Porcine 987P glycolipid receptors on intestinal brush borders and their cognate bacterial ligands

• Published in: Infection and Immunity Vol. 64; no. 9; pp. 3688 - 3693
• Main Authors: Khan, A.S. (University of Pennsylvania, Philadelphia.), Johnston, N.C, Goldfine, H, Schifferli, D.M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.09.1996
• Subjects: Adhesins, Escherichia coli - metabolism; Animals; Antigens, Bacterial - metabolism; Antigens, Surface - metabolism; Bacterial Adhesion; Bacteriology; Biological and medical sciences; Cattle; Ceramides - metabolism; ESCHERICHIA COLI; Escherichia coli - immunology; Escherichia coli - pathogenicity; Fimbriae Proteins; Fundamental and applied biological sciences. Psychology; Glycolipids - chemistry; Glycolipids - metabolism; LECHON; Ligands; Membrane Glycoproteins - chemistry; Membrane Glycoproteins - metabolism; Microbiology; Microvilli - microbiology; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; PORCELET; Receptors, Cell Surface - chemistry; Sulfoglycosphingolipids - chemistry; Sulfoglycosphingolipids - metabolism; Swine; Digestive system; Escherichia coli; Gut; Pilus; Host agent relation; Adhesion; Glycolipid; Proteins; Vertebrata; Brush border; Mammalia; Swine; Bacteria; Artiodactyla; Ungulata; Enterobacteriaceae; Biological receptor
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.64.9.3688-3693.1996

Certain strains of enterotoxigenic Escherichia coli adhere to piglet intestinal epithelial cells by means of the 987P fimbriae. The 987P fimbrial structure consists of a helical arrangement of three fimbrial proteins, namely, the major subunit FasA and two minor subunits, FasF and FasG. FasG, which is located at the fimbrial tip and at various positions along the fimbriae, mediates 987P binding to glycoprotein receptors. In this study, we isolated and analyzed the structure of piglet glycolipid brush border receptors and characterized their cognate ligands on the 987P fimbriae. Two major glycolipid bands recognized by 987P fimbrial probes in thin-layer chromatography overlay assays were further purified by high-performance thin-layer chromatography and shown to comigrate with control galactosylceramide containing hydroxylated fatty acids and with sulfatide. Their structures were confirmed by fast atom bombardment mass spectrometry, which detected homologous series of ceramide monohexoside and sulfatide with hydroxylated fatty acyl chains ranging from h16:0 to h24:0. Assembled 987P fimbriae, pre- and postassembly dissociated fimbrial subunits, and Fab fragments of specific anti-FasG, -FasF, and -FasA were used to inhibit 987P-mediated bacterial binding to the two identified piglet glycolipids and corresponding isoreceptor controls. Only assembled fimbriae and anti-FasG Fab fragments were significantly able to inhibit bacterial binding to sulfatide, indicating that in addition to glycoproteins, FasG recognizes a specific glycolipid of piglet brush borders. In contrast, only anti-FasA Fab fragments were significantly able to inhibit bacterial binding to galactosylceramide with hydroxylated fatty acids and piglet hydroxylated ceramide monohexoside, indicating that FasA may determine a third type of ligand-receptor interaction in the piglet intestines