A novel and sensitive method for the detection of T cell stimulatory epitopes of  / - and  -gliadin

Abstract

Background: It is now generally accepted that coeliac disease (CD) is caused by inflammatory T cell responses to gluten peptides bound to HLA-DQ2 or -DQ8 molecules. There is overwhelming evidence that CD patients can mount T cell responses to peptides found in both a-gliadin and c-gliadin molecules. Assays that would detect the presence or absence of such peptides in food would thus be accurate indicators of safety for consumption by CD patients. Aims: The development of a sensitive method to detect T cell stimulatory epitopes of a-gliadin and c-gliadin molecules in food products. Methods: Monoclonal antibodies (mAb) were raised against peptides encoding the T cell stimulatory epitopes of a-gliadin (amino acids (aa) 59-71) and aa c-gliadin (aa 142-153 and aa 147-159). These mAb competition assays were developed that quantitatively detect T cell stimulatory epitopes present on both intact proteins and peptides of sizes recognisable by CD4 + T cells. Results: With the mAb based competition assays, T cell epitopes were detected in pepsin/trypsin digests of wheat proteins and ethanol extracts of various food products, with detection levels lower than those reached with gluten specific T cells. Moreover, the presence of T cell stimulatory epitopes was also detected in preparations of barley, rye, and triticale, other cereals known to be toxic for CD patients. Conclusions: A new antibody based method has been developed, detecting the presence of T cell stimulatory gluten peptides. This can be used to further ensure the safety of food consumed by CD patients.

Efficient degradation of gluten by a prolyl endoprotease in a gastrointestinal model: implications for coeliac disease

“…The fusion and screening of the hybridomas was performed as described 33. The minimal epitope of the anti-Glia-α20 mAb (FRPQQPYP) was determined using a set of partly overlapping 17-mer synthetic peptides.…”

Characterization of two novel γ-gliadin genes encoded by K genome of Crithopsis delileana and evolution analysis with those from Triticeae

“…It is generally accepted that CD is an inflammatory T cell response to gluten peptides bound to HLA-DQ2 or -DQ8. CD patients mount a T cell response to both major and minor α-and γ-gliadins (Spaenij-Dekking et al, 2004). So, the removal of these peptides is required to render wheat safe for consumption by CD patients (Vader et al, 2003;Shan et al, 2005).…”

Detection and control of gluten as a food allergen

“…As CD is a result of infl ammatory T-cell response, Spaenij-Dekking et al . 53 developed antisera that are able to detect T-cell eptitopes of the α -and γ -gliadin. Gluten quantifi cation may not be completely accurate as the methods used rely on what is targeted and which toxic epitope is present in the food tested.…”

“…Spaenij-Dekking has raised monoclonal antibodies to the proposed immunodominant epitope, in order to address this problem. 53 In addition, the majority of the immunological methods available use antibodies directed at the gliadins and miss some of the glutenins proteins that are now being implicated in disease pathogenesis 16,19 and will need to be considered when selecting reagents for measurement of gluten.…”