The importance of alternative or adjunct treatments to the gluten-free diet in celiac disease is now being recognized. This paper discusses the scientific principles behind the use of caricain for enzyme therapy. Objective: To review the structures of the toxic peptides in A-gliadin that relate to those found by other workers insofar as having key sequences of amino acids or motifs which relate to toxicity, especially in regard to difficulty of digestion or immunogenicity. Methods: Structures of synthetic A-gliadin peptides shown to be toxic in the fetal chick assay were examined before and after digestion with duodenal mucosa from patients in long remission. Synthetic peptides corresponding to the undigested residues were also assayed and the key amino acid sequences compared in order to determine if they could be related to direct toxicity and immunogenicity of the peptides. Results: The results showed that the smallest toxic peptides from celiac mucosal digestion were octa-peptides and that they were obtained in greater yield than similar products from normal digestion. One of those peptides corresponded to residues 12-19 of A-gliadin and contained the key motifs PSQQ and QQQP of De Ritis et al. , whilst the other corresponded to residues 72-79 and contained the key motif PYPQ (extending to PYPQPQ), observed by other workers, especially those who have been investigating immunological activity over the past two decades. Conclusions: The presence of key motifs in undigested residues from celiac mucosal digestion and the greater prevalence of these residues compared with residues from normal digestion justifies our work on enzyme therapy. These studies have also indicated that our use of caricain as an enzyme capable of digesting peptides with two different types of toxicity has a sound scientific basis.
- Klíčová slova
- caricain,
- MeSH
- celiakie * enzymologie terapie MeSH
- cysteinové endopeptidasy farmakologie terapeutické užití MeSH
- enzymoterapie * MeSH
- gliadin * chemie metabolismus toxicita MeSH
- gluteny toxicita účinky léků MeSH
- lidé MeSH
- proteolýza MeSH
- rostlinné proteiny farmakologie terapeutické užití MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza proteinů MeSH
- střevní sliznice patologie MeSH
- tenké střevo patologie MeSH
- tyrosin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
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.
- MeSH
- bezlepková dieta * MeSH
- celiakie enzymologie imunologie terapie MeSH
- Drosophila metabolismus MeSH
- enzymoterapie * MeSH
- gliadin metabolismus MeSH
- gluteny metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- myši inbrední NOD MeSH
- myši MeSH
- proteiny vázající GTP metabolismus MeSH
- proteolýza MeSH
- transglutaminasy metabolismus MeSH
- zánět imunologie metabolismus prevence a kontrola MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- celiakie enzymologie imunologie MeSH
- gluteny imunologie škodlivé účinky MeSH
- Publikační typ
- úvodní články MeSH
- úvodníky MeSH
Celiac disease (CD) is the most common autoimmune enteropathy in the western world caused by the intolerance to gluten in genetically predisposed individuals. CD is characterized by a remarkable rearrangement of the mucosal architecture, in which process myofibroblasts play a crucial role. Myofibroblasts (intestinal subepithelial myofibroblasts and interstitial cells of Cajal) are the most represented mesenchymal cell types in the gut mucosa and are involved in a broad range of biological processes including growth, mucosal protection, repair, inflammation and fibrosis. Myofibroblasts actively contribute to the mucosal changes in CD due to their ability to produce an excessive amount of extracellular matrix and basement membrane components (e.g. collagens, fibronectin, and specific enzymes including tissue transglutaminases) and through the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). The enhanced production of ECM components and MMPs and the altered shape and motility of myofibroblasts in the duodenal mucosa of patients with CD suggest that myofibroblasts may play an essential role in the pathogenesis of CD.
- MeSH
- celiakie * enzymologie patologie MeSH
- duodenum enzymologie patologie sekrece MeSH
- extracelulární matrix imunologie sekrece MeSH
- fibroblasty enzymologie fyziologie patologie MeSH
- lidé MeSH
- matrixové metaloproteinasy imunologie MeSH
- myofibroblasty enzymologie fyziologie patologie MeSH
- střevní sliznice * enzymologie patologie sekrece MeSH
- transglutaminasy imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- celiakie enzymologie MeSH
- dipeptidy metabolismus MeSH
- disacharidy metabolismus MeSH
- gliadin škodlivé účinky MeSH
- myši MeSH
- tenké střevo enzymologie účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- celiakie enzymologie imunologie patologie MeSH
- duodenum enzymologie imunologie patologie MeSH
- gliadin aplikace a dávkování genetika imunologie MeSH
- gluteny aplikace a dávkování chemie MeSH
- lidé MeSH
- metaloproteasy metabolismus MeSH
- peptidové fragmenty genetika imunologie MeSH
- střevní sliznice enzymologie imunologie patologie MeSH
- Check Tag
- lidé MeSH
