Participation of ABH glycoconjugates in the secretory response to Escherichia coli heat-labile toxin in rabbit intestine.
The ability of membrane ABH blood group-active glycoconjugates to act as receptors of the heat-labile enterotoxin of Escherichia coli (LTh) was studied in vitro and in vivo when GM1 was blocked by the cholera toxin B subunit. Rabbits were classified as AB or H based on intestinal ABH-antigenic activities. Brush border membranes from AB rabbits contained 4 times more LTh binding sites than the H ones. LTh interaction could be inhibited by lectins that recognize ABH determinants. LTh induced a similar dose-dependent secretory response in ligated ileal loops of both types of animals. Anti-AB antibodies and Ulex europaeus I lectin could significantly reduce the fluid accumulation in AB and H rabbits, respectively. LTh caused adenylate cyclase activation even when GM1 was blocked, and this effect was abolished by the addition of specific ABH ligands. These results suggest that ABH glycoconjugates are involved in the host secretory response to LTh in rabbit intestine.
Departamento de Química Biológica "Dr. Ranwel Caputto"-CIQUIBIC (CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina. egalvan@dqbfcq.uncor.edu
E M
EM
Galván
G A
GA
Roth
C G
CG
Monferran
D000017:ABO Blood-Group System / Q000276:immunology*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism* / Q000633:toxicity; D002772:Cholera Toxin / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004768:Enterotoxins / Q000378:metabolism* / Q000633:toxicity; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005677:G(M1) Ganglioside / Q000378:metabolism; D006001:Glycoconjugates / Q000378:metabolism*; D007082:Ileum / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D008024:Ligands; D008871:Microvilli / Q000378:metabolism*; D037121:Plant Lectins; D011817:Rabbits
D000017:ABO Blood-Group System; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D006001:Glycoconjugates; D037102:Lectins; D008024:Ligands; D037121:Plant Lectins; C036850:Ulex europaeus lectins; D005677:G(M1) Ganglioside; D002772:Cholera Toxin; C027538:heat-labile enterotoxin, E coli; D000262:Adenylyl Cyclases