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J L Magnani

Publications and source records attributed to J L Magnani.

At least 37 records · Page 2Linked to original sources
PubMed1986

Carbohydrate sequences detected by murine monoclonal antibodies.

The carbohydrate sequences of cell surface glycolipids change during differentiation and oncogenic transformation. To detect these structural changes, murine monoclonal antibodies have been produced in many different laboratories. Some of these antibodies are used to distinguish various cell types such as normal and transformed cells, while others are used to analyze developmentally regulated antigens. Recently, the structures of many of these carbohydrate antigens have been determined. The availability of these well-defined monoclonal antibodies will be useful for the study of the regulation and function of glycoconjugates.

Animals↗
PubMed1986

Identification of Schistosoma mansoni glycolipids that share immunogenic carbohydrate epitopes with glycoproteins.

The immunoreactivity of sera of infected hosts against glycolipids derived from Schistosoma mansoni eggs, adult male worms, and cercariae was analyzed by immunostaining of glycolipids resolved by high-performance thin-layer chromatography. Eggs contained the greatest number of immunogenic glycolipids and bound the largest proportion of serum antibodies. Virtually all of the immunogenic egg glycolipids were neutrally charged and contained oligosaccharide chains larger in size than five sugar residues. The glycolipids of each developmental stage were shown by use of five monoclonal antibodies to share schistosome-specific carbohydrate epitopes that were also present on glycoproteins. Several of the carbohydrate epitopes were expressed throughout the life cycle, yet the overall structures of the glycolipids were not conserved. Quantitative analyses by solid-phase binding assays indicated that the carbohydrate epitopes were differentially expressed between the glycolipids and glycoproteins of developmental stages. Sera from infected humans and mice both contained very high levels of anti-carbohydrate antibodies that were reactive with the glycolipids, irrespective of the stage or intensity of disease. Mice harboring unisexual infections of either male or female worms also recognized the egg glycolipids in a pattern indistinguishable from that of patently infected mice. A greater proportion of the humoral response against egg antigens in infected humans was directed against protein determinants, as compared with infected mice.

Animals↗
PubMed1986

Monoclonal antibody 18B8, which detects synapse-associated antigens, binds to ganglioside GT3 (II3 (NeuAc)3LacCer).

By immunofluorescence, mouse monoclonal antibody 18B8 detects developmentally regulated antigens in chick neural retina. In older embryos and in adults these antigens are localized in discrete laminae within the inner and outer synaptic layers. The antibody binds to several gangliosides that undergo both qualitative and quantitative changes during neuronal development (Grunwald, G.B., Fredman, P., Magnani, J.L., Trisler, D., Ginsburg, V., and Nirenberg, M. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 4008-4012). The simplest of these gangliosides was isolated from lipid extracts of 10-day chick embryonic retinas by DEAE-Sepharose and silicic acid column chromatography. About 300 micrograms was obtained from 9.3 g (wet weight) of retina. The isolated ganglioside was identified as GT3 by enzymatic analysis and by a comparison of its properties with the authentic ganglioside. By immunostaining thin-layer chromatograms with antibody 18B8, GT3 was detected in gangliosides from human neural tissue including cerebellum, optic nerve, and spinal cord, but not in gangliosides from human liver, pancreas, small intestine, adrenals, thyroid, or erythrocytes. GT3 was also found in five of seven human melanoma cell lines.

Animals↗
PubMed1986

A monoclonal antibody against meningococcus group B polysaccharides distinguishes embryonic from adult N-CAM.

The neural cell adhesion molecules (N-CAM) occur chiefly in two molecular forms that are selectively expressed at various stages of development. Highly sialylated forms prevalent in embryonic and neonatal brain are gradually replaced by less sialylated forms as development proceeds. Here we describe a monoclonal antibody raised against the capsular polysaccharides of meningococcus group B (Men B) which specifically distinguishes embryonic N-CAM from adult N-CAM. This antibody recognizes alpha 2-8-linked N-acetylneuraminic acid units (NeuAc alpha 2-8). Immunoblot together with immunoprecipitation experiments with cell lines or tissue extracts showed that N-CAM are the major glycoproteins bearing such polysialosyl units. Moreover we could not detect any sialoglycolipid reactive with this antibody in mouse brain or in the neural cell lines examined. By indirect immunofluorescence staining this anti-Men B antibody decorated cells such as AtT20 (D16/16), which expressed the embryonic forms of N-CAM, but not cells that expressed the adult forms. In primary cultures this antibody allowed us to follow the embryonic-to-adult conversion in individual cells. In addition, the existence of cross-reactive polysialosyl structures on Men B and N-CAM in embryonic brain cells for caution in efforts to develop immunotherapy against neonatal meningitis.

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↗
PubMed1986

Analysis of a human tumor-associated glycoprotein (TAG-72) identified by monoclonal antibody B72.3.

