Publications by authors named "Ricardo Pujol-Borrell"

67 Publications

Peripheral and lung resident memory T cell responses against SARS-CoV-2.

Nat Commun 2021 05 21;12(1):3010. Epub 2021 May 21.

Infectious Diseases Department, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain.

Resident memory T cells (T) positioned within the respiratory tract are probably required to limit SARS-CoV-2 spread and COVID-19. Importantly, T are mostly non-recirculating, which reduces the window of opportunity to examine these cells in the blood as they move to the lung parenchyma. Here, we identify circulating virus-specific T cell responses during acute infection with functional, migratory and apoptotic patterns modulated by viral proteins and associated with clinical outcome. Disease severity is associated predominantly with IFNγ and IL-4 responses, increased responses against S peptides and apoptosis, whereas non-hospitalized patients have increased IL-12p70 levels, degranulation in response to N peptides and SARS-CoV-2-specific CCR7 T cells secreting IL-10. In convalescent patients, lung-T are frequently detected even 10 months after initial infection, in which contemporaneous blood does not reflect tissue-resident profiles. Our study highlights a balanced anti-inflammatory antiviral response associated with a better outcome and persisting T cells as important for future protection against SARS-CoV-2 infection.
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http://dx.doi.org/10.1038/s41467-021-23333-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8140108PMC
May 2021

Coordinated Response to Imported Vaccine-Derived Poliovirus Infection, Barcelona, Spain, 2019-2020.

Emerg Infect Dis 2021 05;27(5):1513-1516

In 2019, the Public Health Agency of Barcelona, Spain, was notified of a vaccine-derived poliovirus infection. The patient had an underlying common variable immunodeficiency and no signs of acute flaccid paralysis. We describe the ongoing coordinated response to contain the infection, which included compassionate-use treatment with pocapavir.
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http://dx.doi.org/10.3201/eid2705.204675DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8084499PMC
May 2021

Simple predictive models identify patients with COVID-19 pneumonia and poor prognosis.

PLoS One 2020 28;15(12):e0244627. Epub 2020 Dec 28.

Universitat Autònoma de Barcelona, Barcelona, Spain.

Background And Aims: Identification of SARS-CoV-2-infected patients at high-risk of poor prognosis is crucial. We aimed to establish predictive models for COVID-19 pneumonia severity in hospitalized patients.

Methods: Retrospective study of 430 patients admitted in Vall d'Hebron Hospital (Barcelona) between 03-12-2020 and 04-28-2020 due to COVID-19 pneumonia. Two models to identify the patients who required high-flow-oxygen-support were generated, one using baseline data and another with also follow-up analytical results. Calibration was performed by a 1000-bootstrap replication model.

Results: 249 were male, mean age 57.9 years. Overall, 135 (31.4%) required high-flow-oxygen-support. The baseline predictive model showed a ROC of 0.800 based on: SpO2/FiO2 (adjusted Hazard Ratio-aHR = 8), chest x-ray (aHR = 4), prior immunosuppressive therapy (aHR = 4), obesity (aHR = 2), IL-6 (aHR = 2), platelets (aHR = 0.5). The cut-off of 11 presented a specificity of 94.8%. The second model included changes on the analytical parameters: ferritin (aHR = 7.5 if ≥200ng/mL) and IL-6 (aHR = 18 if ≥64pg/mL) plus chest x-ray (aHR = 2) showing a ROC of 0.877. The cut-off of 12 exhibited a negative predictive value of 92%.

Conclusions: SpO2/FiO2 and chest x-ray on admission or changes on inflammatory parameters as IL-6 and ferritin allow us early identification of COVID-19 patients at risk of high-flow-oxygen-support that may benefit from a more intensive disease management.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244627PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7769554PMC
January 2021

Polyendocrine autoimmune syndromes reveal mechanisms of tolerance and autoimmunity.

Med Clin (Barc) 2020 06 19;154(11):444-446. Epub 2019 Nov 19.

Servicio de Inmunología, Hospital Universitari Vall d'Hebron y Grupo de Inmunología Diagnóstica, Vall d'Hebron Institut de Recerca, Barcelona. Parte del UAB-Barcelona «FOCIS Center of Excellence»" - www.focisnet.org, Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies (Barcelona) y ERN-RITA center (Barcelona); Departamento Biología Celular, Fisiología e Inmunología, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, España.

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http://dx.doi.org/10.1016/j.medcli.2019.10.003DOI Listing
June 2020

Expanding the Clinical and Genetic Spectra of Primary Immunodeficiency-Related Disorders With Clinical Exome Sequencing: Expected and Unexpected Findings.

Front Immunol 2019 1;10:2325. Epub 2019 Oct 1.

Immunology Division, Department of Cell Biology, Physiology and Immunology, Vall d'Hebron Research Institute, Hospital Universitari Vall d'Hebron, Autonomous University of Barcelona, Barcelona, Spain.

Primary immunodeficiencies (PIDs) refer to a clinically, immunologically, and genetically heterogeneous group of over 350 disorders affecting development or function of the immune system. The increasing use of next-generation sequencing (NGS) technology has greatly facilitated identification of genetic defects in PID patients in daily clinical practice. Several NGS approaches are available, from the unbiased whole exome sequencing (WES) to specific gene panels. Here, we report on a 3-year experience with clinical exome sequencing (CES) for genetic diagnosis of PIDs. We used the TruSight One sequencing panel, which includes 4,813 disease-associated genes, in 61 unrelated patients (pediatric and adults). The analysis was done in 2 steps: first, we focused on a virtual PID panel and then, we expanded the analysis to the remaining genes. A molecular diagnosis was achieved in 19 (31%) patients: 12 (20%) with mutations in genes included in the virtual PID panel and 7 (11%) with mutations in other genes. These latter cases provided interesting and somewhat unexpected findings that expand the clinical and genetic spectra of PID-related disorders, and are useful to consider in the differential diagnosis. We also discuss 5 patients (8%) with incomplete genotypes or variants of uncertain significance. Finally, we address the limitations of CES exemplified by 7 patients (11%) with negative results on CES who were later diagnosed by other approaches (more specific PID panels, WES, and comparative genomic hybridization array). In summary, the genetic diagnosis rate using CES was 31% (including a description of 12 novel mutations), which rose to 42% after including diagnoses achieved by later use of other techniques. The description of patients with mutations in genes not included in the PID classification illustrates the heterogeneity and complexity of PID-related disorders.
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http://dx.doi.org/10.3389/fimmu.2019.02325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6797824PMC
October 2020

Regulation of Expression in the Thyroid and Thymus May Contribute to TSHR Tolerance Failure in Graves' Disease Patients via Two Distinct Mechanisms.

