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PubMed1993

Chromatographic and antigenic properties of Echinococcus granulosus hydatid cyst-derived glycolipids.

The neutral and acidic fraction glycolipids of Echinococcus granulosus metacestode tissue compartments were isolated, defined by their chromatographic and antigenic properties, and assessed as to their efficacy as antigens in the serodiagnosis of human hepatic cystic and alveolar echinococcosis, and other helminthiases. Analyses were accomplished by thin-layer chromatography immunostaining and ELISA. The neutral glycolipid fraction's major carbohydrate epitope was the same as or very similar to that of Taenia crassiceps neutral glyco(sphingo)lipids, as represented by the 'neogala'-series core structure. The blood group-active, carbohydrate epitope P1 was expressed by a number of neutral fraction glycolipid component bands. The reverse-phase, thin-layer chromatography-isolated neutral fraction glycolipid component, designated Ag1, was efficient in the serological discrimination of cystic echinococcosis medium to high-titred sera. Ag1 did not specifically discriminate low-titred sera, i.e., other human helminthiases. The detected sialic acid residues of the acidic fraction glycolipids, on enzymatic cleavage, were identified as N-acylneuraminic acid and terminal. The acidic fraction glycolipids exhibited the paradox of only chemically minor components being antigenic towards cystic and alveolar echinococcosis infection sera. The combined acidic fraction glycolipid components Ra and Rx were capable of serological discrimination between cystic echinococcosis, alveolar echinococcosis and other helminthiases.

Animals↗
PubMed1978

Enzymatic synthesis of blood-group Lewis-specific glycolipids.

A blood-group Lewis precursor glycolipid was isolated from the plasma of a Lewis-negative individual [Le(a--b--)] and treated with fucosyltransferases from human gastric mucosa and GDP-fucose. Subsequently the glycolipid was adsorbed onto Le(a--b--) erythrocytes and the presence of blood-group Lewis antigens was assessed by passive hemagglutination with anti-Lewis sera. It was shown that the precursor glycolipid was enzymatically transformed to blood-group Lewis a (Lea) and Lewis b (Leb) specific glycolipids. Leb-glycolipid was also synthesized by fucosylation of an isolated Lea-glycolipid. Moreover Le(a--b--) erythrocytes were shown to develop Lea and Leb activities when subjected to enzymatic fucosylation, thus showing that Lewis-negative cells carry blood-group Lewis precursor glycolipid on the surface of their membrane. Le(a + b--) erthrocytes, upon enzymatic fucosylation, acquired Leb activity.

Epitopes↗
PubMed2006

The minimal amyloid-forming fragment of the islet amyloid polypeptide is a glycolipid-binding domain.

Several proteins that interact with cell surface glycolipids share a common fold with a solvent-exposed aromatic residue that stacks onto a sugar ring of the glycolipid (CH-pi stacking interaction). Stacking interactions between aromatic residues (pi-pi stacking) also play a pivotal role in the assembly process, including many cases of amyloid fibril formation. We found a structural similarity between a typical glycolipid-binding domain (the V3 loop of HIV-1 gp120) and the minimal amyloid-forming fragment of the human islet amyloid polypeptide, i.e. the octapeptide core module NFGAILSS. In a monolayer assay at the air-water interface, the NFGAILSS peptide specifically interacted with the glycolipid lactosylceramide. The interaction appears to require an aromatic residue, as NLGAILSS was poorly recognized by lactosylceramide, whereas NYGAILSS behaved like NFGAILSS. In addition, we observed that the full-length human islet amyloid polypeptide (1-37) did interact with a monolayer of lactosylceramide, and that the glycolipid film significantly affected the aggregation process of the peptide. As glycolipid-V3 interactions are efficiently inhibited by suramin, a polyaromatic compound, we investigated the effects of suramin on amyloid formation by human islet amyloid polypeptide. We found that suramin inhibited amyloid fibril formation at low concentrations, but dramatically stimulated the process at high concentrations. Taken together, our results indicate that the minimal amyloid-forming fragment of human islet amyloid polypeptide is a glycolipid-binding domain, and provide further experimental support for the role of aromatic pi-pi and CH-pi stacking interactions in the molecular control of the amyloidogenesis process.

Amyloid↗
PubMed1981

Glycolipid receptors for uropathogenic Escherichia coli on human erythrocytes and uroepithelial cells.