Monoclonal antibody B72.3 binds a high-molecular-weight tumor-associated glycoprotein identified as TAG-72. This study reports the partial purification and characterization of TAG-72 from a xenograft of a human carcinoma cell line, LS-174T, which expresses high levels of this antigen. The tumor homogenate was initially fractionated by Sepharose CL-4B chromatography. The high-molecular-weight TAG-72, found in the exclusion volume, was then subjected to two sequential passages through B72.3 antibody affinity columns. At each step of the procedure, TAG-72 content was quantitated using a competition radioimmunoassay, and the degree of purification was expressed as the ratio of antigen in units to total protein. The three-step procedure produced a purification of TAG-72 with minimal contamination by other proteins as shown by polyacrylamide gel electrophoresis, followed by staining with Coomassie Blue or periodic acid/Schiff reagent. The density of affinity-purified TAG-72, as determined by cesium chloride gradient ultracentrifugation, was found to be 1.45 g/ml. This density determination, together with the high molecular weight of TAG-72, its resistance to Chondroitinase digestion, the presence of blood group-related oligosaccharides, and sensitivity to shearing into lower-molecular-weight forms suggest that TAG-72 is a mucin-like molecule.

Antibodies, Monoclonal↗
PubMed1985

Immunostaining free oligosaccharides directly on thin-layer chromatograms.

Oligosaccharides are chromatographed on amino-bonded high-performance thin-layer chromatography silica gel plates and after chromatography the aldehydes on the reducing ends of the oligosaccharides react with the amino groups on the silica gel. Bound oligosaccharides are immunostained directly on the chromatograms by monoclonal antibodies. The binding of antibodies is detected by autoradiography after a second incubation with 125I-labeled goat anti-mouse immunoglobulin. Using this method, 10 pmol of lacto-N-difucopentaose I (Leb hapten) and lacto-N-fucopentaose III (Lex hapten) are detected directly on the thin-layer chromatograms by monoclonal antibodies 10c17 and 534F8, respectively. Previously undescribed larger oligosaccharides containing these epitopes are also detected in human milk. This method may be used to identify and characterize antibody-binding oligosaccharides liberated from glycoconjugates by hydrazinolysis, by trifluoroacetolysis, by ozonolysis, or by treatment with endoglycosidases. This technique may also be used to determine the structural specificity of other carbohydrate-binding proteins such as lectins, toxins, and hormones or of bacteria and viruses that bind to cell surface glycoproteins.

Antibodies, Monoclonal↗
PubMed1985

Monoclonal antibody 18B8 detects gangliosides associated with neuronal differentiation and synapse formation.

Mouse monoclonal antibody 18B8 detects developmentally regulated antigens in chicken retina and brain. The antigens detected by immunofluorescence appear initially on cell bodies in retinas of 6-13 day embryos. In older embryos during synapse formation and in adults, the antigen is localized in discrete laminae within the inner synaptic layer of retina and also is present in the outer synaptic layer and the outer segments of photoreceptor cells. The antigens from retina and brain were purified partially and were shown to be gangliosides of unknown structure that contain at least two sialic acid residues. Gangliosides that are recognized by antibody 18B8 change both qualitatively and quantitatively during neuronal development. These changes were correlated with the spatial and temporal changes in antigen expression detected histochemically.

Animals↗
PubMed1985

Laminin binds specifically to sulfated glycolipids.

Previous studies of the agglutination of erythrocytes by the basement membrane glycoprotein laminin have suggested that laminin binds to gangliosides [Kennedy, D.W., Rohrbach, D.H., Martin, G.R., Momoi, T. & Yamada, K.M. (1983) J. Cell. Physiol. 114, 257-262]. Based on the following evidence, however, we find that laminin binds specifically to sulfatides, not gangliosides. Monogalactosyl sulfatides, purified from sheep erythrocytes with a yield of 4.3 mg/kg of packed cells, bound laminin with high affinity as did authentic bovine brain sulfatide (galactosylceramide-I3-sulfate). The binding activity of these lipids and of total erythrocyte lipids was stable to alkali and neuraminidase treatment but labile to dilute acid under conditions that destroy sulfatides but not gangliosides. Of various glycolipid and phospholipid standards tested, only sulfatides bound laminin with high affinity. Sulfatide binding and agglutinating activities of proteolytic fragments of laminin indicated that the globular end regions of the 200-kDa subunits are required for both activities. Thus, monogalactosylsulfatides, and possibly other more complex sulfated glycolipids, are probably involved in the agglutination of erythrocytes. These results also suggest a physiological function of sulfatides in cell adhesion. The agglutination of erythrocytes by fibronectin is also inhibited by gangliosides [Yamada, K.M., Kennedy, D.W., Grotendorst, G.R. & Momoi, T. (1981) J. Cell. Physiol. 109, 343-351]. Fibronectin, however, did not bind to sulfatides with high affinity but rather bound with low affinity to all anionic lipids tested, including phospholipids, gangliosides, and sulfatides.

