Ability of blood group A-active glycosphingolipids to act as Escherichia coli enteroxin receptors in HT-29 cells

ESTELA M. GALVAN; CLAUDIO D. DIEMA; GERMAN A. ROTH; CLARA G. MONFERRAN

Infectious Diseases Society of America

Año: 2004 vol. 189 p. 1556 - 1556

p style="MARGIN: 0cm 0cm 10pt" class="MsoNormal">We examined the ability of blood group A-active glycoconjugates to act as receptors for Escherichia coli heat-labile type I enterotoxin (LT-I) in HT-29 cells. These cells contained ~4 times more specific binding sites for LT-I than for cholera toxin (CT). Binding of LT-I could not be blocked by the B subunit of CT (CT-B), indicating the existence of LT-I receptors in addition to the glycosphingolipid GM1. LT-I was able to increase levels of cyclic adenosine monophosphate (AMP), even in the presence of CT-B. Helix pomatia and anti-blood group A antibody caused a dose-dependent inhibition of binding of LT-I to cells and production of cyclic AMP. LT-I recognized several complex blood group A-active glycosphingolipids from cells, and this interaction was also interfered with by H. pomatia. Treatment of cells with D,L-threo-1-phenyl-2-hexa