1. Binding of 125 I-crude gluten digest (Frazer's fraction III, FF-III) and 125 I-concanavalin A (Con A) to isolated rat enterocytes and of 125 I-FF-III to human enterocytes was investigated. 2. Specific binding of 125 I-FF-III to rat enterocytes was observed but binding was not inhibited by any of a range of simple and complex saccharides, although casein and bovine serum albumin displaced FF-III at high concentrations. 3. Con A also bound to enterocytes in a specific manner and was inhibited by α-methyl-D-mannoside, confirming a lectin-mediated interaction. 4. 125 I-FF-III exhibited quantitatively similar specific binding to both normal human and coeliac enterocytes. 5. The primary interaction of gliadin peptides with the enterocyte surface membrane is not lectin-mediated and unlikely to be of fundamental importance in the pathogenesis of coeliac disease.
1. The agglutinating properties of a crude gluten digest, purified gliadin fractions and established plant lectins were investigated using mammalian erythrocytes, rat enterocytes and normal and coeliac human enterocytes as the target systems. 2. Gliadin preparations failed to cause agglutination of any of the cells tested, whereas established pure plant lectins were active cell agglutinins. 3. These studies indicate that gliadin peptides do not interact with intestinal cells in a polyvalent, lectin-like manner and as such cannot be regarded as true lectins. 4. Mucosal damage in coeliac disease is unlikely therefore to be related to lectin-like activity of gliadin.