Study and isolation of human intestinal dendritic cell and macrophage subsets.

Dendritic cells and macrophages are the main antigen-presenting cells (APC). In the gut, they control the mechanisms of tolerance toward commensals and nutrients, at the time that they maintain their capacity to trigger immune responses against invading pathogens. Nevertheless, this balance is not perfect as it can get disrupted like in inflammatory bowel disease (where they drive an abnormal immune response against the microbiota) or in coeliac disease (where they trigger an immune response against dietary gluten). Therefore, the study of human intestinal APC subsets is crucial not just to get a deeper insight in the mechanisms of human intestinal homeostasis, but also to understand the pathogenesis of inflammatory bowel disease and coeliac disease. Nevertheless, their study is quite complicated as despite their relevance, their numbers are scare in the intestinal mucosa. Therefore, we hereby describe different approaches to study human intestinal dendritic cell and macrophage subsets in the human intestinal mucosa.

Human intestinal dendritic cell and macrophage subsets in coeliac disease.

Dendritic cells (DC) and macrophages (Mϕ) constitute the most abundant antigen presenting cells in the human intestinal mucosa. In resting conditions, they are essential to maintain the mechanisms of immune tolerance toward food antigens and commensals, at the time that they keep the capacity to initiate and maintain antigen-specific pro-inflammatory immune responses toward invading pathogens. Nevertheless, this delicate equilibrium between immunity and tolerance is not perfect, like in coeliac disease (CD), where DC and Mϕ drive the development of antigen-specific immune responses toward dietary gluten peptides. In this review, we provide therefore a comprehensive discussion about CD pathogenesis, the human intestinal immune system and the biology of intestinal DC and Mϕ both in resting conditions and in CD. Last, but not least, we discuss about all the remaining issues pending to be studied regarding DC and Mϕ contribution toward CD pathogenesis. This may allow the identification of unique and specific factors which may be useful in the clinical practice, as well as identify new therapeutic targets in order to reestablish the loss intestinal homeostasis in CD.

Deletions of specific exons of FHOD3 detected by next-generation sequencing are associated with hypertrophic cardiomyopathy.

Despite new strategies, such as evaluating deep intronic variants and new genes in whole-genome-sequencing studies, the diagnostic yield of genetic testing in hypertrophic cardiomyopathy (HCM) is still around 50%. FHOD3 has emerged as a novel disease-causing gene for this phenotype, but the relevance and clinical implication of copy-number variations (CNVs) have not been determined. In this study, CNVs were evaluated using a comparative depth-of-coverage strategy by next-generation sequencing (NGS) in 5493 HCM probands and 2973 disease-controls. We detected three symmetrical deletions in FHOD3 that involved exons 15 and 16 in three HCM families (no CNVs were detected in the control group). These exons are part of the diaphanous inhibitory domain of FHOD3 protein, considered a cluster of mutations for HCM. The clinical characteristics of the affected carriers were consistent with those reported in FHOD3 in previous studies. This study highlights the importance of performing CNV analysis systematically in NGS genetic testing panels for HCM, and reinforces the relevance of the FHOD3 gene in the disease.

Formin Homology 2 Domain Containing 3 (FHOD3) Is a Genetic Basis for Hypertrophic Cardiomyopathy.

