Refractory coeliac disease (RCD) is a very rare and dangerous form of CD, in which gluten-free diet loses its therapeutic effect and the damage of intestinal mucosa persists. Because of the adherence to the diet, serological markers of CD [immunoglobulin A (IgA) antibodies against gliadin, tissue transglutaminase (tTG) and endomysium] are often missing in RCD patients. We found substantially elevated levels of IgA anti-calreticulin (CRT) antibodies in the sera of almost all RCD patients tested. These sera were negative for IgA antibodies to gliadin and tTG and only some of them showed IgA antibodies to enterocytes. Analysis of patients' IgA reactivity to CRT fragments (quarters and halves) by Western blotting revealed differences in the specificity of IgA antibodies between RCD and CD patients. We therefore used the Pepscan technique with synthetic overlapping decapeptides of CRT to characterize antigenic epitopes recognized by serum IgA antibodies of RCD patients. Employing this method we demonstrated several dominant antigenic epitopes recognized by IgA antibodies of RCD patients on the CRT molecule. Epitope GVTKAAEKQMKD was recognized predominantly by serum IgA of RCD patients. Our results suggest that testing for serum IgA antibodies against CRT and its selected peptide could be a very useful tool in RCD differential diagnosis.
- MeSH
- bezlepková dieta škodlivé účinky MeSH
- celiakie diagnóza imunologie krev MeSH
- ELISA MeSH
- enterocyty chemie imunologie MeSH
- financování organizované MeSH
- gliadin imunologie krev MeSH
- imunoglobulin A imunologie krev MeSH
- kalretikulin imunologie krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- protilátky anti-idiotypické imunologie krev MeSH
- senioři MeSH
- senzitivita a specificita MeSH
- transglutaminasy imunologie krev MeSH
- western blotting MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
To elucidate the role of innate immune responses in celiac disease, we investigated the effect of gliadin on blood monocytes from patients with celiac disease. Gliadin induced substantial TNF-alpha and IL-8 production by monocytes from patients with active celiac disease, lower levels by monocytes from patients with inactive celiac disease, and even lower levels by monocytes from healthy donors. In healthy donor monocytes gliadin induced IL-8 from monocytes expressing HLA-DQ2 and increased monocyte expression of the costimulatory molecules CD80 and CD86, the dendritic cell marker CD83, and the activation marker CD40. Gliadin also increased DNA binding activity of NF-kappaB p50 and p65 subunits in monocytes from celiac patients, and NF-kappaB inhibitors reduced both DNA binding activity and cytokine production. Thus, gliadin activation of HLA-DQ2(+) monocytes leading to chemokine and proinflammatory cytokine production may contribute to the host innate immune response in celiac disease.
- MeSH
- aktivace makrofágů imunologie MeSH
- antigeny CD40 metabolismus MeSH
- antigeny CD80 metabolismus MeSH
- antigeny CD86 metabolismus MeSH
- CD antigeny metabolismus MeSH
- celiakie imunologie metabolismus MeSH
- cytokiny biosyntéza MeSH
- financování organizované MeSH
- gliadin metabolismus MeSH
- HLA-DQ antigeny metabolismus MeSH
- imunoglobuliny metabolismus MeSH
- interleukin-8 biosyntéza MeSH
- lidé MeSH
- membránové glykoproteiny metabolismus MeSH
- monocyty metabolismus MeSH
- NF-kappa B metabolismus MeSH
- peptidové fragmenty MeSH
- průtoková cytometrie MeSH
- TNF-alfa biosyntéza MeSH
- Check Tag
- lidé MeSH
Celiac disease is a chronic inflammatory disease developing in genetically predisposed individuals. Ingested gliadin, the triggering agent of the disease, can cross the epithelial barrier and elicit a harmful T cell-mediated immune response. Dendritic cells (DC) are supposed to play a pivotal role in shaping the immune response. The direction of the immune response toward immunity or tolerance depends on the stage of maturation and the functional properties of the DC. DC become fully functional APC upon maturation by various stimuli. We investigated the effect of a peptic digest of gliadin on the maturation of human monocyte-derived DC. Stimulation of cells with gliadin, in contrast with other tested food proteins, led to enhanced expression of maturation markers (CD80, CD83, CD86, and HLA-DR molecules) and increased secretion of chemokines and cytokines (mainly of IL-6, IL-8, IL-10, TNF-alpha, growth-related oncogene, MCP-1, MCP-2, macrophage-derived chemokine, and RANTES). Maturation was accompanied by a greater capacity to stimulate proliferation of allogeneic T cells and significantly reduced endocytic activity. Furthermore, gliadin-induced phosphorylation of members of three MAPK families (ERK1/2, JNK, and p38 MAPK) was demonstrated. The largest contribution of p38 MAPK was confirmed using its inhibitor SB203580, which markedly down-regulated the gliadin-triggered up-regulation of maturation markers and cytokine production. Gliadin treatment also resulted in increased NF-kappaB/DNA binding activity of p50 and p65 subunits. Taken together, gliadin peptides can contribute to overcoming the stage of unresponsiveness of immature DC by inducing phenotypic and functional DC maturation, resulting in more efficient processing and presentation of gliadin peptides to specific T lymphocytes.
- MeSH
- biologické markery metabolismus MeSH
- buněčná diferenciace účinky léků MeSH
- celiakie etiologie imunologie MeSH
- dendritické buňky cytologie imunologie účinky léků MeSH
- fenotyp MeSH
- financování organizované MeSH
- fosforylace MeSH
- gliadin farmakologie imunologie MeSH
- lidé MeSH
- MAP kinasový signální systém účinky léků MeSH
- mitogenem aktivované proteinkinasy p38 antagonisté a inhibitory metabolismus MeSH
- NF-kappa B metabolismus MeSH
- peptidové fragmenty farmakologie imunologie MeSH
- prezentace antigenu MeSH
- T-lymfocyty imunologie MeSH
- Check Tag
- lidé MeSH
