Targeted Disruption of Gb3/CD77 Synthase Gene Resulted in the Complete Deletion of Globo-series Glycosphingolipids and Loss of Sensitivity to Verotoxins

• Published in: The Journal of biological chemistry 2006-04, Vol.281 (15), p.10230-10235
• Main Authors: Okuda, Tetsuya, Tokuda, Noriyo, Numata, Shin-ichiro, Ito, Masafumi, Ohta, Michio, Kawamura, Kumiko, Wiels, Joelle, Urano, Takeshi, Tajima, Orie, Furukawa, Keiko, Furukawa, Koichi
• Format: Article
• Language: English
• Subjects: Animals; Blotting, Northern; Blotting, Southern; Brain - metabolism; Chromatography, Thin Layer; Cytokines - metabolism; Escherichia coli - pathogenicity; Female; Galactosyltransferases - metabolism; Galactosyltransferases - physiology; Gene Deletion; Gene Expression Regulation; Gene Expression Regulation, Enzymologic; Genetic Vectors; Glycolipids - metabolism; Glycosphingolipids - chemistry; Immunohistochemistry; Inflammation; Interleukin-1 - metabolism; Kidney - metabolism; Kidney Tubules - metabolism; Kinetics; Lipopolysaccharides - chemistry; Lipopolysaccharides - metabolism; Lymphocytes - metabolism; Male; Mice; Mice, Knockout; Microcirculation; Models, Genetic; Mutation; Recombination, Genetic; Reverse Transcriptase Polymerase Chain Reaction; Shiga Toxins - chemistry; Time Factors; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M600057200

To examine whether globotriaosylceramide (Gb3/CD77) is a receptor for verotoxins (VTs) in vivo, sensitivity of Gb3/CD77 synthase null mutant mice to VT-2 and VT-1 was analyzed. Although wild-type mice died after administration of 0.02 μg of VT-2 or 1.0 μg of VT-1, the mutant mice showed no reaction to doses as much as 100 times that administered to wild types. Expression analysis of Gb3/CD77 in mouse tissues with antibody revealed that low, but definite, levels of Gb3/CD77 were expressed in the microvascular endothelial cells of the brain cortex and pia mater and in renal tubular capillaries. Corresponding to the Gb3/CD77 expression, tissue damage with edema, congestion, and cytopathic changes was observed, indicating that Gb3/CD77 (and its derivatives) exclusively function as a receptor for VTs in vivo. The lethal kinetics were similar regardless of lipopolysaccharide elimination in VT preparation, suggesting that basal Gb3/CD77 levels are sufficient for lethal effects of VTs.