BACKGROUND: The genetic cause of hypertrophic cardiomyopathy remains unexplained in a substantial proportion of cases. Formin homology 2 domain containing 3 (FHOD3) may have a role in the pathogenesis of cardiac hypertrophy but has not been implicated in hypertrophic cardiomyopathy. OBJECTIVES: This study sought to investigate the relation between FHOD3 mutations and the development of hypertrophic cardiomyopathy. METHODS: FHOD3 was sequenced by massive parallel sequencing in 3,189 hypertrophic cardiomyopathy unrelated probands and 2,777 patients with no evidence of cardiomyopathy (disease control subjects). The authors evaluated protein-altering candidate variants in FHOD3 for cosegregation, clinical characteristics, and outcomes. RESULTS: The authors identified 94 candidate variants in 132 probands. The variants' frequencies were significantly higher in patients with hypertrophic cardiomyopathy (74 of 3,189 [2.32%]) than in disease control subjects (18 of 2,777 [0.65%]; p < 0.001) or in the gnomAD database (1,049 of 138,606 [0.76%]; p < 0.001). FHOD3 mutations cosegregated with hypertrophic cardiomyopathy in 17 families, with a combined logarithm of the odds score of 7.92, indicative of very strong segregation. One-half of the disease-causing variants were clustered in a small conserved coiled-coil domain (amino acids 622 to 655); odds ratio for hypertrophic cardiomyopathy was 21.8 versus disease control subjects (95% confidence interval: 1.3 to 37.9; p < 0.001) and 14.1 against gnomAD (95% confidence interval: 6.9 to 28.7; p < 0.001). Hypertrophic cardiomyopathy patients carrying (likely) pathogenic mutations in FHOD3 (n = 70) were diagnosed after age 30 years (mean 46.1 ± 18.7 years), and two-thirds (66%) were males. Of the patients, 82% had asymmetric septal hypertrophy (mean 18.8 ± 5 mm); left ventricular ejection fraction <50% was present in 14% and hypertrabeculation in 16%. Events were rare before age 30 years, with an annual cardiovascular death incidence of 1% during follow-up. CONCLUSIONS: FHOD3 is a novel disease gene in hypertrophic cardiomyopathy, accounting for approximately 1% to 2% of cases. The phenotype and the rate of cardiovascular events are similar to those reported in unselected cohorts. The FHOD3 gene should be routinely included in hypertrophic cardiomyopathy genetic testing panels.

Comprehensive genomic diagnosis of non-syndromic and syndromic hereditary hearing loss in Spanish patients.

BACKGROUND: Sensorineural hearing loss (SNHL) is the most common sensory impairment. Comprehensive next-generation sequencing (NGS) has become the standard for the etiological diagnosis of early-onset SNHL. However, accurate selection of target genomic regions (gene panel/exome/genome), analytical performance and variant interpretation remain relevant difficulties for its clinical implementation. METHODS: We developed a novel NGS panel with 199 genes associated with non-syndromic and/or syndromic SNHL. We evaluated the analytical sensitivity and specificity of the panel on 1624 known single nucleotide variants (SNVs) and indels on a mixture of genomic DNA from 10 previously characterized lymphoblastoid cell lines, and analyzed 50 Spanish patients with presumed hereditary SNHL not caused by GJB2/GJB6, OTOF nor MT-RNR1 mutations. RESULTS: The analytical sensitivity of the test to detect SNVs and indels on the DNA mixture from the cell lines was > 99.5%, with a specificity > 99.9%. The diagnostic yield on the SNHL patients was 42% (21/50): 47.6% (10/21) with autosomal recessive inheritance pattern (BSND, CDH23, MYO15A, STRC [n = 2], USH2A [n = 3], RDX, SLC26A4); 38.1% (8/21) autosomal dominant (ACTG1 [n = 3; 2 de novo], CHD7, GATA3 [de novo], MITF, P2RX2, SOX10), and 14.3% (3/21) X-linked (COL4A5 [de novo], POU3F4, PRPS1). 46.9% of causative variants (15/32) were not in the databases. 28.6% of genetically diagnosed cases (6/21) had previously undetected syndromes (Barakat, Usher type 2A [n = 3] and Waardenburg [n = 2]). 19% of genetic diagnoses (4/21) were attributable to large deletions/duplications (STRC deletion [n = 2]; partial CDH23 duplication; RDX exon 2 deletion). CONCLUSIONS: In the era of precision medicine, obtaining an etiologic diagnosis of SNHL is imperative. Here, we contribute to show that, with the right methodology, NGS can be transferred to the clinical practice, boosting the yield of SNHL genetic diagnosis to 50-60% (including GJB2/GJB6 alterations), improving diagnostic/prognostic accuracy, refining genetic and reproductive counseling and revealing clinically relevant undiagnosed syndromes.

Human corneal fibroblast migration and extracellular matrix synthesis during stromal repair: Role played by platelet-derived growth factor-BB, basic fibroblast growth factor, and transforming growth factor-ß1.

