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.

A test for intron function in the yeast actin gene

Many eukaryotic genes contain intervening sequences (IVS), but the rationale for their existence remains a mystery. Previous studies done in our laboratory demonstrated that the intron in a yeast tRNATyr gene, SUP6, does have a function. We used the same approach to determine the role of introns in nuclear genes encoding messenger RNAs. A single actin gene with one intron exists in Saccharomyces cerevisiae. The level of actin in yeast appears to be crucial to viability: either too much or too little actin inhibits growth. Therefore, small effects on synthesis of actin protein resulting from the removal of the actin gene intron would be expected to cause measurable changes in cell growth. In the present study, an intron-deleted actin gene was constructed in vitro and was used to replace the single resident actin gene in a haploid strain. Analysis of the cells carrying the intron-deleted actin gene shows that the intervening sequence is not essential for actin gene expression.

Duration of ECT-induced tachycardia as a measure of seizure length

The duration of ECT-induced tachycardia in 203 seizures of 28 patients was measured. Tachycardia duration was easily determined; it correlated highly with both motor (cuffed arm) and EEG seizure estimates.

Lewis blood group antigens defined by monoclonal anti-colon carcinoma antibodies

Monoclonal antibodies directed against human cancer cells were prepared by the murine hybridoma technique. These antibodies detect Lewis blood group antigens as determined by indirect solid-phase radioimmunoassay, hapten inhibition studies, and chromatogram binding assay. One monoclonal antibody is specific for the Lea terminal carbohydrate of Gal beta 1----3Glc NAc(4----1 alpha Fuc) beta 1----3LacCer. Five monoclonal antibodies react with the Leb terminal carbohydrate sequence of Fuc alpha 1----2Gal beta 1----3GlcNAc(4----1 alpha Fuc) beta 1----3LacCer, and four of these antibodies are highly specific for this glycolipid and do not react with other similar di- and monofucosylated glycolipids. One of the anti-Leb antibodies cross-reacts with blood group H glycolipid and has binding properties similar to those of the previously described antibody NS-10-17 [M. Brockhaus, J. L. Magnani, M. Blaszczyk, Z. Steplewski, H. Koprowski, K.-A. Karlsson, G. Larson, and V. Ginsburg (1981) J. Biol. Chem. 256, 13223-13225]. Two antibodies react with both the Lea and Leb antigens, though both bind preferentially to Leb.

A novel approach to the study of glycolipid receptors for viruses. Binding of Sendai virus to thin-layer chromatograms

A method for the binding of virus to a silica gel thin-layer chromatogram is presented. After development the chromatogram is overlayed with the 125I-labelled virus and the bound virus is autoradiographed. Alternatively, the unlabelled virus may be detected after exposure to monoclonal antibody and labelled anti-antibody. The Sendai virus strain used did not bind to brain gangliosides earlier proposed to be receptors, but bound to human erythrocyte gangliosides. This finding may be explained by the existence of Sendai virus variants with different receptor specificities.

Identification of Leb antigens in meconium of a phenotypically a Le(a+ b-) non-secretor individual

Blood group active fucolipids of human meconium have been shown to correlate to the ABH and Lewis blood groups and to the secretor status of the corresponding children. Using a monoclonal anti-Leb antibody and an antibody to chromatogram binding assay the presence of Leb antigens in meconium of a phenotypically A Le(a+ b-) non-secretor individual is here demonstrated. Phenotype was determined on cord blood and saliva obtained 2 years after birth.

Chemical characterization of a blood group H type pentaglycosylceramide of human small intestine

A blood group H type pentaglycosylceramide was isolated in relatively large amounts from human adult small intestine (52 mg from one individual) and human meconium (fetal origin). The structure was made likely by mass spectrometry and NMR spectroscopy of non-degraded permethylated and permethylated-LiAlH4-reduced glycolipid and by degradation to be Fuc alpha 1 leads to 2Gal beta 1 leads to 3GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer. The ceramide was composed mainly of phytosphingosine and 2-hydroxy 16-24 carbon fatty acids. This novel type 1 chain species (Gal beta 1 leads to 3GlcNAc) was not accompanied by the type 2 chain isomer (Gal beta 1 leads to 4GlcNAc) which in contrast is the sole species in human erythrocyte and dog small intestine.

