Gluten induces an intestinal cytokine response strongly dominated by interferon gamma in patients with celiac disease

To respond or not to respond - a personal perspective of intestinal tolerance

For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research.

The Screening of Critical Related Genes in Celiac Disease Based on Intraepithelial Lymphocytes Investigation: A Bioinformatics Analysis

Background

Celiac disease (CD) is an immunological intestinal disorder, which is characterized by response to gluten. In addition to the environmental factors and dysbiosis of the gut microbiota, genetic susceptibility has an important role in the pathogenesis of this multifactorial disorder. Therefore, this study aims to present the crucial involved genes in CD pathogenesis.

Materials and Methods

In this bioinformatics analysis study, significant differentially expressed genes of intraepithelial lymphocytes (IELs) samples of celiac patients versus normal patients from Gene Expression Omnibus (GEO) database were screened via the protein-protein interaction (PPI) network. The critical nodes based on degree values, betweenness centrality, and fold changes were determined and enriched by ClueGO to find relative biological terms.

Results

According to the network analysis, five central nodes including IL2, PIK3CA, PRDM10, AKT1, and SRC and eight significant differentially expressed genes (DEGs) were determined as the critical genes related to CD. Also, CD4+, CD25+, alpha-beta regulatory T cell differentiation are identified as prominent biological terms in the celiac disease patients.

Conclusion

There is a possible biomarker panel related to CD that can be used as a therapeutic or diagnostic tool to manage the disease.

Coeliac Disease and Mast Cells

Over the last decades, there has been an impressive progress in our understanding of coeliac disease pathogenesis and it has become clear that the disorder is the final result of complex interactions of environmental, genetic, and immunological factors. Coeliac disease is now considered a prototype of T-cell-mediated disease characterized by loss of tolerance to dietary gluten and the targeted killing of enterocytes by T-cell receptor αβ intraepithelial lymphocytes. Accumulating evidence, however, indicates that the induction of a gluten-specific T helper-1 response must be preceded by the activation of the innate immune system. Mast cells are key players of the innate immune response and contribute to the pathogenesis of a multitude of diseases. Here, we review the results of studies aimed at investigating the role of mast cells in the pathogenesis of coeliac disease, showing that these cells increase in number during the progression of the disease and contribute to define a pro-inflammatory microenvironment.

The Revival of the Battle between David and Goliath in the Enteric Viruses and Microbiota Struggle: Potential Implication for Celiac Disease

The human gut is inhabited by overcrowded prokaryotic communities, a major component of which is the virome, comprised of viruses, bacteriophages, archaea, eukaryotes and bacteria. The virome is required for luminal homeostasis and, by their lytic or synergic capacities, they can regulate the microbial community structure and activity. Dysbiosis is associated with numerous chronic human diseases. Since the virome can impact microbial genetics and behavior, understanding its biology, composition, cellular cycle, regulation, mode of action and potential beneficial or hostile activities can change the present paradigm of the cross-talks in the luminal gut compartment. Celiac disease is a frequent autoimmune disease in which viruses can play a role in disease development. Based on the current knowledge on the enteric virome, in relation to celiac disease pathophysiological evolvement, the current review summarizes the potential interphases between the two. Exploring and understanding the role of the enteric virome in gluten-dependent enteropathy might bring new therapeutic strategies to change the luminal eco-event for the patient's benefit.

The Revival of the Battle between David and Goliath in the Enteric Viruses and Microbiota Struggle: Potential Implication for Celiac Disease

The human gut is inhabited by overcrowded prokaryotic communities, a major component of which is the virome, comprised of viruses, bacteriophages, archaea, eukaryotes and bacteria. The virome is required for luminal homeostasis and, by their lytic or synergic capacities, they can regulate the microbial community structure and activity. Dysbiosis is associated with numerous chronic human diseases. Since the virome can impact microbial genetics and behavior, understanding its biology, composition, cellular cycle, regulation, mode of action and potential beneficial or hostile activities can change the present paradigm of the cross-talks in the luminal gut compartment. Celiac disease is a frequent autoimmune disease in which viruses can play a role in disease development. Based on the current knowledge on the enteric virome, in relation to celiac disease pathophysiological evolvement, the current review summarizes the potential interphases between the two. Exploring and understanding the role of the enteric virome in gluten-dependent enteropathy might bring new therapeutic strategies to change the luminal eco-event for the patient's benefit.

Variable Immunogenic Potential of Wheat: Prospective for Selection of Innocuous Varieties for Celiac Disease Patients via in vitro Approach

Celiac Disease (CD) is a multifactorial, autoimmune enteropathy activated by cereal proteins in genetically predisposed individuals carrying HLA DQ2/8 genes. A heterogenous gene combination of the cereal prolamins is documented in different wheat genotypes, which is suggestive of their variable immunogenic potential. In the current study, four wheat varieties (C591, C273, 9D, and K78) identified via in silico analysis were analyzed for immunogenicity by measuring T-cell proliferation rate and levels of inflammatory cytokines (Interferon-γ and Tumor Necrosis Factor-α). Peripheral Blood Mononuclear Cells and biopsy derived T-cell lines isolated from four CD patients in complete remission and two controls were stimulated and cultured in the presence of tissue transglutaminase activated pepsin-trypsin (PT) digest of total gliadin extract from test varieties. The immunogenicity was compared with PBW 621, one of the widely cultivated wheat varieties. Phytohaemagglutinin-p was taken as positive control, along with unstimulated cells as negative control. Rate of cell proliferation (0.318, 0.482; 0.369, 0.337), concentration of IFN- γ (107.4, 99.2; 117.9, 99.7 pg/ml), and TNF- α (453.8, 514.2; 463.8, 514.2 pg/ml) was minimum in cultures supplemented with wheat antigen from C273, when compared with other test varieties and unstimulated cells. Significant difference in toxicity levels among different wheat genotypes to stimulate celiac mucosal T-cells and PBMC's was observed; where C273 manifested least immunogenic response amongst the test varieties analyzed.