The development of treatments that modulate corneal wound healing to avoid fibrosis during tissue repair is important for the restoration of corneal transparency after an injury. To date, few studies have studied the influence of growth factors (GFs) on human corneal fibroblast (HCF) expression of extracellular matrix (ECM) proteins such as collagen types I and III, proteoglycans such as perlecan, or proteins implicated in cellular migration such as α5ß1-integrin and syndecan-4. Using in vitro HCFs, a mechanical wound model was developed to study the influence of the GFs basic fibroblast GF (bFGF), platelet-derived GF (PDGF-BB) and transforming GF-ß1 (TGFß1) on ECM protein production and cellular migration. Our results show that mechanical wounding provokes the autocrine release of bFGF and TGFß1 at different time points during the wound closure. The HCF response to PDGF-BB was a rapid closure due to fast cellular migration associated with a high focal adhesion replacement and a high expression of collagen and proteoglycans, producing nonfibrotic healing. bFGF stimulated nonfibrotic ECM production and limited the migration process. Finally, TGFß1 induced expression of the fibrotic markers collagen type III and α5ß1 integrin, and it inhibited cellular migration due to the formation of focal adhesions with a low turnover rate. The novel in vitro HCF mechanical wound model can be used to understand the role played by GFs in human corneal repair. The model can also be used to test the effects of different treatments aimed at improving the healing process. Copyright © 2016 John Wiley & Sons, Ltd.

Association of the IL-15 and IL-15Rα genes with celiac disease.

Celiac disease is a chronic autoimmune condition triggered by dietary gluten in genetically predisposed individuals and the treatment is a strict gluten-free diet. The major predisposing genes are HLA-DQA1 and HLA-DQB1, but these are not sufficient for disease development. One of the candidate genes worth studying is interleukin (IL)-15 gene, together with its specific receptor, IL-15Rα, as they participate in promoting lymphocyte signaling and survival, and the establishment of appropriate conditions for villous atrophy, then acting as key players in the immunopathogenesis of CD. Here we analyze IL-15 and IL-15Rα genes in samples from the Spanish Consortium for Genetics of Celiac Disease (CEGEC) collection, identifying two regulatory single-nucleotide polymorphisms (SNP) that might be associated with celiac disease: rs4956400 (p-value 0.0112, OR 1.21, 95% CI 1.04-1.40) and rs11100722 (p-value 0.0087, OR 1.24, 95% CI 1.06-1.45), both located upstream the IL15 gene. When the expression of both genes was assessed, these two SNPs were found to be correlated with IL-15 higher protein expression. Besides, rs8177655 from IL15RA was also associated to mRNA IL-15 expression in CD patients. Finally, three SNPs from IL15RA intronic regions, rs2296141, rs3136614 and rs3181148, and another from its 3'UTR region, rs2229135, could be related to the age of diagnosis of celiac disease patients.

New IL-15 receptor-α splicing variants identified in intestinal epithelial Caco-2 cells.

IL-15 is a pleiotropic cytokine related to IL-2 which acts at a broader level than its counterpart. It is presented through its specific high-affinity receptor, IL-15Rα. Both cytokine and receptor are tightly regulated at multiple levels and are widely distributed. Thus, deregulation of their expression leads to an inflammatory immune response. Variants of splicing of IL-15Rα have been described in immune and barrier cells; however, their presence has not been focused on intestinal epithelial cells. In this study, we describe five new alternative variants of splicing of IL-15Rα in Caco-2 cells. Four of them were expressed into proteins inside Caco-2 cells, but these were unable to bind IL-15 or to follow the secretory pathway. However, the expression of mRNA itself might be relevant to diseases such as celiac disease, inflammatory bowel disease or colorectal cancer.

Chemokine (C-C Motif) Receptor 2 Mediates Dendritic Cell Recruitment to the Human Colon but Is Not Responsible for Differences Observed in Dendritic Cell Subsets, Phenotype, and Function Between the Proximal and Distal Colon.