Front Immunol 2019 18;10:1695. Epub 2019 Jul 18.

Immunology Division, FOCIS Center of Excellence, Hospital Universitari Vall d'Hebron, Barcelona, Spain.

Graves' disease (GD) involves the presence of agonistic auto-antibodies against the thyrotropin receptor (TSHR), which are responsible for the clinical symptoms. While failure of TSHR tolerance is central to GD pathogenesis, the process leading to this failure remains poorly understood. Two mechanisms intimately linked to tolerance have been proposed to explain the association of SNPs located in intron 1 to GD: (1) differential alternative splicing in the thyroid; and (2) modulation of expression in the thymus. To elucidate the relative contribution to these two mechanisms to GD pathogenesis, we analyzed the level of full-length and ST4 and ST5 isoform expression in the thyroid ( = 49) and thymus ( = 39) glands, and the influence of intron 1-associated SNPs on such expression. The results show that: (1) the level of flTSHR and ST4 expression in the thymus was unexpectedly high (20% that of the thyroid); (2) while flTSHR is the predominant isoform, the levels are similar to ST4 (ratio flTSHR/ST4 = 1.34 in the thyroid and ratio flTSHR/ST4 in the thymus = 1.93); (3) next-generation sequencing confirmed the effect of the TSHR intron 1 polymorphism on TSHR expression in the thymus with a bias of 1.5 ± 0.2 overexpression of the protective allele in the thymus compared to the thyroid; (4) GD-associated intron 1 SNPs did not influence alternative splicing of ST4 and ST5 in the thyroid and thymus; and (5) three-color confocal imaging showed that TSHR is associated with both thymocytes, macrophages, and dendritic cells in the thymus. Our findings confirm the effect of intron 1 polymorphisms on thymic TSHR expression and we present evidence against an effect on the relative expression of isoforms. The high level of ST4 expression in the thymus and its distribution within the tissue suggest that this would most likely be the isoform that induces central tolerance to TSHR thus omitting most of the hinge and transmembrane portion. The lack of central tolerance to a large portion of TSHR may explain the relatively high frequency of autoimmunity related to TSHR and its clinical consequence, GD.
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http://dx.doi.org/10.3389/fimmu.2019.01695DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657650PMC
October 2020

Distinct pattern of peripheral lymphocyte subsets in Graves' disease with persistency of anti-TSHR autoantibodies.

Autoimmunity 2019 Aug - Sep;52(5-6):220-227. Epub 2019 Jul 31.

Immunology Division, LCMN Germans Trias i Pujol University Hospital Badalona, Barcelona, Spain.

Graves' disease (GD) is characterized by the production of autoantibodies against the TSHR (TRAbs). With long-term treatment, serum concentrations of TRAbs decline but in some patients, despite being clinically stable, TRAbs persist for many years. To investigate whether GD patients with persistence of TRAbs constitute a subset of patients that could be identified by phenotypic analysis of circulating lymphocytes, suggesting disease heterogeneity. Peripheral blood lymphocytes (including naïve, memory and effector T and B cells, Th17, regulatory T cells (Treg), recent thymic emigrants (RTEs) and double positive CD4CD8 (DP) cells) were analysed by flow cytometry in a cross-sectional study in 25 clinically stable GD patients, five patients at onset of GD disease and 40 healthy donors (HDs). GD patients with persistence of TRAbs showed a lower percentage of Treg and lower absolute numbers of central and effector memory CD8 T cells than HD. No differences in RTEs were found in peripheral blood from GD patients compared to HD. Stable GD patients had higher percentage of DP cells of effector phenotype than HD. Using extensive phenotypic analysis of lymphocyte subpopulations, it is possible to detect changes that help to identify patients with persistent TSHR antibodies and may contribute to understand why the autoimmune response is maintained.
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http://dx.doi.org/10.1080/08916934.2019.1646253DOI Listing
July 2020

Analysis of the PD-1/PD-L1 axis in human autoimmune thyroid disease: Insights into pathogenesis and clues to immunotherapy associated thyroid autoimmunity.

J Autoimmun 2019 09 8;103:102285. Epub 2019 Jun 8.

Immunology Division Hospital Universitari Vall d'Hebron, 119-129 Passeig Vall d'Hebron, 08035, Barcelona, Spain; Vall d'Hebron Institute of Research (VHIR), 119-129 Passeig Vall d'Hebron, 08035, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona, 08193, Bellaterra (Barcelona), Spain. Electronic address:

