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1.
Case Rep Oncol ; 16(1): 1436-1442, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028570

RESUMO

Introduction: Esophageal involvement in high-grade serous ovarian carcinoma is a rare phenomenon when advanced systemic disease is detected. Dysphagia is the most common guide symptom. However, diagnosis is often delayed due to its submucosal process that is not early seen in endoscopic initial evaluation, while computerized tomography (CT) scan usually shows concentric thickening of the esophageal layers and gives the suspected diagnosis. Case Presentation: We present the case of a patient who died of mediastinitis caused by an esophageal perforated ulceration due to infiltration of high-grade serous ovarian carcinoma. In addition, this is the first case report of severe esophageal candidiasis associated that delayed diagnosis and subsequent oncological treatment. Conclusion: Esophageal secondary infiltration must be suspected when a patient has a history of malignancy combined with consistent CT findings.

2.
Front Immunol ; 14: 1163316, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37187762

RESUMO

Cytotoxic lymphocytes kill target cells through polarized release of the content of cytotoxic granules towards the target cell. The importance of this cytotoxic pathway in immune regulation is evidenced by the severe and often fatal condition, known as hemophagocytic lymphohistiocytosis (HLH) that occurs in mice and humans with inborn errors of lymphocyte cytotoxic function. The clinical and preclinical data indicate that the damage seen in severe, virally triggered HLH is due to an overwhelming immune system reaction and not the direct effects of the virus per se. The main HLH-disease mechanism, which links impaired cytotoxicity to excessive release of pro-inflammatory cytokines is a prolongation of the synapse time between the cytotoxic effector cell and the target cell, which prompts the former to secrete larger amounts of cytokines (including interferon gamma) that activate macrophages. We and others have identified novel genetic HLH spectrum disorders. In the present update, we position these newly reported molecular causes, including CD48-haploinsufficiency and ZNFX1-deficiency, within the pathogenic pathways that lead to HLH. These genetic defects have consequences on the cellular level on a gradient model ranging from impaired lymphocyte cytotoxicity to intrinsic activation of macrophages and virally infected cells. Altogether, it is clear that target cells and macrophages may play an independent role and are not passive bystanders in the pathogenesis of HLH. Understanding these processes which lead to immune dysregulation may pave the way to novel ideas for medical intervention in HLH and virally triggered hypercytokinemia.


Assuntos
Citocinas , Linfo-Histiocitose Hemofagocítica , Humanos , Animais , Camundongos , Citocinas/metabolismo , Linfo-Histiocitose Hemofagocítica/etiologia , Linfócitos/metabolismo , Citotoxicidade Imunológica , Interferon gama
3.
Artigo em Inglês | MEDLINE | ID: mdl-34535569

RESUMO

BACKGROUND AND OBJECTIVES: Encouraged by the enormous progress that the identification of specific autoantigens added to the understanding of neurologic autoimmune diseases, we undertook here an in-depth study of T-cell specificities in the autoimmune disease multiple sclerosis (MS), for which the spectrum of responsible autoantigens is not fully defined yet. The identification of target antigens in MS is crucial for therapeutic strategies aimed to induce antigen-specific tolerance. In addition, knowledge of relevant T-cell targets can improve our understanding of disease heterogeneity, a hallmark of MS that complicates clinical management. METHODS: The proliferative response and interferon gamma (IFN-γ) release of CSF-infiltrating CD4+ T cells from patients with MS against several autoantigens was used to identify patients with different intrathecal T-cell specificities. Fresh CSF-infiltrating and paired circulating lymphocytes in these patients were characterized in depth by ex vivo immunophenotyping and transcriptome analysis of relevant T-cell subsets. Further examination of these patients included CSF markers of inflammation and neurodegeneration and a detailed characterization with respect to demographic, clinical, and MRI features. RESULTS: By testing CSF-infiltrating CD4+ T cells from 105 patients with MS against seven long-known myelin and five recently described GDP-l-fucose synthase peptides, we identified GDP-l-fucose synthase and myelin oligodendrocyte glycoprotein (35-55) responder patients. Immunophenotyping of CSF and paired blood samples in these patients revealed a significant expansion of an effector memory (CCR7- CD45RA-) CD27- Th1 CD4+ cell subset in GDP-l-fucose synthase responders. Subsequent transcriptome analysis of this subset demonstrated expression of Th1 and cytotoxicity-associated genes. Patients with different intrathecal T-cell specificities also differ regarding inflammation- and neurodegeneration-associated biomarkers, imaging findings, expression of HLA class II alleles, and seasonal distribution of the time of the lumbar puncture. DISCUSSION: Our observations reveal an association between autoantigen reactivity and features of disease heterogeneity that strongly supports an important role of T-cell specificity in MS pathogenesis. These data have the potential to improve patient classification in clinical practice and to guide the development of antigen-specific tolerization strategies.


