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2.
Open Forum Infect Dis ; 6(9): ofz317, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31660400

RESUMO

Latent Epstein-Barr virus (EBV) infection can clinically reactivate in immunosuppressed individuals causing lymphoproliferative disease and rarely hepatitis. In this study, we provide in vivo and in vitro evidence that Treponema pallidum infection can cause EBV reactivation with hepatitis in an immunocompetent patient. We report the diagnostic challenges and immunological findings of coinciding syphilis and EBV-associated hepatitis. Using an in vitro EBV-reactivation assay, we demonstrate that T pallidum reactivates latent EBV in a Toll-like receptor (TLR)2/B-cell receptor signaling-dependent manner. Epstein-Barr virus-associated reactivation or lymphoproliferation should be considered in infections with pathogens that activate TLR2.

3.
Nat Immunol ; 20(10): 1311-1321, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31527833

RESUMO

Whether screening the metabolic activity of immune cells facilitates discovery of molecular pathology remains unknown. Here we prospectively screened the extracellular acidification rate as a measure of glycolysis and the oxygen consumption rate as a measure of mitochondrial respiration in B cells from patients with primary antibody deficiency. The highest oxygen consumption rate values were detected in three study participants with persistent polyclonal B cell lymphocytosis (PPBL). Exome sequencing identified germline mutations in SDHA, which encodes succinate dehydrogenase subunit A, in all three patients with PPBL. SDHA gain-of-function led to an accumulation of fumarate in PPBL B cells, which engaged the KEAP1-Nrf2 system to drive the transcription of genes encoding inflammatory cytokines. In a single patient trial, blocking the activity of the cytokine interleukin-6 in vivo prevented systemic inflammation and ameliorated clinical disease. Overall, our study has identified pathological mitochondrial retrograde signaling as a disease modifier in primary antibody deficiency.

4.
JAMA Oncol ; 5(7): 1043-1047, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31021392

RESUMO

Importance: Immunotherapy with checkpoint inhibitors targeting the PD-1 (programmed cell death 1) axis has brought notable progress in patients with non-small cell lung cancer (NSCLC) and other cancers. However, autoimmune toxic effects are frequent and poorly understood, making it important to understand the pathophysiologic processes of autoimmune adverse effects induced by checkpoint inhibitor therapy. Objective: To gain mechanistic insight into autoimmune skin toxic effects induced by anti-PD-1 treatment in patients with non-small cell lung cancer. Design, Setting, and Participants: This prospective cohort study was conducted from July 1, 2016, to December 31, 2018. Patients (n = 73) with non-small cell lung cancer who received anti-PD-1 therapy (nivolumab or pembrolizumab) were recruited from 4 different centers in Switzerland (Kantonsspital St Gallen, Spital Grabs, Spital Wil, and Spital Flawil). Peripheral blood mononuclear cells, tumor biopsy specimens and biopsies from sites of autoimmune skin toxic effects were collected over a 2-year period, with patient follow-up after 1 year. Main Outcomes and Measures: Response to treatment, overall survival, progression-free survival, and development of autoimmune toxic effects (based on standard laboratory values and clinical examinations). Results: Of the cohort of 73 patients with NSCLC (mean [SD] age, 68.1 [8.9] years; 44 [60%] men), 25 (34.2% [95% CI, 24.4%-45.7%]) developed autoimmune skin toxic effects, which were more frequent in patients with complete remission or partial remission (68.2% [95% CI, 47.3%-83.6%]) than those with progressive or stable disease (19.6% [95% CI, 11.0%-32.5%]) (χ2 = 14.02, P < .001). Nine T-cell antigens shared between tumor tissue and skin were identified. These antigens were able to stimulate CD8+ and CD4+ T cells in vitro. Several of the antigen-specific T cells found in blood samples were also present in autoimmune skin lesions and lung tumors of patients who responded to anti-PD-1 therapy. Conclusions and Relevance: These findings highlight a potential mechanism of checkpoint inhibitor-mediated autoimmune toxic effects and describe the association between toxic effects and response to therapy; such an understanding will help in controlling adverse effects, deciphering new cancer antigens, and further improving immunotherapy.