Autoimmune thyroid diseases (AITDs), i.e., Graves' disease (GD) and Hashimoto thyroiditis (HT), are the most prevalent organ-specific autoimmune diseases, but their pathogenesis is still incompletely understood. The PD-1/PD-L1 pathway is an important mechanism of peripheral tolerance that has not been investigated in AITDs. Here, we report the analysis of the expression of PD-1, PD-L1 and PD-L2 in PBMCs, infiltrating thyroid lymphocytes (ITLs) and in thyroid follicular cells (TFCs) in GD, HT and multinodular goiter (MNG) patients and healthy controls PBMCs (HC). By combining flow cytometry, tissue immunofluorescence and induction experiments on primary and thyroid cell line cultures, we show that: 1) while PD-1+ T cells are moderately expanded in PBMCs from GD vs HC, approximately half of T cells in the infiltrate are PD-1+ including some PD-1; 2) PD-L1, but not PD-L2, is expressed by 81% of GD glands and in 25% of non-autoimmune glands; 3) PD-L1, was expressed by TFCs in areas that also contain abundant PD-1 positive T cells but; 4) co-localization in TFCs indicated only partial overlap between the smaller areas of the PD-L1+ and the larger areas of HLA class II+ expression; 5) IFNγ is capable of inducing PD-L1 in >90% of TFCs in primary cultures and cell lines. Collectively these results indicate that the PD-1/PD-L1 axis is operative in AITD glands and may restrain the autoimmune response. Yet the discrepancy between easy induction in vitro and the limited expression in vivo (compared to HLA) suggests that PD-L1 expression in vivo is partially inhibited in GD and HT glands. In conclusions 1) the PD-1/PD-L1 pathway is activated in AITD glands but probably not to the extent to inhibit disease progression and 2) Thyroid autoimmunity arising after PD-1/PD-L1 blocking therapies in cancer patients may result from interfering PD-1/PD-L1 tolerance mechanism in thyroid with minimal (focal) thyroiditis. Finally acting on the PD-1/PD-L1 pathway could be a new approach to treat AITD and other organ-specific autoimmunity in the future.
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http://dx.doi.org/10.1016/j.jaut.2019.05.013DOI Listing
September 2019

Serum protein electrophoresis and complement deficiencies: a veteran but very versatile test in clinical laboratories.

Clin Chem Lab Med 2019 07;57(8):e179-e182

Immunology Department, Hospital Universitari Vall d'Hebron (HUVH), Diagnostic Immunology, Vall d'Hebron Research Institute (VHIR), Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona (UAB), Barcelona, Spain.

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http://dx.doi.org/10.1515/cclm-2018-1121DOI Listing
July 2019

One-step nucleic acid amplification for intraoperative analysis of sentinel lymph node in papillary thyroid carcinoma.

Eur J Endocrinol 2019 01;180(1):21-29

Endocrine Surgery Division, Department of General Surgery, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.

Objective Lymphadenectomy in papillary thyroid carcinoma (PTC) is controversial. It is indicated whenever metastases have been proven before or during surgery and as a prophylactic treatment in high-risk patients. However, 30-50% of cN0 patients become pN1 postoperatively. In PTC, selective-sentinel-lymph-node-biopsy (SLNB) with conventional intraoperative analysis is 8% false negative. One-step nucleic acid amplification (OSNA) is a molecular technique which allows real-time detection of mRNA encoding for cytokeratin 19. OSNA has been introduced in intraoperative analysis of several tumors to reduce false-negative rates and distinguish micrometastasis from macrometastasis. Our objective was to evaluate the impact of the introduction of OSNA in the intraoperative evaluation of the sentinel node (SN) in PTC. Design We analyzed a series of 35 patients subjected to SLNB. Methods All the dissected nodes, SN and non-SN, were evaluated with OSNA and cytology. Results We obtained a total of 110 SN. SLNB proved positive in 14 patients (40%) with cytology and in 23 (65.7%) with OSNA (P < 0.001). In the 29 patients with subsequent lymphadenectomy we obtained 360 lymph nodes ((52 positive in cytology (14.4%) and 107 in OSNA (29.7%)). Lymphadenectomy proved positive in 16 patients according to cytology (55%) and in 24 according to OSNA (83%) (P = 0002). The majority of patients with micrometastasis in SN showed only micrometastasis in lymphadenectomy. Conclusions The present study shows selective-sentinel-lymph-node-biopsy with one-step nucleic acid amplification technique to be feasible in papillary thyroid carcinoma. The quantitative nature of one-step nucleic acid amplification paves the way toward a more personalized surgical approach, limiting lymphadenectomy to patients with intraoperative evidence of macrometastasis in the sentinel node.
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http://dx.doi.org/10.1530/EJE-18-0624DOI Listing
January 2019

Central Tolerance Mechanisms to TSHR in Graves' Disease: Contributions to Understand the Genetic Association.

Horm Metab Res 2018 Dec 5;50(12):863-870. Epub 2018 Nov 5.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Barcelona, Catalonia, Spain.

In the last 3 years, the association of thyrotropin receptor gene (TSHR) variations to Graves' disease (GD) has been confirmed. It is now well established that a 30 Kb region of intron 1 of the TSHR gene is linked to GD predisposition. Elucidating the mechanism(s) by which these polymorphisms confer susceptibility is difficult but would constitute an important advance in endocrine autoimmunity in general. Two hypotheses, both postulating TSHR gene regulatory mechanisms, are discussed. One postulates differential level of expression in the thymus, involving central tolerance. The other postulates a shift in TSHR differential splicing leading to the production of soluble proteins that will have easy access to antigen presenting cells, so it is focused in peripheral tolerance. A combination of the 2 hypothesis is feasible, especially under the light of recent evidence that have identified epigenetic factors acting on TSHR intron 1.
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http://dx.doi.org/10.1055/a-0755-7927DOI Listing
December 2018

Extended immunophenotyping reference values in a healthy pediatric population.

Cytometry B Clin Cytom 2019 05 17;96(3):223-233. Epub 2018 Oct 17.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Barcelona, Catalonia, Spain.

Background: For the accurate diagnosis of immunodeficiencies is crucial to compare patients' immunology laboratory values with age-sex matched controls, yet there is a paucity of normal values for most populations.

Objectives: To define appropriate reference values of extended lymphocyte subpopulations and T-cell receptor excision circle (TRECs) levels in healthy pediatric donors between 1 month and 18 years of age.

Methods: Extended immunophenotyping values were obtained by analysis of multiparameter flow cytometry panels for the following subpopulations: CD4+ and CD8+ Naive, Effector, Effector Memory and Central Memory, T helper subpopulations and their degrees of activation, T Regulatory cells, Recent Thymic Emigrants (RTE), B Lymphocyte subpopulations (Transitional, Naive, Preswitch-Memory, Switch-Memory, Plasmablasts, CD21low, and Exhausted), and subpopulations for Monocytes, NK cells and Dendritic Cells.

