Intragastric administration of transamidated gliadin interferes with the systemic and intestinal immune responses to wheat gliadin in DQ8 transgenic mice.

We have previously shown the ability of transamidated gluten (spf) to modulate both innate and adaptive intestinal immunity elicited by wheat gliadin in HLA-DQ8 transgenic mice (DQ8 mice), a model of gluten sensitivity. Herein, we evaluated the influence of spf when administered intragastrically on the immune response to native gliadin in DQ8 mice. To address the issue, we analysed three regimens of antigen administration: before immunisation (pre-treatment), during immunisation (co-treatment) and through breast milk during the lactating phase (suckling treatment).

Modulation of Mouse Dendritic Cells In Vitro by Lactobacillus gasseri Postbiotic Proteins.

Different lactobacilli are probiotics for their beneficial effects that confer to the host. Recently, some of these effects were associated with released metabolic products/constituents (postbiotics). In the present study, the potential immunomodulatory capacity of the probiotic Lactobacillus gasseri OLL2809 cell-free supernatant (sup) was investigated in murine bone marrow-derived dendritic cells (DCs).

High Fat Diet-Wheat Gliadin Interaction and its Implication for Obesity and Celiac Disease Onset: In Vivo Studies.

The intestinal immune system plays a crucial role in obesity and insulin resistance. An altered intestinal immunity is associated with changes to the gut microbiota, barrier function, and tolerance to luminal antigens. Lipid metabolism and its unbalance can also contribute to acute and chronic inflammation in different conditions.

The HLA-DQ8 transgenic mouse: A model to study the immune and cytotoxic responses to wheat gliadin.

A complete understanding of celiac disease (CD) pathogenesis has been hindered to date because of the lack of adequate in vivo models. Herein, we describe two in vivo approaches in HLA-DQ8-transgenic mice to study the intrinsic cytoxicity and immune features of wheat gliadin. By adopting the first method, we explored the mucosal architecture of the small intestine following the intra-gastric administration of wheat gliadin in mice treated with indomethacin, an inhibitor of cyclooxygenases.

Transamidated wheat gliadin induces differential antigen recognition in the small intestine of HLA/DQ8 transgenic mice.

A lifelong gluten-free diet (GFD) is currently the only available therapy for coeliac disease (CD). However, GFD compliance is difficult and alternative strategies are envisaged in the near future. We previously found that wheat gliadin following transamidation by microbial transglutaminase (mTG) does not induce IFN-γ secretion by intestinal T cells from CD patients.

Next generation strategies to recover immunological tolerance in celiac disease.

Celiac disease (CD) is an autoimmune disease that occurs in genetically predisposed individuals following the ingestion of gluten. Its prevalence is rising worldwide. A gluten-free (GF) diet is mandatory for the management of CD.

Beneficial effects of a wheat cultivar on diabetes incidence evaluated in non-obese diabetic mice and after simulated gastroduodenal digestion.

Wheat consumption can represent one of the nutritional factors involved in the onset of diabetes. We specifically investigated the potential diabetogenic effects of Hammurabi, a wheat cultivar, in non-obese diabetic (NOD) mice and analysed the levels of resistant starch in pasta manufactured with Hammurabi after gastroduodenal digestion. NOD mice were fed with Hammurabi, bread wheat or rice flour to evaluate diabetes incidence and insulitis score.

Transamidation Down-Regulates Intestinal Immunity of Recombinant α-Gliadin in HLA-DQ8 Transgenic Mice.

Enzymatic transamidation of gliadins by microbial transglutaminase (mTG) inhibits interferon-γ (IFN-γ) secretion by intestinal T cell lines in patients with celiac disease (CD). To gain insight into the cellular mechanisms underlying the down-regulatory effects of transamidation, we tested a single recombinant α-gliadin (r-gliadin) harbouring two immunodominant peptides, p13 (aa. 120-139) and p23 (aa.

First morphological-level insights into the efficiency of green tea catechins and grape seed procyanidins on a transgenic mouse model of celiac disease enteropathy.

Alternative or complementary treatments to a gluten-free diet are urgently needed for Celiac Disease. By exploiting the health-promoting properties of polyphenols on a transgenic mouse model of Celiac Disease enteropathy, this study provides the first in vivo evidence regarding the ability of 1 mg day-1 doses of green tea catechins and grape seed procyanidins to ameliorate some of the most characteristic histological changes of gliadin-treated DQ8 mice, including villus flattening, crypt hyperplasia, and infiltration of intraepithelial lymphocytes. Mechanistically, polyphenols were found to increase the intestinal nucleophilic tone of DQ8 mice by orchestrating an adaptive antioxidant response characterized by enhanced GSR enzyme activity and GSH content.

