Addressing proteolytic efficiency in enzymatic degradation therapy for celiac disease

Celiac disease is triggered by partially digested gluten proteins. Enzyme therapies that complete protein digestion in vivo could support a gluten-free diet, but the barrier to completeness is high. Current options require enzyme amounts on the same order as the protein meal itself. In this study, we evaluated proteolytic components of the carnivorous pitcher plant (Nepenthes spp.) for use in this context. Remarkably low doses enhance gliadin solubilization rates, and degrade gliadin slurries within the pH and temporal constraints of human gastric digestion. Potencies in excess of 1200:1 (substrate-to-enzyme) are achieved. Digestion generates small peptides through nepenthesin and neprosin, the latter a novel enzyme defining a previously-unknown class of prolyl endoprotease. The digests also exhibit reduced TG2 conversion rates in the immunogenic regions of gliadin, providing a twin mechanism for evading T-cell recognition. When sensitized and dosed with enzyme-treated gliadin, NOD/DQ8 mice did not show intestinal inflammation, when compared to mice challenged with only pepsin-treated gliadin. The low enzyme load needed for effective digestion suggests that gluten detoxification can be achieved in a meal setting, using metered dosing based on meal size. We demonstrate this by showing efficient antigen processing at total substrate-to-enzyme ratios exceeding 12,000:1

Anti-α-gliadin antibodies (AGA) in the serum of coeliac children and controls recognize an identical collection of linear epitopes of α-gliadin

Anti-gliadin antibodies can be found in the serum of patients with overt and subclinical coeliac disease, but also in that of some controls. The aim of the present study was to identify the linear epitopes of the α-gliadin molecule to which the humoral response is directed. Therefore, the IgG and IgA antibody reactivity against an overlapping set of synthetic peptides covering the entire sequence of α-gliadin was measured in the sera from patients with coeliac disease, from controls with elevated titres of anti-gliadin antibodies and from healthy children using an ELISA technique. The antibodies mainly recognize peptides derived from the N-terminal region of α-gliadin, containing the motif QPFXXQXPY. Reactivity was also detected against two other synthetic peptides, which do not contain this motif and represent a sequence encoded further to the C-terminal region of α-gliadin. Anti-gliadin antibodies in sera from patients with coeliac disease and from controls recognize the same linear epitopes. Thus, serological investigation of the specificity of these antibodies using a peptide ELISA does not allow discrimination between patients and controls

Review article: future research on coeliac disease - a position report from the European multistakeholder platform on coeliac disease (CDEUSSA).

BACKGROUND: CDEUSSA is a Specific Support Action project from the Sixth Framework Programme Priority of the European Union (EU). Its aim is to bring together basic and applied research in the area of coeliac disease (CD). This paper reviews the main issues that are a result of the CDEUSSA initiative. AIM: To identify the major issues in need of investigation in the areas of clinical aspects, treatment, prevention and public health. METHODS: Key stakeholders, representing a wide range of knowledge with crucial importance for CD research and practice, have participated in two workshops aimed at identifying and proposing to the EU, as high priority research, topics in the areas of clinical aspects, treatment, prevention and public health. RESULTS: In public health, the overall goal should be to improve quality of life of the European population by implementing primary prevention strategies, early diagnosis and improved treatments for CD. New treatment strategies need to be developed. The option of primary prevention should be fully explored, which requires combined epidemiological, clinical and basic scientific research efforts. Such studies should also consider the importance of gene-environment interactions in the development of CD. Increased knowledge is needed on the natural history of CD. Diagnostic criteria need to be revised. CONCLUSIONS: To achieve these goals, a collaboration of the stakeholders is fundamental, including research and patient organizations, as well as industries within both diagnostics and food production