Assuntos
Esclerose Múltipla/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Linfócitos T/imunologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Esclerose Múltipla/fisiopatologia , Glicoproteína Mielina-Oligodendrócito/imunologia
4.
J Allergy Clin Immunol ; 148(2): 381-393, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33872655

RESUMO

BACKGROUND: Recognition of viral nucleic acids is one of the primary triggers for a type I interferon-mediated antiviral immune response. Inborn errors of type I interferon immunity can be associated with increased inflammation and/or increased susceptibility to viral infections as a result of dysbalanced interferon production. NFX1-type zinc finger-containing 1 (ZNFX1) is an interferon-stimulated double-stranded RNA sensor that restricts the replication of RNA viruses in mice. The role of ZNFX1 in the human immune response is not known. OBJECTIVE: We studied 15 patients from 8 families with an autosomal recessive immunodeficiency characterized by severe infections by both RNA and DNA viruses and virally triggered inflammatory episodes with hemophagocytic lymphohistiocytosis-like disease, early-onset seizures, and renal and lung disease. METHODS: Whole exome sequencing was performed on 13 patients from 8 families. We investigated the transcriptome, posttranscriptional regulation of interferon-stimulated genes (ISGs) and predisposition to viral infections in primary cells from patients and controls stimulated with synthetic double-stranded nucleic acids. RESULTS: Deleterious homozygous and compound heterozygous ZNFX1 variants were identified in all 13 patients. Stimulation of patient-derived primary cells with synthetic double-stranded nucleic acids was associated with a deregulated pattern of expression of ISGs and alterations in the half-life of the mRNA of ISGs and also associated with poorer clearance of viral infections by monocytes. CONCLUSION: ZNFX1 is an important regulator of the response to double-stranded nucleic acids stimuli following viral infections. ZNFX1 deficiency predisposes to severe viral infections and a multisystem inflammatory disease.


Assuntos
Antígenos de Neoplasias/genética , Sequenciamento do Exoma , Predisposição Genética para Doença , Doenças da Imunodeficiência Primária/imunologia , Viroses/genética , Antígenos de Neoplasias/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Inflamação/diagnóstico por imagem , Inflamação/genética , Inflamação/imunologia , Masculino , Doenças da Imunodeficiência Primária/diagnóstico por imagem , Doenças da Imunodeficiência Primária/genética , Viroses/diagnóstico por imagem , Viroses/imunologia
5.
Inform Health Soc Care ; 46(3): 273-290, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-33685325

RESUMO

Several studies have shown that, due to their features, mobile applications have a great potential to address mental health in depression and anxiety. We carried out a systematic review of publications from the last 10 years: from 1 January 2010 until 31 March 2020. Systematic reviews and meta-analyses related to the research question were also selected to identify other potentially eligible studies. The literature search in selected databases returned a total of 3,011 records from which a total of 22 articles were finally selected. The main conclusion of the study is that most of the scientific evidence found supports the hypothesis that mobile applications significantly improve the symptoms associated with depression and anxiety. Therefore, their effectiveness as a digital tool in the treatment of such health problems is proven. However, further studies and further evaluations of mobile applications are required (also in other languages) to incorporate this resource into the healthcare context. In addition, since mobile applications allow reinforcing concepts such as patient empowerment, shared decision-making and health literacy, their use would be highly positive for depression and anxiety, where there is a strong element of self-managing the disease.


