Gangliotetraosylceramide is a major glycolipid of epithelial cells of mouse small intestine

Novel Leb-like Helicobacter pylori-binding glycosphingolipid created by the expression of human alpha-1,3/4-fucosyltransferase in FVB/N mouse stomach

The "Le(b) mouse" was established as a model for investigations of the molecular events following Le(b)-mediated adhesion of Helicobacter pylori to the gastric epithelium. By the expression of a human alpha-1,3/4-fucosyltransferase in the gastric pit cell lineage of FVB/N transgenic mice, a production of Le(b) glycoproteins in gastric pit and surface mucous cells was obtained in this "Le(b) mouse," as demonstrated by binding of monoclonal anti-Le(b) antibodies. To explore the effects of the human alpha-1,3/4-fucosyltransferase on glycosphingolipid structures, neutral glycosphingolipids were isolated from stomachs of transgenic alpha-1,3/4-fucosyltransferase-expressing mice. A glycosphingolipid recognized by BabA-expressing H. pylori was isolated and characterized by mass spectrometry and proton NMR as Fuc alpha 2Gal beta 3(Fuc alpha 4)GalNAc beta 4 Gal beta 4 Glc beta 1Cer, i.e., a novel Le(b)-like glycosphingolipid on a ganglio core. In addition, two other novel glycosphingolipids were isolated from the mouse stomach epithelium that were found to be nonbinding with regard to H. pylori. The first was a pentaglycosylceramide, GalNAc beta 3 Gal alpha 3(Fuc alpha 2)Gal beta 4 Glc beta 1Cer, in which the isoglobotetrasaccharide has been combined with Fuc alpha 2 to yield an isoglobotetraosylceramide with an internal blood group B determinant. The second one was an elongated fucosyl-gangliotetraosylceramide, GalNAc beta 3(Fuc alpha 2)Gal beta 3GalNAc beta 4Gal beta 4 Glc beta 1Cer.

Glycolipid binding epitopes involved in adherence of the periodontitis-associated bacterium Porphyromonas gingivalis

The ability of the periodontal pathogen Porphyromonas gingivalis to use different glycolipid structures as receptors has previously been demonstrated. The bacterium adhered to acid and nonacid glycolipids originating from human organs and to nonacid glycolipids of porcine origin. The aim of the present study was to analyze these binding epitopes by structural characterization. Glycolipid fractions with positive bacterial binding from e.g. human and porcine origin, were purified by the high performance liquid chromatography technique and thereafter used in bacterial overlay assays with (35)S-labeled P. gingivalis. Purified fractions with positive binding were structurally characterized by proton nuclear magnetic resonance spectroscopy. Complementing thin-layer chromatograms and bacterial overlay assays with pure reference glycolipid fractions and competition experiments with lactose were performed to define potential receptors. The P. gingivalis binding epitopes, including cerebrosides with nonhydroxy fatty acids, lactosylceramide with hydroxy fatty acids, sulfatides, lacto-, neolacto- and gangliotetraosylceramides, are in several instances similar to those found for other bacteria, e.g. H. pylori, H. influenzae and N. meningitidis. In addition P. gingivalis also bound to the Galalpha4Gal epitope of the globo series of glycolipids. In the future these results may be valuable for development of new treatment strategies, such as anti-adhesion therapies and vaccines specifically directed against P. gingivalis infection.

Real-time PCR quantification of bacterial adhesion to Caco-2 cells: competition between bifidobacteria and enteropathogens

Probiotic bacteria play an important role in protecting the host from intestinal colonization of pathogenic bacteria. We have developed a new analytical approach based on a real-time PCR technique for quantifying Bifidobacterium adhesion to intestinal epithelial cells. Real-time PCR analysis showed that adhesion to enterocyte-like Caco-2 cells represented a variable phenotype in the genus Bifidobacterium, enabling classification of three adhesion behaviors: high adhesiveness (>40 bifidobacterial cells/Caco-2 cell); adhesiveness (5-40 bifidobacterial cells/Caco-2 cell); no adhesiveness (<5 bifidobacterial cells/Caco-2 cell). This molecular methodology was successfully used in competition studies in enteropathogens. All bifidobacterial strains examined evidenced displacement activity towards important enteropathogens (S. typhimurium, Y. enterocolitica and E. coli EPEC). Real-time PCR is a rapid, accurate and sensitive method for detecting and quantifying different bacterial genera and species simultaneously adhering to a epithelial cell monolayer.