Ex vivo immunomodulatory effect of ethanolic extract of propolis during Celiac Disease: involvement of nitric oxide pathway

Celiac Disease (CeD) is a chronic immune-mediated enteropathy, in which dietary gluten induces an inflammatory reaction, predominantly in the duodenum. Propolis is a resinous hive product, collected by honeybees from various plant sources. Propolis is well-known for its anti-inflammatory, anti-oxidant and immunomodulatory effects, due to its major compounds, polyphenols and flavonoids. The aim of our study was to assess the ex vivo effect of ethanolic extract of propolis (EEP) upon the activity and expression of iNOS, along with IFN-γ and IL-10 production in Algerian Celiac patients. In this context, PBMCs isolated from peripheral blood of Celiac patients and healthy controls were cultured with different concentrations of EEP. NO production was measured using the Griess method, whereas quantitation of IFN-γ and IL-10 levels was performed by ELISA. Inducible nitric oxide synthase (iNOS) expression, NFκB and pSTAT-3 activity were analyzed by immunofluorescence assay. Our results showed that PBMCs from Celiac patients produced high levels of NO and IFN-γ compared with healthy controls (HC). Interestingly, EEP reduced significantly, NO and IFN-γ levels and significantly increased IL-10 levels at a concentration of 50 µg/mL. Importantly, EEP downmodulated the iNOS expression as well as the activity of NFκB and pSTAT-3 transcription factors. Altogether, our results highlight the immunomodulatory effect of propolis on NO pathway and on pro-inflammatory cytokines. Therefore, we suggest that propolis may constitute a potential candidate to modulate inflammation during Celiac Disease and has a potential therapeutic value.

Galectins in Intestinal Inflammation: Galectin-1 Expression Delineates Response to Treatment in Celiac Disease Patients

Galectins, a family of animal lectins characterized by their affinity for N-acetyllactosamine-enriched glycoconjugates, modulate several immune cell processes shaping the course of innate and adaptive immune responses. Through interaction with a wide range of glycosylated receptors bearing complex branched N-glycans and core 2-O-glycans, these endogenous lectins trigger distinct signaling programs thereby controling immune cell activation, differentiation, recruitment and survival. Given the unique features of mucosal inflammation and the differential expression of galectins throughout the gastrointestinal tract, we discuss here key findings on the role of galectins in intestinal inflammation, particularly Crohn’s disease, ulcerative colitis, and celiac disease (CeD) patients, as well as in murine models resembling these inflammatory conditions. In addition, we present new data highlighting the regulated expression of galectin-1 (Gal-1), a proto-type member of the galectin family, during intestinal inflammation in untreated and treated CeD patients. Our results unveil a substantial upregulation of Gal-1 accompanying the anti-inflammatory and tolerogenic response associated with gluten-free diet in CeD patients, suggesting a major role of this lectin in favoring resolution of inflammation and restoration of mucosal homeostasis. Thus, a coordinated network of galectins and their glycosylated ligands, exerting either anti-inflammatory or proinflammatory responses, may influence the interplay between intestinal epithelial cells and the highly specialized gut immune system in physiologic and pathologic settings.

Translational Chemistry Meets Gluten-Related Disorders

Gluten‐related disorders are a complex group of diseases that involve the activation of the immune system triggered by the ingestion of gluten. Among these, celiac disease, with a prevalence of 1 %, is the most investigated, but recently, a new pathology, named nonceliac gluten sensitivity, was reported with a general prevalence of 7 %. Finally, there other less‐prevalent gluten‐related diseases such as wheat allergy, gluten ataxia, and dermatitis herpetiformis (with an overall prevalence of less than 0.1 %). As mentioned, the common molecular trigger is gluten, a complex mixture of storage proteins present in wheat, barley, and a variety of oats that are not fully degraded by humans. The most‐studied protein related to disease is gliadin, present in wheat, which possesses in its sequence many pathological fragments. Despite a lot of effort to treat these disorders, the only effective method is a long‐life gluten‐free diet. This Review summarizes the actual knowledge of gluten‐related disorders from a translational chemistry point of view. We discuss what is currently known from the literature about the interaction of gluten with the gut and the critical host responses it evokes and, finally, connect them to our current and novel molecular understanding of the supramolecular organization of gliadin and the 33‐mer gliadin peptide fragment under physiological conditions.

New coeliac disease treatments and their complications

The only accepted treatment for coeliac disease is strict adherence to a gluten-free diet. This type of diet may give rise to reduced patient quality of life with economic and social repercussions. For this reason, dietary transgressions are common and may elicit intestinal damage. Several treatments aimed at different pathogenic targets of coeliac disease have been developed in recent years: modification of gluten to produce non-immunogenic gluten, endoluminal therapies to degrade gluten in the intestinal lumen, increased gluten tolerance, modulation of intestinal permeability and regulation of the adaptive immune response. This review evaluates these coeliac disease treatment lines that are being researched and the treatments that aim to control disease complications like refractory coeliac disease.

Laser Capture Microdissection as a Tool to Study the Mucosal Immune Response in Celiac Disease

Laser capture microdissection (LCM) is a powerful tool for selection and isolation of single cells or compartments from complex primary tissues to perform molecular analyses. Celiac disease is a genetic autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. Increased intraepithelial lymphocytes and the presence of the lamina propria inflammatory infiltrate of the duodenal mucosa is a common part of the disease. These cells promote inflammatory processes through the release of cytokines. Here, we describe the use of LCM and real-time quantitative PCR (RT-qPCR) to analyze cytokine profile information in distinct duodenal mucosa tissue compartments of celiac patients.

