Glycolipids of human large intestine: difference in glycolipid expression related to anatomical localization, epithelial/non-epithelial tissue and the ABO, Le and Se phenotypes of the donors

Abstract

Human large intestine specimens were obtained during elective surgery from donors of known blood group ABO, Lewis and secretor phenotypes. The intestinal epithelial cells were isolated from the non-epithelial tissue in one case and in another case mucosa tissue was obtained by scraping. Total non-acid glycolipid and ganglioside fractions were isolated from the tissue specimens, analyzed by thin-layer chromatography and detected by chemical reagents and autoradiography after staining the plate with various blood group monoclonal antibodies and bacterial toxins. The amount of non-acid glycolipids present in the large intestine epithelial cells was 3.9 μg/mg of cell protein and in the non-epithelial tissue 0.39 mg/g dry tissue weight. The epithelial cells contained monoglycosylceramides and blood group Le a pentaglycosylceramides as major compounds together with small amounts of diglycosylceramides. In addition, trace amounts of tri- and tetra-glycosylceramides together with more complex glycolipids were present. The non-epithelial tissue contained mopno-, di-, tri- and tetra-glycosylceramides as major non-acid components. Blood group ABH glycolipids were present in trace amounts in the non-epithelial part of the large intestine. Le a pentaglycosylceramide was the major blood group glycolipid present in all Le-positive individuals independent of the secretor status. Le b glycolipids were present in trace amounts in secretor individuals but completely lacking in non-secretors. Trace amounts of X antigens were found in all individuals, while Y antigens were only present in secretor individuals. The Le a, Le b, X and Y glycolipids were located in the epithelial cells. The gangliosides were present mainly in the non-epithelial tissue (65–350 nmol of sialic acid/g dry weight) and only trace amounts (less than 0.014 nmol/mg of cell protein) were found in the epithelial cells. The major gangliosides of the non-epithelial tissue were identified as GM 3, GM 1, GD 3, GD 1a, GD 1b, GT 1b and GQ 1b. In addition, several minor gangliosides were also present. Binding of cholera toxin to the thin-layer plate revealed trace amounts of the GM 1 ganglioside in the epithelial cell ganglioside fraction.