A specific family of glycolipids, the globoseries, was shown to act as receptors on human uroepithelial cells and erythrocytes for the majority of uropathogenic Escherichia coli strains attaching to or hemagglutinating those cells. This was demonstrated in three different ways: (i) correlation between the natural presence of glycolipid in the target cell (erythrocytes of different species) and binding of bacteria; (ii) inhibition of attachment to human uroepithelial cells by preincubation of bacteria and glycolipid; and (iii) induction of binding to unreactive cells by coating of these cells with glycolipid. Strains reacting with the receptor agglutinated guinea pig erythrocytes in a mannose-resistant way after, but not before, coating of the cells with globotetraosylceramide. Unrelated glycolipids were not recognized. The reaction was made independent of simultaneous occurrence of mannose-sensitive adhesions on the strains by addition of D-mannose. The receptor-coated cells were used as a tool to screen for prevalence of receptor recognition in a collection of 453 E. coli strains isolated from patients with urinary tract infection or from the stools of healthy children. Of 150 strains attaching to human uroepithelial cells and agglutinating human erythrocytes, 121 bound to globotetraosylceramide (81%). Globoside recognition was especially frequent among pyelonephritis strains (74/81). The glycolipid composition of the urogenital epithelium and kidney tissue and the ability of uropathogenic E. coli to bind to these glycolipids may be a determinant in host-parasite interaction leading to urinary tract infection.

Animals↗
PubMed1967

Endotoxic glycolipid from a heptoseless mutant of Salmonella minnesota.

The endotoxin of a heptoseless mutant of Salmonella minnesota R595 was extracted with phenol-water. Most of this material was found distributed in the insoluble fraction of the extract. The results showed that the R595 endotoxin behaved as a lipid rather than as a lipopolysaccharide (LPS). The preparation, although it does not contain O-specific polysaccharides, does contain 2-keto-3-deoxyoctonic acid (KDO), hexosamine, and several other unidentified compounds. Therefore, the term "glycolipid" is used in this paper instead of lipopolysaccharide. The crude glycolipid fraction, which was soluble in a mixture of chloroform-methanol (8:2), was purified by a procedure including fractionation with organic solvents and by different-column chromatographic methods. Although a chromatographic fraction of the glycolipid showed homogeneity in most systems investigated, the presence of contaminants could not be excluded. Chemical analysis of the glycolipids showed the absence of hexoses and heptoses. Constituents which were found were hexosamine, KDO, fatty acids, and phosphorus, which showed a relatively simple chemical composition. Partial acidic hydrolysis of the glycolipid yielded hexosamine-phosphates, as described in "Lipid A" fractions of smooth LPS preparations. Thin-layer chromatography of the partially hydrolyzed glycolipid showed a pattern similar to "Lipid A" fractions of other strains. The biological activity of the glycolipid was at the same level as that of other gram-negative endotoxins. Pyrogenicity, Shwartzman reactivity, and chick embryo ld(50) values were as high or higher than those of purified Serratia marcescens endotoxin preparations, but mouse ld(50) measurements gave significantly lower results.

Amino Acids↗
PubMed1990

Fucosylation of glycolipids in PC12 cells is dependent on the sequence of nerve growth factor treatment and adenylate cyclase activation.

Synthesis of complex glycosphingolipids was analyzed in cultures of PC12 cells treated with nerve growth factor (NGF) and forskolin, either sequentially or simultaneously. For the sequential treatment, forskolin was added following 15 days of NGF treatment and cultures were continued for 3 additional days. For simultaneous treatment, cells maintained in medium with no additives received both agents and were then incubated for 3 additional days. Sequential NGF/forskolin treatment induced hypertrophy in PC12 cells and produced cells which had more neuron-like characteristics than cells treated with NGF alone. Simultaneous treatment initially accelerated the outgrowth of neurites and then reduced neurite elongation. Sequential treatment of PC12 cells resulted in a greater than 50% increase in the incorporation of fucose into neutral glycolipids and gangliosides compared to treatment with NGF alone. Galactose incorporation was unchanged, indicating that there was no net increase in glycolipid synthesis. The lack of an increase in total glycolipid accumulation was confirmed using monoclonal antibodies reacting with specific fucosylated and nonfucosylated PC12 cell glycolipids. However, TLC immunostaining analysis revealed that sequential NGF/forskolin treatment selectively altered the expression of some neutral glycolipid species. In contrast to the effects of the sequential treatment, simultaneous NGF and forskolin treatment was accompanied by a decrease in the incorporation of fucose and galactose into neutral glycolipids and gangliosides. These findings suggest that the timing of exposure to neuronotrophic factors and agents which activate adenylate cyclase might in part account for developmentally regulated patterns of glycoconjugate expression and provide further evidence that fucosylation of glycolipids may be associated with maturation of sympathetic neurons.

