THE ACTIVITIES OF PEPTIDE-31-43, PEPTIDE-44-55 AND PEPTIDE-56-68 OF A-GLIADIN ON IN-VITRO CULTURES OF CACO-2 CELLS

In previous studies, various A-gliadin peptides with known amino acid sequences have been tested for their damaging effects on in vitro cult ured atrophic coeliac mucosa. The largest common sequences among the i n vitro toxic peptides were (gln)(3)-pro and pro-ser-(gln)(2). Three o f these active A-gliadin fragments were synthesised and characterised, namely, the peptides corresponding to the amino acid sequences ''31-4 3'' and ''44-55'', which contain the sequences (gln)(3)-pro and pro-se r-(gln)(2), respectively, and the ''56-68'' fragment lacking both acti ve amino acid sequences. While the ''56-68'' A-gliadin peptide was com pletely inactive in CaCo-2 cells, the other two peptides were cytotoxi c toward these cells to different extents. Our results confirm that Ca Co-2 cells are a suitable model for the identification of toxic peptid es responsible for coeliac pathogenesis.