Assuntos
Aplicativos Móveis , Telemedicina , Ansiedade , Depressão , Humanos , Prescrições
7.
Transl Res ; 210: 8-25, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30953609

RESUMO

Type 1 diabetes (T1D) is a chronic metabolic disease of unknown etiology that results from ß-cell destruction. The onset of the disease, which arises after a long asymptomatic period of autoimmune attack, may be followed by a relapsing and remitting progression, a phenomenon that is most evident during the partial remission phase (PR). This stage lasts for a few months, shows minor requirements of exogenous insulin and could be explained by a recovery of immunological tolerance. This study aims to identify new biomarkers at early stages of pediatric T1D that reflect immunoregulatory changes. To that end, pediatric patients with T1D (n = 52) and age-related control subjects (n = 30) were recruited. Immune response-related molecules and lymphocyte subsets were determined starting at T1D onset and until the second year of progression. Results showed that circulating TGF-ß levels decreased during PR, and that betatrophin concentration was increased in all the considered stages without differing among studied checkpoints. Moreover, an increase of regulatory T, B and NK subsets was found during T1D progression, probably reflecting an attempt to restore self-tolerance. By contrast, a reduction in monocyte levels was observed at the early stages of diabetes. The results reveal significant changes in immunological parameters during the different early stages of T1D in children, which could ultimately serve as potential biomarkers to characterize the progression of T1D.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Proteína 8 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina/sangue , Biomarcadores/sangue , Índice de Massa Corporal , Estudos de Casos e Controles , Criança , Diabetes Mellitus Tipo 1/sangue , Progressão da Doença , Feminino , Humanos , Memória Imunológica , Subpopulações de Linfócitos/metabolismo , Masculino , Monócitos/metabolismo , Hormônios Peptídicos/sangue , Projetos Piloto , Indução de Remissão , Fator de Crescimento Transformador beta/sangue
8.
Sci Transl Med ; 10(462)2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30305453

RESUMO

Multiple sclerosis is an immune-mediated autoimmune disease of the central nervous system that develops in genetically susceptible individuals and likely requires environmental triggers. The autoantigens and molecular mimics triggering the autoimmune response in multiple sclerosis remain incompletely understood. By using a brain-infiltrating CD4+ T cell clone that is clonally expanded in multiple sclerosis brain lesions and a systematic approach for the identification of its target antigens, positional scanning peptide libraries in combination with biometrical analysis, we have identified guanosine diphosphate (GDP)-l-fucose synthase as an autoantigen that is recognized by cerebrospinal fluid-infiltrating CD4+ T cells from HLA-DRB3*-positive patients. Significant associations were found between reactivity to GDP-l-fucose synthase peptides and DRB3*02:02 expression, along with reactivity against an immunodominant myelin basic protein peptide. These results, coupled with the cross-recognition of homologous peptides from gut microbiota, suggest a possible role of this antigen as an inducer or driver of pathogenic autoimmune responses in multiple sclerosis.


Assuntos
Autoantígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Fucose/metabolismo , Glucosiltransferases/metabolismo , Cadeias HLA-DRB3/metabolismo , Esclerose Múltipla/imunologia , Alelos , Sequência de Aminoácidos , Encéfalo/metabolismo , Células Clonais , Humanos , Esclerose Múltipla/líquido cefalorraquidiano , Proteína Básica da Mielina/metabolismo , Peptídeos/química , Peptídeos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
9.
Cell ; 175(1): 85-100.e23, 2018 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-30173916