Results: Median values and the 10th and 90th percentiles were obtained for 32 lymphocyte and monocyte subpopulations, and for TRECs levels in each age group of children. Naive CD4+ and CD8+ T-cell populations tended to decrease with age, with significant difference between the groups, in parallel with the reduction in thymic function assessed by TRECs counts and the recent thymic emigrant population. Relative numbers of Th cell populations tended to increase with age. The percentage of class-switched B cell populations showed a significant increase between the youngest group and the others.

Conclusion: This study provides essential data for interpreting extended immunophenotyping profiles in the pediatric and young adult populations, which could be of value for the diagnosis of PIDs and immune-mediated diseases, particularly those associated with subtle immunological abnormalities. © 2018 International Clinical Cytometry Society.
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http://dx.doi.org/10.1002/cyto.b.21728DOI Listing
May 2019

Th1-skewed profile and excessive production of proinflammatory cytokines in a NFKB1-deficient patient with CVID and severe gastrointestinal manifestations.

Clin Immunol 2018 10 29;195:49-58. Epub 2018 Jul 29.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona (UAB), Barcelona, Catalonia, Spain; Jeffrey Model Foundation Excellence Center, Barcelona, Catalonia, Spain; Area of Clinical and Molecular Genetics, Hospital Universitari Vall d'Hebron (HUVH), Barcelona, Catalonia, Spain. Electronic address:

Monoallelic loss-of-function mutations in NFKB1 were recently recognized as the most common monogenic cause of common variable immunodeficiency (CVID). The prototypic clinical phenotype of NFKB1-deficient patients includes common CVID features, such as hypogammaglobulinaemia and sinopulmonary infections, plus other highly variable individual manifestations. Here, we describe a patient with a profound CVID phenotype and severe gastrointestinal manifestations, including chronic and recurrent diarrhoea. Using an NGS customized panel of 323 genes related to primary immunodeficiencies, we identified a novel monoallelic loss-of-function mutation in NFKB1 leading to a truncated protein (c.1149delT/p.Gly384Glu ∗ 48). Interestingly, we also found a rare variant in NOD2 previously associated with Crohn's disease (p.His352Arg). Our patient had hypogammaglobulinaemia with a small number of B cells, most of which were naïve. The most noteworthy findings included marked skewing towards a Th1 phenotype in peripheral blood T cells and excessive production of proinflammatory cytokines (IL-1β, TNFα). The patient's 6-year-old daughter, a carrier of the NFKB1 mutation, is clinically asymptomatic, but has started to show cellular and molecular changes. This case of NFKB1 deficiency appears to be a combination of immunodeficiency and a hyperinflammatory state. The current situation of the patient's daughter provides a glimpse of the preclinical phase of the condition.
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http://dx.doi.org/10.1016/j.clim.2018.07.015DOI Listing
October 2018

AIRE genetic variants and predisposition to polygenic autoimmune disease: The case of Graves' disease and a systematic literature review.

Hum Immunol 2016 Aug 4;77(8):643-651. Epub 2016 Jun 4.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Barcelona 08035, Catalonia, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona (UAB), Bellaterra 08193, Catalonia, Spain. Electronic address:

Autoimmune Regulator (AIRE) is a transcriptional regulator that is crucial for establishing central tolerance as illustrated by the Mendelian Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) syndrome associated with AIRE-inactivating recessive or dominant mutations. Polymorphisms in AIRE have been proposed to be implicated in genetic susceptibility to non-Mendelian organ specific autoimmune diseases. Because there is evidence that in predisposition to Graves' disease (GD) central tolerance is crucial, we investigated whether AIRE polymorphisms could modulate risk of GD. A case-control association study using 29 variants and conducted in 150 GD patients and 200 controls did not detect any significant association. This result is not exceptional: a systematic review of the literature, including GWAS, on the association of AIRE variants with organ specific autoimmune diseases did not show clear associations; similarly heterozygous recessive mutations are not associated to non-Mendelian autoimmunity. Dominant negative mutations of AIRE are associated to autoimmunity but as mild forms of APECED rather than to non-Mendelian organ specific autoimmunity. The lack of association of common AIRE polymorphisms with polygenic autoimmune diseases is counterintuitive as many other genes less relevant for immunological tolerance have been found to be associated. These findings give rise to the intriguing possibility that evolution has excluded functionally modifying polymorphisms in AIRE.
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http://dx.doi.org/10.1016/j.humimm.2016.06.002DOI Listing
August 2016

Clinical laboratory standard capillary protein electrophoresis alerted of a low C3 state and lead to the identification of a Factor I deficiency due to a novel homozygous mutation.

Immunol Lett 2016 06 14;174:19-22. Epub 2016 Apr 14.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.

Complement factor I (CFI) deficiency is typically associated to recurrent infections with encapsulated microorganisms and, less commonly, to autoimmunity. We report a 53-years old male who, in a routine control for non-alcoholic fatty liver disease, presented a flat beta-2 fraction at the capillary protein electropherogram. Patient's clinical records included multiple oropharyngeal infections since infancy and an episode of invasive meningococcal infection. Complement studies revealed reduced C3, low classical pathway activation and undetectable Factor I. CFI gene sequencing showed a novel inherited homozygous deletion of 5 nucleotides in exon 12, causing a frameshift leading to a truncated protein. This study points out that capillary protein electrophoresis can alert of possible states of low C3, which, once confirmed and common causes ruled out, can lead to CFI and other complement deficiency diagnosis. This is important since they constitute a still underestimated risk of invasive meningococcemia that can be greatly reduced by vaccination.
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http://dx.doi.org/10.1016/j.imlet.2016.04.011DOI Listing
June 2016

Novel Mutations Causing C5 Deficiency in Three North-African Families.

J Clin Immunol 2016 05 30;36(4):388-96. Epub 2016 Mar 30.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.