Adenylyl Cyclases↗
PubMed1992

Characteristic distribution of glycolipids in gadoid fish nerve tissues and its bearing on phylogeny.

Glycolipids were isolated from nerve tissues of gadoid fishes including Alaskan pollack and Pacific cod. Their chemical structures were determined by gas-liquid chromatography and gas chromatography-mass spectrometry, and their constituents were analyzed in detail and compared with those of glycolipids from other fish groups. The results revealed that gadoid fish nerve membranes contain peculiar glycolipid molecular species that are distinctly different from those in other teleostean fishes and higher vertebrates. The mole percentage ratio of the four major glycolipids (cerebroside-sulfatide-galactosylglyceride-sulfogalactosylglyce ride) was 48:12:25:15, indicating profound accumulation of glycoglycerolipids. Galactosylglyceride and sulfogalactosylglyceride were primarily of the diacyl type (greater than 90%), the major fatty acids being 16:0 and 18:1. An abundance of glucocerebroside (25 to 55% of cerebroside) and its fatty acid ester (37 to 47% of ester cerebroside) was noted. Cerebroside and sulfatide were characterized by the absence of hydroxy and odd numbered fatty acids, and 24:1 acid was a predominant component of both glucocerebroside and galactocerebroside. Subcellular fractionation revealed that myelin membranes comprised such unusual glycolipid constituents as those seen in whole nerve tissues. A vertebrate whose nerve membranes consist of such peculiar glycolipid molecules has not previously been reported. The characteristics of the glycolipid composition in gadoid fishes are discussed in relation to myelin functions, physicochemical properties of nerve membranes, and the phylogenic significance of this fish group.

Animals↗
PubMed1986

Glycolipid antigen expression in human lung cancer.

Several mouse monoclonal antibodies which recognize carbohydrate sequences distinguish between different types of human lung cancer immunohistologically. These antibodies bind to glycolipid antigens produced by the cancer cells. When these glycolipids are separated by thin-layer chromatography, immunostaining of the chromatograms yields complex patterns of antigen-positive bands. To determine whether glycolipid patterns are useful in the classification of lung cancer, 16 human lung cancer cell lines comprising the major histological types of primary lung cancer were studied. Neutral glycolipids and gangliosides were isolated and separated by thin-layer chromatography. Six anti-carbohydrate antibodies which recognize structurally related antigens were used for immunostaining. Neuraminidase treatment of the chromatograms was used to detect "cryptic" sialylated antigens. All the cell lines were unique with regard to the type, amount, and chromatography pattern of the glycolipid antigens produced. Small cell lung cancer cell lines synthesized the greatest variety of antigens, whereas cell lines with large cell cytology synthesized the least. Interestingly, there was an inverse relationship between expression of some glycolipid antigens and DNA amplification of the c-myc oncogene. This suggests that enhanced c-myc expression may influence the types of glycolipids expressed at the surface of lung tumor cells.

ABO Blood-Group System↗
PubMed1987

The GDP-fucose:N-acetylglucosaminide 3-alpha-L-fucosyltransferases of LEC11 and LEC12 Chinese hamster ovary mutants exhibit novel specificities for glycolipid substrates.