RESUMO

Multiple sclerosis is an autoimmune disease that is caused by the interplay of genetic, particularly the HLA-DR15 haplotype, and environmental risk factors. How these etiologic factors contribute to generating an autoreactive CD4+ T cell repertoire is not clear. Here, we demonstrate that self-reactivity, defined as "autoproliferation" of peripheral Th1 cells, is elevated in patients carrying the HLA-DR15 haplotype. Autoproliferation is mediated by memory B cells in a HLA-DR-dependent manner. Depletion of B cells in vitro and therapeutically in vivo by anti-CD20 effectively reduces T cell autoproliferation. T cell receptor deep sequencing showed that in vitro autoproliferating T cells are enriched for brain-homing T cells. Using an unbiased epitope discovery approach, we identified RASGRP2 as target autoantigen that is expressed in the brain and B cells. These findings will be instrumental to address important questions regarding pathogenic B-T cell interactions in multiple sclerosis and possibly also to develop novel therapies.


Assuntos
Linfócitos B/patologia , Subtipos Sorológicos de HLA-DR/imunologia , Esclerose Múltipla/imunologia , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes/fisiopatologia , Linfócitos B/metabolismo , Encéfalo/patologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/fisiologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Subtipos Sorológicos de HLA-DR/genética , Humanos , Esclerose Múltipla/genética , Esclerose Múltipla/fisiopatologia , Receptores de Antígenos de Linfócitos T , Células Th1/fisiologia
10.
Front Immunol ; 9: 509, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29616027

RESUMO

The antigen-specific activation of pathogenic T cells is considered essential in the initiation and maintenance of multiple sclerosis (MS). The site of activation, the differential involvement of CD4+, and CD8+ T cells, their functional phenotype, and specificity, are important aspects to understand MS pathogenesis. The analysis of clonal expansions of brain-infiltrating T cells may reveal local antigen-driven activation or specific brain homing and allow the identification of putatively pathogenic T cells. We used high-throughput T cell receptor ß-chain variable gene (TRBV) sequencing (-seq) of genomic (g)DNA, which reflects the quantity and diversity of the TRBV repertoire, to characterize three white matter demyelinating lesions with different location and inflammatory activity, and paired peripheral blood memory CD4+ and CD8+ T cell pools from a secondary progressive (SP)MS patient. Our results revealed an important sharing of clonally expanded T cells with identical TRBV sequence (clonotypes) across MS lesions independently of their proximity or inflammatory activity. Comparison with circulating T cells showed that the most frequent brain-infiltrating CD8+, but not CD4+ clonotypes were also those with highest frequency in the peripheral blood, indicating clonal expansion inside the brain or specific brain homing of CD4+ but not CD8+ T cells. Parallel TRBV-seq of complementary (c)DNA that reflects the activation status of the cells, revealed differences between lesions regarding inflammatory activity and appears to facilitate the identification of putatively pathogenic T cells in active lesions. Approaches to identify pathogenic T cells in brain lesions using TRBV-seq may benefit from focusing on lesions with high inflammatory activity and from combining gDNA and cDNA sequencing.


Assuntos
Encéfalo/imunologia , Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Esclerose Múltipla Crônica Progressiva/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/fisiologia , Autopsia , Circulação Sanguínea , Proliferação de Células , Células Cultivadas , Células Clonais , DNA Complementar/genética , Humanos , Memória Imunológica , Ativação Linfocitária
11.
Ann Neurol ; 79(3): 404-18, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26874214