5.
J Immunother Cancer ; 7(1): 50, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30786924

RESUMO

BACKGROUND: Long-term survival of stage IV melanoma patients has improved significantly with the development of immune checkpoint inhibitors (CIs). Reliable biomarkers to predict response and clinical outcome are needed. METHODS: We investigated the role of melanoma-associated antibodies as predictive markers for CI therapy in two independent cohorts. In cohort 1, a prospective study, we measured specific antibodies before treatment, after one week and after six to nine weeks of treatment. Cohort 2 consisted of serum samples prior to CI therapy initiation. ELISA assays were performed to quantify specific IgG directed against melanocyte differentiation antigens tyrosinase-related proteins 1 and 2 (TRP1/TYRP1 and TRP2/TYRP2), glycoprotein 100 (gp100), MelanA/MART1, and the cancer-testis antigen NY-ESO-1. Response was defined as either complete or partial remission on CT scan according to RECIST 1.1. RESULTS: In cohort 1, baseline levels of these antibodies were higher in the responder group, although statistical significance was only reached for NY-ESO-1 (p = 0.007). In cohort 2, significantly higher antibody baseline levels for MelanA/MART1 (p = 0.003) and gp100 (p = 0.029) were found. After pooling the results from both cohorts, higher levels of MelanA/MART1 (p = 0.013), TRP1/TYRP1 (p = 0.048), TRP2/TYRP2 (p = 0.047) and NY-ESO-1 (p = 0.005) specific antibodies at baseline were independently associated with response. CONCLUSIONS: Melanoma-associated antibodies may be candidate biomarkers for response and survival in metastatic melanoma patients being treated with CIs. These markers may be used to complement patient assessment, in combination with PD-L1 status, tumor-infiltrating lymphocytes and tumor mutational burden, with the aim to predict outcome of CI treatment in patients with metastatic melanoma. TRIAL REGISTRATION: Ethikkommission Ostschweiz, EKOS 16/079 https://ongoingprojects.swissethics.ch/runningProjects_list.php?q=%28BASECID~contains~2016-00998%29&orderby=dBASECID .

6.
J Immunother ; 42(3): 89-93, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30768543

RESUMO

Checkpoint inhibitors have improved survival of metastatic melanoma. However, reliable biomarkers to predict response are still needed. Immunoglobulin G (IgG) antibody subclasses reflect immunocompetence in individuals and are known to be involved in essential functions in our immune system. This prospective study evaluated the association between serum IgG with its subclasses IgG1, IgG2, IgG3, and IgG4 and antitumor response according to RECIST 1.1. Serum samples from 49 patients were prospectively collected before the start of treatment with a checkpoint inhibitor. We observed a statistically significant association of baseline IgG2 with response to therapy (P=0.011). After defining optimal cutpoints, we found significant associations between total IgG (>9.66 g/L, P=0.038), IgG1 (>6.22 g/L, P=0.025), IgG2 (>2.42 g/L, P=0.019), and IgG3 (>0.21 g/L, P=0.034) with progression-free survival. Prolonged overall survival was associated with elevated IgG2 (>2.42 g/L, P=0.043). Together, these findings define total IgG and subclasses as predictors of clinical successful checkpoint inhibition in metastatic melanoma patients.