Liquid chromatography "on-flow" 1H nuclear magnetic resonance on native glycosphingolipid mixtures together with gas chromatography/mass spectrometry on the released oligosaccharides for screening and characterisation of carbohydrate-based antigens from pig lungs

Glycosphingolipids were prepared from pig lung and pooled into two fractions with (i) < or = 3 sugar residues, and (ii) > or = 3 sugar residues. Oligosaccharides were prepared and used for gas chromatography, gas chromatography/mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. The glycolipid fractions i and ii were further characterised and purified using a novel method based on high performance liquid chromatography "on-flow" proton nuclear magnetic resonance. The LC "on-flow" NMR technique showed good chromatographic separation and gave NMR spectral information which could be used as guidance for pooling of the separated mixture glycolipids. Conventional 1H NMR, thin layer immunostaining, gas chromatography, gas chromatography/mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry were used to characterise the glycolipids and to validate LC-NMR spectral data.

Characterisation of human natural anti-sheep xenoantibodies

Currently, the pig species is regarded as the most likely organ donor for human xenotransplantation in the future. However, it cannot be granted that the pig will be the optimal species of choice. We have studied human anti-sheep antibodies in comparison with anti-pig antibodies. The anti-sheep lymphocytotoxic and hemagglutination titers were in the range 8 to 128 and 2 to 32, respectively, in single individuals, which were considerably lower than the anti-pig titers of these individuals. Perfusion of sheep kidneys with human blood reduced the anti-sheep xenoantibody titers to zero as measured by lymphocytotoxic, hemagglutination, and sheep aortic endothelial cell antibody binding assays. The perfused kidneys showed generalised depositions of human IgM and C3c in the vascular tree and focal depositions of C1q and fibrin. Obliteration of capillaries by human platelets and polymorphonuclear cells were observed. Total neutral glycolipid fractions were isolated from sheep intestinal, pancreatic, and kidney tissues. By using a chromatogram binding assay, a monoclonal anti-Forssman antibody identified a single compound with five sugar residues in all organs. Several glycolipid bands were stained in all organs by the Gal(alpha)1-specific lectin I-B4 from Griffonia (Bandeiraea) Simplicifolia. A human AB serum pool showed staining by both IgG and IgM antibodies of the Forssman and Gal(alpha)1-terminating components as well as some other, not structurally identified, components. The Forssman and Gal(alpha)1-reactivity in human sera could be eliminated by immunoadsorption using Forssman and Gal(alpha)1-3Gal-immunoadsorbent columns, respectively. Immunostaining of sheep kidney tissue sections showed the presence of Gal(alpha)1-terminating epitopes by immunoperoxidase and immunogold silver staining techniques. Proximal convoluted tubules showed a strong staining, while thin loops of Henle, collecting ducts, urothelium, and vessels showed a weaker staining. Distal convoluted tubules and thick loops of Henle were completely negative. In summary, human serum contains anti-sheep xenoantibodies reacting mainly with the Forssman and Gal(alpha)1-determinants in sheep tissues and the anti-sheep antibody titers are lower than the corresponding anti-pig titers.

The lactosylceramide binding specificity of Helicobacter pylori

The possible role of glycosphingolipids as adhesion receptors for the human gastric pathogen Helicobacter pylori was examined by use of radiolabeled bacteria, or protein extracts from the bacterial cell surface, in the thin-layer chromatogram binding assay. Of several binding specificities found, the binding to lactosylceramide is described in detail here, the others being reported elsewhere. By autoradiography a preferential binding to lactosylceramide having sphingosine/phytosphingosine and 2-D hydroxy fatty acids was detected, whereas lactosylceramide having sphingosine and nonhydroxy fatty acids was consistently nonbinding. A selective binding of H. pylori to lactosylceramide with phytosphingosine and 2-D hydroxy fatty acid was obtained when the different lactosylceramide species were incorporated into liposomes, but only in the presence of cholesterol, suggesting that this selectivity may be present also in vivo . Importantly, lactosylceramide with sphingosine and hydroxy fatty acids does not bind in this assay. Furthermore, a lactosylceramide-based binding pattern obtained for different trisaccharide glycosphingolipids is consistent with the assumption that this selectivity is due to binding of a conformation of lactosylceramide in which the oxygen of the 2-D fatty acid hydroxyl group forms a hydrogen bond with the Glc hydroxy methyl group, yielding an epitope presentation different from other possible conformers. An alternative conformation that may come into consideration corresponds to the crystal structure found for cerebroside, in which the fatty acid hydroxyl group is free to interact directly with the adhesin. By isolating glycosphingolipids from epithelial cells of human stomach from seven individuals, a binding of H.pylori to the diglycosylceramide region of the non-acid fraction could be demonstrated in one of these cases. Mass spectrometry showed that the binding-active sample contained diglycosylceramides with phytosphingosine and 2-D hydroxy fatty acids with 16-24 carbon atoms in agreement with the results related above.