RESUMO

OBJECTIVE: Symptomatic infections of the central nervous system (CNS) with JC polyomavirus (JCV) usually occur as a result of immunocompromise and manifest as progressive multifocal leukoencephalopathy (PML) or granule cell neuronopathy (GCN). After immune reconstitution, some of these cases may show long-term persistence of JCV and delayed clinical improvement despite inflammation. METHODS: We followed 4 patients with multiple sclerosis, who developed natalizumab-associated PML or GCN with regard to JC viral load and JCV-specific T-cell responses in the CNS. All of them experienced immune reconstitution inflammatory syndrome (IRIS), but in 2 cases JCV persisted > 21 months after IRIS accompanied by delayed clinical improvement. RESULTS: Persistence of JCV was associated with a lack of JCV VP1-specific T-cell responses during immune reconstitution in 1 of the patients. Detailed analysis of the brain infiltrate in another patient with neuronal persistence of JCV revealed strong infiltration of CD8(+) T cells and clonal expansion of activated CD8(+) effector T cells with a CD4(dim) CD8(+) phenotype, both exhibiting exquisite specificity for conserved epitopes of JCV large T antigen. However, clearance of JCV was not efficient, because mutations in the major capsid protein VP1 caused reduced CD4(+) T-cell responses against the identified JCV variant and subsequently resulted in a decline of CD8(+) T-cell responses after IRIS. INTERPRETATION: Our findings suggest that efficient CD4(+) T-cell recognition of neurotropic JCV variants is crucial to support CD8(+) T cells in combating JCV infection of the CNS.


Assuntos
Evasão da Resposta Imune/imunologia , Síndrome Inflamatória da Reconstituição Imune/imunologia , Vírus JC/fisiologia , Leucoencefalopatia Multifocal Progressiva/imunologia , Leucoencefalopatia Multifocal Progressiva/virologia , Esclerose Múltipla/imunologia , Adulto , Encéfalo/imunologia , Encéfalo/virologia , Feminino , Humanos , Síndrome Inflamatória da Reconstituição Imune/virologia , Vírus JC/classificação , Vírus JC/genética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/virologia
12.
Eur J Immunol ; 46(3): 593-608, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26639224

RESUMO

Autoreactive B lymphocytes play a key role as APCs in diaebetogenesis. However, it remains unclear whether B-cell tolerance is compromised in NOD mice. Here, we describe a new B lymphocyte transgenic NOD mouse model, the 116C-NOD mouse, where the transgenes derive from an islet-infiltrating B lymphocyte of a (8.3-NODxNOR) F1 mouse. The 116C-NOD mouse produces clonal B lymphocytes with pancreatic islet beta cell specificity. The incidence of T1D in 116C-NOD mice is decreased in both genders when compared with NOD mice. Moreover, several immune selection mechanisms (including clonal deletion and anergy) acting on the development, phenotype, and function of autoreactive B lymphocytes during T1D development have been identified in the 116C-NOD mouse. Surprisingly, a more accurate analysis revealed that, despite their anergic phenotype, 116C B cells express some costimulatory molecules after activation, and induce a T-cell shift toward a Th17 phenotype. Furthermore, this shift on T lymphocytes seems to occur not only when both T and B cells contact, but also when helper T (Th) lineage is established. The 116C-NOD mouse model could be useful to elucidate the mechanisms involved in the generation of Th-cell lineages.


Assuntos
Linfócitos B/imunologia , Anergia Clonal , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Tolerância Imunológica/genética , Ativação Linfocitária , Células Th17/imunologia , Animais , Deleção Clonal , Citocinas/genética , Citocinas/imunologia , Tolerância Imunológica/imunologia , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Fenótipo , Baço/anatomia & histologia , Baço/citologia , Baço/imunologia , Transgenes
13.
Ann Clin Transl Neurol ; 2(9): 875-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26401510

RESUMO

OBJECTIVE: Multiple sclerosis (MS) is a disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Based on infiltrating immune cells, deposition of humoral factors and loss of oligodendrocytes and/or myelin proteins, four lesion patterns have been described. Pattern II is characterized by antibody and complement deposition in addition to T-cell infiltration. MS is considered a T-cell-mediated disease, but until now the study of pathogenic T cells has encountered major challenges, most importantly the limited access of brain-infiltrating T cells. Our objective was to identify, isolate, and characterize brain-infiltrating clonally expanded T cells in pattern II MS lesions. METHODS: We used next-generation sequencing to identify clonally expanded T cells in demyelinating pattern II brain autopsy lesions, subsequently isolated these as T-cell clones from autologous cerebrospinal fluid and functionally characterized them. RESULTS: We identified clonally expanded CD8(+) but also CD4(+) T cells in demyelinating pattern II lesions and for the first time were able to isolate these as live T-cell clones. The functional characterization shows that T cells releasing Th2 cytokines and able to provide B cell help dominate the T-cell infiltrate in pattern II brain lesions. INTERPRETATION: Our data provide the first functional evidence for a putative role of Th2/Tc2 cells in pattern II MS supporting the existence of this pathogenic phenotype and questioning the protective role that is generally ascribed to Th2 cells. Our observations are important to consider for future treatments of pattern II MS patients.