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. In particular, we previously reported a significant suppression of the systemic cell-mediated response toward wheat gliadin in DQ8 transgenic mice receiving nasally a recombinant α-gliadin. To gain further insight about the cellular mechanisms underlying the tolerogenic properties of this molecule, we analysed different preparations of the recombinant α-gliadin, alone or conjugated to the adjuvant cholera toxin (CT), by in vitro challenge with spleen CD4⁺ T cells from gliadin-sensitized DQ8 tg mice. We found that a partially purified preparation of recombinant α-gliadin (r-gliadin) induced a significantly higher production of IFN-γ than native gliadin as well as HPLC purified r-gliadin. Interestingly, r-gliadin, but not HPLC purified r-gliadin, stimulated the gliadin-specific expression of IL-10 in CD4⁺ T cells. No significant cytotoxic effect was induced by r-gliadin in MODE-K cells, a murine model of enterocytes. Notably, a conjugate CT-r-gliadin failed in stimulating IFN-γ, whereas IL-10 secretion was still induced in gliadin-specific CD4⁺ T cells. In conclusion, our results showed that DCs, pulsed with CT-r-gliadin in vitro, could modulate the ongoing Th1-like T cell response toward wheat gliadin. This finding provides new insight into the design of immunomodulatory protocols potentially useful for CD.

Enteropathy-associated T cell lymphoma subtypes are characterized by loss of function of SETD2

Enteropathy-associated T cell lymphoma (EATL) is the most common oncologic complication of celiac disease. Moffitt and colleagues identify novel EATL-defining mutations in SETD2, as well as clinically relevant mutations in the JAK-STAT pathway.

Enteropathy-associated T cell lymphoma (EATL) is a lethal, and the most common, neoplastic complication of celiac disease. Here, we defined the genetic landscape of EATL through whole-exome sequencing of 69 EATL tumors. SETD2 was the most frequently silenced gene in EATL (32% of cases). The JAK-STAT pathway was the most frequently mutated pathway, with frequent mutations in STAT5B as well as JAK1, JAK3, STAT3, and SOCS1. We also identified mutations in KRAS, TP53, and TERT. Type I EATL and type II EATL (monomorphic epitheliotropic intestinal T cell lymphoma) had highly overlapping genetic alterations indicating shared mechanisms underlying their pathogenesis. We modeled the effects of SETD2 loss in vivo by developing a T cell–specific knockout mouse. These mice manifested an expansion of γδ T cells, indicating novel roles for SETD2 in T cell development and lymphomagenesis. Our data render the most comprehensive genetic portrait yet of this uncommon but lethal disease and may inform future classification schemes.

Reovirus infection triggers inflammatory responses to dietary antigens and development of celiac disease

Viral infections have been proposed to elicit pathological processes leading to the initiation of T helper 1 (TH1) immunity against dietary gluten and celiac disease (CeD). To test this hypothesis and gain insights into mechanisms underlying virus-induced loss of tolerance to dietary antigens, we developed a viral infection model that makes use of two reovirus strains that infect the intestine but differ in their immunopathological outcomes. Reovirus is an avirulent pathogen that elicits protective immunity, but we discovered that it can nonetheless disrupt intestinal immune homeostasis at inductive and effector sites of oral tolerance by suppressing peripheral regulatory T cell (pTreg) conversion and promoting TH1 immunity to dietary antigen. Initiation of TH1 immunity to dietary antigen was dependent on interferon regulatory factor 1 and dissociated from suppression of pTreg conversion, which was mediated by type-1 interferon. Last, our study in humans supports a role for infection with reovirus, a seemingly innocuous virus, in triggering the development of CeD.

Immunogenetic Pathogenesis of Celiac Disease and Non-celiac Gluten Sensitivity

Celiac disease is the most common oral intolerance in Western countries. It results from an immune response towards gluten proteins from certain cereals in genetically predisposed individuals (HLA-DQ2 and/or HLA-DQ8). Its pathogenesis involves the adaptive (HLA molecules, transglutaminase 2, dendritic cells, and CD4(+) T-cells) and the innate immunity with an IL-15-mediated response elicited in the intraepithelial compartment. At present, the only treatment is a permanent strict gluten-free diet (GFD). Multidisciplinary studies have provided a deeper insight of the genetic and immunological factors and their interaction with the microbiota in the pathogenesis of the disease. Similarly, a better understanding of the composition of the toxic gluten peptides has improved the ways to detect them in food and drinks and how to monitor GFD compliance via non-invasive approaches. This review, therefore, addresses the major findings obtained in the last few years including the re-discovery of non-celiac gluten sensitivity.

CD4 T-cell cytokines synergize to induce proliferation of malignant and nonmalignant innate intraepithelial lymphocytes

Refractory celiac disease type II (RCDII) is a severe complication of celiac disease (CD) characterized by the presence of an enlarged clonal population of innate intraepithelial lymphocytes (IELs) lacking classical B-, T-, and natural killer (NK)-cell lineage markers (Lin^-IELs) in the duodenum. In ∼50% of patients with RCDII, these Lin^-IELs develop into a lymphoma for which no effective treatment is available. Current evidence indicates that the survival and expansion of these malignant Lin^-IELs is driven by epithelial cell-derived IL-15. Like CD, RCDII is strongly associated with HLA-DQ2, suggesting the involvement of HLA-DQ2-restricted gluten-specific CD4⁺ T cells. We now show that gluten-specific CD4⁺ T cells isolated from CD duodenal biopsy specimens produce cytokines able to trigger proliferation of malignant Lin^-IEL lines as powerfully as IL-15. Furthermore, we identify TNF, IL-2, and IL-21 as CD4⁺ T-cell cytokines that synergistically mediate this effect. Like IL-15, these cytokines were found to increase the phosphorylation of STAT5 and Akt and transcription of antiapoptotic mediator bcl-x_L Several small-molecule inhibitors targeting the JAK/STAT pathway blocked proliferation elicited by IL-2 and IL-15, but only an inhibitor targeting the PI3K/Akt/mTOR pathway blocked proliferation induced by IL-15 as well as the CD4⁺ T-cell cytokines. Confirming and extending these findings, TNF, IL-2, and IL-21 also synergistically triggered the proliferation of freshly isolated Lin^-IELs and CD3^-CD56⁺ IELs (NK-IELs) from RCDII as well as non-RCDII duodenal biopsy specimens. These data provide evidence implicating CD4⁺ T-cell cytokines in the pathogenesis of RCDII. More broadly, they suggest that adaptive immune responses can contribute to innate IEL activation during mucosal inflammation.