8.
Am J Transplant ; 19(1): 238-246, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29920932

RESUMO

New-onset diabetes mellitus after transplantation (NODAT) is a complication following solid organ transplantation (SOT) and may be related to immune or inflammatory responses. We investigated whether single nucleotide polymorphisms (SNPs) within 158 immune- or inflammation-related genes contribute to NODAT in SOT recipients. The association between 263 SNPs and NODAT was investigated in a discovery sample of SOT recipients from the Swiss Transplant Cohort Study (STCS, n1  = 696). Positive results were tested in a first STCS replication sample (n2  = 489) and SNPs remaining significant after multiple test corrections were tested in a second SOT replication sample (n3  = 156). Associations with diabetic traits were further tested in several large general population-based samples (n > 480 000). Only SP110 rs2114592C>T remained associated with NODAT in the STCS replication sample. Carriers of rs2114592-TT had 9.9 times (95% confidence interval [CI]: 3.22-30.5, P = .00006) higher risk for NODAT in the combined STCS samples (n = 1184). rs2114592C>T was further associated with NODAT in the second SOT sample (odds ratio: 4.8, 95% CI: 1.55-14.6, P = .006). On the other hand, SP110 rs2114592C>T was not associated with diabetic traits in population-based samples, suggesting a specific gene-environment interaction, possibly due to the use of specific medications (ie, immunosuppressants) in transplant patients and/or to the illness that may unmask the gene effect.

9.
PLoS One ; 13(6): e0198330, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29879160

RESUMO

Directed migration of cells relies on their ability to sense directional guidance cues and to interact with pericellular structures in order to transduce contractile cytoskeletal- into mechanical forces. These biomechanical processes depend highly on microenvironmental factors such as exposure to 2D surfaces or 3D matrices. In vivo, the majority of cells are exposed to 3D environments. Data on 3D cell migration are mostly derived from intravital microscopy or collagen-based in vitro assays. Both approaches offer only limited controllability of experimental conditions. Here, we developed an automated microfluidic system that allows positioning of cells in 3D microenvironments containing highly controlled diffusion-based chemokine gradients. Tracking migration in such gradients was feasible in real time at the single cell level. Moreover, the setup allowed on-chip immunocytochemistry and thus linking of functional with phenotypical properties in individual cells. Spatially defined retrieval of cells from the device allows down-stream off-chip analysis. Using dendritic cells as a model, our setup specifically allowed us for the first time to quantitate key migration characteristics of cells exposed to identical gradients of the chemokine CCL19 yet placed on 2D vs in 3D environments. Migration properties between 2D and 3D migration were distinct. Morphological features of cells migrating in an in vitro 3D environment were similar to those of cells migrating in animal tissues, but different from cells migrating on a surface. Our system thus offers a highly controllable in vitro-mimic of a 3D environment that cells traffic in vivo.


Assuntos
Quimiocina CCL19/farmacologia , Células Dendríticas/citologia , Microfluídica/instrumentação , Análise de Célula Única/métodos , Animais , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Quimiotaxia , Células Dendríticas/efeitos dos fármacos , Dispositivos Lab-On-A-Chip , Camundongos
10.
NPJ Vaccines ; 3: 17, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29796310

RESUMO

Pneumococcal conjugate vaccine (PCV) is recommended for adults with chronic disease. Extensive limb swelling (ELS) is an acute vigorous local inflammatory reaction following vaccination. Predisposing immune system correlates and the influence of ELS on vaccine responses are not known. Here, we report a case of a 67-year-old woman with a history of multiple pneumonias who had a detailed immunological work-up pre-vaccination because of suspected immunodeficiency. Four days following a first vaccination with PCV13 she developed ELS-mimicking erysipelas. Treatment with 20 mg cortisone completely alleviated symptoms within 2 days. Skin biopsy showed a dense dermal and subdermal infiltration dominated by CD4+ T cells and macrophages. In a multiplexed serotype-specific measurement of the anti-pneumococcal IgG response, the patient showed very broad and strong vaccine responses. Pre-vaccination titers were low for the vaccine serotypes. We did not find in vivo nor in vitro evidence of an excessive T cell response to the diphtheria-derived PCV carrier protein. However, we could demonstrate a high antibody titer to a non-vaccine serotype, indicating in vivo pre-exposure to pneumococcus bacteria. Thus, traces of pneumococcal proteins included in PCV13 may have boosted pre-existing pneumococcus-specific T helper cells, which subsequently orchestrated ELS. Our case raises awareness for the risk of vaccine-induced ELS, especially in patients with a history of recurrent pneumococcal disease and thus partial immunity.