BACKGROUND & AIMS: Most knowledge about gastrointestinal (GI)-tract dendritic cells (DC) relies on murine studies where CD103+ DC specialize in generating immune tolerance with the functionality of CD11b+/- subsets being unclear. Information about human GI-DC is scarce, especially regarding regional specifications. Here, we characterized human DC properties throughout the human colon. METHODS: Paired proximal (right/ascending) and distal (left/descending) human colonic biopsies from 95 healthy subjects were taken; DC were assessed by flow cytometry and microbiota composition assessed by 16S rRNA gene sequencing. RESULTS: Colonic DC identified were myeloid (mDC, CD11c+CD123-) and further divided based on CD103 and SIRPα (human analog of murine CD11b) expression. CD103-SIRPα+ DC were the major population and with CD103+SIRPα+ DC were CD1c+ILT3+CCR2+ (although CCR2 was not expressed on all CD103+SIRPα+ DC). CD103+SIRPα- DC constituted a minor subset that were CD141+ILT3-CCR2-. Proximal colon samples had higher total DC counts and fewer CD103+SIRPα+ cells. Proximal colon DC were more mature than distal DC with higher stimulatory capacity for CD4+CD45RA+ T-cells. However, DC and DC-invoked T-cell expression of mucosal homing markers (ß7, CCR9) was lower for proximal DC. CCR2 was expressed on circulating CD1c+, but not CD141+ mDC, and mediated DC recruitment by colonic culture supernatants in transwell assays. Proximal colon DC produced higher levels of cytokines. Mucosal microbiota profiling showed a lower microbiota load in the proximal colon, but with no differences in microbiota composition between compartments. CONCLUSIONS: Proximal colonic DC subsets differ from those in distal colon and are more mature. Targeted immunotherapy using DC in T-cell mediated GI tract inflammation may therefore need to reflect this immune compartmentalization.

Increased Intraepithelial Vα24 Invariant NKT Cells in the Celiac Duodenum.

Celiac Disease (CD) is an interferon (IFN)γ-mediated duodenal hypersensitivity to wheat gluten occurring in genetically predisposed individuals. Gluten-free diet (GFD) leads to a complete remission of the disease. Vα24-restricted invariant NKT (iNKT) cells are important to maintain immune homeostasis in the gut mucosa because of their unique capacity to rapidly produce large quantities of both T-helper (Th)1 and Th2 cytokines upon stimulation. We studied the presence of these cells in the CD duodenum. Duodenal biopsies were obtained from 45 untreated-CD patients (uCD), 15 Gluten Free Diet-CD patients (GFD-CD), 44 non-inflamed non-CD controls (C-controls) and 15 inflamed non-CD controls (I-controls). Two populations from Spain and Argentina were recruited. Messenger RNA (mRNA) expression of Vα24-Jα18 (invariant TCRα chain of human iNKT cells), IFNγ and intracellular transcription factor Forkhead Box P3 (Foxp3), and flow cytometry intraepithelial lymphocyte (IEL) profile were determined. Both uCD and GFD-CD patients had higher Vα24-Jα18 mRNA levels than non-CD controls (I and C-controls). The expression of Vα24-Jα18 correlated with Marsh score for the severity of mucosal lesion and also with increased mRNA IFNγ levels. uCD and GFD-CD patients had decreased mRNA expression of FoxP3 but increased expression of Vα24-Jα18, which revealed a CD-like molecular profile. Increased numbers of iNKT cells were confirmed by flow cytometry within the intraepithelial lymphocyte compartment of uCD and GFD-CD patients and correlated with Vα24-Jα18 mRNA expression. In conclusion, we have found an increased number of iNKT cells in the duodenum from both uCD and GFD-CD patients, irrespective of the mucosal status. A CD-like molecular profile, defined by an increased mRNA expression of Vα24-Jα18 together with a decreased expression of FoxP3, may represent a pro-inflammatory signature of the CD duodenum.

Human colon-derived soluble factors modulate gut microbiota composition.