Diagnosis and Updates in Celiac Disease

Celiac disease is an autoimmune disorder induced by gluten in genetically susceptible individuals. It can result in intraintestinal and extraintestinal manifestations of disease including diarrhea, weight loss, anemia, osteoporosis, or lymphoma. Diagnosis of celiac disease is made through initial serologic testing and then confirmed by histopathologic examination of duodenal biopsies. Generally celiac disease is a benign disorder with a good prognosis in those who adhere to a gluten-free diet. However, in refractory disease, complications may develop that warrant additional testing with more advanced radiologic and endoscopic methods. This article reviews the current strategy to diagnose celiac disease and the newer modalities to assess for associated complications.

Thioredoxin-1 Selectively Activates Transglutaminase 2 in the Extracellular Matrix of the Small Intestine: IMPLICATIONS FOR CELIAC DISEASE

Transglutaminase 2 (TG2) catalyzes transamidation or deamidation of its substrates and is ordinarily maintained in a catalytically inactive state in the intestine and other organs. Aberrant TG2 activity is thought to play a role in celiac disease, suggesting that a better understanding of TG2 regulation could help to elucidate the mechanistic basis of this malady. Structural and biochemical analysis has led to the hypothesis that extracellular TG2 activation involves reduction of an allosteric disulfide bond by thioredoxin-1 (TRX), but cellular and in vivo evidence for this proposal is lacking. To test the physiological relevance of this hypothesis, we first showed that macrophages exposed to pro-inflammatory stimuli released TRX in sufficient quantities to activate their extracellular pools of TG2. By using the C35S mutant of TRX, which formed a metastable mixed disulfide bond with TG2, we demonstrated that these proteins specifically recognized each other in the extracellular matrix of fibroblasts. When injected into mice and visualized with antibodies, we observed the C35S TRX mutant bound to endogenous TG2 as its principal protein partner in the small intestine. Control experiments showed no labeling of TG2 knock-out mice. Intravenous administration of recombinant TRX in wild-type mice, but not TG2 knock-out mice, led to a rapid rise in intestinal transglutaminase activity in a manner that could be inhibited by small molecules targeting TG2 or TRX. Our findings support the potential pathophysiological relevance of TRX in celiac disease and establish the Cys³⁷⁰-Cys³⁷¹ disulfide bond of TG2 as one of clearest examples of an allosteric disulfide bond in mammals.

Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities

Theterm gluten intolerance may refer to three types of human disorders: autoimmune celiac disease (CD), allergy to wheat and non-celiac gluten sensitivity (NCGS). Gluten is a mixture of prolamin proteins present mostly in wheat, but also in barley, rye and oat. Gluten can be subdivided into three major groups: S-rich, S-poor and high molecular weight proteins. Prolamins within the groups possess similar structures and properties. All gluten proteins are evolutionarily connected and share the same ancestral origin. Gluten proteins are highly resistant to hydrolysis mediated by proteases of the human gastrointestinal tract. It results in emergence of pathogenic peptides, which cause CD and allergy in genetically predisposed people. There is a hierarchy of peptide toxicity and peptide recognition by T cells. Nowadays, there are several ways to detoxify gluten peptides: the most common is gluten-free diet (GFD), which has proved its effectiveness; prevention programs, enzymatic therapy, correction of gluten pathogenicity pathways and genetically modified grains with reduced immunotoxicity. A deep understanding of gluten intolerance underlying mechanisms and detailed knowledge of gluten properties may lead to the emergence of novel effective approaches for treatment of gluten-related disorders.

Transglutaminase 2-specific coeliac disease autoantibodies induce morphological changes and signs of inflammation in the small-bowel mucosa of mice

Coeliac disease is hallmarked by an abnormal immune reaction against ingested wheat-, rye- and barley-derived gluten and the presence of transglutaminase 2 (TG2)-targeted autoantibodies. The small-bowel mucosal damage characteristic of the disorder develops gradually from normal villus morphology to inflammation and finally to villus atrophy with crypt hyperplasia. Patients with early-stage coeliac disease have TG2-autoantibodies present in serum and small-intestinal mucosa and they may already suffer from abdominal symptoms before the development of villus atrophy. Previously, we have shown that intraperitoneal injections of coeliac patient-derived sera or purified immunoglobulin fraction into mice induce a condition mimicking early-stage coeliac disease. In the current study, we sought to establish whether recombinantly produced patient-derived TG2-targeted autoantibodies are by themselves sufficient for the development of such an experimentally induced condition in immune-compromised mice. Interestingly, mice injected with coeliac patient TG2-antibodies had altered small-intestinal mucosal morphology, increased lamina propria cellular infiltration and disease-specific autoantibodies deposited in the small bowel, but did not evince clinical features of the disease. Thus, coeliac patient-derived TG2-specific autoantibodies seem to be sufficient for the induction of subtle small-bowel mucosal alterations in mice, but the development of clinical features probably requires additional factors such as other antibody populations relevant in coeliac disease.

Mast cell activation disease and the modern epidemic of chronic inflammatory disease

A large and growing portion of the human population, especially in developed countries, suffers 1 or more chronic, often quite burdensome ailments which either are overtly inflammatory in nature or are suspected to be of inflammatory origin, but for which investigations to date have failed to identify specific causes, let alone unifying mechanisms underlying the multiple such ailments that often afflict such patients. Relatively recently described as a non-neoplastic cousin of the rare hematologic disease mastocytosis, mast cell (MC) activation syndrome-suspected to be of greatly heterogeneous, complex acquired clonality in many cases-is a potential underlying/unifying explanation for a diverse assortment of inflammatory ailments. A brief review of MC biology and how aberrant primary MC activation might lead to such a vast range of illness is presented.

Elderly Onset Celiac Disease: A Narrative Review

Celiac sprue is a chronic disease, which usually occurs in children and young adults. However, it can develop in any age group, and the prevalence is increasing even in the elderly population. The atypical patterns of clinical presentation in this age group sometimes can cause a delay in diagnosis. Given the lower sensitivity and specificity of serological tests in the aged population, clinical suspect often arises in the presence of complications (autoimmune disorders, fractures, and finally, malignancy) and must be supported by endoscopic and imaging tools. In this review, we highlight the incidence and prevalence of celiac disease in the elderly, the patterns of clinical presentation, diagnosis, and the most frequent complications, with the aim of increasing awareness and reducing the diagnostic delay of celiac disease even in the elderly population.