11.
J Allergy Clin Immunol ; 142(6): 1932-1946, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29729943

RESUMO

BACKGROUND: Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative immune regulator. Heterozygous CTLA4 germline mutations can cause a complex immune dysregulation syndrome in human subjects. OBJECTIVE: We sought to characterize the penetrance, clinical features, and best treatment options in 133 CTLA4 mutation carriers. METHODS: Genetics, clinical features, laboratory values, and outcomes of treatment options were assessed in a worldwide cohort of CTLA4 mutation carriers. RESULTS: We identified 133 subjects from 54 unrelated families carrying 45 different heterozygous CTLA4 mutations, including 28 previously undescribed mutations. Ninety mutation carriers were considered affected, suggesting a clinical penetrance of at least 67%; median age of onset was 11 years, and the mortality rate within affected mutation carriers was 16% (n = 15). Main clinical manifestations included hypogammaglobulinemia (84%), lymphoproliferation (73%), autoimmune cytopenia (62%), and respiratory (68%), gastrointestinal (59%), or neurological features (29%). Eight affected mutation carriers had lymphoma, and 3 had gastric cancer. An EBV association was found in 6 patients with malignancies. CTLA4 mutations were associated with lymphopenia and decreased T-, B-, and natural killer (NK) cell counts. Successful targeted therapies included application of CTLA-4 fusion proteins, mechanistic target of rapamycin inhibitors, and hematopoietic stem cell transplantation. EBV reactivation occurred in 2 affected mutation carriers after immunosuppression. CONCLUSIONS: Affected mutation carriers with CTLA-4 insufficiency can present in any medical specialty. Family members should be counseled because disease manifestation can occur as late as 50 years of age. EBV- and cytomegalovirus-associated complications must be closely monitored. Treatment interventions should be coordinated in clinical trials.


Assuntos
Antígeno CTLA-4/genética , Síndromes de Imunodeficiência/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Síndromes de Imunodeficiência/diagnóstico por imagem , Síndromes de Imunodeficiência/terapia , Masculino , Pessoa de Meia-Idade , Mutação , Fenótipo , Adulto Jovem
12.
Immunity ; 48(3): 542-555.e6, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29523440

RESUMO

Glycolysis is linked to the rapid response of memory CD8+ T cells, but the molecular and subcellular structural elements enabling enhanced glucose metabolism in nascent activated memory CD8+ T cells are unknown. We found that rapid activation of protein kinase B (PKB or AKT) by mammalian target of rapamycin complex 2 (mTORC2) led to inhibition of glycogen synthase kinase 3ß (GSK3ß) at mitochondria-endoplasmic reticulum (ER) junctions. This enabled recruitment of hexokinase I (HK-I) to the voltage-dependent anion channel (VDAC) on mitochondria. Binding of HK-I to VDAC promoted respiration by facilitating metabolite flux into mitochondria. Glucose tracing pinpointed pyruvate oxidation in mitochondria, which was the metabolic requirement for rapid generation of interferon-γ (IFN-γ) in memory T cells. Subcellular organization of mTORC2-AKT-GSK3ß at mitochondria-ER contact sites, promoting HK-I recruitment to VDAC, thus underpins the metabolic reprogramming needed for memory CD8+ T cells to rapidly acquire effector function.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Retículo Endoplasmático/metabolismo , Metabolismo Energético , Memória Imunológica , Mitocôndrias/metabolismo , Transdução de Sinais , Respiração Celular , Retículo Endoplasmático/ultraestrutura , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicólise , Membranas Intracelulares/metabolismo , Ativação Linfocitária , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Mitocôndrias/ultraestrutura , Modelos Biológicos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/deficiência
14.
Eur Heart J Cardiovasc Imaging ; 19(8): 933-940, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29126277