A multispecific saline-soluble lectin from the parasitic fungus Arthrobotrys oligospora. Similarities in the binding specificities compared with a lectin from the mushroom agaricus bisporus

Several fungi can express high levels of saline-soluble and low-molecular-mass lectins that bind to glycoproteins such as fetuin and different mucins but not bind to any monosaccharides. In this paper, we report the binding specificities of such a lectin (designated AOL) isolated from the nematophagous fungus Arthrobotrys oligospora. The results show that AOL is a multispecific lectin that interacts with the following ligands: (a) Several sulfated glycoconjugates including sulfatide, dextran sulfate, and fucoidan. The specificity of this binding was indicated by experiments showing that none of the tested neutral- and sialic-acid-containing glycolipids, chondroitin sulfates B and C, heparin, and polyvinyl sulfate bound to AOL; (b) Phosphatidic acid and phospatidylglycerol, two out of several tested phospholipids. (c) N-linked and O-linked sugar chains bound to intact fetuin. The involvement of such sugar structures was demonstrated by analyzing the binding of AOL to chemically deglycosylated (trifluoromethanesulfonic acid) fetuin. Treating fetuin with O-glycosidase and N-glycosidase indicated that AOL bound to Gal beta GaLNAc alpha-Ser/Thr and to some N-linked complex sugars, respectively. Further assays demonstrated that AOL could interact with several other glycoproteins containing O-linked and/or N-linked sugar chains. The observations that AOL did not bind to free N-linked sugars isolated from fetuin, or to fetuin treated with trypsin or pronase, or to any of the tested neoglycoproteins and glycolipids with neutral- or sialic acid-containing sugars, indicated that the sugar chains need to be bound to an intact peptide backbone to interact with AOL. We have recently shown that the deduced primary structure of AOL has a high similarity to the sequence of a saline-soluble lectin isolated from the mushroom Agaricus bisporus (ABL) (Rosén, S., Kata, M., Persson, Y., Lipniunas, P. H., Wikström, M., van den Hondel, C. A. M. J. J., van den Brink, J. M., Rask, L., Hedén L.-O. and Tunlid, A., see companion paper). It is well known that ABL binds to Gal beta 3GaLNAc alpha-Ser/Thr, and in this paper we demonstrate that ABL binds to sulfatide, phosphatidic acid, phospatidylglycerol, and possibly also to the same N-linked complex sugars as AOL. The above data indicate that AOL and ABL are members of a novel family of fungal lectins sharing similar primary structure and binding properties.

Glycoconjugate receptors for P-fimbriated Escherichia coli in the mouse. An animal model of urinary tract infection

Glycosphingolipids were isolated from kidneys, urethers, and bladders (including urethrae) of C3H/HeN mice. Binding was studied of a clinical isolate and recombinant strains of uropathogenic P-fimbriated Escherichia coli to these glycolipids. A series of receptor-active glycolipids with Gal alpha 4Gal in common, previously shown to be recognized by these bacteria, was identified by use of specific monoclonal antibodies, fast-atom bombardment and electron-impact mass spectrometry, and proton nuclear magnetic resonance spectroscopy: galabiosylceramide (Gal alpha 4Gal beta Cer), globotriaosylceramide (Gal alpha 4Gal beta 4Glc beta Cer), globoside (GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer), the Forssman glycolipid (GalNAc alpha 3GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer), Gal beta 4GlcNAc beta 6(Gal beta 3)GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer, and Gal beta 4(Fuc alpha 3)GlcNAc beta 6(Gal beta 3)GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer. The binding pattern for mouse kidney glycolipids differed from that for kidney glycolipids of man and monkey. In particular, the dominant 8-sugar glycolipid in the mouse was not detected in the primates. A second difference was found in the binding of E. coli to kidney glycoproteins on blots after electrophoresis; the mouse showed distinct receptor-active bands while human and monkey did not. These differences may be of relevance when using the mouse as a model for clinical urinary tract infection of man.