Systematic review and meta-analysis of the association between IL18RAP rs917997 and CCR3 rs6441961 polymorphisms with celiac disease risks

OBJECTIVES

We performed a systematic review and meta-analysis to estimate the polymorphism effects of IL18RAP and CCR3 on celiac disease susceptibility.

METHODS

PubMed and Web of Science databases were searched (to June 2015) on IL18RAP rs917997 and CCR3 rs6441961 polymorphisms.

RESULTS

The meta-analysis included 16 and 7 studies for rs917997 and rs6441961, respectively. The minor risk A allele at both rs917997 and rs6441961 carried risks (odds ratios) of 1.24 (95% CI 1.18-1.31) and 1.21 (95% CI 1.12-1.31), respectively. These alleles contributed to increase risks in all celiac disease patients by 5.04 and 6.35%. The estimated lambdas were 0.73 and 0.51, suggesting that an additive model would be the best choice for both gene effects.

CONCLUSIONS

This meta-analysis provides robust estimates that IL18RAP rs917997 and CCR3 rs6441961 are potential risk factors for celiac disease in European populations. Studies are needed to confirm these findings in different ethnicities.

Current knowledge on psoriasis and autoimmune diseases

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways.

The potential utility of tight junction regulation in celiac disease: focus on larazotide acetate

Celiac disease (CD) is a common chronic immune disease triggered by gluten. Gliadin peptides pass through the epithelial layers, either paracellularly or transcellularly, to launch a potent adaptive immune response in the lamina propria. This aberrant immune response leads to diverse gastrointestinal and extra-gastrointestinal symptoms. Currently, the only treatment for CD is a strict lifelong adherence to a gluten-free diet (GFD), which can be challenging. An early effect of gluten in CD is an increase in gut permeability. Larazotide acetate, also known as AT-1001, is a synthetic peptide developed as a permeability regulator primarily targeting CD. In vitro studies indicate that larazotide acetate is capable of inhibiting the actin rearrangement caused by gliadin and clinical studies have been conducted using this peptide as a therapy for CD.

Celiac disease: role of intestinal compartments in the mucosal immune response

Different approaches have been used to study the pattern of cytokines in celiac disease (CD). Laser capture microdissection (LCM) is a powerful tool for the isolation of specific tissue compartments. We aimed to investigate the mucosal immune response that takes place in different intestinal compartments of CD patients, dissected by LCM, analyzing cytokine expression profile. Frozen section of jejunum was obtained from 15 untreated CD and 15 control. Surface epithelium and lamina propria compartment were isolated by LCM. RNA from each LCM sample was extracted and, after a retrotranscription step, messenger RNA levels for MxA, IL-15, TNF-α, IFN-γ, IL-17α, IL-21, IL-10, and TGF-β were determined by quantitative reverse transcriptase-PCR. Increased gene expression levels of MxA, IL-15, TNF-α, IL-10, and TGF-β was observed in the surface epithelium of untreated CD with respect to control. Furthermore, all the cytokines investigated were upregulated in the lamina propria of untreated CD as compared to control. Within the untreated CD group the expression of IL-15 was higher, in the surface epithelium than in the lamina propria, whereas the expression levels of IL-17 and IL-21 were higher in the lamina propria than in the surface epithelium. Finally, high levels of IL-10 and TGF-β were detected in both compartments of untreated CD biopsies. In CD, surface epithelium and lamina propria compartments, play a prominent role in determining innate and adaptive immunity, respectively. Conversely, surface epithelium and lamina propria produce high levels of anti-inflammatory cytokines, suggesting that both compartments are involved in the immunoregulatory response.

In the Intestinal Mucosa of Children With Potential Celiac Disease IL-21 and IL-17A are Less Expressed than in the Active Disease

OBJECTIVES

Potential celiac disease (CD) patients are at an increased risk to developing CD as indicated by positive CD-associated serology. We investigated in duodenal mucosa of such patients the presence of both IL-21 and IL-17A and the role of gliadin peptides and IL-15 in their expression.

METHODS

Duodenal biopsies from 76 active CD, 90 potential CD, and 58 control patients were analyzed for IL-21 and/or IL-17A production by quantitative real-time PCR, immunohistochemistry, flow cytometry, and ELISA. The presence of IL-21 receptor was investigated by western blot. Potential CD duodenal fragments were cultured with gliadin peptides (PTG) and/or IL-15 and the expression/production of IL-21 and IL-17A assessed by quantitative real-time PCR and by immunohistochemistry.

RESULTS

In potential CD, IL-21 was lower than in active CD, in terms of RNA expression (P<0.01), density of lamina propria (LP) IL-21(+) cells (P<0.05), and protein secretion (P<0.05). Also, IL-21R was weakly detectable in potential CD. Several LP cell types produced IL-21 in CD. In potential CD, CD4(+)IL-21(+) cells increased after PMA-ionomycin stimulation and co-produced IFN-γ but not IL-17A. After 24 hours of culture stimulation with PTG, IL-21-producing cells increased but not the ones producing IL-17A. This increase was further enhanced by the addition of IL-15 to culture medium.

CONCLUSIONS

In potential CD, IL-21 is less expressed than in active CD; however, IL-21-producing cells are present and prone to respond after specific stimuli. This suggests a key role of IL-21 in the progression of mucosal damage in CD.

Celiac disease as a model for the evolution of multifactorial disease in humans

Celiac disease (CD) is a multifactorial chronic inflammatory condition that results in injury of the mucosal lining of the small intestine upon ingestion of wheat gluten and related proteins from barley and rye. Although the exact mechanisms leading to CD are not fully understood, the genetic basis of CD has been relatively well characterized. In this review we briefly review the history of discovery, clinical presentation, pathophysiology, and current understanding of the genetics underlying CD risk. Then, we discuss what is known about the current distribution and evolutionary history of genes underlying CD risk in light of other evolutionary models of disease. Specifically, we conclude that the set of loci underlying CD risk did not cohesively evolve as a response to a single past selection event such as the development of agriculture. Rather, deterministic and stochastic evolutionary processes have both contributed to the present distribution of variation in CD risk loci. Selection has shaped some components of this network, but this selection appears to have occurred at different points in the past. Other parts of the CD risk network have likely arisen due to stochastic processes such as genetic drift.