RESUMO

Aims: The usefulness of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography ([18F]FDG-PET/CT) for diagnosing giant cell arteritis (GCA) has been previously reported. Yet, the interpretation of PET scans is not clear-cut. The present study aimed at determining the best method to analyse PET/CT in a large, real-life cohort of patients presenting with suspicion of GCA. Methods and results: One hundred and three patients with clinical suspicion of GCA undergoing PET/CT between 2006 and 2012 were included. Clinical data were retrieved from patients' charts. PET/CT was categorized by visual scoring of the uptake and by the artery/liver standardized uptake values (SUV) ratios. Diagnosis of GCA was confirmed in 68 patients and excluded in 35 patients, which served as the controls. GCA patients were older (median age 75 vs. 68 years), and presented more often with ischaemic symptoms. The best discrimination between GCA patients and controls was achieved for PET/CT findings within the supra-aortic arteries (sensitivity 0.71, specificity 0.91 for a SUV/LE cut-off value of 1.0). Specificity of PET/CT for the aorta and the iliofemoral arteries was lower (<0.34). Visual scoring correlated poorly to SUV measurements (Kendall Tau-b 0.13-0.55) and had a lower diagnostic accuracy (sensitivity 0.77, specificity 0.75). Prednisone treatment for ≥10 days significantly reduced PET/CT sensitivity (P = 0.009). Conclusion: SUV based analysis of PET/CT enhances diagnostic accuracy with best discrimination in the supra-aortic region, particularly in steroid naïve patients. For discrimination based on the aorta and the iliofemoral region, higher cut-off values have to be applied, resulting in lower sensitivities for diagnosing GCA.


Assuntos
Fluordesoxiglucose F18 , Arterite de Células Gigantes/diagnóstico por imagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial , Biópsia por Agulha , Estudos de Coortes , Feminino , Seguimentos , Arterite de Células Gigantes/patologia , Hospitais Universitários , Humanos , Imuno-Histoquímica , Masculino , Curva ROC , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Suíça , Fatores de Tempo , Acuidade Visual
16.
BMC Med ; 15(1): 174, 2017 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-28942732

RESUMO

BACKGROUND: Uncertainty about factors influencing the susceptibility and triggers for Graves' disease persists, along with a wide variation in the response to anti-thyroid drugs, currently at approximately 50% of non-responders. The aim of this narrative review is to summarize immunological concepts, with a combined endocrine and immunological perspective, to highlight potential new areas of research. MAIN TEXT: Relevant studies were identified through a systematic literature search using the PubMed and EMBASE databases in March 2016. No cut-offs regarding dates were imposed. We used the terms "Graves' Disease" or "Basedow" or "thyrotoxicosis" together with the terms "etiology", "pathophysiology", "immunodeficiency", "causality", and "autoimmunity". The terms "orbitopathy", "ophthalmopathy", and "amiodarone" were excluded. Articles in English, French, German, Croatian, Spanish, and Italian were eligible for inclusion. CONCLUSIONS: While concepts such as the impact of iodine, smoking, human leucocyte antigen, infections, and ethnicity are established, new ideas have emerged. Pertaining evidence suggests the involvement of autoimmunity and immunodeficiency in the pathophysiology of Graves' disease. Recent studies point to specific immunological mechanisms triggering the onset of disease, which may also serve as targets for more specific therapies.