Characterization of the specificity of binding of Moluccella laevis lectin to glycosphingolipids

The specificity of Moluccella laevis lectin was investigated by analysing its binding to glycosphingolipids separated on thin-layer chromatograms or adsorbed on microtitre wells. The binding activity of the lectin was highest for glycosphingolipids with terminal alpha-linked N-acetylgalactosamine, both in linear structures, as the Forssman glycosphingolipid, GalNAc alpha 3GalNAc beta 3Gal alpha 4Glc beta 1Cer, and in branched structures, as glycosphingolipids with the blood group A determinant, GalNAc alpha 3(Fuc alpha 2)Gal beta. In addition, the lectin bound, though considerably more weakly, to linear glycosphingolipids with terminal alpha-linked galactose. When considering the use of the M. laevis lectin for biochemical and medical purposes this cross-reactivity may be of importance.

Cell surface ligands for rotavirus: mouse intestinal glycolipids and synthetic carbohydrate analogs

Rotaviral binding to receptors on epithelial cells in the small intestine is thought to be a key event in the infection process and may be carbohydrate-mediated. Strain SA11 of rotavirus bound in vitro both to glycolipids isolated from mouse small intestine and to authentic glycolipids using thin layer chromatography overlay and microtiter well adsorption assays. Neutral mouse intestinal glycolipids which bound rotavirus were GA1 (Gal beta 1----3GalNAc beta 1---4Glc beta 1----4Glc beta 1----1-ceramide) and pentaosylceramides with terminal N-acetylgalactosamine, while acidic lipids which bound rotavirus included cholesterol 3-sulfate and two compounds termed bands 80 and 81. Digestion with ceramide glycanase suggested that bands 80 and 81 have lactosyl ceramide cores and an unidentified acidic moiety(s). No sialic-acid-containing glycolipids tested were active in viral binding. Band 81, which may have a ganglio core, bound rotavirus with greatest avidity, followed by GA1. Of authentic glycolipids assayed, only GA1 and GA2 (GalNAc beta 1----4Gal beta 1----4Glc beta 1----1-ceramide) displayed rotaviral binding. A phosphatidylethanolamide dipalmitoyl-containing neoglycolipid analog of GA2 bound rotavirus with avidity similar to native GA2. Substitution of beta 1----4-linked GlcNAc or beta 1----3-linked GalNAc for terminal GalNAc of GA2 neoglycolipid supported rotaviral binding, while other substitutions abrogated it. These findings suggest that a carbohydrate epitope similar to that of GA2 is sufficient for in vitro rotaviral binding, although binding may be enhanced by galactose and/or an acidic moiety in a secondary epitope.

The resolution into molecular species on desorption of glycolipids from thin-layer chromatograms, using combined thin-layer chromatography and fast-atom-bombardment mass spectrometry

Using a specially designed, motorised t.l.c.-f.a.b.-m.s. probe with continuous desorption and scanning over a moving t.l.c. plate, it was shown that glycolipids with identical carbohydrate sequences were well resolved into molecular species with differences in long-chain base and fatty acid. There was no serious diffusion of the glycolipids into the matrix. The technique is demonstrated for sulphatides (one and two sugar residues) isolated from human kidney, GM3 ganglioside isolated from human malignant melanoma, and chemically modified gangliotetraosylceramide from mouse intestine. T.l.c.-f.a.b.m.s. is convenient for sequencing and composition analysis of receptor-active glycolipids, the biological activity of which can be monitored in parallel by overlay on the t.l.c. plate with proteins, viruses, bacteria, or animal cells.

