| 1. |
- Breimer, Michael, 1951, et al.
(författare)
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Glycosphingolipid composition of epithelial cells isolated along the villus axis of small intestine of a single human individual
- 2012
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 22:12, s. 1721-1730
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Tidskriftsartikel (refereegranskat)abstract
- A 6-cm fresh proximal ileum surgical specimen from a blood group A(1)Le(a-b+) secretor individual was used for stepwise isolation of epithelial cells from villus tip to crypt bottom by gentle washing with ethylenediaminetetraacetic acid-containing buffer. Acid and non-acid sphingolipids were prepared from the epithelial cell fractions and the non-epithelial intestinal residue. Molecular information on the sphingolipid composition was obtained without further isolation of individual species by applying thin-layer chromatography using chemical and biological (monoclonal antibodies, cholera toxin, Escherichia coli) detection reagents, mass spectrometry and proton NMR spectroscopy of derivatized glycolipids. In this way, the structure of major and minor saccharides, ceramide components and their relative amounts were obtained. Epithelial cells and non-epithelial residue were distinctly different in their sphingolipid composition. Sphingomyelin was the major single component in both compartments. Characteristic for epithelial cells was the dominance of monoglycosylceramides, sulphatides and blood group fucolipids (mainly Le(b) hexaglycosylceramides and ALe(b) heptaglycosylceramides). The non-epithelial residue had about five times less glycolipids mainly mono-, di-, tri- and tetra-glycosylceramides and gangliosides, including the GM1 ganglioside. The ceramides were more hydroxylated (1-2 additional hydroxyls) in epithelial cell glycolipids compared with the non-epithelial residue. Combined with a separate detailed study on the glycoproteins of the same epithelial cell preparation, this human intestinal sample is the only epithelial cell preparation where both protein- and lipid-linked saccharides are characterized in detail.
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| 2. |
- Bäcker, Annika E., 1965, et al.
(författare)
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Biochemical and enzymatic characterization of blood group ABH and related histo-blood group glycosphingolipids in the epithelial cells of porcine small intestine.
- 1997
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 7:7, s. 943-53
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Tidskriftsartikel (refereegranskat)abstract
- Non-acid glycosphingolipids were isolated from small intestinal epithelial cells of a single blood group A pig. One very predominant blood group compound was obtained chemically pure upon HPLC fractionation. It was characterized by mass spectrometry and 1H NMR spectroscopy to be the type 1 chain blood group A hexaglycosylceramide. Support for the presence of minute amounts of additional A glycolipids was obtained by mass spectrometry and immunostaining of TLC plates with anti-A antibodies specific for A type 2 chain, A type 3 and 4 chain, and the ALe(b) determinant. Among precursor chains, globoside (type 4) and lactotetraosylceramide (type 1) were immunologically identified, whereas no neolactotetraosylceramide (type 2) and gangliotetraosylceramide reactivities were detected. We addressed the question whether the predominant expression of type 1 chain based A glycolipids reflects a restricted glycolipid precursor chain specificity of the alpha 1-2 fucosyl- and/or the alpha 1-3 N-acetylgalactosaminyltransferases, or if the biosynthesis of the precursor chains themselves is regulated. All precursor core saccharides, lacto- (type 1), neolacto-(type 2), and gangliotetraosylceramide as well as globopentaosylceramide (type 4), could serve as acceptors for fucose in vitro when a crude microsomal fraction obtained from mechanically released, porcine intestinal epithelial cells was used as an enzyme source. Under the same conditions an N-acetylgalactosamine residue could be transferred to the blood group H structures based on these core saccharide chains. Lactotriaosylceramide, but not gangliotriaosylceramide, could serve as an acceptor for UDP-galactose. When the product was digested with beta-galactosidase (EC 3.2.1.23) from S.pneumoniae, under conditions where it specifically cleaves Gal beta 1-4 residues, approximately 40% of the radioactivity was cleaved off, indicating that a substantial amount of neolactotetraosylceramide was made in vitro, as opposed to the predominance of lactotetraosylceramide-based structures found in vivo.
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| 3. |
- Gustafsson, A., et al.
(författare)
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Carbohydrate-dependent inhibition of Helicobacter pylori colonization using porcine milk
- 2006
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 16:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Breast milk has a well-known anti-microbial effect, which is in part due to the many different carbohydrate structures expressed. This renders it a position as a potential therapeutic for treatment of infection by different pathogens, thus avoiding the drawbacks of many antibiotics. In a previous study, we showed that pigs express the Helicobacter pylori receptors, sialyl Lewis x (Le x) and Le b, on various milk proteins. Here, we investigate the pig breed- and individual-specific expression of these epitopes, as well as the inhibitory capacity of porcine milk on H. pylori binding and colonization. Milk proteins from three different pig breeds were analysed by western blotting using antibodies with known carbohydrate specificity. An adhesion assay was used to investigate the capacity of pig milk to inhibit H. pylori binding to neoglycoproteins carrying Le b and sialyl-di-Le x. alpha1,3/4-fucosyltransferase transgenic FVB/N mice, known to express Le b and sialyl Le x in their gastric epithelium, were colonized by H. pylori and were subsequently treated with Le b- and sialyl Le x-expressing or nonexpressing porcine milk, or water (control) only. The degree of H. pylori colonization in the different treatment groups was quantified. The expression of the Le b and sialyl Le x carbohydrate epitopes on pig milk proteins was breed- and individual specific and correlated to the ability of porcine milk to inhibit H. pylori adhesion in vitro and H. pylori colonization in vivo. Milk from certain pig breeds may have a therapeutic and/or prophylactic effect on H. pylori infection.
