Targeted disruption of Gb3/CD77 synthase gene resulted in the complete deletion of globo-series glycosphingolipids and loss of sensitivity to verotoxins.
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 microg of VT-2 or 1.0 microg 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.
Department of Biochemistry II, Nagoya University School of Medicine, Tsurumai, Showa-ku, Nagoya 466-0065, Japan.
Tetsuya
T
Okuda
Noriyo
N
Tokuda
Shin-ichiro
S
Numata
Masafumi
M
Ito
Michio
M
Ohta
Kumiko
K
Kawamura
Joelle
J
Wiels
Takeshi
T
Urano
Orie
O
Tajima
Keiko
K
Furukawa
Koichi
K
Furukawa
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D001921:Brain / Q000378:metabolism; D002855:Chromatography, Thin Layer; D016207:Cytokines / Q000378:metabolism; D004926:Escherichia coli / Q000472:pathogenicity; D005260:Female; D005700:Galactosyltransferases / Q000378:metabolism / Q000502:physiology*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D005822:Genetic Vectors; D006017:Glycolipids / Q000378:metabolism; D006028:Glycosphingolipids / Q000737:chemistry*; D007150:Immunohistochemistry; D007249:Inflammation; D007375:Interleukin-1 / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism; D007700:Kinetics; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008833:Microcirculation; D008957:Models, Genetic; D009154:Mutation; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022603:Shiga Toxins / Q000737:chemistry*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016207:Cytokines; D006017:Glycolipids; D006028:Glycosphingolipids; D007375:Interleukin-1; D008070:Lipopolysaccharides; D022603:Shiga Toxins; D014409:Tumor Necrosis Factor-alpha; D005700:Galactosyltransferases; C045097:UDP-galactose-lactosylceramide alpha 1-4-galactosyltransferase