A monoclonal IgM antibody to a methylcholanthrene-induced tumour. I. Specificity for alpha-N-acetylgalactosamine but with no cross-reactivity to the human blood group A determinant

A monoclonal IgM antibody, H17, has been obtained from rats immunized with mouse fibrosarcoma cells from an in vitro established methylcholanthrene (MCA)-induced tumour. H17 shows specific and very selective binding to alpha-N-acetylgalactosamine (GalNAc alpha) when tested for reactivity to a panel of glycolipids. It cross-reacts with GalNAc alpha on the Forssman antigen extracted from dog small intestine, but not from the human blood group A determinant, a finding not commonly observed among antibodies with this specificity. Despite its specificity, H17 does not react with TA3-Ha, a mouse mammary adenocarcinoma, known to express the Tn antigen (GalNAc alpha-O-Ser/Thr). The uniqueness of H17 probably relates to the fact that it has been generated against an MCA-induced tumour rather than against the pure saccharide itself. Minimum energy conformation structures of different GalNAc alpha containing saccharide molecules were computer modelled to allow a plausible interpretation of the accessible site of GalNAc alpha for successful interaction with the H17 paratope as compared to other GalNAc alpha binding antibodies.

Erythrocyte gangliosides act as receptors for Neisseria subflava: identification of the Sia-1 adhesin

Neisseria gonorrhoeae was recently shown to bind to a subset of lactose-containing glycolipids (N. Strömberg, C. Deal, G. Nyberg, S. Normark, M. So, and K.-A. Karlsson, Proc. Natl. Acad. Sci. USA 85:4902-4906, 1988). A number of commensal Neisseria strains were also shown to be lactose binders. In addition, Neisseria subflava bound to immobilized gangliosides, such as hematoside and sialosyl paragloboside, carrying the NeuAc alpha 2-3Gal beta 1-4Glc sequence. To a lesser extent, N. gonorrhoeae also bound to this receptor in vitro. In N. subflava GN01, this binding property mediated agglutination of human erythrocytes in a neuraminidase-sensitive fashion. Nitrosoguanidine-induced nonhemagglutinative mutants of N. subflava GN01 had lost the ability to bind hematoside and sialosylparagloboside but remained able to bind lactosylceramide and gangliotetraosylceramide. These mutants fell into three classes with respect to their outer membrane protein profiles in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Class 1 mutants were identical to the parent strain save for the loss of a 27-kilodalton (kDa) protein. Class 2 mutants showed an outer membrane protein profile identical to that of the wild type, whereas mutants belonging to class 3 showed a number of changes, including the apparent absence of the 27-kDa protein. The 27-kDa protein from N. subflava GN01 was purified from the supernatant. A polyclonal antiserum to the purified Sia-1 protein as well as a Sia-1-specific monoclonal antibody inhibited hemagglutination by strain GN01. The purified Sia-1 protein in the presence of diluted anti-Sia-1 antiserum mediated a neuraminidase-sensitive hemagglutination. The purified Sia protein from a class 2 mutant was not able to hemagglutinate when cross-linked with antibodies, suggesting that it is a mutant form of Sia-1 affected in the receptor-binding site. Immunoelectron microscopy with a Sia-1-specific monoclonal antibody revealed that the adhesin was nonfimbrial in nature, with aggregates of the adhesin extended out from the cells in a patchy fashion.

Glycosphingolipid receptors for Pseudomonas aeruginosa

The binding of Pseudomonas aeruginosa to glycosphingolipids and to buccal and bronchial epithelial cells was analyzed. Three independently expressed specificities were found by bacterial binding to glycosphingolipids separated by thin-layer chromatography. All strains bound gangliotria- and gangliotetrasylceramide. All but one of the strains bound sialic acid-containing glycosphingolipids and lactosylceramide. The latter two specificities could be separated in that the lactosylceramide binding was retained and the sialic acid binding was suppressed when bovine serum albumin was used as a blocking agent in the thin-layer chromatography assay. The attachment to buccal epithelial cells, like the binding to sialylated compounds and lactosylceramide, was abolished by Formalin treatment of the bacteria, suggesting the importance of these specificities for cell adherence. In contrast, the binding to gangliotria- and gangliotetraosylceramide was retained by nonattaching Formalin-treated bacteria.