The commensal microbiota modulates immunological and metabolic aspects of the intestinal mucosa contributing to development of human gut diseases including inflammatory bowel disease. The host/microbiota interaction often referred to as a crosstalk, mainly focuses on the effect of the microbiota on the host neglecting effects that the host could elicit on the commensals. Colonic microenvironments from three human healthy controls (obtained from the proximal and distal colon, both in resting conditions and after immune - IL-15- and microbiota - LPS-in vitro challenges) were used to condition a stable fecal population. Subsequent 16S rRNA gene-based analyses were performed to study the effect induced by the host on the microbiota composition and function. Non-supervised principal component analysis (PCA) showed that all microbiotas, which had been conditioned with colonic microenvironments clustered together in terms of relative microbial composition, suggesting that soluble factors were modulating a stable fecal population independently from the treatment or the origin. Our findings confirmed that the host intestinal microenvironment has the capacity to modulate the gut microbiota composition via yet unidentified soluble factors. These findings indicate that an appropriate understanding of the factors of the host mucosal microenvironment affecting microbiota composition and function could improve therapeutic manipulation of the microbiota composition.

Altered human gut dendritic cell properties in ulcerative colitis are reversed by Lactobacillus plantarum extracellular encrypted peptide STp.

SCOPE: The human/microbiota cross-talk is partially mediated by bacteria-derived peptides like Serine-Threonine peptide (STp), which is resistant to gut proteolysis, is found in the human healthy colon and induces regulatory properties on gut dendritic cells (DCs); here we characterized human gut DC in ulcerative colitis (UC) patients and studied the effect of STp on their properties. METHODS AND RESULTS: Human colonic DC from healthy controls and UC patients were isolated, conditioned for 24 h +/- STp and characterized by flow cytometry, immunohistochemistry, and electron microscopy. Expression of immature DC markers DC-SIGN and ILT3, and Toll-like receptors were increased on gut UC-DC. Langerin (involved in phagocytosis), lymph node homing marker CCR7, and activation markers CD40/CD80/CD86 were decreased in UC. Gut DC had restricted stimulatory capacity for T-cells in UC. Conditioning of DC with STp in vitro reduced Toll-like receptor expression, increased CD40 and CD80 expression, and restored their stimulatory capacity. CONCLUSION: Colonic DCs display an abnormal immature phenotype in UC, which was partially restored following STp treatment. Bacteria-derived metabolites, like STp, seem to have a role in gut homeostasis that is missing in UC so they might lead a new era of probiotic products setting the basis for nondrug dietary therapy in inflammatory bowel disease.

Detection of specific IgA antibodies against a novel deamidated 8-Mer gliadin peptide in blood plasma samples from celiac patients.

We studied whether celiac disease (CD) patients produce antibodies against a novel gliadin peptide specifically generated in the duodenum of CD patients by a previously described pattern of CD-specific duodenal proteases. Fingerprinting and ion-trap mass spectrometry of CD-specific duodenal gliadin-degrading protease pattern revealed a new 8-mer gliadin-derived peptide. An ELISA against synthetic deamidated 8-mer peptides (DGP 8-mer) was used to study the presence of IgA anti-DGP 8-mer antibodies in plasma samples from 81 children (31 active CD patients (aCD), 17 CD patients on a gluten-free diet (GFD), 10 healthy controls (C) and 23 patients with other gastrointestinal pathology (GP)) and 101 adults (16 aCD, 12 GFD, 27 C and 46 GP-patients). Deamidation of the 8-mer peptide significantly increased the reactivity of the IgA antibodies from CD patients against the peptide. Significant IgA anti-DGP 8-mer antibodies levels were detected in 93.5% of aCD-, 11.8% of GFD- and 4.3% of GP-patients in children. In adults, antibodies were detected in 81.3% of aCD-patients and 8.3% of GFD-patients while were absent in 100% of C- and GP-patients. Duodenal CD-specific gliadin degrading proteases release an 8-mer gliadin peptide that once deamidated is an antigen for specific IgA antibodies in CD patients which may provide a new accurate diagnostic tool in CD.

IL-6 promotes immune responses in human ulcerative colitis and induces a skin-homing phenotype in the dendritic cells and Tcells they stimulate.