Characterization of monoclonal antibodies specific for the Lewis a human blood group determinant

Four hybridoma cell lines were derived from the spleen cells of mice immunized with the neutral glycolipids of human meconium. The antibodies secreted by these lines were specific for the Lewis a antigen of the human Lewis blood group system as determined by solid phase immunoassay using synthetic carbohydrate antigens and by plate binding assay and thin layer chromatography-autoradiography using natural glycolipid antigens. Coating protein A-bearing Staphylococcus aureus with one of the antibodies yielded a stable reagent that produced rapid agglutination of Lewis a positive human erythrocytes. The fine structural specificity of these antibodies was assessed by competition radioimmunoassay using synthetic structural analogs of Lewis a conjugated to bovine serum albumin. One antibody was specific for the Lewis a trisaccharide (Gal beta 1 leads to 3(Fuc alpha 1 leads to 4) beta GlcNAc), while a second recognized the entire Lea (1 leads to 3) beta Gal tetrasaccharide. The third and fourth were directed at topography largely provided by only the alpha Fuc and beta GlcNAc units. These monoclonal antibodies not only represent potentially useful reagents for detecting the Lewis a antigen but also provide a system for studying precise relationships between anticarbohydrate antibody structure and binding specificity.

Mouse monoclonal antibodies against human cancer cell lines with specificities for blood group and related antigens. Characterization by antibody binding to glycosphingolipids in a chromatogram binding assay

Solid phase radioimmunoassay and a chromatogram binding assay were used to characterize the binding specificities of five monoclonal antibodies generated from mice immunized with human tumor cell lines when tested against various glycolipids. Four antibodies derived from mice immunized with pancreatic carcinoma cells detected specifically the human blood group B determinant, Gal alpha 1 leads to 3Gal (2 comes from 1 alpha Fuc). These antibodies preferred type 2 (Gal beta 1 leads to 4GlcNAc) glycolipids. No reactivity was detected with a rat B determinant based on GalNAc. An antibody derived following immunization with a rectal carcinoma cell line was shown to have binding properties identical with those of an antibody that reacts specifically with the stage-specific embryonic mouse antigen (SSEA-1), bearing the determinant Gal beta 1 leads to 4GlcNAc (3 comes from 1 alpha Fuc) (Gooi, H. C., Feizi, T., Kapadia, A., Knowles, B. B., Solter, D., and Evans, M. J. (1981) Nature 292, 156-158). Thin layer chromatography was used to detect the binding of a monoclonal anti-tumor antibody recently shown to react with a sialylated Lea glycolipid (Magnani, J. L., Nilsson, B., Brockhaus, M., Zopf, D., Steplewski, Z., Koprowski, H., and Ginsburg, V. (1982) Fed. Proc 41, 898) and an anti-Leb antibody (Brockhaus, M., Magnani, J. L., Blaszczyk, M., Steplewski, Z., Koprowski, H., Karlsson, K.-A., Larson, G., and Ginsburg, V. (1981) J. Biol. Chem. 256, 13223-13225) to mixtures of glycolipids from normal and tumor tissues.

Mass spectrometry of a human tumor glycolipid antigen being defined by mouse monoclonal antibody NS-19-9

With an antibody-to-chromatogram binding assay to follow the preparation a glycolipid was isolated from human pancreatic carcinoma using a mouse monoclonal antibody of apparent specificity for gastrointestinal tumors. Direct probe mass spectrometry of three derivatives established the sugar sequence as NeuAc-hexose-(fucose)N-acetylhexosamine-hexose-hexose and the ceramide to be composed mainly of phytosphingosine and 16-24 carbon 2-hydroxy fatty acids. NMR spectroscopy of two of the derivatives made likely the presence of the sequence Gal beta 1 leads to 3GlcNAc(4 comes from 1 alpha Fuc)beta 1 leads to, which is the blood group Lewis a determinant. This is in agreement with recent results from degradation studies.

Chemical fingerprinting of non-acid glycosphingolipids in meconium of a human individual of blood group B Le(a-b+) and secretor

In an attempt to elucidate blood group polymorphism systematically in human intestinal tissue, glycosphingolipids of meconia of single individuals have been studied. In this report we describe the major glycosphingolipids in meconium of a newborn typed as a B Le(a-b+) secretor. The glycolipids were analysed as four subfractions obtained after deacetylation of fractions from silicic acid column chromatography of the peracetylated total non-acid glycolipid extract. Chemical characterization (mass spectrometry and 1H-NMR spectroscopy of permethylated and LiA1H4-reduced permethylated derivatives) and immunological characterization (haemagglutination-inhibition of native glycolipids in the liposome form) revealed a very complex pattern of fucosyl-containing glycolipids, probably the result of several blood group glycosyltransferase activities. The major fucolipids, all based on lactotetraosylceramide, had a characteristic ceramide of mainly phytosphingosine and 2-hydroxy fatty acids with 16 and 20-24 carbon atoms.