Identification of carbohydrate structures that are possible receptors for Neisseria gonorrhoeae

Different strains and isogenic variants of Neisseria gonorrhoeae were assayed for their ability to bind glycolipids extracted from various sources. Among a large number of reference glycolipids, binding was observed only to lactosylceramide [Gal(beta 1-4)Glc(beta 1-1)Cer], isoglobotriaosylceramide [Gal(alpha 1-3)Gal(beta 1-4)Glc(beta 1-1)Cer], gangliotriaosylceramide [GalNAc(beta 1-4)Gal(beta 1-4)Glc(beta 1-1)Cer], and gangliotetraosylceramide [Gal(beta 1-3)GalNAc(beta 1-4)Gal(beta 1-4)Glc(beta 1-1)Cer]. The latter two glycolipids bound gonococci with the highest affinity. Lactosylceramide and gangliotriaosylceramide were found in glycolipid preparations from ME180 cells, an epithelial cell line derived from a human cervical carcinoma, and thus are possible receptors for gonococci. The gonococcal surface component that bound the above glycolipids is a protein distinct from pilin and protein II.

Glycosphingolipids of cultured human colon carcinoma cells and their drug-resistant sublines

Human colon carcinoma cells were analyzed for lipid phosphorus, cholesterol and glycosphingolipids. Ceramide mono-, di- and trihexosides and sulfatides were isolated by column and thin-layer chromatography and determined quantitatively on the basis of their hexose content. The complex lipid fractions so isolated were only partially resolved with the material available. Gangliosides GM2 and GM3 and globoside were major components of the fraction and were determined on the basis of their hexose, hexosamine and neuraminic acid content. The HCT 116, 116a and 116b cells contained no fucolipids. Cell lines resistant to mitomycin C, teniposide and etoposide were developed and analyzed. Over the 5 year period of the study sulfatides declined to about one-fourth of their original amounts in both parent and drug-adapted cells. HCT 116 cells adapted to mitomycin C and teniposide had 30% less ceramide monohexoside and a 45% greater cholesterol to lipid phosphorus ratio than the parent cells. Reductions in ceramide dihexoside in the drug-adapted cells were greater than those of the ceramide monohexoside. Galabiosyl ceramide was the major ceramide dihexoside in all the cells and accumulated in HCT 116a to levels 4-6-fold greater than that of the other lines as the only dihexoside.

The glycosphingolipid composition of the placenta of a blood group P fetus delivered by a blood group Pk1 woman and analysis of the anti-globoside antibodies found in maternal serum

To further define the molecules that may mediate spontaneous abortion due to maternal-fetal blood group incompatibility within the P blood group system, we have examined the fine specificities of maternal antibodies and the glycolipid antigens from the placenta of a P infant born to a Pk1 mother. Maternal antibodies obtained during therapeutic plasmapheresis were analyzed to determine their reactivities with placental glycolipid extracts on thin-layer plates. Second antibodies specific for IgM, IgG, and IgA revealed immunoglobulins of all of these classes strongly reactive with one major placental glycolipid that comigrates with globoside. GC/MS analysis confirmed that the major P-active pentaglycosylceramide of placenta has the same structure as that previously shown for the P antigen of red blood cells: GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc-Cer. Serum antibodies partially purified by affinity chromatography on globoside-octyl-Sepharose specifically recognize glycolipids that contain terminal GalNAc beta 1-3Gal . . . residues and also recognize the same sequence as an internal determinant in some, but not all, glycolipids with extended globoside core regions. Thus, in the blood group P incompatible fetus, the major P antigen present in placenta has the same carbohydrate structure as the P antigen present in fetal and adult erythrocytes and might be a target for the maternal immune system.

Structural aspects of blood group glycosphingolipids in the gastrointestinal tract

The epithelial cells of the gastrointestinal tract from different species show a very variable expression of blood group active glycosphingolipids. The core saccharide sequences are typical for the species as, for example, type 1 chains (Gal beta 1----3GlcNAc) are found in the small intestine of man, rat, and pig and type 2 chains (Gal beta 1----4GlcNAc) are found in the small intestine of dog, rabbit, and cat. The mouse is atypical with the ganglioseries as the major core saccharide of the small intestine. Blood group A determinants can be found in the small intestine of man, rat, dog, rabbit, and cat, and the blood group B determinant in man and rabbit. Studies on the blood group active glycosphingolipids along the gastrointestinal tract of rat have revealed a complex distribution. The glandular cells of the stomach and epithelial cells of the large intestine express blood group B active glycosphingolipids. The cores of these are the ganglioseries, and the isogloboseries in the stomach and the lacto- (type 1) and neolactoseries (type 2) in the large intestine. The type 2 component is only expressed as a difucosyl and the type 1 as a monofucosyl compound. The epithelial cells of the small intestine are devoid of blood group B glycolipids, but express blood group H structures of which some has a branched core saccharide. One rat strain is lacking blood group A structures in the small intestine, but another is converting the H precursors to blood group A compounds. Both these strains always express blood group A structures in the large intestine. The expression of blood group A glycosphingolipids in the small intestine is inherited as a dominant trait.

