The Use of Monoclonal Antibodies to Detect Gluten in Foods

Celiac.com 10/29/2008 - The intestinal inflammation that arises when people with celiac disease consume wheat, rye or barley occurs when HLA-DQ2-restricted CD4+ T-cells recognize peptides derived from gluten in the food. Peptides that stimulate an immune response like this are found in both gliadins and glutenins.

A team of researchers based in the Netherlands recently discovered that particular types of antibodies called monoclonal antibodies react to the presence of gluten proteins in much the same way that the human HLA-DQ2-restricted CD4+ T-cells do, and that monoclonal antibodies offer promise for reliably detecting the presence of wheat, barley, rye, and even oat gluten in food products.

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The team was made up of Cristina Mitea, Yvonne Kooy-Winkelaar, Peter van Veelen, Arnoud de Ru, Jan W Drijfhout, Frits Koning and Liesbeth Dekking. They recently set out to assess the specificity of 5 different types of monoclonal antibodies in how they react to T-cell stimulatory peptides found in alpha - and gamma-gliadins and in low- and high-molecular-weight glutenins, and to compare it with the specificity of patient-derived T-cells.

The team assessed the reaction levels of selected monoclonal antibodies with gluten peptides, enzymatic gluten digests, and intact gluten proteins, and compared the results to those for gluten-specific T-cells by using a combination of immunologic and biochemical techniques. They also assessed the reactivity of the monoclonal antibodies with gluten homologues in barley, rye, and oats.

They found that the specificity of the monoclonal antibodies largely overlaps with that of gluten-specific T-cells. Moreover, monoclonal antibodies detect several distinct homologous peptides present in gluten proteins.

The results showed that monoclonal antibodies that react to the immune-triggering peptides found in both gliadins and glutenins can be used to screen food for the presence of immune-triggering peptides. All monoclonal antibodies, except those that are LMW-specific, also detect storage proteins present in barley and rye, whereas the {gamma} -gliadin-specific monoclonal antibodies also recognize oat proteins.

This discovery could lead to the development of a reliable test for detecting harmful gluten and related proteins and peptides in food products, or for determining if food products labeled as gluten-free were indeed free of gluten.

American Journal of Clinical Nutrition, Vol. 88, No. 4, 1057-1066, October 2008