The complement system plays a central role in defense to encapsulated bacteria through opsonization and membrane attack complex (MAC) dependent lysis. The three activation pathways (classical, lectin, and alternative) converge in the cleavage of C5, which initiates MAC formation and target lysis. C5 deficiency is associated to recurrent infections by Neisseria spp. In the present study, complement deficiency was suspected in three families of North-African origin after one episode of invasive meningitis due to a non-groupable and two uncommon Meningococcal serotypes (E29, Y). Activity of alternative and classical pathways of complement were markedly reduced and the measurement of terminal complement components revealed total C5 absence. C5 gene analysis revealed two novel mutations as causative of the deficiency: Family A propositus carried a homozygous deletion of two adenines in the exon 21 of C5 gene, resulting in a frameshift and a truncated protein (c.2607_2608del/p.Ser870ProfsX3 mutation). Families B and C probands carried the same homozygous deletion of three consecutive nucleotides (CAA) in exon 9 of the C5 gene, leading to the deletion of asparagine 320 (c.960_962del/p.Asn320del mutation). Family studies confirmed an autosomal recessive inheritance pattern. Although sharing the same geographical origin, families B and C were unrelated. This prompted us to investigate this mutation prevalence in a cohort of 768 North-African healthy individuals. We identified one heterozygous carrier of the p.Asn320del mutation (allelic frequency = 0.065 %), indicating that this mutation is present at low frequency in North-African population.
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http://dx.doi.org/10.1007/s10875-016-0275-4DOI Listing
May 2016

Clinical and structural impact of mutations affecting the residue Phe367 of FOXP3 in patients with IPEX syndrome.

Clin Immunol 2016 Feb 31;163:60-5. Epub 2015 Dec 31.

Immunology Division, Hospital Universitari Vall d'Hebron (HUVH). Vall d'Hebron Research Institute (VHIR), Barcelona, Catalonia, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona (UAB), Barcelona, Catalonia, Spain.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic autoimmune disease characterized by early-onset life-threatening multisystemic autoimmunity. This rare hereditary disorder is caused by loss-of-function mutations in the gene encoding the forkhead box P3 (FOXP3) transcription factor, which plays a key role in the differentiation and function of CD4(+)CD25(+) natural regulatory T cells (Tregs), essential for the establishment and maintenance of natural tolerance. We identified a novel mutation in the FOXP3 gene affecting the Phe367 residue of the protein (F367V) in a family with three male siblings affected by IPEX. Two other mutations affecting the FOXP3 Phe367 residue (F367L and F367C) have been described previously. This unique situation of three mutations affecting the same residue in FOXP3 led us to study the molecular impact of these mutations on the structure of FOXP3 protein. Structure analysis showed that Phe367 is involved in a rich interaction network related to both monomer and dimer structure stabilization, and is crucial for FOXP3 regulatory activity. The relevance of this location is confirmed by the results of SIFT and PolyPhen-2 pathogenicity predictions for F367V mutation. In summary, as assessment of the pathogenicity of a novel mutation is crucial to achieve a proper molecular diagnosis, we analysed the impact of mutations affecting the Phe367 residue using a combined approach that provides a mechanistic view of their pathogenic effect.
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http://dx.doi.org/10.1016/j.clim.2015.12.014DOI Listing
February 2016

Central T cell tolerance: Identification of tissue-restricted autoantigens in the thymus HLA-DR peptidome.

J Autoimmun 2015 Jun 21;60:12-9. Epub 2015 Apr 21.

Immunology Unit, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain. Electronic address:

Promiscuous gene expression (pGE) of tissue-restricted self-antigens (TRA) in medullary thymic epithelial cells (mTECs) is in part driven by the Autoimmune Regulator gene (AIRE) and essential for self-tolerance. The link between AIRE functional mutations and multi-organ autoimmunity in human and mouse supports the role of pGE. Deep sequencing of the transcriptome revealed that mouse mTECs potentially transcribe an unprecedented range of >90% of all genes. Yet, it remains unclear to which extent these low-level transcripts are actually translated into proteins, processed and presented by thymic APCs to induce tolerance. To address this, we analyzed the HLA-DR-associated thymus peptidome. Within a large panel of peptides from abundant proteins, two TRA peptides were identified: prostate-specific semenogelin-1 (an autoantigen in autoimmune chronic prostatitis/chronic pelvic pain syndrome) and central nervous system-specific contactin-2 (an autoantigen in multiple sclerosis). Thymus expression of both genes was restricted to mTECs. SEMG1 expression was confined to mature HLA-DR(hi) mTECs of male and female donors and was AIRE-dependent, whereas CNTN2 was apparently AIRE-independent and was expressed by both populations of mTECs. Our findings establish a link between pGE, MHC-II peptide presentation and autoimmunity for bona fide human TRAs.
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http://dx.doi.org/10.1016/j.jaut.2015.03.004DOI Listing
June 2015

Graves' disease TSHR-stimulating antibodies (TSAbs) induce the activation of immature thymocytes: a clue to the riddle of TSAbs generation?

J Immunol 2015 May 23;194(9):4199-206. Epub 2015 Mar 23.

Vall d'Hebron Institute de Recerca, 08035 Barcelona, Spain; Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; Servei d'Immunologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain;

Graves' disease (GD) is an autoimmune thyroid disease defined by the production of stimulating autoantibodies to the thyroid-stimulating hormone receptor (TSHR) (TSAbs) that induce a sustained state of hyperthyroidism in patients. We previously demonstrated that TSHR, the target of this autoimmune response, is also a key susceptibility gene for GD, probably acting through thymic-dependent central tolerance. We also showed that TSHR is, unexpectedly, expressed in thymocytes. In this report, we confirm the expression of TSHR in thymocytes by protein immunoblotting and quantitative PCR, and show that expression is confined to maturing thymocytes. Using functional assays, we show that thymic TSHR is functional and that TSAbs can stimulate thymocytes through this receptor. This new activity of TSAbs on thymocytes may: 1) explain GD-associated thymic enlargement (hyperplasia), and 2) suggest the provocative hypothesis that the continuous stimulation of thymocytes by TSAbs could lead to a vicious cycle of iterative improvement of the affinity and stimulating capability of initially low-affinity antibacterial (e.g., Yersinia) Abs cross-reactive with TSHR, eventually leading to TSAbs. This may help to fill one of the gaps in our present understanding of unusual characteristics of TSAbs.
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http://dx.doi.org/10.4049/jimmunol.1500183DOI Listing
May 2015

Autoimmune predisposition in Down syndrome may result from a partial central tolerance failure due to insufficient intrathymic expression of AIRE and peripheral antigens.

