. This binding is competitively blocked by fucosylated oligosaccharides and fucose-binding lectins. CTB binds the LeX glycan in vitro when this moiety is linked to proteins but not to ceramides, and this binding can be blocked by mAb to LeX. Inhibition of glycosphingolipid synthesis or sialylation in GM1-deficient C6 rat glioma cells results in sensitization to CT-mediated intoxication. Finally, CT gavage produces an intact diarrheal response in knockout mice lacking GM1 even after additional reduction of glycosphingolipids. Hence our results show that CT can induce toxicity in the absence of GM1 and support a role for host glycoproteins in CT intoxication. These findings open up new avenues for therapies to block CT action and for design of detoxified enterotoxin-based adjuvants.
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| 5. |
- Jin, Chunsheng, et al.
(författare)
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Helicobacter pylori-binding nonacid glycosphingolipids in the human stomach
- 2018
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Ingår i: Journal of Biological Chemistry. - : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 293:44, s. 17248-17266
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh-)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh-)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Le(x), Le(a), and H type 2 pentaosylceramides, and the Le(y) hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Le(b) hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALe(b) heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x(2) pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.
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| 6. |
- Madar Johansson, Miralda, et al.
(författare)
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Characterization of moose intestinal glycosphingolipids
- 2015
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Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 0282-0080 .- 1573-4986. ; 32:6, s. 393-412
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Tidskriftsartikel (refereegranskat)abstract
- As a part of a systematic investigation of the species-specific expression of glycosphingolipids, acid and non-acid glycosphingolipids were isolated from three small intestines and one large intestine of the moose (Alces alces). The glycosphingolipids were characterized by binding of monoclonal antibodies, lectins and bacteria in chromatogram binding assays, and by mass spectrometry. The non-acid fractions were complex mixtures, and all had glycosphingolipids belonging to the lacto- and neolactoseries (lactotriaosylceramide, lactotetraosylceramide, neolactotetraosylceramide, Galα3-Lex hexaosylceramide, and lacto-neolactohexaosylceramide), globo-series (globotriaosylceramide and globotetraosylceramide), and isogloboseries (isoglobotriaosylceramide). Penta- and heptaglycosylceramides with terminal Galili determinants were also characterized. Furthermore, glycosphingolipids with terminal blood group O determinants (H triaosylceramide, H type 2 pentaosylceramide, H type 1 penta- and heptaosylceramide) were characterized in two of the moose small intestines, and in the one large intestine, while the third small intestine had glycosphingolipids with terminal blood group A determinants (A tetraosylceramide, A type 1 hexa- and octaosylceramide, A dodecaosylceramide). The acid glycosphingolipid fractions of moose small and large intestine contained sulfatide, and the gangliosides GM3, GD3, GD1a, GD1b, and also NeuGc and NeuAc variants of the Sda ganglioside and the sialyl-globopenta/SSEA-4 ganglioside. In humans, the NeuAc-globopenta/SSEA-4 ganglioside is a marker of embryonic and adult stem cells, and is also expressed in several human cancers. This is the first time sialyl-globopentaosylceramide/SSEA-4 has been characterized in a fully differentiated normal tissue, and also the first time NeuGc-globopentaosylceramide has been characterized. © 2015 The Author(s).
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| 7. |
- Padra, Médea, 1986, et al.
(författare)
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Helicobacter suis binding to carbohydrates on human and porcine gastric mucins and glycolipids occurs via two modes
- 2018
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Ingår i: Virulence. - : Informa UK Limited. - 2150-5594 .- 2150-5608. ; 9:1, s. 898-918
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter suis colonizes the stomach of most pigs and is the most prevalent non-Helicobacter pylori Helicobacter species found in the human stomach. In the human host, H. suis contributes to the development of chronic gastritis, peptic ulcer disease and MALT lymphoma, whereas in pigs it is associated with gastritis, decreased growth and ulcers. Here, we demonstrate that the level of H. pylori and H. suis binding to human and pig gastric mucins varies between individuals with species dependent specificity. The binding optimum of H. pylori is at neutral pH whereas that of H. suis has an acidic pH optimum, and the mucins that H. pylori bind to are different than those that H. suis bind to. Mass spectrometric analysis of mucin O-glycans from the porcine mucin showed that individual variation in binding is reflected by a difference in glycosylation; of 109 oligosaccharide structures identified, only 14 were present in all examined samples. H. suis binding to mucins correlated with glycans containing sulfate, sialic acid and terminal galactose. Among the glycolipids present in pig stomach, binding to lactotetraosylceramide (Gal beta 3GlcNAc beta 3Gal beta 4Glc beta 1Cer) was identified, and adhesion to Gal beta 3GlcNAc beta 3Gal beta 4Glc at both acidic and neutral pH was confirmed using other glycoconjugates. Together with that H. suis bound to DNA (used as a proxy for acidic charge), we conclude that H. suis has two binding modes: one to glycans terminating with Gal beta 3GlcNAc, and one to negatively charged structures. Identification of the glycan structures H. suis interacts with can contribute to development of therapeutic strategies alternative to antibiotics.