Assuntos
Doença de Graves/imunologia , Síndromes de Imunodeficiência , Animais , Autoimunidade , Doença de Graves/genética , Humanos , Síndromes de Imunodeficiência/genética
17.
J Clin Immunol ; 37(7): 707-714, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28825155

RESUMO

Mutations in Sp110 are the underlying cause of veno-occlusive disease with immunodeficiency (VODI), a combined immunodeficiency that is difficult to treat and often fatal. Because early treatment is critically important for patients with VODI, broadly usable diagnostic tools are needed to detect Sp110 protein deficiency. Several factors make establishing the diagnosis of VODI challenging: (1) Current screening strategies to identify severe combined immunodeficiency are based on measuring T cell receptor excision circles (TREC). This approach will fail to identify VODI patients because the disease is not associated with severe T cell lymphopenia at birth; (2) the SP110 gene contains 17 exons, making it a challenge for Sanger sequencing. The recently developed next-generation sequencing (NGS) platforms that can rapidly determine the sequence of all 17 exons are available in only a few laboratories; (3) there is no standard functional assay to test for the effects of novel mutations in Sp110; and (4) it has been difficult to use flow cytometry to identify patients who lack Sp110 because of the low level of Sp110 protein in peripheral blood lymphocytes. We report here a novel flow cytometric assay that is easily performed in diagnostic laboratories and might thus become a standard assay for the evaluation of patients who may have VODI. In addition, the assay will facilitate investigations directed at understanding the function of Sp110.


Assuntos
Citometria de Fluxo/métodos , Hepatopatia Veno-Oclusiva/diagnóstico , Síndromes de Imunodeficiência/diagnóstico , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas Nucleares/metabolismo , Linfócitos T/metabolismo , Adenoviridae/genética , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Hepatopatia Veno-Oclusiva/metabolismo , Humanos , Síndromes de Imunodeficiência/metabolismo , Leucócitos Mononucleares/citologia , Masculino , Antígenos de Histocompatibilidade Menor/genética , Proteínas Nucleares/genética
18.
Clin Endocrinol (Oxf) ; 87(5): 609-616, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28833367

RESUMO

OBJECTIVES: Graves' hyperthyroidism (GH) interferes with iron metabolism and elevates ferritin. The precise mechanisms remain unclear. The influence of thyroid hormones on the synthesis/regulation of hepcidin, an important regulator of iron metabolism, remains uncharacterized. DESIGN: Prospective observational study. PATIENTS: We included patients (n = 31) with new-onset and untreated GH. MEASUREMENTS: Laboratory parameters indicative of iron metabolism (ferritin, transferrin, hepcidin), inflammatory markers/cytokines and smoking status were assessed at the diagnosis of GH (T0) and at euthyroidism (T1) in the same patients using multivariable analyses. Hepcidin was measured by mass spectrometry (hepcidinMS ) and ELISA (hepcidinEL ). The impact of T3 on hepatic hepcidin expression was studied in a cell culture model using HepG2 cells. RESULTS: Median ferritin levels were significantly lower and transferrin significantly higher at T1 than at T0. HepcidinMS levels were lower in males and females at T1 (statistically significant in males only). No statistically significant difference in hepcidinEL was detected between T0 and T1. Plasma levels of inflammatory markers (high-sensitive CRP, procalcitonin) and cytokines (interleukin 6, interleukin 1ß, tumour necrosis factor α) were not different between T0 and T1. Smokers tended to have lower fT3 and fT4 at T0 than nonsmoking GH patients. T3 significantly induced hepcidin mRNA expression in HepG2 cells. CONCLUSIONS: Iron metabolism in patients with GH undergoes dynamic changes in patients with GH that resemble an acute-phase reaction. Inflammatory parameters and cytokines were unaffected by thyroid status. Gender and smoking status had an impact on ferritin, hepcidin and thyroid hormones.


