ABSTRACT
OBJECTIVE: To determine whether in vitro induction of endomysial antibodies is an in vitro marker of coeliac toxicity. DESIGN: To determine whether in vitro endomysial antibodies induced by gliadin incubation correlate with histological damage induced by in vitro gliadin challenge. METHODS: Small-bowel organ cultures from seven patients with treated coeliac disease were incubated in an organ culture system with gliadin; histological damage was morphometrically evaluated and endomysial antibodies were measured in the organ culture supernatant by indirect immunofluorescence. RESULTS: Although incubation with gliadin caused histological damage, there was no detectable production of endomysial antibody. CONCLUSIONS: In vitro, endomysial antibody induction cannot be used as a marker of coeliac toxicity. Endomysial antibodies are not necessary for generating the histological lesion of coeliac disease.
Subject(s)
Autoantibodies/biosynthesis , Celiac Disease/immunology , Celiac Disease/pathology , Duodenum/pathology , Gliadin/toxicity , Adult , Aged , Autoantibodies/blood , Biomarkers/blood , Celiac Disease/diagnosis , Duodenum/immunology , Female , Fluorescent Antibody Technique, Indirect , Gliadin/immunology , Humans , Male , Middle Aged , Muscle, Smooth/immunology , Organ Culture Techniques , Predictive Value of TestsABSTRACT
BACKGROUND: A-gliadin residues 31-49 (peptide A) binds to HLA-DQ2 and is toxic to coeliac small bowel. Analogues of this peptide, which bind to DQ2 molecules but are non-toxic, may be a potential route to inducing tolerance to gliadin in patients with coeliac disease. METHODS: Toxicity was investigated with small bowel organ culture in six patients with untreated coeliac disease, four with treated coeliac disease and six controls. Analogue peptides comprised alanine substituted variants of peptide A at L31 (peptide D), P36 (E), P38 (F), P39 (G) and P42 (H). RESULTS: Peptides D and E were toxic in biopsies from some patients. Peptides F, G and H were not toxic. CONCLUSIONS: Peptide F, which binds to DQ2 more strongly than peptide A, is not toxic in patients with coeliac disease in-vitro; this could be an initial step towards investigation of the induction of tolerance to gliadin in patients affected by coeliac disease.
Subject(s)
Celiac Disease/immunology , Gliadin/immunology , HLA-DQ Antigens/metabolism , Peptide Fragments/immunology , Adult , Aged , Aged, 80 and over , Amino Acid Sequence , Case-Control Studies , Celiac Disease/metabolism , Female , Humans , Jejunum/immunology , Male , Middle Aged , Molecular Sequence Data , Organ Culture Techniques , Protein BindingSubject(s)
Celiac Disease/etiology , Celiac Disease/immunology , Antigen-Presenting Cells/drug effects , Antigen-Presenting Cells/immunology , Celiac Disease/genetics , Gliadin/immunology , Gliadin/pharmacology , HLA Antigens/biosynthesis , HLA Antigens/genetics , Humans , Intestinal Mucosa/drug effects , Intestinal Mucosa/immunology , Macrophages/drug effects , Macrophages/immunology , Receptors, Interleukin-2/metabolism , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
Coeliac disease (CD) is a disorder of the small intestine, characterized by villous atrophy, due to an intolerance to dietary gluten in genetically susceptible individuals, which responds to gluten withdrawal. The underlying immunological mechanisms causing the disorder are still being worked out. In recent years a wide range of clinical presentations has become increasingly apparent, as has a lengthening list of associated conditions. Severe malabsorption with steatorrhoea and profound weight loss is seen infrequently, perhaps as a result of earlier diagnosis and the recognition of 'silent' and 'latent' disease. The prevalence of CD as judged by population screening with, in particular, anti-endomysial antibodies, appears to be much higher than that found with clinically apparent cases. There are a variety of well recognized complications, the commonest probably being osteopenia and osteoporosis. The marked increased risk of lymphoma can be avoided by a strict gluten-free diet. Follow-up of patients needs to be lifelong with prompt investigation of new symptoms and blood test abnormalities.
Subject(s)
Celiac Disease , Celiac Disease/complications , Celiac Disease/diagnosis , Celiac Disease/epidemiology , Celiac Disease/therapy , HumansABSTRACT
The nature of the immunopathogenic relationship underlying the very strong association of coeliac disease (CD) to the HLA-DQ (A1*0501, B1*0201) genotype is not known, but probably relates to binding of gluten-derived epitopes to the HLA-DQ (alpha1*0501, beta1*0201) heterodimer (DQ2). These epitopes have not yet been defined. In this study we have tested the binding of various gluten-derived peptides to DQ2 in a cellular assay using Epstein-Barr virus (EBV)-transformed B lymphocytes and murine fibroblast transfectants. One of these peptides (peptide A), which has previously been shown to exacerbate the CD lesion in vitro and in vivo, was found to bind to DQ2, albeit only moderately, lending further credence to its possible role in the pathogenesis of CD. The nature of peptide A's binding to DQ2 was explored with truncated and conservative point substituted analogues and compared with the published DQ2 binding motif, the results of which explain the observed level of binding.
