Characterization of two gangliosides from human leukemic polymorphonuclear leukocytes

Glycosphingolipids of normal and leukemic human leukocytes

We have reviewed the studies on neutral glycosphingolipids and gangliosides of normal and leukemia human leukocytes. In this review, we examine (a) the glycosphingolipid composition of various leukocyte populations, (b) the differences in glycosphingolipids found among subsets of these cells, (c) the possible use of these compounds as markers of differentiation, and (d) the changes in glycosphingolipid composition that occur with leukemogenesis.

Isolation and characterization of glycosphingolipids from human leukocytes. A unique glycosphingolipid pattern in a case of acute myelomonoblastic leukemia

Neutral glycosphingolipids and gangliosides were isolated from the malignant cells of a patient with acute myelomonoblastic leukemia. Structural analyses were performed by gas-liquid chromatography and by high-performance liquid chromatography combined with enzymatic hydrolysis of glycosphingolipids using glycosidases. We found that, in contrast to normal leukocytes and chronic leukemia cells which have only a single tetraosylceramide species, these acute myelomonoblastic leukemia cells have approximately equal amounts of both globo- and neolactotetraosylceramide. This is the first population of human leukocytes in which we found two families of neutral glycosphingolipids to be present. The ganglioside fraction was composed of appreciable quantities of both NeuAc alpha 2 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer (GM3, hematoside) and NeuAc alpha 2 leads to 3Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer (sialoparagloboside). These cells did not have the 'leukocyte-specific' N-acetylneuraminosyllactotriaosylceramide found in normal human lymphocytes and neutrophils. These results are discussed in relation to normal leukocyte differentiation and acute leukemia. The present study also illustrates the usefulness of combining enzymatic degradation with high-performance liquid chromatography for glycosphingolipid structural determination.

Ganglioside composition of rabbit thymus

Gangliosides of rabbit thymus were extracted and analyzed by the ganglioside-mapping procedure developed previously. 1 g of thymus contained 205.1 nmol of lipid-bound sialic acid and the relative amounts of monosialoganglioside and di- and trisialoganglioside fractions were 76.6 and 23.3%, respectively, as based on lipid-bound sialic acid. No ganglioside containing N-acetylgalactosamine was detected in rabbit thymus. The predominant component was N-glycoloylneuraminosyl lacto-N-norhexaosyl ceramide, NeuGc(alpha, 2-3)Gal(beta, 1-4)GlcNAc(beta, 1-3)Gal(beta, 1-4)GlcNAc(beta, 1-3)Gal(beta, 1-4)Glc(beta, 1-1) ceramide, which constituted 38.4% of the total gangliosides. The other major gangliosides were N-glycoloylneuraminosyl lacto-N-neotetraosyl ceramide (31.3%), GD3 containing N-glycoloylneuraminic acid (11.8%), GM3 containing N-glycoloylneuraminic acid (10.6%) and GM3 containing N-acetylneuraminic acid (6.4%). C-18 sphingosine was the only long-chain base in all the gangliosides. Palmitic acid was the major fatty acid of thymus gangliosides and chromatographically more polar gangliosides contained higher proportions of palmitic acid: 46.3% in GM3, 47.5% in GD3, 60.2% in N-glycoloylneuraminosyl lacto-N-neotetraosyl ceramide and 89.6% in N-glycoloylneuraminosyl lacto-N-norhexaosyl ceramide.

Characterization of gangliosides in human leucocytes

Lipids extracted from leucocyte pellets with chloroform-methanol were applied to a DEAE-Sephadex column an the gangliosides were eluted with 0.2M sodium acetate in methanol. The eluate was desalted by Sephadex G-50 column chromatography. The purified ganglioside was spotted on the high-performance than-layer plate. The plate was developed and sprayed with resorcinol reagents and heated. Seventeen bands of gangliosides were demonstrated in normal human leucocytes. The composition of these gangliosides was different in the various kinds of leucocytes. Amounts of GM3 ganglioside were apparently greater in normal lymphocytes and leukaemic cells than in granulocytes. Among the acute-leukaemic cells, some kinds of complex gangliosides were much more abundant in myelogenous cells than in lymphocytic cells. These changes in ganglioside composition are suggested as new biochemical markers for leukaemic cells.

Gangliosides of calf thymus and of normal and leukemic bovine lymphocytes

The gangliosides of calf thymus and of lymphocytes from blood, lymph nodes, lymph and spleen of normal and leukemic cows were investigated in an attempt to determine whether there exists a relation between the ganglioside composition and the maturity of the lymphocytes. With all normal peripheral lymphocytes studied the largely prevailing (up to 97%) ganglioside component was found to be N-glycoloylneuraminosyllactosylceramide. The ganglioside spectrum of calf thymus was much more complex and included at least six different components. By thin-layer chromatography, methylation analysis and neuraminidase treatment they were identified as N-glycoloylneuraminosyl and N-acetylneuraminosyl lactosylceramides, N-glycoloylneuraminosylneolactotetraosylceramide, di-(N-glycoloylneuraminosyl), di-(N-acetylneuraminosyl) lactosylceramides and N-glycoloylneuraminosyl-N-acetylneuraminosyllactosylceramide. The ganglioside spectra of leukemic peripheral lymphocytes were different from those of normal peripheral lymphocytes and resembled the ganglioside profile of the thymus. The data obtained indicate that, in the normal animal, the development of thymocytes into mature peripheral lymphocytes is accompanied by loss of disialosyl-gangliosides and sialosylneolactotetraosylceramide. It is concluded that both the structure and the composition of the lymphocyte ganglioside become more simple during maturation and ageing of the lymphocyte.