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| 4. |
- Liu, J., et al.
(författare)
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Anti-pig antibody adsorption efficacy of {alpha}-Gal carrying recombinant P-selectin glycoprotein ligand-1/immunoglobulin chimeras increases with core 2 {beta}1, 6-N-acetylglucosaminyltransferase expression
- 2005
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 15:6, s. 571-83
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Tidskriftsartikel (refereegranskat)abstract
- We have previously described the construction of a P-selectin glycoprotein ligand-1-mouse immunoglobulin Fc fusion protein, which when transiently coexpressed with the porcine alpha1,3 galactosyltransferase in COS cells becomes a very efficient adsorber of xenoreactive, anti-pig antibodies. To relate the adsorption capacity with the glycan expression of individual fusion proteins produced in different cell lines, stable CHO-K1, COS, and 293T cells producing this fusion protein have been engineered. On alpha1,3 galactosyltransferase coexpression, high-affinity adsorbers were produced by both COS and 293T cells, whereas an adsorber of lower affinity was derived from CHO-K1 cells. Stable coexpression of a core 2 beta1,6 N-acetylglucosaminyltransferase in CHO-K1 cells led to increased alpha-Gal epitope density and improved anti-pig antibody adsorption efficacy. ESI-MS/MS of O-glycans released from PSGL-1/mIgG(2b) produced in an alpha1,3 galactosyl- and core 2 beta1,6 N-acetylglucosaminyltransferase expressing CHO-K1 cell clone revealed a number of structures with carbohydrate sequences consistent with terminal Gal-Gal. In contrast, no O-glycan structures with terminal Gal-Gal were identified on the fusion protein when expressed alone or in combination with the alpha1,3 galactosyltransferase in CHO-K1 cells. In conclusion, the density of alpha-Gal epitopes on PSGL-1/mIgG(2b) was dependent on the expression of O-linked glycans with core 2 structures and lactosamine extensions. The structural complexity of the terminal Gal-Gal expressing O-glycans with both neutral as well as sialic acid-containing structures is likely to contribute to the high adsorption efficacy.
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| 5. |
- Löfling, Jonas, et al.
(författare)
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Studies of Lewis antigens and H. pylori adhesion in CHO cell lines engineered to express Lewis b determinants.
- 2008
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 18:7, s. 494-501
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Tidskriftsartikel (refereegranskat)abstract
- Many microbes bind and adhere via adhesins to host cell carbohydrates as an initial step for infection. Therefore, cell lines expressing Lewis b (Le(b)) determinants were generated as a potential model system for Helicobacter pylori colonization and infection, and their expression of blood group Lewis determinants was characterized. CHO-K1 cells were stably transfected with selected glycosyltransferase cDNAs, and two Le(b) positive clones, 1C5 and 2C2, were identified. Expression of Lewis (Le(a), Le(b), Le(x), and Le(y)) determinants was analyzed by flow cytometry of intact cells, SDS-PAGE/Western blot of solubilized glycoproteins, and thin layer chromatography immunostaining of isolated glycolipids (GL). Binding of H. pylori to cells was examined by microscopy and quantified. Flow cytometry showed that 1C5 and 2C2 were Le(a) and Le(b) positive. 1C5 expressed Le(b) on O-linked, but not N-linked, glycans and only weakly on GLs. In contrast, 2C2 expressed Le(b) on N-, O-glycans, and GLs. Furthermore, both clones expressed Le(a) on N- and O-glycans but not on GLs. 2C2, but not 1C5, stained positively for Le(y) on N-linked glycans and GLs. Both clones, as well as the parental CHO-K1 cells, expressed Le(x) on GLs. A Le(b)-binding H. pylori strain bound to the 1C5 and 2C2 cells. In summary, two glycosyltransferase transfected CHO-K1 cell clones differed regarding Lewis antigen expression on N- and O-linked glycans as well as on GLs. Both clones examined supported adhesion of a Le(b)-binding H. pylori strain and may thus be a useful in vitro model system for H. pylori colonization/infection studies.
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| 6. |
- Svensson, Lola, 1948, et al.
(författare)
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The structural basis of blood group A-related glycolipids in an A3 red cell phenotype and potential explanation to a serological phenomenon
- 2011
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 21:2, s. 162-174
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Tidskriftsartikel (refereegranskat)abstract
- Glycolipids from the red cells of a rare blood group A subgroup individual, expressing the blood group A(3) phenotype with the classical mixed-field agglutination phenomenon, A(2(539G>A))/O(1) genotype, and an unusual blood group A glycolipid profile, were submitted to a comprehensive biochemical and structural analysis. To determine the nature of blood group A glycolipids in this A(3) phenotype, structural determination was carried out with complementary techniques including proton nuclear magnetic resonance (1D and 2D), mass spectrometry (MS) (nano-electrospray ionization/quadrupole time-of-flight and tandem mass spectrometry) and thin layer chromatography with immunostaining detection. As expected, total blood group A structures were of low abundance, but contrary to expectations extended-A type 2 and A type 3 glycolipids were more dominant than A hexaglycosylceramides based on type 2 chain (A-6-2 glycolipids), which normally is the major A glycolipid. Several para-Forssman (GalNAcbeta3GbO(4)) structures, including extended forms, were identified but surmised not to contribute to the classic mixed-field agglutination of the A(3) phenotype. It is proposed that the low level of A antigen combined with an absence of extended branched glycolipids may be the factor determining the mixed-field agglutination phenomenon in this individual.
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| 7. |
- 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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