In vitro systems for study of cereal proteins toxic in coeliac disease

By De Vincenzi, M. - De Ritis, G. - Dessi, M.R.

For a number of years, we have been carrying out investigations intended to clarify the nature of the toxic gliadin peptides, and whether different species and/or cultivars of wheat are tolerated to varying extents by people suffering from coeliac disease. Our investigations have been carried out using three main biological systems: 1) cultures of biopsy specimens of human intestinal mucosa; 2) cultures of rat fetal intestine; and 3) cultures of erythroid K562(S) cells. Using these systems, we have tested several peptide mixtures prepared from gliadin and non-gliadin fractions extracted from wheats having various degrees of ploidy and from other cereals. Fraction preparation has been carried out by means of sequential digestion with pepsin and trypsin under experimental conditions simulating protein digestion in man. The results obtained indicate that the pathological symptoms associated with intolerance to gluten are largely due to the cytotoxic activity of wheat gliadin peptides toward immature enterocytes.