Previous studies have shown that the GDP-fucose:N-acetylglucosaminide 3-alpha-L-fucosyltransferase (alpha (1,3) fucosyltransferase (Fuc-T)) activities expressed by the Chinese hamster ovary cell mutants LEC11 (Fuc-TI) and LEC12 (Fuc-TII) are different enzymes and indicated that Fuc-TI might act on sialylated lactosamine sequences (Campbell, C., and Stanley, P. (1984) J. Biol. Chem. 259, 11208-11214). In this paper we show that CSLEX-1, a monoclonal antibody specific for NeuNac alpha (2,3)Gal beta (1,4)(Fuc alpha (1,3))GlcNAc beta 1 sequences, bound to LEC11 cells but not to LEC12 cells. Direct evidence that Fuc-TI could act on sialylated substrates was sought with a series of glycolipid acceptors. Optimal assay conditions in crude cell extracts were determined with nLc4, a glycolipid which accepted fucose with both Fuc-TI and Fuc-TII to generate the Lex antigenic determinant. The two enzymes differed in their detergent sensitivities, pH optima, Mn2+ requirements, and apparent Km values for nLc4. When sialylated glycolipids were examined as substrates, Fuc-TI added fucose to IV3NeuNAcnLc4 but not to IV6NeuNAcnLc4, whereas Fuc-TII was unable to utilize either glycolipid as a substrate. Further studies showed that Fuc-TI and Fuc-TII possess novel specificities for glycolipids containing two lactosamine sequences as potential fucose acceptors. Fuc-TI exhibited good activities with VI3NeuNAcnLc6 and VI6NeuNAcnLc6 whereas Fuc-TII had very low activity with both substrates. Glycosidase digestions of the labeled products showed that Fuc-TI added fucose primarily to the internal N-acetylglucosamine of both glycolipids. The same preference for the internal N-acetylglucosamine was shown by Fuc-TI when nLc6 was the acceptor. In contrast, Fuc-TII preferred to transfer fucose to the external acceptor site of nLc6, consistent with the low activities of Fuc-TII with sialylated nLc6 derivatives. Thus the two enzymes preferentially add fucose to different N-acetylglucosamines in the same substrate, nLc6. This indicates that the biosynthetic pathway for fucosylation of polylactosamine sequences in glycolipids and glycoproteins will vary depending upon the particular alpha (1,3)fucosyltransferase present.

Animals↗
PubMed1988

Glycolipid stage-specific embryonic antigens (SSEA-1) in kidneys of male and female C57BL/6J and beige adult mice.

SSEA-1 glycolipids from the kidneys of normal male and female as well as beige mutant mice were isolated and their structures were examined by component analysis, mass spectrometry, immunoblotting, and permethylation studies. These antigens were shown to be extended globoside derivatives as reported by Sekine et al. (1987. J. Biochem. 101:553-562). Quantitative high performance liquid chromatography analyses revealed that the concentration of SSEA-1 glycolipids were four-to fivefold greater in male than female mice. Essentially no SSEA-1 glycolipids were excreted in the urine of normal male mice and thus are not components of the multilamellar lysosomes normally excreted. Testosterone is known to induce the hypertrophy of proximal tubule cells that involves the formation of multilamellar lysosomes and results in the accumulation and excretion of these bodies and associated lysosomal enzymes and specific glycolipids. The present results indicate that in male mice there is also an increase in subcellular structures that contain SSEA-1 glycolipids. The amount of SSEA-1 glycolipids in male beige mice were greater than in normal mice on a per kidney basis. Thus, the increase is in proportion to the kidney hypertrophy seen in beige mouse kidneys. Beige mutant mice appear to have a primary defect in the excretion of multilamellar lysosomes which produces a secondary hypertrophy with an accompanying increase in SSEA-1 glycolipids.

Animals↗
PubMed1978

Possible role of macrophage glycolipids as receptors for migration inhibitory factor (MIF).

Guinea pig peritoneal exudate cells incubated with water soluble glycolipids obtained from macrophages show an enhanced response to migration inhibitory factor. Incorporation of these glycolipids into liposomes greatly facilitates their interaction with indicator cells. Enhancement of peritoneal exudate cell responsiveness to migration inhibitory factor was specific for glycolipids from guinea pig macrophages. Glycolipids extracted from guinea pig brain and polymorphonuclear leukocytes as well as several bovine and porcine glycolipids had no effect. Specificity of enhancement was not due merely to a preferential association of macrophage glycolipids with indicator cells. The possible role of macrophage glycolipids as receptors for MIF is discussed.

Animals↗
PubMed1971

Neutral glycolipids in leukemic and nonleukemic leukocytes.

Neutral lipids, free and total cholesterol, glycolipids, and phospholipids were determined in 20 preparations of leukocytes distributed in four groups. Group I consisted of leukocytes from nonleukemic patients; group II, from patients with chronic myelogenous leukemia; group III, from patients with chronic lymphocytic leukemia; and group IV, from patients with acute leukemia. Two neutral glycolipids were found in nonleukemic mixed leukocyte populations. They were identified as glucosylceramide and lactosylceramide. The same glycolipids were also present in leukemic cells, but striking differences in glycolipid composition were found in various types of leukocytes. Glycolipids accounted for 8.9-12.6% of the total lipids in leukocytes from group I, 11.4-20.4% in group II, 1.2-1.6% in group III, and 0.5-4.9% in group IV. Glucosylceramide was the only glycolipid found in seven out of eight analyzed samples of lymphocytes, both normal and leukemic. Lactosylceramide was the major glycolipid in preparations consisting mainly of polymorphonuclear, myeloid, and blastic cells. Only lactosylceramide was found in platelets, where its concentration was about 100 times lower than in mixed leukocyte populations.

