Recent studies suggested that gliadin proteins from the ancient diploid einkorn wheat
Triticum monococcum
retained a reduced number of immunogenic peptides for celiac disease patients because of a ...high
in vitro
digestibility with respect to hexaploid common wheat. In this study, we compared the immunological properties of gliadins from two
Triticum monococcum
cultivars (Hammurabi and Norberto-ID331) with those of a
Triticum durum
cultivar (Adamello). Gliadins were digested by mimicking the
in vitro
gastrointestinal digestion process that includes the brush border membrane peptidases. Competitive ELISA, based on R5 monoclonal antibody, showed that gastrointestinal digestion reduced the immunogenicity of
Triticum monococcum
gliadins; conversely, the immunogenic potential of
Triticum durum
gliadins remained almost unchanged by the
in vitro
digestion. The immune stimulatory activity was also evaluated by detecting the IFN-γ production in gliadin-reactive T-cell lines obtained from the small intestinal mucosa of HLA-DQ2+ celiac disease patients. Interestingly, gastrointestinal digestion markedly reduced the capability of
Triticum monococcum
gliadins (
p
<0.05) of both cultivars to activate T cells, while it slightly affected the activity of
Triticum durum
. In conclusion, our results showed that
Triticum durum
was almost unaffected by the
in vitro
gastrointestinal digestion, while
Triticum monococcum
had a marked sensibility to digestion, thus determining a lower toxicity for celiac disease patients.
Celiac disease (CD) is a frequent inflammatory intestinal disease, with a genetic background, caused by gliadin-containing food. Undigested gliadin peptides P31-43 and P57-68 induce innate and ...adaptive T cell-mediated immune responses, respectively. Alterations in the cell shape and actin cytoskeleton are present in celiac enterocytes, and gliadin peptides induce actin rearrangements in both the CD mucosa and cell lines. Cell shape is maintained by the actin cytoskeleton and focal adhesions, sites of membrane attachment to the extracellular matrix. The locus of the human Lipoma Preferred Partner (LPP) gene was identified as strongly associated with CD using genome-wide association studies (GWAS). The LPP protein plays an important role in focal adhesion architecture and acts as a transcription factor in the nucleus. In this study, we examined the hypothesis that a constitutive alteration of the cell shape and the cytoskeleton, involving LPP, occurs in a cell compartment far from the main inflammation site in CD fibroblasts from skin explants. We analyzed the cell shape, actin organization, focal adhesion number, focal adhesion proteins, LPP sub-cellular distribution and adhesion to fibronectin of fibroblasts obtained from CD patients on a Gluten-Free Diet (GFD) and controls, without and with treatment with A-gliadin peptide P31-43. We observed a "CD cellular phenotype" in these fibroblasts, characterized by an altered cell shape and actin organization, increased number of focal adhesions, and altered intracellular LPP protein distribution. The treatment of controls fibroblasts with gliadin peptide P31-43 mimics the CD cellular phenotype regarding the cell shape, adhesion capacity, focal adhesion number and LPP sub-cellular distribution, suggesting a close association between these alterations and CD pathogenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Celiac disease (CD) occurs frequently, and is caused by ingestion of prolamins from cereals in subjects with a genetic predisposition. The small intestinal damage depends on an intestinal ...stress/innate immune response to certain gliadin peptides (e.g., A-gliadin P31-43) in association with an adaptive immune response to other gliadin peptides (e.g., A-gliadin P57-68). Gliadin and peptide P31-43 affect epithelial growth factor receptor (EGFR) signaling and CD enterocyte proliferation. The reason why the stress/innate immune and proliferative responses to certain gliadin peptides are present in CD and not in control intestine is so far unknown. The aim of this work is to investigate if, in CD, a constitutive alteration of enterocyte proliferation and signaling exists that may represent a predisposing condition to the damaging effects of gliadin. Immunofluorescence and immunohistochemistry were used to study signaling in CD fibroblasts and intestinal biopsies. Western blot (WB) analysis, immunoprecipitation, and quantitative PCR were also used. We found in CD enterocytes enhancement of both proliferation and Epidermal Growth Factor Receptor (EGFR)/ligand system. In CD enterocytes and fibroblasts we found increase of the phosphorylated downstream signaling molecule Extracellular Signal Regulated Kinase (ERK); block of the ERK activation normalizes enterocytes proliferation in CD mucosa. In conclusion the same pathway, which gliadin and gliadin peptide P31-43 can interfere with, is constitutively altered in CD cells. This observation potentially explains the specificity of the damaging effects of certain gliadin peptides on CD intestine.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Celiac Disease (CD) is an autoimmune disease characterized by inflammation of the intestinal mucosa due to an immune response to wheat gliadins. Some gliadin peptides (e.g., A-gliadin P57-68) induce ...an adaptive Th1 pro-inflammatory response. Other gliadin peptides (e.g., A-gliadin P31-43) induce a stress/innate immune response involving interleukin 15 (IL15) and interferon α (IFN-α). In the present study, we describe a stressed/inflamed celiac cellular phenotype in enterocytes and fibroblasts probably due to an alteration in the early-recycling endosomal system. Celiac cells are more sensitive to the gliadin peptide P31-43 and IL15 than controls. This phenotype is reproduced in control cells by inducing a delay in early vesicular trafficking. This constitutive lesion might mediate the stress/innate immune response to gliadin, which can be one of the triggers of the gliadin-specific T-cell response.