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| 8. |
- Pakharukova, N., et al.
(författare)
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Structural basis for Acinetobacter baumannii biofilm formation
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 115:21, s. 5558-5563
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Tidskriftsartikel (refereegranskat)abstract
- Acinetobacter baumannii-a leading cause of nosocomial infections-has a remarkable capacity to persist in hospital environments and medical devices due to its ability to form biofilms. Biofilm formation is mediated by Csu pili, assembled via the "archaic" chaperone-usher pathway. The X-ray structure of the CsuC-CsuE chaperone-adhesin preassembly complex reveals the basis for bacterial attachment to abiotic surfaces. CsuE exposes three hydrophobic finger-like loops at the tip of the pilus. Decreasing the hydrophobicity of these abolishes bacterial attachment, suggesting that archaic pili use tip-fingers to detect and bind to hydrophobic cavities in substrates. Antitip antibody completely blocks biofilm formation, presenting a means to prevent the spread of the pathogen. The use of hydrophilic materials instead of hydrophobic plastics in medical devices may represent another simple and cheap solution to reduce pathogen spread. Phylogenetic analysis suggests that the tip-fingers binding mechanism is shared by all archaic pili carrying two-domain adhesins. The use of flexible fingers instead of classical receptor-binding cavities is presumably more advantageous for attachment to structurally variable substrates, such as abiotic surfaces.
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| 9. |
- Pakharukova, Natalia, et al.
(författare)
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Structural basis for Myf and Psa fimbriae-mediated tropism of pathogenic strains of Yersinia for host tissues.
- 2016
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Ingår i: Molecular microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 102:4, s. 593-610
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Tidskriftsartikel (refereegranskat)abstract
- Three pathogenic species of the genus Yersinia assemble adhesive fimbriae via the FGL-chaperone/usher pathway. Closely related Y. pestis and Y. pseudotuberculosis elaborate the pH6 antigen (Psa), which mediates bacterial attachment to alveolar cells of the lung. Y. enterocolitica, instead, assembles the homologous fimbriae Myf of unknown function. Here, we discovered that Myf, like Psa, specifically recognizes β1-3- or β1-4-linked galactose in glycosphingolipids, but completely lacks affinity for phosphatidylcholine, the main receptor for Psa in alveolar cells. The crystal structure of a subunit of Psa (PsaA) complexed with choline together with mutagenesis experiments revealed that PsaA has four phosphatidylcholine binding pockets that enable super-high-avidity binding of Psa-fibres to cell membranes. The pockets are arranged as six tyrosine residues, which are all missing in the MyfA subunit of Myf. Conversely, the crystal structure of the MyfA-galactose complex revealed that the galactose-binding site is more extended in MyfA, enabling tighter binding to lactosyl moieties. Our results suggest that during evolution, Psa has acquired a tyrosine-rich surface that enables it to bind to phosphatidylcholine and mediate adhesion of Y. pestis/pseudotuberculosis to alveolar cells, whereas Myf has specialized as a carbohydrate-binding adhesin, facilitating the attachment of Y. enterocolitica to intestinal cells.
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| 10. |
- Säljö, Karin, 1981, et al.
(författare)
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Comparison of the glycosphingolipids of human induced pluripotent stem cells and human embryonic stem cells
- 2017
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 27:4, s. 291-305
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Tidskriftsartikel (refereegranskat)abstract
- High expectations are held for human-induced pluripotent stem cells (hiPSC) since they are established from autologous tissues thus overcoming the risk of allogeneic immune rejection when used in regenerative medicine. However, little is known regarding the cell-surface carbohydrate antigen profile of hiPSC compared with human embryonic stem cells (hESC). Here, glycosphingolipids were isolated from an adipocyte-derived hiPSC line, and hiPSC and hESC glycosphingolipids were compared by concurrent characterization by binding assays with carbohydrate-recognizing ligands and mass spectrometry. A high similarity between the nonacid glycosphingolipids of hiPSC and hESC was found. The nonacid glycosphingolipids P1 pentaosylceramide, x2 pentaosylceramide and H type 1 heptaosylceramide, not previously described in human pluripotent stem cells (hPSC), were characterized in both hiPSC and hESC. The composition of acid glycosphingolipids differed, with increased levels of GM3 ganglioside, and reduced levels of GD1a/GD1b in hiPSC when compared with hESC. In addition, the hESC glycosphingolipids sulf-globopentaosylceramide and sialyl-globotetraosylceramide were lacking in hiPSC. Neural stem cells differentiating from hiPSC had a reduced expression of sialyl-lactotetra, whereas expression of the GD1a ganglioside was significantly increased. Thus, while sialyl-lactotetra is a marker of undifferentiated hPSC, GD1a is a novel marker of neural differentiation.
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