Blood Cell Count↗
PubMed1983

Tumor-associated glycolipid antigens defined by monoclonal antibodies.

Four types of glycolipid changes have been observed associated with oncogenic transformation: 1) incomplete synthesis, 2) neosynthesis, 3) a shifting a glycolipid synthesis from one series to another, and 4) the change of glycolipid organization in membranes. Both incomplete synthesis and neosynthesis result in the accumulation of glycolipid markers which are distinctive to tumor cells and can be defined by monoclonal antibodies. Glycolipids with X determinant, particularly those with di- or poly-fucosylated structure in a large variety of human adenocarcinoma, GD3 ganglioside in human melanoma, and ceramide trihexoside in Burkitt lymphoma are among these glycolipid markers which have been well characterized. These glycolipid markers can be useful targets for diagnosis and therapy of human cancer.

Animals↗
PubMed1984

Characterization of glycolipids synthesized in an identified neuron of Aplysia californica.

Because radioactive precursors can be injected directly into the cell body or axon of R2, a giant, identified neuron of the Aplysia abdominal ganglion, it was possible to show that glycolipid is synthesized in the cell body, inserted into membranes along with glycoprotein, and then exported into the axon within organelles that are moved by fast axonal transport. After intrasomatic injection of N-[3H]-acetyl-D-galactosamine, five major 3H-glycolipids were identified using thin layer polysilicic acid glass fiber chromatography. At least two of the lipids are negatively charged. Analysis of 32P-labeled lipid from the abdominal ganglion revealed the presence of 2-aminoethylphosphonate, indicating that these polar substances are sphingophosphonoglycolipids. The major 3H-glycolipids synthesized in R2 are similar to a family of phospholipids isolated from the skin of A. kurodai, previously characterized by Araki et al. (Araki, S., Y. Komai, and M. Satake (1980) Biochem J. 87: 503-510). Since sialic acid is absent in Aplysia as in other invertebrates, these polar glycolipids may function like gangliosides in vertebrates. The polar 3H-glycolipids are synthesized and incorporated into intracytoplasmic membranes solely in the cell body. Direct injection of the labeled sugar into the axon revealed no local synthesis or exchange of glycolipid. Moreover, there was no indication for transfer from glial cells into axoplasm. Although the incorporation of N-[3H]-acetyl-D-galactosamine into glycolipid is not affected by anisomycin, an effective inhibitor of protein synthesis, the export into the axon of membranes containing the newly synthesized lipid is completely blocked by the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylgalactosamine↗
PubMed1983

Changes in nervous system glycolipids during metamorphosis of Xenopus laevis.

Qualitative and quantitative changes occurring in the myelin marker glycolipids, cerebrosides, sulfatides, and monogalactosyl diglyceride, in the nervous system (brain, spinal cord, and tail) of Xenopus laevis during its metamorphic stages were analyzed by normal and reverse-phase high performance liquid chromatography. The concentration of these glycolipids increased rapidly in brain until the tadpole reached the middle of metamorphosis, fluctuated slightly, decreased until metamorphosis was completed, and increased once more as the frog matured. Similar changes were observed in the spinal cord, but the decrease of glycolipids occurred at a later stage of metamorphosis. The glycolipid level in tail nerve reached a peak at the beginning of metamorphosis and then rapidly decreased. The ratios of hydroxycerebroside and hydroxysulfatide to respective nonhydroxylipids in brain, spinal cord, and tail remained constant throughout the metamorphic change but differed in each tissue. The tail contained the highest ratio. The glycolipids in sciatic nerve generated during the metamorphosis had an even higher hydroxyl lipid/nonhydroxy lipid ratio. The cerebrosides contained extremely high concentrations of monounsaturated fatty acids with very long carbon chains (C22-C25) and this homolog composition remained almost unchanged throughout metamorphosis. These results indicate that active degradation of these glycolipids, and probably of myelin, occurs but the glycolipid composition of myelin appears to remain the same throughout the metamorphic process. The significance of these findings is discussed from a morphological standpoint.

Animals↗
PubMed1981

Cellular and thylakoid-membrane glycolipids of Chlamydomonas reinhardtii 137+.