Dendritic cells (DCs) control the type and location of immune responses. Ulcerative colitis (UC) is considered a Th2 disease mediated by IL-13 where up to one third of patients can develop extraintestinal manifestations. Colonic biopsies from inflamed and noninflamed areas of UC patients were cultured in vitro and their supernatants were used to condition human blood enriched DCs from healthy controls. Levels of IL-13 in the culture supernatants were below the detection limit in most cases and the cytokine profile suggested a mixed profile rather than a Th2 cytokine profile. IL-6 was the predominant cytokine found in inflamed areas from UC patients and its concentration correlated with the Mayo endoscopic score for severity of disease. DCs conditioned with noninflamed culture supernatants acquired a regulatory phenotype with decreased stimulatory capacity. However, DCs conditioned with inflamed culture supernatants acquired a proinflammatory phenotype with increased expression of the skin-homing chemokine CCR8. These DCs did not have decreased T-cell stimulatory capacity and primed T cells with the skin-homing CLA molecule in an IL-6-dependent mechanism. Our results highlight the role of IL-6 in UC and question the concept of UC as a Th2 disease and the relevance of IL-13 in its etiology.

IL-15 modulates the effect of retinoic acid, promoting inflammation rather than oral tolerance to dietary antigens.

The physiological immune response in the intestine against dietary proteins and commensal flora is characterized by regulatory mechanisms (tolerance) that prevent harmful consequences. Intestinal dendritic cells (DCs) have a central role in the development of immunosuppressive regulatory T cells owing to their ability to produce TGF-ß and retinoic acid (RA). However, the article under evaluation shows an unexpected effect of RA - that of promoting a proinflammatory phenotype in intestinal DCs involved in the generation of inflammatory immune responses to dietary antigens. By using a double transgenic murine model that resembles human celiac disease, it was demonstrated that RA synergizes with IL-15 in promoting the breakdown of gluten tolerance and the development of enteropathy. The tissue microenvironment modulates DC function, and immune therapies that are based on RA aiming to restore oral tolerance should be used with caution because the presence of IL-15 (and/or other proinflammatory cytokines) may have undesirable effects.

Percutaneous liver biopsy: patients' point of view.

INTRODUCTION: Hepatic fibrosis can be assessed through serum markers or by the implementation of new non-invasive techniques, such as elastography. We must know patients' opinion on percutaneous liver biopsy (PLB) when it comes to comparing it with other procedures. AIMS: To know the point of view of patients undergoing a PLB with regard to information provided to them, as well as the procedures and biopsy consequences. PATIENTS AND METHODS: A questionnaire was sent by mail to 178 patients who underwent PLB from April 2006 to May 2010. Answers were analyzed. Results are expressed in percentages and compared based on gender and age (younger or older than 47 years of age) (Chi-square test). RESULTS: Ninety patients of the group answered, 44 females, mean age 47 ± 12 years. The answers revealed that 93% of patients rated the information concerning the reasons for a PLB as adequate (86% women and 100% men). As for the information concerning the objective of the procedure, 88% of patients regarded it as adequate (81% of women vs. 93% of men, p = 0.08). As for the information concerning the risks of a biopsy, 77.7% see it as sufficient. About 12.20% of patients did not receive any information on the physician who asked for the PLB, or who performed it. PLB was considered very painful by 14% of patients, painful by 21%, bothersome by 41.1% and barely bothersome by 23% of patients. Thirty-five percent of patients required analgesia after the puncture. Even though 92% of patients regard PLB as a useful procedure, 46% of them have not received any treatment or a different nutritional regime (55.8%, among those older than 47 years of age, p = 0.03). Eighty percent of patients think that PLB has more benefits than drawbacks, although 87% would have opted for a less aggressive technique as long as it would have provided the same information. But 21% of patients would have also preferred a less aggressive technique, even though it provided fewer details. CONCLUSIONS: In general, PLB is widely approved by patients and is also regarded as a useful procedure. One out of six patients would rather choose a less-aggressive technique even if it provided less information. PLB does not involve changes in the treatment in around a half of patients.