An antigen present in rat adenocarcinoma and normal colon non-epithelial stroma is a novel Forssman-like glycolipid based on isoglobotetraosylceramide

A glycolipid with blood group A activity detected in the non-epithelial stroma of normal rat colon but not in epithelial cells (Hansson, G.C., Karlsson, K.-A., and Thurin, J. (1984) Biochim. Biophys. Acta 792, 281-292), was purified to homogeneity from normal rat colon and rat colon adenocarcinoma. Mass spectrometry and 1H-NMR spectroscopy of the intact permethylated derivative and gas chromatography after degradation revealed the structure GalNAc alpha 1----3GAINAc beta 1----3Gal alpha 1----3Gal beta 1----4Glc beta 1----1Cer, with the predominant ceramide containing sphingosine and non-hydroxylated 24:0 fatty acid. This identifies this glycolipid as a novel Forssman-like glycolipid, which is a tumor-associated antigen by definition, since it is not present in the normal rat large intestinal epithelium cells but in rat adenocarcinoma derived from these cells.

Globoseries glycosphingolipids of human meconium

Globoside and an extended globoseries glycosphingolipid with a blood group H determinant were isolated from pooled human meconia and structurally characterized by mass spectrometry, proton NMR spectroscopy, and degradational techniques using GC and GC-MS analyses. Both species contained mainly phytosphingosine and hydroxy fatty acids characteristic for human intestinal epithelial cells. With the same techniques also minor amounts of globoside with sphingosine and nonhydroxy fatty acids and a novel globoseries tetraglycosyl ceramide with a terminal N-acetylglucosamine were isolated and structurally characterized.

Distribution of glycosphingolipids and ceramide of rat small intestinal mucosa

Previous studies have suggested that glycosphingolipids may be involved in a number of physiological functions of the small intestinal mucosa. Regional variations in many of these processes exist along the length of this organ. In the present studies, the glycosphingolipid and ceramide composition of the proximal, middle and distal thirds of the rat small intestine were characterized and compared. Mono- and trihexosylceramide were the major neutral glycolipids and hematoside (GM3), the principal ganglioside of this organ. Monohexosylceramide was the major glycolipid of the proximal segment, whereas trihexosylceramide predominated in the distal segments. The total content of neutral glycolipids, ceramide and gangliosides as well as the content of the individual glycosphingolipids and ceramide were highest in the distal segment, intermediate in the middle and lowest in the proximal segment. Additionally, regional variations were noted in the fatty acid composition of the major glycosphingolipids. These differences in the composition of glycolipids and ceramide along the length of the intestine may be responsible, at least partially, for the regional functional specialization seen in this organ.

Carbohydrate-specific adhesion of bacteria to thin-layer chromatograms: a rationalized approach to the study of host cell glycolipid receptors

Conditions have been adapted for the binding of intact bacteria to glycosphingolipids in a thin-layer chromatogram. Bacteria labeled externally with 125I or metabolically with other isotopes are layered on the plate and after repeated washing the bound bacteria are detected by autoradiography. Using this technique several kinds of bacteria have been shown to adhere to the plate in a carbohydrate-specific way with practically no background binding. Among the advantages of the method is the possible detection of a minor receptor component of a complex mixture extracted from a target cell, facilitating the isolation of the receptor for structural studies. In addition, the multivalent solid-phase presentation of the receptor candidate should also reveal low-affinity binding sites, which may escape detection in traditional inhibition experiments with soluble oligosaccharides.

Hormonal effects on the development changes of mouse small intestinal glycolipids

The composition of intestinal glycosphingolipids during normal and hormone-perturbed development was investigated. The concentrations of glycosphingolipids of mouse small intestine were affected by the injection of thyroxine or cortisone during suckling and weaning periods. GDla was reduced by the hormonal treatment among major gangliosides, GM3, GM1 and GD1a, of mouse small intestine during the suckling period. In contrast, asialo GM1 was precociously produced by the treatment, which scarcely found in control suckling mouse small intestine. The results showed that these hormones were related to developmental alteration of small-intestinal glycolipids.