The HLA genes, located in the MHC region on chromosome 6p21.3, play an important role in many autoimmune disorders, such as celiac disease (CD), type 1 diabetes (T1D), rheumatoid arthritis, multiple ...sclerosis, psoriasis and others. Known HLA variants that confer risk to CD, for example, include DQA1*05/DQB1*02 (DQ2.5) and DQA1*03/DQB1*0302 (DQ8). To diagnose the majority of CD patients and to study disease susceptibility and progression, typing these strongly associated HLA risk factors is of utmost importance. However, current genotyping methods for HLA risk factors involve many reactions, and are complicated and expensive. We sought a simple experimental approach using tagging SNPs that predict the CD-associated HLA risk factors.
Our tagging approach exploits linkage disequilibrium between single nucleotide polymorphism (SNPs) and the CD-associated HLA risk factors DQ2.5 and DQ8 that indicate direct risk, and DQA1*0201/DQB1*0202 (DQ2.2) and DQA1*0505/DQB1*0301 (DQ7) that attribute to the risk of DQ2.5 to CD. To evaluate the predictive power of this approach, we performed an empirical comparison of the predicted DQ types, based on these six tag SNPs, with those executed with current validated laboratory typing methods of the HLA-DQA1 and -DQB1 genes in three large cohorts. The results were validated in three European celiac populations.
Using this method, only six SNPs were needed to predict the risk types carried by >95% of CD patients. We determined that for this tagging approach the sensitivity was >0.991, specificity >0.996 and the predictive value >0.948. Our results show that this tag SNP method is very accurate and provides an excellent basis for population screening for CD. This method is broadly applicable in European populations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Celiac disease (CD) is a multifactorial autoimmune disease induced by ingestion of gluten in genetically predisposed individuals. Despite technological progress, the diagnosis of CD is still based on ...duodenal biopsy as it was 50 years ago. In this study we analysed the expression of CD-associated genes in small bowel biopsies of patients and controls in order to explore the multivariate pathway of the expression profile of CD patients. Then, using multivariant discriminant analysis, we evaluated whether the expression profiles of these genes in peripheral blood monocytes (PBMs) differed between patients and controls.
Thirty-seven patients with active and 11 with treated CD, 40 healthy controls and 9 disease controls (Crohn's disease patients) were enrolled.
Several genes were differentially expressed in CD patients versus controls, but the analysis of each single gene did not provided a comprehensive picture. A multivariate discriminant analysis showed that the expression of 5 genes in intestinal mucosa accounted for 93% of the difference between CD patients and controls. We then applied the same approach to PBMs, on a training set of 20 samples. The discriminant equation obtained was validated on a testing cohort of 10 additional cases and controls, and we obtained a correct classification of all CD cases and of 91% of the control samples. We applied this equation to treated CD patients and to disease controls and obtained a discrimination of 100%.