Chemical fingerprinting of glycosphingolipids in meconium of a human blood group O Le(a-b+) secretor

Studying blood group polymorphism, as expressed in intestinal tissue of single individuals, total non-acid glycosphingolipids of meconium of individual human newborns have been prepared. Silicic acid column chromatography of the acetylated derivatives were used for a stepwise separation into four groups of glycolipids from each individual meconium. By the combined use of mass spectrometry and NMR spectroscopy of permethylated and LiA1H4-reduced, permethylated derivatives and by immunology of the native fractions all the major glycolipids were identified, although in mixtures. The interest was focused on fucolipids known to be strictly regulated by the ABO, H, Le and Se genes. The fucosylated glycolipids of an O Le (a-b+) secretor child were dominated by blood group H-active and Lewis-active mon- and difucosyl compounds with 5-6 sugar residues and having a core lactotetraosyl structure. The lipophilic part was dominated by 2-hydroxy fatty acids with 16 and 20-24 carbon atoms bounds to either sphingosine of phytosphingosine.

Monoclonal antibodies directed against the human Leb blood group antigen

Four monoclonal antibodies produced by hybridomas obtained from a mouse immunized with a human adenocarcinoma cell line SW1116 (Koprowski, H., Steplewski, Z., Mitchell, K., Herlyn, M., Herlyn, D., and Fuhrer, P. (1979) Somatic Cell Genet. 5, 957-972) are directed against the Leb antigen of the human Lewis blood group system. Their specificities were established by binding studies using purified Leb-active ceramide hexasaccharide and by hapten inhibition studies involving oligosaccharides obtained from human milk.

Molecular characterization of cell surface antigens of fetal tissue. Detailed analysis of glycosphingolipids of meconium of a human O Le(a--b+) secretor

The glycosphingolipids of meconium of a human O Le(a--b+) secretor have been subjected to structural and immunological characterization. Mass spectrometry, proton NMR spectroscopy, and gas-liquid chromatography were used for chemical analyses, and haemagglutination-inhibition for immunological characterization. The great amounts of glycolipids present also facilitated the analyses of minor species constituting only 1% or less of the total weight of the non-acid glycolipids. Glucosylceramide and galactosylceramide were the dominating glycolipids comprising 15 and 30%, respectively, of the total weight. The diglycosylceramides found were lactosylceramide and digalactosylceramide. The globo series was represented by globotriaosylceramide, small amounts of globotetraosylceramide, part of which had ceramide of phytosphingosine and hydroxy fatty acid, and a minor species of monofucosyl hexaglycosylceramide with an inner globotetraose oligosaccharide. No Forssman or Forssman-like antigen was found. The lacto series, quantitatively approximately 30% of the total weight, was mainly represented by lactotetraosylceramide and H-active, Lea-active, and Leb-active glycolipids with 5-6 sugars based on lactotetraosylceramide. Minor species having 0-3 fucoses in their carbohydrate chains and carrying up to 11 sugar residues were also identified. Great amounts of free ceramides were also found to be typical for this tissue.

Blood group type glycosphingolipids of human cord blood erythrocytes

The non-acid glycosphingolipids of cord blood erythrocytes, pooled from blood groups O and A respectively, were characterized by mass spectrometry in combination with immunologic and thin-layer chromatographic analyses. The glycosphingolipid pattern was compared to that of adult erythrocytes. Just as for adult blood, the major glycosphingolipid species were lactosylceramide and globotetraosylceramide (globoside). The triglycosylceramide fraction was quantitatively smaller in cord red blood cells and was also enriched in a triglycosylceramide with a terminal hexosamine, as conclusively shown by mass spectrometry. The amount of blood group A and H active glycosphingolipids appeared to be less in cord blood cells compared to adult cells was glycolipids with longer, probably branched chain structures were not detected. In contrast, increased amounts of penta- and hexaglycosylceramides lacking fucose and possibly being biosynthetic precursor substances to the ordinary blood group A and H glycosphingolipids were found typical for cord blood cells.

Structural characterization of lactotetraosylceramide, a novel glycosphingolipid isolated from human meconium

In the course of work on a systematic structural mapping of nonacid glycosphingolipids of human meconia, special attention was given to a major component preliminarily identified as an isomer of neolactotetraosylceramide (paragloboside). This component was isolated in its pure form from meconium of a blood group O individual and subjected to detailed structural analyses, using mass spectrometry and proton NMR spectroscopy on intact permethylated and permethylated-reduced (LiAlH4) derivatives, and gas liquid chromatography on degradational products of native, permethylated, and permethylated-reduced derivatives. The isolated compound was conclusively shown to have the structure Galp beta 1 yields 3GlcNAcp beta 1 yields 3Galp beta 1 yields 4Glcp beta 1 yields 1Cer, and is thus identified as lactotetraosylceramide. The major fatty acids were 2-hydroxy fatty acids with 16 and 20 to 24 carbon atoms, and the bases were sphingosine and phytosphingosine. This glycolipid, although not isolated and structurally characterized before, has long been thought of as a precursor substance of the Lewis active glycolipids and of ABH-active glycolipids with a type 1 saccharide chain.