The murine enterocyte cell line Mode-K is a novel and reliable in vitro model for studies on gluten toxicity.

The resemblance of physiological traits of cell lines with their target/original tissue is an important prerequisite for the choice of the in vitro model. Although cytoprotective defenses, activated by the nuclear factor erythroid 2-related factor2 (Nrf2), have a preeminent importance in intestinal protection, nevertheless their levels inin vitro models have been never compared with those of their original tissue. Basal level of Nrf2-mediated defenses in murine enterocyte cells (Mode-K) and in human colon adenocarcinoma cells -at differentiated (DCaco2) or confluent stage (CCaco2)- were compared with those found in mouse or human duodenum.

Microbial transglutaminase: A biotechnological tool to manage gluten intolerance.

Celiac disease (CD) is a chronic immune-mediated disease in which gluten ingestion leads to damage of the small intestinal mucosa in genetically susceptible individuals. The enteropathy is mainly induced by the production of IFN-γ from intestinal CD4T cells that recognise gliadin peptides following deamidation by tissue transglutaminase. The only available therapy is a strict, lifelong gluten-free diet (GFD).

Innate immunity is a late event in the onset of gliadin-specific enteropathy in the HLA-DQ8 mice.

Celiac disease (CD) is a food enteropathy that occurs in genetically susceptible individuals following the ingestion of gluten. Both gluten cytotoxicity and immunity activation play a role in CD pathogenesis; however, the chronological assessment of the different pathogenic mechanisms remains elusive. The models developed so far have only partially addressed this issue.

Prunus Mahaleb Fruit Extract Prevents Chemically Induced Colitis and Enhances Mitochondrial Oxidative Metabolism via the Activation of the Nrf2 Pathway.

Scope: Polyphenols exhibit their antioxidant activity downstream the activation of the nuclear factor erythroid 2-related factor 2 pathway (Nrf2), but the connection between lipid metabolism and the Nrf2 pathway is still unknown. Flavonoid-rich concentrated extract from Prunus mahaleb (mahaleb concentrated fruit extract; MCFE) may act on oxido-reductive homeostasis and hepatic lipid metabolism via Nrf2.

Methods & Results: MCFE ability to enhance the activity of Nrf2-mediated antioxidant/detoxifying enzymes is investigated in liver and colon of BALB/c mice.

Dietary Supplementation with Fish Oil or Conjugated Linoleic Acid Relieves Depression Markers in Mice by Modulation of the Nrf2 Pathway.

Inflammation and oxidative stress play an important role in the pathogenesis of depressive disorders and nuclear erythroid related factor 2 (Nrf2), a regulator of RedOx homeostasis and inflammation, is a promising target for depression prevention/treatment. As fish oil (FO) and conjugated linoleic acid (CLA) are known Nrf2 inducers, their protective ability is comparatively evaluated in a murine model of depression (MRL/MpJ-Fas ). Oxidative stress, fatty acids content, and critical factors reflecting brain functioning-namely brain-derived neurotrophic factor (BDNF), synaptic markers, and cholinergic signaling-are preliminarily evaluated in the frontal cortex of 8-week (Young) and in 22-week old animals (Old), which are used as model of depression.

Tailoring the immune response to wheat gliadin by enzymatic transamidation.

Enzymatic transamidation of wheat gliadin by microbial transglutaminase inhibits IFN-γ secretion by intestinal T cell lines from celiac disease (CD) patients. Here, we analysed its effects on intestinal biopsies from CD patients and studied the underlying mechanisms in HLA-DQ8 transgenic (tg) mice, a model of T-cell mediated gluten sensitivity. In vitro challenge with a soluble form of transamidated gliadin (spf) upregulated IL-10 transcript levels in human biopsy samples.

Conjugated linoleic acid prevents age-dependent neurodegeneration in a mouse model of neuropsychiatric lupus via the activation of an adaptive response.

Oxidative stress is a key mediator of autoimmune/neurodegenerative disorders. The antioxidant/anti-inflammatory effect of a synthetic conjugated linoleic acid (CLA) mixture in MRL/MpJ-Fas mice (MRL/), an animal model of neuropsychiatric lupus, was previously associated with the improvement of nuclear factor-E2-related factor 2 (Nrf2) defenses in the spleen and liver. However, little is known about the neuroprotective ability of a CLA mixture.

Immunomodulatory activity of recombinant α-gliadin conjugated to cholera toxin in DQ8 transgenic mice.

Coeliac disease (CD) is characterized by an intestinal lesion sustained by an abnormal mucosal T-cell response to wheat gliadin. An immunological approach that is able to suppress this immune response is a perspective worth pursuing. Several strategies of antigen administration have been aimed at the downregulation of pathogenic T-cells.