The glycolipids of the green alga Chlamydomonas reinhardtii 137+ have been quantitated in the phototrophically-cultured cell and in its thylakoid membrane. Three lipids, the galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), and the sulfated glycolipid sulfoquinovosyldiacylglycerol (SL), constitute the total glycolipid complement and some 70-80% of the total polar lipid at both levels. About 70% of the alga's sulfolipid, but only about half of its galactolipid, is localized in the thylakoid. The three cellular and thylakoid glycolipids all contain prominent hexadecanoic and octadecanoic fatty acids. Quantitatively, each lipid has a distinctive acyl profile, making SL the most highly saturated and MGDG the least saturated glycolipid. Differences between the fatty acid profiles of each corresponding cellular and thylakoid glycolipid indicate that discrimination of the glycolipid species assembled into photosynthetic membrane takes place during thylakoid membrane biogenesis.

Cell Membrane↗
PubMed1980

Possible role of glycolipid in development, cell growth regulation, and transformation.

1) A progressive branching of lacto-N-glycosyl carbohydrate chain linked to glycolipid and to band 3 protein has been observed during the development of fetal to adult human erythrocytes. A linear repeating structure of Gal beta 1 leads to 4GlcNac beta 1 leads to 3Gal was converted to a branched structure Gal beta 1 leads to 4GlcNac beta 1 leads to 3(Gal beta 1 leads to 4GlcNAc beta 1 leads to 6)Gal beta 1 leads to 4GlcNac. Some of the linear structure represents i-antigen, and some of the branched structure represents I-antigen. Such changes of carbohydrate structure in membrane coincide with the switch from fetal hemoglobin (HbF) to adult hemoglobin (HbA) synthesis, and may define the stage of differentiation in cellular function. 2) Cell-to-cell contact induces enhancement of a particular type of glycolipid synthesis (contact response). A mimic "contact response" of GM3 synthesis was observed when sparse growing culture was treated with the affinity purified anti-GM3 ganglioside Fab. The synthesis of GM3 ganglioside was enhanced severalfold, but not the synthesis of GM2, GM1, and GD1a. Growth of antibody-treated 3T3 cells was inhibited and showed reduced cell saturation density. Some cellular proteins which had specific affinity with glycolipids were released by ethidium bromide. Addition of such cellular proteins in 3T3 cell culture induced a reduction of cell saturation density. These results suggest that a particular glycolipid (contact-sensitive glycolipid) could be a receptor for a particular cell surface protein that may induce "contact inhibition." Some carbohydrate chains such as Gal beta 1 leads to #GalNAc beta 1 leads to 4Gal leads to R, which is common both to glycolipid and glycoprotein may be receptor growth stimulation from serum in vitro. Therefore, growth inhibition induced by anti-glycolipid Fab or by cell surface protein could be due to a block of the recepting growth stimulation through serum factors.

Animals↗
PubMed2005

Establishment of cells exhibiting mutated glycolipid synthesis from mouse thymus by immortalization with SV-40 virus.

Immortalization with simian virus-40 and cloning of immortalized cells from mouse thymus were performed to establish cell lines for characterization of the mode of glycolipid expression in the thymic cells. Among the 25 cell lines obtained, three lines with different morphologies were established, that is, epithelial (IMTH-E), fibroblastic (IMTH-F), and asterisk-like (IMTH-I) cells, and their glycolipids, together with those in the thymus, were determined systematically. The major glycolipids in mouse thymus were the globo- and ganglio-series, both of which, were co-expressed in the three cell lines established. However, the mode of modification of the globo- and ganglio-series was distinct for each cell line. As to the globo-series, the structures with the longest carbohydrate chain for IMTH-E, -F, and -I cells were Gb3Cer, Gb4Cer, and Forssman antigen, respectively, having stepwise shorter carbohydrates at the nonreducing termini. Although the acidic glycolipids in IMTH-E cells comprised GM3 and GM2, and their sulfated isomers, IMTH-F and -I cells expressed GMlb and GDlc for the alpha-pathway, and up to GDI a for the a-pathway of ganglio-series glycolipids. GMlb-GalNAc present in the thymus was not detected in IMTH-F and -I cells, probably due to the lower synthetic activity for the metabolic intermediate Gg4Cer. The results indicate that the immortalization technique is useful for obtaining individual cells having unique glycolipid profiles for analysis of the functional significance and metabolism of glycolipids in the thymus.

Animals↗