15.
PLoS Pathog ; 10(8): e1004333, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25165855

RESUMO

Epstein Barr virus (EBV) infection expands CD8+ T cells specific for lytic antigens to high frequencies during symptomatic primary infection, and maintains these at significant numbers during persistence. Despite this, the protective function of these lytic EBV antigen-specific cytotoxic CD8+ T cells remains unclear. Here we demonstrate that lytic EBV replication does not significantly contribute to virus-induced B cell proliferation in vitro and in vivo in a mouse model with reconstituted human immune system components (huNSG mice). However, we report a trend to reduction of EBV-induced lymphoproliferation outside of lymphoid organs upon diminished lytic replication. Moreover, we could demonstrate that CD8+ T cells against the lytic EBV antigen BMLF1 can eliminate lytically replicating EBV-transformed B cells from lymphoblastoid cell lines (LCLs) and in vivo, thereby transiently controlling high viremia after adoptive transfer into EBV infected huNSG mice. These findings suggest a protective function for lytic EBV antigen-specific CD8+ T cells against EBV infection and against virus-associated tumors in extra-lymphoid organs. These specificities should be explored for EBV-specific vaccine development.


Assuntos
Linfócitos B/virologia , Transformação Celular Viral/fisiologia , Infecções por Vírus Epstein-Barr/imunologia , Linfócitos T Citotóxicos/imunologia , Transferência Adotiva , Animais , Linfócitos T CD8-Positivos/imunologia , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Reação em Cadeia da Polimerase em Tempo Real
16.
Artigo em Inglês | MEDLINE | ID: mdl-24741337

RESUMO

Natalizumab was the first monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS) based on its short-term efficacy and overall tolerability. However, the incidence of treatment-associated progressive multifocal leukoencephalopathy (PML), an infection of the brain caused by the John Cunningham virus, jeopardized this efficacious treatment from the beginning. Eight years after licensing of natalizumab, long-term studies confirm the considerable and sustained efficacy of natalizumab, although the PML complication still threatens one of the most successful treatments available for RRMS. During these years, considerable progress has been made in identification of risk factors that allow more effective management of PML risk. In addition, long-term studies to define better when to start or stop treatment and to optimize treatment strategies after cessation of natalizumab are ongoing, and hopefully will improve management and will allow natalizumab to remain as a valuable therapeutic option for patients with highly active RRMS.

17.
PLoS One ; 8(5): e63296, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23691013

RESUMO

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.


Assuntos
Autoimunidade , Células Dendríticas/metabolismo , Dinoprostona/biossíntese , Fagocitose , Animais , Proliferação de Células , Células Dendríticas/citologia , Células Dendríticas/imunologia , Perfilação da Expressão Gênica , Camundongos , Camundongos Endogâmicos NOD , Linfócitos T Reguladores/citologia
18.
J Clin Gastroenterol ; 47(4): 308-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23388848

RESUMO

Celiac disease (CD) is an autoimmune disorder, which damages the small intestine and is caused by ingestion of gluten in genetically susceptible individuals. The only known effective treatment is a lifelong gluten-free diet. Genetic risk factors have been identified and nearly all patients are HLA-DQ2 and/or HLA-DQ8 positive. Specific autoantibodies, IgA antitissue transglutaminase-2, antiendomysium, and antideaminated forms of gliadin peptide antibodies, are widely used as diagnostic aids in celiac patients. However, the discovery of new biomarkers may help in the diagnosis and follow-up of the disease. Recently, the molecule REG Iα, involved in tissue regeneration, has been proposed as a new biomarker of CD. REG Iα expression is increased in the target tissue and in the sera of celiac patients during damage and inflammation, decreasing after gluten-free diet. In this article we review the main biomarkers for diagnosis and monitoring of CD, focusing on the immune response-related mechanisms.