J Immunol 2014 Oct 12;193(8):3872-9. Epub 2014 Sep 12.

Divisió d'Immunologia, Hospital Universitari Vall d'Hebron, Vall d'Hebron Institut de Recerca, Barcelona 08035, Spain; Departament de Biologia Cellular, de Fisiologia i d'Immunologia, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain.

Down syndrome (DS), or trisomy of chromosome 21, is the most common genetic disorder associated with autoimmune diseases. Autoimmune regulator protein (AIRE), a transcription factor located on chromosome 21, plays a crucial role in autoimmunity by regulating promiscuous gene expression (pGE). To investigate if autoimmunity in DS is promoted by the reduction of pGE owing to dysregulation of AIRE, we assessed the expression of AIRE and of several peripheral tissue-restricted Ag genes by quantitative PCR in thymus samples from 19 DS subjects and 21 euploid controls. Strikingly, despite the 21 trisomy, AIRE expression was significantly reduced by 2-fold in DS thymuses compared with controls, which was also confirmed by fluorescent microscopy. Allele-specific quantification of intrathymic AIRE showed that despite its lower expression, the three copies are expressed. More importantly, decreased expression of AIRE was accompanied by a reduction of pGE because expression of tissue-restricted Ags, CHRNA1, GAD1, PLP1, KLK3, SAG, TG, and TSHR, was reduced. Of interest, thyroid dysfunction (10 cases of hypothyroidism and 1 of Graves disease) developed in 11 of 19 (57.9%) of the DS individuals and in none of the 21 controls. The thymuses of these DS individuals contained significantly lower levels of AIRE and thyroglobulin, to which tolerance is typically lost in autoimmune thyroiditis leading to hypothyroidism. Our findings provide strong evidence for the fundamental role of AIRE and pGE, namely, central tolerance, in the predisposition to autoimmunity of DS individuals.
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http://dx.doi.org/10.4049/jimmunol.1400223DOI Listing
October 2014

Gene expression signature of tolerance and lymphocyte subsets in stable renal transplants: results of a cross-sectional study.

Transpl Immunol 2014 Jun 5;31(1):11-6. Epub 2014 May 5.

Nephrology Department, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.

Background: In kidney transplants operational tolerance has been associated with up-regulation of B cell differentiation genes and an increased number of total, naive and transitional peripheral B cells. The aim is to evaluate tolerance biomarkers in different cohorts of stable renal transplants under immunosuppression.

Methods: This is a cross-sectional study conducted in renal transplants. We evaluate genetic tolerance signature and lymphocyte subsets in stable transplants treated with calcineurin inhibitors (CNI) at 1 (n=15), 5 (n=14) and 10 (n=16) years, and azathioprine-treated transplants followed 30 years (n=8). Healthy volunteers (n=10) and patients with chronic rejection (n=15) served as controls.

Results: We confirm that peripheral expression of IGKV1D-13 and IGKV4-1 genes by RT-PCR distinguish tolerant (n=10) from stable transplants (n=10) provided by the International Tolerance Network. Tolerance signature was defined as the lowest expression for both genes in tolerant patients. In CNI-treated patients, genetic signature of tolerance and B cells showed a time-dependent increase not observed in azathioprine-treated patients (p<0.01). Genetic tolerance signature was observed in 0% at 1, 7% at 5 and 25% at 10-years while it was not observed in azathioprine-treated and chronic rejection patients. Fifteen out of 16 CNI-treated transplants at 10 years were revaluated 3 months apart. Nine did not show the tolerance signature in any determination, 4 in one and 2 in both determinations. Genetic signature of tolerance was associated with an increase of total, naive and transitional B cells (p<0.05).

Conclusions: IGKV1D-13 and IGKV4-1 gene expression and its linked B cell populations increase during follow up in CNI-treated patients. At 10 years, 2 out of 15 CNI treated patients consistently express biomarkers associated with true tolerance. In azathioprine-treated patients these biomarkers were down-regulated.
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http://dx.doi.org/10.1016/j.trim.2014.04.008DOI Listing
June 2014

A novel splice site mutation in the SERPING1 gene leads to haploinsufficiency by complete degradation of the mutant allele mRNA in a case of familial hereditary angioedema.

J Clin Immunol 2014 Jul 24;34(5):521-3. Epub 2014 Apr 24.

Immunology Division, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron (HUVH), Barcelon, Spain.

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1INH) is a rare autosomal-dominant and life-threatening disorder caused by mutations in SERPING1 gene. It is characterized by attacks of angioedema involving the skin and/or the mucosa of the upper airways, as well as the intestinal mucosa. Here we report the case of a patient with HAE-C1INH without family history of angioedema. By sequencing the SERPING1 gene we detected a novel mutation (c.1249 + 5G > A) affecting the 5' donor splice site in intron 7. We analyzed the SERPING1 cDNA expecting a defect in splicing process but only the wild type allele was detected. SNP analysis of the cDNA sequence demonstrated that only one of the two alleles was present, indicating that the mRNA from the mutated allele was completely degraded. This study reinforces the concept of incomplete penetrance of this disorder since the patients' mother never presented any sign of angioedema despite carrying the same mutation.
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http://dx.doi.org/10.1007/s10875-014-0042-3DOI Listing
July 2014

Identification and characterization of a novel splice site mutation in the SERPING1 gene in a family with hereditary angioedema.

Clin Immunol 2014 Feb 4;150(2):143-8. Epub 2013 Dec 4.

Allergy Unit, Internal Medicine Department, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.

Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1INH) is a rare autosomal-dominant disease caused by mutations in SERPING1 gene. The main clinical feature of C1INH deficiency is the spontaneous edema of the subcutaneous and submucosal layers. More than 280 different mutations scattering the entire SERPING1 gene have been reported. We identified and characterized a new mutation in SERPING1 gene in a Spanish family with hereditary angioedema. The mutation (c.685 + 2 T > A) disrupts the donor splice site of intron 4 leading to the loss of exon 4 in mutant mRNA. We demonstrated that mutant mRNA is mostly degraded, probably by the surveillance pathway no-go mRNA decay. Bioinformatic analysis showed that the mutant protein, if produced, would be non-functional since the protein lacks a stretch of 45 amino acids affecting the functional RCL loop. Finally, we found a reduction of the wild-type mRNA expression in c.685 + 2 T > A carriers.
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http://dx.doi.org/10.1016/j.clim.2013.11.013DOI Listing
February 2014

Peptides presented by HLA class I molecules in the human thymus.

J Proteomics 2013 Dec 9;94:23-36. Epub 2013 Sep 9.

Immunology Unit, Department of Cell Biology, Physiology and Immunology and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.

Unlabelled: The thymus is the organ in which T lymphocytes mature. Thymocytes undergo exhaustive selection processes that require interactions between the TCRs and peptide-HLA complexes on thymus antigen-presenting cells. The thymic peptide repertoire associated with HLA molecules must mirror the peptidome that mature T cells will encounter at the periphery, including peptides that arise from tissue-restricted antigens. The transcriptome of specific thymus cell populations has been widely studied, but there are no data on the HLA-I peptidome of the human thymus. Here, we describe the HLA-I-bound peptide repertoire from thymus samples, showing that it is mostly composed of high-affinity ligands from cytosolic and nuclear proteins. Several proteins generated more than one peptide, and some redundant peptides were found in different samples, suggesting the existence of antigen immunodominance during the processes that lead to central tolerance. Three HLA-I ligands were found to be derived from proteins expressed by stromal cells, including one from the protein TBATA (or SPATIAL), which is present in the thymus, brain and testis. The expression of TBATA in medullary thymic epithelial cells has been reported to be AIRE dependent. Thus, this report describes the first identification of a thymus HLA-I natural ligand derived from an AIRE-dependent protein with restricted tissue expression.

Biological Significance: We present the first description of the HLA-I-bound peptide repertoire from ex vivo thymus samples. This repertoire is composed of standard ligands from cytosolic and nuclear proteins. Some peptides seem to be dominantly presented to thymocytes in the thymus. Most importantly, some HLA-I associated ligands derived from proteins expressed by stromal cells, including one peptide, restricted by HLA-A*31:01, arising from an AIRE-dependent protein with restricted tissue expression.
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http://dx.doi.org/10.1016/j.jprot.2013.08.023DOI Listing
December 2013

Composition of the HLA-DR-associated human thymus peptidome.

Eur J Immunol 2013 Sep 12;43(9):2273-82. Epub 2013 Jul 12.

Immunology Unit, Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Biologia Cel·lular, Fisiologia i Immunologia (BCFI), Universitat Autònoma de Barcelona, Barcelona, Spain.

Major histocompatibility complex class II (MHC-II) molecules bind to and display antigenic peptides on the surface of antigen-presenting cells (APCs). In the absence of infection, MHC-II molecules on APCs present self-peptides and interact with CD4(+) T cells to maintain tolerance and homeostasis. In the thymus, self-peptides bind to MHC-II molecules expressed by defined populations of APCs specialised for the different steps of T-cell selection. Cortical epithelial cells present peptides for positive selection, whereas medullary epithelial cells and dendritic cells are responsible for peptide presentation for negative selection. However, few data are available on the peptides presented by MHC molecules in the thymus. Here, we apply mass spectrometry to analyse and identify MHC-II-associated peptides from five fresh human thymus samples. The data show a diverse self-peptide repertoire, mostly consisting of predicted MHC-II high binders. Despite technical limitations preventing single cell population analyses of peptides, these data constitute the first direct assessment of the HLA-II-bound peptidome and provide insight into how this peptidome is generated and how it drives T-cell repertoire formation.
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http://dx.doi.org/10.1002/eji.201243280DOI Listing
September 2013

Efferocytosis promotes suppressive effects on dendritic cells through prostaglandin E2 production in the context of autoimmunity.

PLoS One 2013 15;8(5):e63296. Epub 2013 May 15.

Department of Immunology, Germans Trias i Pujol Research Institute, Autonomous University of Barcelona, Badalona, Spain.

Introduction: Efferocytosis is a crucial process by which apoptotic cells are cleared by phagocytes, maintaining immune tolerance to self in the absence of inflammation. Peripheral tolerance, lost in autoimmune processes, may be restored by the administration of autologous dendritic cells loaded with islet apoptotic cells in experimental type 1 diabetes.

Objective: To evaluate tolerogenic properties in dendritic cells induced by the clearance of apoptotic islet cells, thus explaining the re-establishment of tolerance in a context of autoimmunity.

Methods: Bone marrow derived dendritic cells from non-obese diabetic mice, a model of autoimmune diabetes, were generated and pulsed with islet apoptotic cells. The ability of these cells to induce autologous T cell proliferation and to suppress mature dendritic cell function was assessed, together with cytokine production. Microarray experiments were performed using dendritic cells to identify differentially expressed genes after efferocytosis.

Results: Molecular and functional changes in dendritic cells after the capture of apoptotic cells were observed. 1) Impaired ability of dendritic cells to stimulate autologous T cell proliferation after the capture of apoptotic cells even after proinflammatory stimuli, with a cytokine profile typical for immature dendritic cells. 2) Suppressive ability of mature dendritic cell function. 3) Microarray-based gene expression profiling of dendritic cells showed differential expression of genes involved in antigen processing and presentation after efferocytosis. 4) Prostaglandin E2 increased production was responsible for immunosuppressive mechanism of dendritic cells after the capture of apoptotic cells.

Conclusions: The tolerogenic behaviour of dendritic cells after islet cells efferocytosis points to a mechanism of silencing potential autoreactive T cells in the microenvironment of autoimmunity. Our results suggest that dendritic cells may be programmed to induce specific immune tolerance using apoptotic cells; this is a viable strategy for a variety of autoimmune diseases.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063296PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654963PMC
January 2014

Regulatory T cells and other lymphocyte subpopulations in patients with melanoma developing interferon-induced thyroiditis during high-dose interferon-α2b treatment.

