Toward the Assessment of Food Toxicity for Celiac Patients: Characterization of Monoclonal Antibodies to a Main Immunogenic Gluten Peptide

Abstract

Background and AimsCeliac disease is a permanent intolerance to gluten prolamins from wheat, barley, rye and, in some patients, oats. Partially digested gluten peptides produced in the digestive tract cause inflammation of the small intestine. High throughput, immune-based assays using monoclonal antibodies specific for these immunotoxic peptides would facilitate their detection in food and enable monitoring of their enzymatic detoxification. Two monoclonal antibodies, G12 and A1, were developed against a highly immunotoxic 33-mer peptide. The potential of each antibody for quantifying food toxicity for celiac patients was studied.MethodsEpitope preferences of G12 and A1 antibodies were determined by ELISA with gluten-derived peptide variants of recombinant, synthetic or enzymatic origin.ResultsThe recognition sequences of G12 and A1 antibodies were hexameric and heptameric epitopes, respectively. Although G12 affinity for the 33-mer was superior to A1, the sensitivity for gluten detection was higher for A1. This observation correlated to the higher number of A1 epitopes found in prolamins than G12 epitopes. Activation of T cell from gluten digested by glutenases decreased equivalently to the detection of intact peptides by A1 antibody. Peptide recognition of A1 included gliadin peptides involved in the both the adaptive and innate immunological response in celiac disease.ConclusionsThe sensitivity and epitope preferences of the A1 antibody resulted to be useful to detect gluten relevant peptides to infer the potential toxicity of food for celiac patients as well as to monitor peptide modifications by transglutaminase 2 or glutenases.

Sensitive detection of cereal fractions that are toxic to celiac disease patients by using monoclonal antibodies to a main immunogenic gluten peptide

“…This is again consistent with previously published results, in which EP-B2 substantially detoxified similar bread digests, but the synergistic combination of EP-B2 with SC PEP was required to dramatically reduce the intestinal T-cell reactivity of these digests (Gass et al, 2007). The intensity of the signal obtained with the A1 moAb in our assay was therefore proportional to the potential damage caused to a CD patient by a commercial gluten source (Morón et al, 2008b).…”

“…We investigated whether the G12/A1 moAbs were able to detect the presence of gliadin 33-mer-related epitopes in prolamines from various cereals (Morón et al, 2008a;2008b). To obtain quantitative data on the capacity of these antibodies to detect coeliac-toxic prolamines, we performed an indirect ELISA with samples of wheat, barley, rye, oats, rice, and maize (Figure 2).…”

Sensitive gluten determination in gluten-free foods by an electrochemical aptamer-based assay

“…Gli 1 aptamer is not able to bind oat proteins while Gli 4 aptamer recognises avenins but with less affinity than the rest of prolamins from CD toxic cereals. This result is interesting because the antibodies G12 and A1, also raised against the 33-mer peptide, weakly binds to avenins although 33-mer is not present in their sequence [26]. The sensitivity order to prolamins was, however, different:…”

Measurement of Gluten in Food Products: Proficiency‐Testing Rounds as a Measure of Precision and Applicability

“…This is an important requirement since oats are a crucial component for gluten-free food. Other test kits as, for example, the ELISA based on the G12 monoclonal antibody show a signiicant cross-reactivity to certain oat varieties which make this system not suitable for oat-based materials [13]. Another conclusion that can be drawn from Table 1 is the fact that blank soya materials do not exert positive results after Cocktail (patented) extraction.…”