Inmunología de la enfermedad celíaca / Immunology of celiac disease

La enfermedad celíaca es un trastorno inflamatorio del intestino delgado inducido por la ingestión de gluten de trigo y otras prolaminas en individuos genéticamente susceptibles, que se manifiesta por linfocitosis intraepitelial y de lámina propia, pérdida de vellosidades, remodelación tisular y presencia de anticuerpos antitransglutaminasa. El modelo patogénico más aceptado depende de la inmunidad adaptativa tras la estimulación de linfocitos T CD4+ por péptidos de gluten modificados por la transglutaminasa tisular y restricción por moléculas HLA-DQ2/DQ8, que producen citocinas proinflamatorias. El gluten activa también la inmunidad innata y la citotoxicidad epitelial mediada por linfocitos intraepiteliales. Aunque no está claro aún cuál es el efecto de los anticuerpos específicos, la disponibilidad de marcadores serológicos e inmunogenéticos como herramientas diagnósticas ha propiciado el avance en el conocimiento de la enfermedad celíaca y la revisión de los criterios diagnósticos, especialmente en los individuos adultos con expresión mínima o atípica de la enfermedad (AU)

Celiac disease is an inflammatory disorder of the small intestine induced by intake of wheat gluten and other prolamines in genetically susceptible individuals. This disease is manifested by an increased number of intraepithelial and lamina propria lymphocytes, villous atrophy, tissue remodeling and the presence of anti-transglutaminase antibodies. The most widely accepted pathogenic model is based on adaptive immunity after T CD4+lymphocyte stimulation by tissue transglutamine-modified gluten peptides and HLA-DQ2/DQ8 restriction, which produce proinflammatory cytokines. Gluten also activates innate immunity and epithelial cytotoxicity mediated by intraepithelial lymphocytes. Although the effect of specific antibodies remains unclear, the availability of serological and immunogenetic markers as diagnostic tools has increased our knowledge of celiac disease and has led to a reevaluation of the diagnostic criteria, especially in adults with minimal or atypical disease expression (AU)

The simultaneous high expression of Vα24, IFN-γ and FoxP3 characterizes the liver of children with type I autoimmune hepatitis.

The immunopathogenesis of type I autoimmune hepatitis (AIH-I) might involve the deregulation of different cellular processes. Here, we investigated the liver expression of selected cytokines and genes of regulatory cell populations in children both at diagnosis and during biochemical remission following immunosuppressive treatment (AIH-Ir). We found a higher Vα24, IFN-γ, FoxP3, IL-27p28, IL-12p40 and IL-21 expression at diagnosis as well as a positive correlation between IL-21 and transaminase levels. Interestingly, only IFN-γ and FoxP3 were decreased in AIH-Ir. An "AIH-I phenotype" (high Vα24, IFN-γ and FoxP3 expression at diagnosis) was observed in only 5 out of 22 AIH-Ir patients but not in controls. These results indicate a local deregulation of the innate and adaptive immune responses with an increased transcriptional activity of immunoregulatory cells at diagnosis. In addition, IL-21 is highlighted as a mediator of liver injury. AIH-Ir is characterized by a partial reversal of the deregulated response.

[Immunology of celiac disease]. / Inmunología de la enfermedad celíaca.

Celiac disease is an inflammatory disorder of the small intestine induced by intake of wheat gluten and other prolamines in genetically susceptible individuals. This disease is manifested by an increased number of intraepithelial and lamina propria lymphocytes, villous atrophy, tissue remodeling and the presence of anti-transglutaminase antibodies. The most widely accepted pathogenic model is based on adaptive immunity after T CD4(+)lymphocyte stimulation by tissue transglutamine-modified gluten peptides and HLA-DQ2/DQ8 restriction, which produce proinflammatory cytokines. Gluten also activates innate immunity and epithelial cytotoxicity mediated by intraepithelial lymphocytes. Although the effect of specific antibodies remains unclear, the availability of serological and immunogenetic markers as diagnostic tools has increased our knowledge of celiac disease and has led to a reevaluation of the diagnostic criteria, especially in adults with minimal or atypical disease expression.