Assuntos
Ferritinas/sangue , Doença de Graves/metabolismo , Hepcidinas/metabolismo , Ferro/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Citocinas/metabolismo , Feminino , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Transferrina/metabolismo , Tri-Iodotironina/farmacologia
19.
Rheumatology (Oxford) ; 56(5): 829-834, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28064210

RESUMO

Objectives: Autoantibodies are useful biomarkers for diagnosing and monitoring treatment in some autoimmune diseases. Antibodies against isoforms of 14-3-3 protein have been proposed as biomarkers for the presence of aortic aneurysm in large-vessel vasculitis (LVV). Here, we aimed to evaluate the diagnostic role and potential immunopathological involvement of anti-14-3-3 antibodies in newly diagnosed LVV patients. Methods: Antibodies against three isoforms of 14-3-3 (γ, ɛ and ζ) were measured in 90 subjects: 48 GCA and 3 Takayasu's arteritis (TA) patients, and 39 controls (non-inflammatory and inflammatory diseases), using a multiplexed bead-based immunoassay and immunoprecipitation studies. The positive cut-off value was defined based on young healthy controls. Anti-14-3-3 IgG antibodies in LVV patients were compared with those in controls in order to assess their diagnostic performance, and the relationship of anti-14-3-3 IgG antibodies to the immunohistopathology of artery explants was assessed. Results: Antibodies against all three 14-3-3 isoforms were detected in LVV patients as well as in age-matched inflammatory and non-inflammatory controls. Among LVV patients, detection of antibodies targeting 14-3-3 ɛ and ζ was associated with more severe disease. Detection of antibodies against 14-3-3 γ was linked to latent Toxoplasma gondii infection, a parasite that secrets a 14-3-3 homologue, suggesting potential cross-reactivity. Conclusion: Detection of antibodies against 14-3-3 proteins at the time of LVV diagnosis is not disease-specific. Their presence at high levels in LVV patients with stroke, aortitis and-in a previous study-aneurysm formation may indicate an association with extensive tissue destruction. The relevance of 14-3-3 antibodies in non-LVV patients needs to be investigated in larger cohorts.


Assuntos
Proteínas 14-3-3/imunologia , Autoanticorpos/metabolismo , Arterite de Células Gigantes/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aortite/imunologia , Biomarcadores/metabolismo , Feminino , Arterite de Células Gigantes/diagnóstico , Humanos , Imunoglobulina G/metabolismo , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/imunologia , Arterite de Takayasu/imunologia , Toxoplasma/imunologia , Toxoplasmose/imunologia , Remodelação Vascular/imunologia , Adulto Jovem
20.
Nat Microbiol ; 2: 16268, 2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-28112722

RESUMO

Host control of infections crucially depends on the capability to kill pathogens with reactive oxygen species (ROS). However, these toxic molecules can also readily damage host components and cause severe immunopathology. Here, we show that neutrophils use their most abundant granule protein, myeloperoxidase, to target ROS specifically to pathogens while minimizing collateral tissue damage. A computational model predicted that myeloperoxidase efficiently scavenges diffusible H2O2 at the surface of phagosomal Salmonella and converts it into highly reactive HOCl (bleach), which rapidly damages biomolecules within a radius of less than 0.1 µm. Myeloperoxidase-deficient neutrophils were predicted to accumulate large quantities of H2O2 that still effectively kill Salmonella, but most H2O2 would leak from the phagosome. Salmonella stimulation of neutrophils from normal and myeloperoxidase-deficient human donors experimentally confirmed an inverse relationship between myeloperoxidase activity and extracellular H2O2 release. Myeloperoxidase-deficient mice infected with Salmonella had elevated hydrogen peroxide tissue levels and exacerbated oxidative damage of host lipids and DNA, despite almost normal Salmonella control. These data show that myeloperoxidase has a major function in mitigating collateral tissue damage during antimicrobial oxidative bursts, by converting diffusible long-lived H2O2 into highly reactive, microbicidal and locally confined HOCl at pathogen surfaces.


Assuntos
Peróxido de Hidrogênio/metabolismo , Neutrófilos/enzimologia , Peroxidase/metabolismo , Fagossomos/microbiologia , Explosão Respiratória , Salmonella/metabolismo , Animais , Simulação por Computador , Humanos , Ácido Hipocloroso/metabolismo , Cinética , Camundongos , Neutrófilos/imunologia , Oxirredução , Estresse Oxidativo , Fagossomos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salmonella/patogenicidade
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