Animals↗
PubMed1985

Normal salivary mucin contains the gastrointestinal cancer-associated antigen detected by monoclonal antibody 19-9 in the serum mucin of patients.

Monoclonal antibody 19-9 produced by a hybridoma prepared from spleen cells of a mouse immunized with a human colon carcinoma cell line, detects an antigen in sera from many patients with gastrointestinal and pancreatic cancer. This antibody is directed against a carbohydrate with the sugar sequence (Formula: see text) In many gastrointestinal and pancreatic cancers this sequence occurs in a monosialoganglioside containing a sialylated Lea-active pentasaccharide (sialylated lacto-N-fucopentaose II, IV3-alpha-NeuNAc-III4-alpha-Fuc-LcOse4). In the sera of cancer patients the antigen occurs as a mucin. The antigen is also found in salivary mucin from many normal individuals belonging to the Le(a+b-) or Le(a-b+) blood group but not in salivary mucin from normal individuals belonging to the Le(a-b-) blood group. There is more antigen in mucin from individuals belonging to the Le(a+b-) blood group than in mucin from individuals belonging to the Le(a-b+) blood group.

Antibodies, Monoclonal↗
PubMed1985

Anti-My-28, an antigranulocyte mouse monoclonal antibody, binds to a sugar sequence in lacto-N-neotetraose.

Anti-My-28 is an IgM kappa monoclonal antibody produced by a hybridoma prepared from spleen cells of a mouse immunized with normal human granulocytes. By immunofluorescence it binds to human granulocytes but not to monocytes and lymphocytes. However, after treating cells with neuraminidase, the antibody also binds to lymphocytes and monocytes and to many leukemic cell lines and patient leukemic blast cells. Anti-My-28 binds to several neutral glycolipids and desialylated gangliosides of leukocytes and erythrocytes as detected by radioimmunoassay and immunostaining of thin-layer chromatograms. It recognizes a sugar sequence in lacto-N-neotetraose, Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc. This tetrasaccharide occurs in the glycolipids paragloboside and sialosylparagloboside, and its distal trisaccharide sequence is found in higher glycolipids and in glycoproteins.

Antibodies, Monoclonal↗
PubMed1984

Monoclonal antibodies PMN 6, PMN 29, and PM-81 bind differently to glycolipids containing a sugar sequence occurring in lacto-N-fucopentaose III.

Three monoclonal antibodies, PMN 6, PMN 29, and PM-81, bind myeloid cells. Antibodies PMN 6 and PMN 29 bind specifically to granulocytes but differ in their ability to bind some other cell lines [E. D. Ball, R. F. Graziano, L. Shen, and M. W. Fanger (1982) Proc. Natl. Acad. Sci. USA 79, 5374-5378]. Antibody PM-81, in addition to granulocytes, also binds to eosinophils, monocytes, and most acute myelocytic leukemia cells [E. D. Ball, R. F. Graziano, and M. W. Fanger (1983) J. Immunol. 130, 2937-2941]. Despite these differences, the binding of all three antibodies to cells was inhibited by the oligosaccharide, lacto-N-fucopentaose III [Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc]. Solid-phase radioimmunoassays using purified glycolipids containing sugar sequences found in lacto-N-fucopentaose III demonstrated different binding characteristics for each antibody. PM-81 bound lower concentrations of glycolipids than PMN 29, while PMN 6 required the highest concentration of glycolipids for binding. Autoradiography of thin-layer chromatograms of glycolipid antigens supported these results. The binding of these monoclonal antibodies to cells probably depends on the density of antigens on the cell surface, each antibody requiring a different density. Thus, cells containing antigen below a certain threshold concentration may not bind low-affinity antibodies.

Antibodies, Monoclonal↗
PubMed1984

Monoclonal antibody A2B5 reacts with many gangliosides in neuronal tissue.

Monoclonal antibody A2B5, clone 105, obtained from a mouse immunized with 8-day chicken embryo retinas, reacts with most neuronal cells in chicken retina as revealed by immunofluorescence studies [G.S. Eisenbarth, F.S. Walsh, and M. Nirenberg (1979), Proc. Natl. Acad. Sci. USA 75: 4913-4917]. The antibody binds to many antigens, presumably gangliosides, present in ganglioside fractions from chicken brain, chicken retina, and human brain, as detected by autoradiography of thin-layer chromatograms. Most of the antigens, which are found in the mono-, di-, tri-, and polysialoganglioside fractions, do not correspond in chromatographic mobility to any of the major gangliosides of these tissues, as revealed by orcinol reagent. Apart from the fact that only one neuraminidase-labile sialyl residue is required for binding, the carbohydrate sequence recognized by the antibody is not known. There is a qualitative and quantitative change in the ganglioside antigens in chicken brain and retina during development. The less sialylated antigens appear first, followed by the more sialylated ones. The adult tissues contain little ganglioside antigen.

Aging↗