Microwave-based treatments of wheat kernels do not abolish gluten epitopes implicated in celiac disease.

Microwave based treatment (MWT) of wet wheat kernels induced a striking reduction of gluten, up to <20 ppm as determined by R5-antibodybased ELISA, so that wheat could be labeled as gluten-free. In contrast, analysis of gluten peptides by G12 antibody-based ELISA, mass spectrometry-based proteomics and in vitro assay with T cells of celiac subjects, indicated no difference of antigenicity before and after MWT. SDS-PAGE analysis and Raman spectroscopy demonstrated that MWT simply induced conformational modifications, reducing alcohol solubility of gliadins and altering the access of R5-antibody to the gluten epitopes.

E2 multimeric scaffold for vaccine formulation: immune response by intranasal delivery and transcriptome profile of E2-pulsed dendritic cells.

Background: The E2 multimeric scaffold represents a powerful delivery system able to elicit robust humoral and cellular immune responses upon systemic administrations. Here recombinant E2 scaffold displaying the third variable loop of HIV-1 Envelope gp120 glycoprotein was administered via mucosa, and the mucosal and systemic immune responses were analysed. To gain further insights into the molecular mechanisms that orchestrate the immune response upon E2 vaccination, we analysed the transcriptome profile of dendritic cells (DCs) exposed to the E2 scaffold with the aim to define a specific gene expression signature for E2-primed immune responses.

Mucosal immunity induced by gliadin-presenting spores of Bacillus subtilis in HLA-DQ8-transgenic mice.

The induction of mucosal immunity requires efficient antigen delivery and adjuvant systems. Probiotic bacterial strains are considered to be very promising tools to address both of these needs. In particular, Bacillus subtilis spores are currently under investigation as a long-lived, protease-resistant adjuvant system for different antigens.

Adaptive response activated by dietary cis9, trans11 conjugated linoleic acid prevents distinct signs of gliadin-induced enteropathy in mice.

Purpose: The beneficial effects of conjugated linoleic acid (CLA) mixture (cis9, trans11, c9; trans10, cis12, t10) against gliadin-induced toxicity in HLA-DQ8-transgenic mice (DQ8) have been associated with improved duodenal cytoprotective mechanisms [nuclear factor-E2-related factor-2, Nrf2; acylpeptide hydrolase (APEH)/proteasome]. The present study was aimed at investigating the ability of individual CLA isomers to improve the efficacy of these defensive mechanisms and to protect against duodenal injury caused by the combined administration of gliadin and indomethacin (GI).

Methods: Gluten-mediated enteropathy was induced in DQ8 mice by three intra-gastric administration of gliadin (20 mg kg(-1)/bw) and indomethacin (15 mg L(-1)) in drinking water for 10 days (GI).

Modulatory activity of Lactobacillus rhamnosus OLL2838 in a mouse model of intestinal immunopathology.

Gut microbiota and probiotic strains play an important role in oral tolerance by modulating regulatory and effector cell components of the immune system. We have previously described the ability of Lactobacilli to influence both the innate and adaptive immunity to wheat gluten, a food antigen, in mouse. In this study, we further explored the immunomodulatory mechanisms elicited in this model by testing three specific probiotic strains, namely L.

Gliadin intake alters the small intestinal mucosa in indomethacin-treated HLA-DQ8 transgenic mice.

Celiac disease (CD) is an enteropathy caused by the ingestion of wheat gluten in genetically susceptible individuals. A complete understanding of the pathogenic mechanisms in CD has been hindered because of the lack of adequate in vivo models. In the present study, we explored the events after the intragastric administration of gliadin and of the albumin/globulin fraction from wheat in human leukocyte antigen-DQ8 transgenic mice (DQ8 mice) treated with indomethacin, an inhibitor of cyclooxygenases (COXs).

Non-recombinant display of the B subunit of the heat labile toxin of Escherichia coli on wild type and mutant spores of Bacillus subtilis.

Background: Mucosal infections are a major global health problem and it is generally accepted that mucosal vaccination strategies, able to block infection at their entry site, would be preferable with respect to other prevention approaches. However, there are still relatively few mucosal vaccines available, mainly because of the lack of efficient delivery systems and of mucosal adjuvants. Recombinant bacterial spores displaying a heterologous antigen have been shown to induce protective immune responses and, therefore, proposed as a mucosal delivery system.

Biochemical modifications of gliadins induced by microbial transglutaminase on wheat flour.

Background: Celiac disease (CD) is an immune-mediated disorder caused by the ingestion of wheat gluten. A lifelong, gluten-free diet is required to normalize the intestinal mucosa. We previously found that transamidation by microbial transglutaminase (mTGase) suppressed the gliadin-specific immune response in intestinal T-cell lines from CD patients and in models of gluten sensitivity.