The combined expression of 4 genes allows one to discriminate between CD patients and controls, and between CD patients on a gluten-free diet and disease controls. Our results contribute to the understanding of the complex interactions among CD-associated genes, and they may represent a starting point for the development of a molecular diagnosis of celiac disease.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In Vitro–Deranged Intestinal Immune Response to Gliadin in Type 1 Diabetes
Renata Auricchio 1 ,
Francesco Paparo 1 ,
Maria Maglio 1 ,
Adriana Franzese 1 ,
Francesca Lombardi 1 ,
Giuliana Valerio 1 ,
...Gerardo Nardone 2 ,
Selvaggia Percopo 1 ,
Luigi Greco 1 and
Riccardo Troncone 1
1 Department of Pediatrics and European Laboratory for the Investigation of Food-Induced Diseases, University “Federico II,”
Naples, Italy
2 Department of Experimental Medicine, University “Federico II,” Naples, Italy
Address correspondence and reprint requests to Dr. Renata Auricchio, Dipartimento di Pediatria, Università Federico II, via
Sergio Pansini 5, I-80131 Napoli, Italy. E-mail: reauricc{at}tin.it
Abstract
Dietary gluten has been associated with an increased risk of type 1 diabetes. We have evaluated inflammation and the mucosal
immune response to gliadin in the jejunum of patients with type 1 diabetes. Small intestinal biopsies from 17 children with
type 1 diabetes without serological markers of celiac disease and from 50 age-matched control subjects were examined by immunohistochemistry.
In addition, biopsies from 12 type 1 diabetic patients and 8 control subjects were cultured with gliadin or ovalbumin peptic-tryptic
digest and examined for epithelial infiltration and lamina propria T-cell activation. The density of intraepithelial CD3 + and γδ + cells and of lamina propria CD25 + mononuclear cells was higher in jejunal biopsies from type 1 diabetic patients versus control subjects. In the patients’
biopsies cultured with peptic-tryptic gliadin, there was epithelial infiltration by CD3 + cells, a significant increase in lamina propria CD25 + and CD80 + cells and enhanced expression of lamina propria CD54 and crypt HLA-DR. No such phenomena were observed in control subjects,
even those with celiac disease–associated HLA haplotypes. In conclusion, signs of mucosal inflammation were present in jejunal
biopsies from type 1 diabetic patients, and organ culture studies indicate a deranged mucosal immune response to gliadin.
CD, celiac disease
Footnotes
Accepted March 19, 2004.
Received July 29, 2003.
DIABETES
ABSTRACT
Objectives:
The ESPGHAN 2012 coeliac disease (CD) diagnostic guidelines aimed to guide physicians in accurately diagnosing CD and permit omission of duodenal biopsies in selected cases. ...Here, an updated and expanded evidence‐based guideline is presented.
Methods:
Literature databases and other sources of information were searched for studies that could inform on 10 formulated questions on symptoms, serology, human leukocyte antigen genetics, and histopathology. Eligible articles were assessed using QUADAS2. GRADE provided a basis for statements and recommendations.
Results:
Various symptoms are suggested for case finding, with limited contribution to diagnostic accuracy. If CD is suspected, measurement of total serum IgA and IgA‐antibodies against transglutaminase 2 (TGA‐IgA) is superior to other combinations. We recommend against deamidated gliadin peptide antibodies (DGP‐IgG/IgA) for initial testing. Only if total IgA is low/undetectable, an IgG‐based test is indicated. Patients with positive results should be referred to a paediatric gastroenterologist/specialist. If TGA‐IgA is ≥10 times the upper limit of normal (10× ULN) and the family agrees, the no‐biopsy diagnosis may be applied, provided endomysial antibodies (EMA‐IgA) will test positive in a second blood sample. Human leukocyte antigen DQ2‐/DQ8 determination and symptoms are not obligatory criteria. In children with positive TGA‐IgA <10× ULN at least 4 biopsies from the distal duodenum and at least 1 from the bulb should be taken. Discordant results between TGA‐IgA and histopathology may require re‐evaluation of biopsies. Patients with no/mild histological changes (Marsh 0/I) but confirmed autoimmunity (TGA‐IgA/EMA‐IgA+) should be followed closely.
Conclusions:
CD diagnosis can be accurately established with or without duodenal biopsies if given recommendations are followed.
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