Transcriptome Analysis of CD4+ T Cells in Coeliac Disease Reveals Imprint of BACH2 and IFNγ Regulation

Genetic studies have to date identified 43 genome wide significant coeliac disease susceptibility (CD) loci comprising over 70 candidate genes. However, how altered regulation of such disease associated genes contributes to CD pathogenesis remains to be elucidated. Recently there has been considerable emphasis on characterising cell type specific and stimulus dependent genetic variants. Therefore in this study we used RNA sequencing to profile over 70 transcriptomes of CD4+ T cells, a cell type crucial for CD pathogenesis, in both stimulated and resting samples from individuals with CD and unaffected controls. We identified extensive transcriptional changes across all conditions, with the previously established CD gene IFNy the most strongly up-regulated gene (log2 fold change 4.6; P_adjusted = 2.40x10^-11) in CD4+ T cells from CD patients compared to controls. We show a significant correlation of differentially expressed genes with genetic studies of the disease to date (P_adjusted = 0.002), and 21 CD candidate susceptibility genes are differentially expressed under one or more of the conditions used in this study. Pathway analysis revealed significant enrichment of immune related processes. Co-expression network analysis identified several modules of coordinately expressed CD genes. Two modules were particularly highly enriched for differentially expressed genes (P<2.2x10^-16) and highlighted IFNy and the genetically associated transcription factor BACH2 which showed significantly reduced expression in coeliac samples (log2FC -1.75; P_adjusted = 3.6x10^-3) as key regulatory genes in CD. Genes regulated by BACH2 were very significantly over-represented among our differentially expressed genes (P<2.2x10^-16) indicating that reduced expression of this master regulator of T cell differentiation promotes a pro-inflammatory response and strongly corroborates genetic evidence that BACH2 plays an important role in CD pathogenesis.

Celiac disease and non-celiac gluten sensitivity

Celiac disease is a multisystem immune based disorder that is triggered by the ingestion of gluten in genetically susceptible individuals. The prevalence of celiac disease has risen in recent decades and is currently about 1% in most Western populations. The reason for this rise is unknown, although environmental factors related to the hygiene hypothesis are suspected. The pathophysiology of celiac disease involves both the innate and adaptive immune response to dietary gluten. Clinical features are diverse and include gastrointestinal symptoms, metabolic bone disease, infertility, and many other manifestations. Although a gluten-free diet is effective in most patients, this diet can be burdensome and can limit quality of life; consequently, non-dietary therapies are at various stages of development. This review also covers non-celiac gluten sensitivity. The pathophysiology of this clinical phenotype is poorly understood, but it is a cause of increasing interest in gluten-free diets in the general population.

Onset of Thrombin Generation Occurs More Rapidly in Pediatric Patients With Celiac Disease

OBJECTIVE

Celiac disease (CD) is a risk factor for venous thromboembolism (VTE) and stroke, but the mechanisms are unclear. Continuous measurement of thrombin generation in plasma is a feasible way to detect hypercoagulable changes. The aim of this pilot study was to investigate thrombin generation in pediatric patients with CD compared with pediatric controls.

METHODS

Plasma samples were collected from 19 pediatric patients with CD and 20 healthy controls. In each patient diagnosed as having CD, thrombin generation was determined twice by means of calibrated automated thrombography. The first measurement was undertaken when CD was diagnosed; the second measurement was undertaken after normalization of their IgA antitissue transglutaminase antibody (tTG-Ab) titers following a gluten-free diet. In the controls, measurement for TTG-Ab and thrombin generation was undertaken once during recruitment.

RESULTS

Patients with CD at diagnosis showed a significantly shorter lag time compared with controls (P < 0.001) and a shorter time-to-peak compared with controls (P < 0.02). These differences were no longer detectable after normalization of TTG-Ab values. The overall amount of generated thrombin, represented by the endogenous thrombin potential (ETP), showed no significant difference between the study groups.

CONCLUSIONS

Our results show that alterations in coagulation can be found in untreated CD that may help to explain the described increased risk of stroke or VTE. A shorter lag time in patients with untreated CD indicates a more rapid onset of thrombin generation as a sign of hypercoagulability. ETP, the best predictive parameter for thromboembolic disease, however, was not altered.

Effect of anti-gliadin IgY antibody on epithelial intestinal integrity and inflammatory response induced by gliadin

BACKGROUND

Pepsin-trypsin resistant gliadin (PT-gliadin) promotes intestinal tissue inflammation and increases paracellular permeability of immunogenic gliadin peptides into the lamina propria. This leads to the complications seen in the pathogenesis of celiac disease (CD). In this study, specific anti-gliadin IgY antibody was produced and evaluated for its efficacy on gliadin induced intestinal integrity impairment and proinflammatory effects on intestinal epithelial (Caco-2) cell culture model for CD.

METHODS

Caco-2 (passages 20-24) monolayers were subjected to 7 experimental conditions (n=3 each): phosphate buffered saline (PBS; control), pancreatic digested-casein (PD-casein; negative control), PT-gliadin (positive control), non-specific IgY with PT-gliadin, and anti-wheat gliadin IgY with PT-gliadin at a ratio of 1:6,000, 1:3,000 and 1:1,500. Caco-2 monolayers were then evaluated for effects of gliadin and/or anti-wheat gliadin IgY after 24 h exposure. Enzyme-linked immunosorbent assay (ELISA) was used to quantify anti-inflammatory markers (TNF-α and IL-1β) 5 days after cells were exposed to PT-gliadin and/or anti-wheat gliadin IgY.