Assuntos
Autoanticorpos/sangue , Doença Celíaca/diagnóstico , Antígenos HLA-DQ/genética , Litostatina/sangue , Animais , Autoimunidade , Biomarcadores/sangue , Doença Celíaca/sangue , Doença Celíaca/dietoterapia , Doença Celíaca/genética , Doença Celíaca/imunologia , Dieta Livre de Glúten , Marcadores Genéticos , Humanos , Valor Preditivo dos Testes , Prognóstico , Índice de Gravidade de Doença
19.
J Virol ; 87(6): 3393-408, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23302880

RESUMO

JC polyomavirus (JCV) infection is highly prevalent and usually kept in a persistent state without clinical signs and symptoms. It is only during immunocompromise and especially impaired CD4(+) T cell function in the brain, as seen in AIDS patients or natalizumab-treated multiple sclerosis patients, that JCV may cause progressive multifocal leukoencephalopathy (PML), an often life-threatening brain disease. Since CD4(+) T cells likely play an important role in controlling JCV infection, we here describe the T cell response to JCV in a group of predominantly HLA-DR-heterozygotic healthy donors (HD) by using a series of overlapping 15-mer peptides spanning all JCV-encoded open reading frames. We identified immunodominant epitopes and compared T cell responses with anti-JCV VP1 antibody production and with the presence of urinary viral shedding. We observed positive JCV-specific T cell responses in 28.6% to 77.6%, humoral immune response in 42.6% to 89.4%, and urinary viral shedding in 36.4% to 45.5% of HD depending on the threshold. Four immunodominant peptides were mapped, and at least one immunogenic peptide per HLA-DRB1 allele was detected in DRB1*01(+), DRB1*07(+), DRB1*11(+), DRB1*13(+), DRB1*15(+), and DRB1*03(+) individuals. We show for the first time that JCV-specific T cell responses may be directed not only against JCV VP1 and large T antigen but also against all other JCV-encoded proteins. Heterozygotic DRB1*04:01(+) individuals showed very low T cell responses to JCV together with normal anti-VP1 antibody levels and no urinary viral shedding, indicating a dominant-negative effect of this allele on global JCV-directed T cell responses. Our data are potentially relevant for the development of vaccines against JCV.


Assuntos
Epitopos de Linfócito T/análise , Cadeias HLA-DRB1/imunologia , Vírus JC/imunologia , Proteoma/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Mapeamento de Epitopos , Feminino , Cadeias HLA-DRB1/genética , Humanos , Epitopos Imunodominantes/análise , Masculino , Pessoa de Meia-Idade , Urina/virologia , Eliminação de Partículas Virais
20.
Biomarkers ; 18(2): 178-80, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23312007

RESUMO

Celiac disease is an autoimmune disorder induced by gluten in genetically predisposed people. The discovery of new biomarkers may help in the diagnosis and follow-up of celiac patients. Regenerating islet-derived 1 alpha (REGIα)--a biomarker related to tissue regeneration--is increased in serum at the onset of the disease, decreasing after gluten-free diet (GFD). As REGIα is a 18 kDa soluble glycoprotein, it may be detected in urine samples, increasing in celiac patients. We have determined REGIα levels by ELISA. No differences were found among patients (onset or after GFD) and controls and no correlation exists among REGIα in sera and urine.


Assuntos
Doença Celíaca/sangue , Doença Celíaca/urina , Litostatina/sangue , Litostatina/urina , Adolescente , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Estudos de Casos e Controles , Doença Celíaca/diagnóstico , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino
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