Clin Endocrinol (Oxf) 2013 Apr;78(4):621-8

Department of Endocrinology and Nutrition, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, spain.

Context: One of the side effects of interferon-alpha therapy is interferon-induced thyroiditis (IIT). The role of lymphocyte subpopulations in IIT melanoma patients remains to be defined.

Objective: Our objective was to assess different peripheral blood lymphocyte subpopulations, mainly regulatory T cells (Tregs), in melanoma patients who developed IIT.

Design, Patients And Methods: From 30 melanoma patients receiving high-dose interferon (HDI)-alpha 2b (IFN-α2b) treatment, those who developed IIT (IIT patients) were selected and compared with patients who did not develop IIT (Co-MM) and healthy controls (Co-H). Peripheral blood mononuclear cells were obtained before treatment (BT), mid-treatment (MT), end of treatment (ET), 24 weeks post-treatment and at appearance of IIT (TT).

Results: Nine patients developed IIT (30%): four Hashimoto's thyroiditis and five destructive thyroiditis. An increase in Tregs was observed in both melanoma groups during HDI treatment. A decrease in CD3(+) , NKT lymphocyte subpopulations and Bcl2 expression on B cells was also observed in both groups. However, no changes were observed in the percentage of CD4(+) , CD8(+) , CD3(+) γδ(+) , CD19(+) , transitional B cells (CD24(high) CD38(high) CD19(+) CD27(-) ), natural killer (NK), invariant NKT (iNKT) lymphocytes and Th1/Th2 balance when BT was compared with ET. At TT, IIT patients had a higher Tregs percentage than Co-MM (P = 0·012) and Co-H (P = 0·004), a higher iNKT percentage than Co-MM (P = 0·011), a higher transitional B cells percentage than Co-H (P = 0·015), a lower CD3(+) percentage than Co-H (P = 0·001) and a lower Bcl2 expression on B cells than Co-H (P < 0·001).

Conclusions: Our results point to the immunomodulatory effects of IFN-α on different lymphocyte subpopulations and a possible role of Tregs in melanoma patients who developed IIT.
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http://dx.doi.org/10.1111/cen.12036DOI Listing
April 2013

TLR-activated conventional DCs promote γ-secretase-mediated conditioning of plasmacytoid DCs.

J Leukoc Biol 2012 Jul 24;92(1):133-43. Epub 2012 Apr 24.

Laboratori d’Immunobiologia i Diagnòstic Molecular (LIRAD), Banc de Sang i Teixits (BST), Departament de BiologiaCel·lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Institut d’Investigació Germans Trias i Pujol, Barcelona, Spain.

Cooperative events between DC subsets involve cell contact and soluble factors. Upon viral challenge, murine pDCs induce cDC cooperation through CD40-CD40L interactions and IL-15 secretion, whereas in humans, the same effect is mediated by IFN-α. Conversely, during bacterial infections, pDC maturation may be induced by activated cDCs, although no mechanisms had been described so far. Here, we investigate how human pDCs are "conditioned" by cDCs. Blood-borne DC subsets (cDCs and pDCs) were sorted from healthy donors. IL-3-maintained pDCs were cocultured with LPS-activated, poly (I:C)-activated, or control cDCs [cDC(LPS), cDC(P(I:C)), cDC(CTRL)]. Coculture experiments showed that cDC(LPS)-conditioned pDCs up-regulated maturation markers, such as CD25 and CD86, whereas SNs contained higher amounts of IL-6 and CCL19 compared with control conditions. Gene-expression analyses on sorted cDC(LPS) or cDC(P(I:C)) conditioned pDCs confirmed the induction of several genes, including IL-6 and CCL19 and remarkably, several Notch target genes. Further studies using the γ-secretase/Notch inhibitor DAPT and soluble Notch ligands resulted in a significantly reduced expression of canonical Notch target genes in conditioned pDCs. DAPT treatment also hampered the secretion of CCL19 (but not of IL-6) by cDC(LPS) conditioned pDCs. These results reveal the involvement of γ-secretase-mediated mechanisms, including the Notch pathway, in the cell contact-dependent communication between human DC subsets. The resulting partial activation of pDCs after encountering with mature cDCs endows pDCs with an accessory function that may contribute to T cell recruitment and activation.
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http://dx.doi.org/10.1189/jlb.0911452DOI Listing
July 2012

Stable antigen-specific T-cell hyporesponsiveness induced by tolerogenic dendritic cells from multiple sclerosis patients.

Eur J Immunol 2012 Mar;42(3):771-82

Laboratory of Immunobiology for Research and Diagnosis, Blood and Tissue Bank, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Institut d'Investigació Germans Trias i Pujol, Badalona, Spain.

Multiple sclerosis (MS) is a chronic demyelinating autoimmune disease of the central nervous system. Current therapies decrease the frequency of relapses and limit, to some extent, but do not prevent disease progression. Hence, new therapeutic approaches that modify the natural course of MSneed to be identified. Tolerance induction to self-antigens using monocyte-derived dendritic cells (MDDCs) is a promising therapeutic strategy in autoimmunity. In this work, we sought to generate and characterize tolerogenic MDDCs (tolDCs) from relapsing-remitting (RR) MSpatients, loaded with myelin peptides as specific antigen, with the aim of developing immunotherapeutics for MS. MDDCs were generated from both healthy-blood donors and RR-MSpatients, and MDDCmaturation was induced with a proinflammatory cytokine cocktail in the absence or presence of 1α,25-dihydroxyvitamin-D(3) , a tolerogenicity-inducing agent. tolDCs were generated from monocytes of RR-MSpatients as efficiently as from monocytes of healthy subjects. The RR-MStolDCs expressed a stable semimature phenotype and an antiinflammatory profile as compared with untreated MDDCs. Importantly, myelin peptide-loaded tolDCs induced stable antigen-specific hyporesponsiveness in myelin-reactive T cells from RR-MS patients. These results suggest that myelin peptide-loaded tolDCs may be a powerful tool for inducing myelin-specific tolerance in RR-MS patients.
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http://dx.doi.org/10.1002/eji.201141835DOI Listing
March 2012
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