RESULTS

Among other conditions, anti-wheat gliadin IgY at a ratio of 1:3,000 (anti-gliadin IgY: PT-gliadin) significantly prevented gliadin toxicity on Caco-2 by maintaining intestinal integrity, inhibiting phenol red permeation, and inhibiting gliadin absorption and production of proinflammatory cytokines (TNF-α and IL-1β) as compared to PT-gliadin stimulated cultures (P < 0.05).

CONCLUSION

The anti-wheat gliadin IgY antibody produced in this study has proved to inhibit absorption of gliadin and gliadin-induced inflammatory response in Caco2 cell culture model of CD. Anti-gliadin IgY, therefore has potential to be used as an oral passive antibody therapy to treat CD.

Wheat-related disorders reviewed: making a grain of sense

Wheat-related disorders have become a growing area of clinical and scientific interest and can be categorized broadly as: autoimmune-mediated; allergic; and non-autoimmune/non-allergic conditions. Non-celiac gluten sensitivity (NCGS) and non-celiac wheat sensitivity (NCWS) present on this spectrum as disorders associated with adverse gastrointestinal and extra-intestinal manifestations following exposure to gluten and/or other wheat-related constituents. NCGS/NCWS is increasingly considered in patients with unexplained symptoms after the exclusions of celiac disease and wheat allergy. As objective diagnostic data and specific biomarkers are lacking, response to a gluten-free/wheat-free diet can confirm the presence of NCGS/NCWS. An association with irritable bowel syndrome has been detected, and the effects of other food components, such as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, may contribute. Our organization and synthesis of extant knowledge pertaining to wheat-related disorders may advance current practice and research efforts toward an improved understanding of NCGS/NCWS as an evolving clinical entity.

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. Furthermore, a non-recombinant approach has been developed based on the stable adsorption of antigen on the spore surface. In the present study, we explored this strategy as a means of modulating the immune response to wheat gliadin, the triggering agent of celiac disease (CD), an enteropathy driven by inflammatory CD4(+) T cells. Gliadin adsorption was tested on untreated or autoclaved wild-type (wt) and mutant (cotH or cotE) spores. We found that gliadin was stably and maximally adsorbed by autoclaved wt spores. We then tested the immune properties of the spore-adsorbed gliadin in HLA-DQ8-transgenic mice, which express one of the two HLA heterodimers associated with CD. In vitro, spore-adsorbed gliadin was efficiently taken up by mouse dendritic cells (DCs). Interestingly, gliadin-pulsed DCs efficiently stimulated splenic CD4(+) T cells from mice immunised with spore-adsorbed gliadin. Nasal pre-dosing with spore-adsorbed gliadin failed to down-regulate the ongoing cellular response in gliadin-sensitised DQ8 mice. Notably, naïve mice inoculated intranasally with multiple doses of spore-adsorbed gliadin developed an intestinal antigen-specific CD4(+) T cell-mediated response. In conclusion, our data highlight the ability of spore-adsorbed gliadin to elicit a T-cell response in the gut that could be exploitable for developing immune strategies in CD.

Local communication among mucosal immune cells in patients with celiac disease

In patients with celiac disease, gluten consumption causes inflammation of the duodenum, and, to a lesser extent, the proximal jejunum. Immune-dominant gluten peptides are modified by the enzyme TG2, leading to their high-affinity binding to HLA-DQ2 or HLA-DQ8 molecules, present in people with a predisposition to celiac disease. Gluten peptide-loaded HLA-DQ2 or HLA-DQ8 molecules are recognized by highly conserved receptors on CD4(+) T cells in the lamina propria. B cells specific for TG2 and modified gluten peptides are also abundant in the lamina propria of patients with celiac disease. In the epithelium, interleukin-15 activates intraepithelial lymphocytes that promote destruction of epithelial cells. However, it is not clear how the immune responses in the lamina propria and the epithelium, separated by a basement membrane, are linked. We review the immune processes that occur in the lamina propria and their potential effects on epithelial pathology in celiac disease.

TNFA Haplotype Genetic Testing Improves HLA in Estimating the Risk of Celiac Disease in Children

Background

TNF-α and IFN-γ play a role in the development of mucosal damage in celiac disease (CD). Polymorphisms of TNFA and IFNG genes, as well as of the TNFRSF1A gene, encoding the TNF-α receptor 1, might underlie different inter-individual disease susceptibility over a common HLA risk background. The aims of this study were to ascertain whether five SNPs in the TNFA promoter (-1031T>C,-857C>T,-376G>A,-308G>A,-238G>A), sequence variants of the TNFRSF1A gene and IFNG +874A>T polymorphism are associated with CD in a HLA independent manner.

Methods

511 children (244 CD, 267 controls) were genotyped for HLA, TNFA and INFG (Real Time PCR). TNFRSF1A variants were studied (DHPLC and sequence).

Results

Only the rare TNFA-1031C (OR=0.65, 95% CI:0.44-0.95), -857T (OR=0.42, 95% CI:0.27-0.65), -376A (OR=2.25, 95% CI:1.12-4.51) and -308A (OR=4.76, 95% CI:3.12-7.26) alleles were significantly associated with CD. One TNFRSF1A variant was identified (c.625+10A>G, rs1800693), but not associated with CD. The CD-correlated TNFA SNPs resulted in six haplotypes. Two haplotypes were control-associated (CCGG and TTGG) and three were CD-associated (CCAG, TCGA and CCGA). The seventeen inferred haplotype combinations were grouped (A to E) based on their frequencies among CD. Binary logistic regression analysis documented a strong association between CD and HLA (OR for intermediate risk haplotypes=178; 95% CI:24-1317; OR for high risk haplotypes=2752; 95% CI:287-26387), but also an HLA-independent correlation between CD and TNFA haplotype combination groups. The CD risk for patients carrying an intermediate risk HLA haplotype could be sub-stratified by TNFA haplotype combinations.

Conclusion

TNFA promoter haplotypes associate with CD independently from HLA. We suggest that their evaluation might enhance the accuracy in estimating the CD genetic risk.

Vaccination and other antigen-specific immunomodulatory strategies in celiac disease

BACKGROUND

Celiac disease (CD) results from an alteration in the oral tolerance to dietary gluten. The response to gluten is normally tightly regulated and involves the secretion of TGF-β and IL-10 from different subtypes of regulatory T cells (Tregs). Interestingly, in addition to proinflammatory cytokines, the inflamed CD mucosa also contains high levels of T cell-derived IL-10 compared with treated CD patients or normal donors. Furthermore, most studies describe an increase in the number of Foxp3+ Tregs in the small intestinal mucosa in CD patients compared to controls. This paradoxical condition suggests that regulatory mechanisms might operate to counterbalance the abnormal gliadin-triggered immune activation in untreated mucosa. Indeed, addition of exogenous IL-10 to mucosal cultures from treated CD patients can suppress gliadin-induced T cell activation. Considering the central role of adaptive immunity in CD, the development of strategies to stimulate these mechanisms is a primary goal of efforts to restore gluten tolerance. Key Messages: Different immunomodulatory strategies have been explored. NexVax2, a desensitizing vaccine that uses three dominant gluten peptides administered subcutaneously to induce a tolerogenic response in CD patients, is under development. Alternatively, the potential of substituted, cyclic or dimeric peptide analogues as blockers to prevent HLA from binding to the immunodominant gliadin epitopes has been demonstrated in vitro. In line with these results, we recently found that modified (transamidated) gliadins influenced the immune response in intestinal biopsy samples from CD patients with overt disease by drastically reducing the production of IFN-γ. Notably, in a mouse model, transamidated gliadins reverted the phenotype of the gliadin-inducible immune response from an inflammatory phenotype to an anti-inflammatory phenotype.

CONCLUSIONS

Various approaches are currently under investigation to recover gluten tolerance based on the use of both modified and native antigen molecules. More specific studies are now required to test the efficacy of such strategies for preventing CD.

The present and the future in the diagnosis and management of celiac disease

Celiac disease is an autoimmune enteropathy caused by gluten in genetically predisposed individuals. In celiac disease, adaptive and innate immune activation results in intestinal damage and a wide range of clinical manifestations. In the past, celiac disease was thought to result in signs and symptoms solely related to the gastrointestinal tract. Now, more than half of the adult population presents with extra-intestinal manifestations that can also be expected to improve on a gluten-free diet. For this reason, it is recommended that physicians have a low threshold of suspicion for celiac disease. Current knowledge of the immune pathogenesis of this autoimmune disease has served as a catalyst for the development of novel diagnostic tools and therapeutics. Over the years, highly sensitive and specific serological assays, in addition to genetic markers, have been found to target specific steps in the cascade pathway of celiac disease. Also the advent of the gluten challenge has enabled experts to design diagnostic algorithms and monitor clinical responses in clinical trials. The gluten challenge has provided substantial benefit in the advance of novel therapeutics as an adjuvant treatment to the gluten free diet. Generally, a strict gluten-free diet is highly burdensome to patients and can be limited in its efficacy. Alternative therapies-including gluten modification, modulation of intestinal permeability and immune response-could be central to the future treatment of celiac disease.

IL-15: a central regulator of celiac disease immunopathology

Interleukin-15 (IL-15) exerts many biological functions essential for the maintenance and function of multiple cell types. Although its expression is tightly regulated, IL-15 upregulation has been reported in many organ-specific autoimmune disorders. In celiac disease, an intestinal inflammatory disorder driven by gluten exposure, the upregulation of IL-15 expression in the intestinal mucosa has become a hallmark of the disease. Interestingly, because it is overexpressed both in the gut epithelium and in the lamina propria, IL-15 acts on distinct cell types and impacts distinct immune components and pathways to disrupt intestinal immune homeostasis. In this article, we review our current knowledge of the multifaceted roles of IL-15 with regard to the main immunological processes involved in the pathogenesis of celiac disease.

Gliadin-dependent cytokine production in a bidimensional cellular model of celiac intestinal mucosa

The downstream cascade of the inflammatory response to gliadin in celiac intestinal mucosa encompasses the early activation of the innate immunity that triggers the adaptive response. Therefore, the in vitro study of the pathogenic mechanism of celiac disease (CD) on enterocytes alone or mucosal T lymphocytes alone does not fully consider all the aspects of gliadin-dependent inflammation. Although the in vitro culture of specimens of intestinal mucosa obtained from celiac patients is the gold standard for the study of CD, this technique presents several technical challenges and the bioptic specimens are not easily available. So, in this paper, we described the gliadin-dependent cytokine production in a bidimensional cellular system, which is able to mimic both the innate and the adaptive steps of the mucosal immune response of CD. In the upper compartment, the intestinal epithelial cells are grown on a filter, and in the lower compartment, the mononuclear cells isolated from peripheral blood of celiac patients are cultured. Cells were apically exposed to the toxic gliadin peptide p31-43 for 3 h and then with the immunodominant gliadin fragment pα-9 for 21 h. The incubation with gliadin peptides resulted in increased levels of IL-15, INF-γ, IL-6, tumor necrosis factor (TNF)-α, IL-1β, and CCL 2, 3 and 4 in the basal supernatants, with respect to cells exposed to medium alone. The p31-43-driven epithelial priming of mucosal response consists of transglutaminase (TG2)-mediated deamidation of the immunostimulatory gliadin peptides, as demonstrated by the inhibition of pα-9 activity, when the system is exposed to blocking anti-TG2 antibody.

Impaired responses to gliadin and gut microbes of immune cells from mice with altered stress-related behavior and premature immune senescence

Stress is associated with impaired communication between the nervous and immune systems leading to immunosenescence and increased disease risk. We investigated whether leukocytes from mice with altered stress-related behavior and premature immunosenescence, as well as from chronologically aged mice differently responded ex vivo to celiac disease (CD) triggers (gliadin) and intestinal bacteria by ELISA and flow cytometry and differed in microbiota composition. We found that altered stress-related behavior and premature immunosenescence led to alterations in T lymphocytes and cytokine release of immune cells basally and in response to peptic fragments of gliadin and commensal and pathogenic bacteria, possibly increasing susceptibility to CD in adulthood.