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1.
Horm Metab Res ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38621693

RESUMO

Papillary thyroid carcinoma (PTC) is characterized by T cell infiltration and frequently by the presence of anti-thyroglobulin antibodies (TgAbs). The role of cellular immunity and of TbAbs in this context is a matter of debate. The aim of our study was to correlate the presence of TgAbs, tumor epitope-specific T cells and the clinical outcome of PTC patients. We studied n=183 consecutive patients with a diagnosis of PTC which were treated with total thyroidectomy plus 131I ablation. During a follow-up of in mean 97 months, most of the PTC patients had no signs of tumor relapse (n=157 patients). In contrast, one patient had serum Tg levels above the detection limit and<1 ng/ml, two patients Tg serum levels≥1 ng/ml and<2 ng/ml and n=23 patients had Tg serum levels≥2 ng/ml. Morphological signs of tumor recurrence were seen in 14 patients; all of these patients had serum Tg levels≥2 ng/ml. Importantly, with the exception of one patient, all TgAb positive PTC patients (n=27) had no signs of tumor recurrence as the serum Tg levels were below the assays functional sensitivities. Tetramer analyses revealed a higher number of tumor epitope-specific CD8+T cells in TgAb positive patients compared to TgAb negative PTC patients. In summary, we show that the occurrence of TgAbs may have an impact on the clinical outcome in PTC patients. This might be due to a tumor epitope-specific cellular immunity in PTC patients.

2.
Horm Metab Res ; 54(12): 852-858, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36427494

RESUMO

One feature of papillary thyroid cancer (PTC) is the frequently present somatic BRAFV600E mutation. PTCs are also characterized by a lymphocytic infiltration, which may correlate with an improved clinical outcome. The objective of the study was the characterization of BRAFV600E specific anti-immunity in PTC patients and correlation analyses with the clinical outcome. Fourteen HLA A2 positive PTC patients were included into the study of whom tumor tissue samples were also available. Of those, 8 PTC patients revealed a somatic BRAFV600E mutation. All PTC patients were also MHC class II typed. Tetramer analyses for detection of MHC class I and MHC class II-restricted, BRAFV600E epitope-specific T cells using unstimulated and peptide-stimulated T cells were performed; correlation analyses between MHC phenotypes, T cell immunity, and the clinical course were performed. In regard to unstimulated T cells, a significantly higher amount of BRAFV600E epitope specific T cells was detected compared to a control tetramer. Importantly, after overnight peptide stimulation a significantly higher number of BRAFV600E positive and BRAF WT epitope-specific T cells could be seen. In regard to the clinical course, however, no significant differences were seen, neither in the context of the initial tumor size, nor in the context of lymph node metastases or peripheral metastastic spread. In conclusion, we clearly demonstrated a BRAF-specific tumor immunity in PTC-patients which is, however, independent of a BRAFV600E status of the PTC patients.


Assuntos
Proteínas Proto-Oncogênicas B-raf , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide , Humanos , Progressão da Doença , Epitopos de Linfócito T/imunologia , Genes MHC da Classe II/imunologia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/imunologia , Linfócitos T/imunologia , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/imunologia , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/patologia , Mutação , Imunidade/genética
3.
Clin Endocrinol (Oxf) ; 94(6): 1004-1011, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33484159

RESUMO

OBJECTIVE: The aim of the study was the quantification of circulating tumour cells (CTCs) in differentiated thyroid cancer (DTC) patients before and 6 weeks after radioiodine therapy (RIT). CONTEXT: Circulating tumour cells (CTCs) were described more recently in cancer patients, mostly correlating with poor outcome and advanced metastases. DESIGN: Peripheral blood for identification and quantification of CTC before RIT or/and 6 weeks after RIT was provided by 55 DTC patients that received RIT for remnant tissue ablation. PATIENTS: 13 follicular thyroid cancer (FTC) patients, 31 papillary thyroid cancer (PTC) patients and 11 patients having the follicular variant PTC (FV-PTC) were included. MEASUREMENTS: Peripheral blood mononuclear cells (PBMCs) were isolated and EpCAM-positive CTCs were counted by immune fluorescent staining. RESULTS: A CTC positivity of 31.8% before RIT could be observed. Six weeks after RIT, the CTC positivity was reduced to 13.6%. Paired data at both time points of blood sampling could be gathered for n = 33 DTC patients. These patients had significantly higher CTC numbers before RIT than 6 weeks afterwards (0.27 ± 0.47 vs 0.05 ± 0.15, P = .0215). Additionally, significantly reduced CTC numbers were also demonstrated in pre-RIT CTC-positive patients (0.88 ± 0.43 vs 0.05 ± 0.16, P = .0039). CONCLUSION: Our results indicate a reducing effect on the number of CTCs by RIT. Therefore, CTC enumeration should be considered as efficient tool for treatment monitoring during RIT.


Assuntos
Adenocarcinoma Folicular , Células Neoplásicas Circulantes , Neoplasias da Glândula Tireoide , Adenocarcinoma Folicular/radioterapia , Humanos , Radioisótopos do Iodo/uso terapêutico , Leucócitos Mononucleares , Neoplasias da Glândula Tireoide/radioterapia
4.
BMC Res Notes ; 13(1): 282, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522271

RESUMO

OBJECTIVE: Fibroblast growth factor receptor (FGFR) 2 regulates the development of the adrenal gland in mice. In addition, FGFR2-mediated signalling has been shown to prevent apoptosis and to enhance proliferation in adrenocortical precursor cells. The activation of the Wingless/Int-1 (WNT)/beta catenin pathway as a key mechanism of adrenocortical tumourigenesis has been linked to FGFR2 signalling in other cell types. Therefore we hypothesised that FGFR2 expression may also play a role in adrenocortical carcinoma (ACC). We conducted a pilot study and analysed protein expression of FGFR2 in 26 ACCs using immunohistochemistry technique. Data on the CTNNB1 mutation status and clinical data were correlated to the expression of FGFR2. RESULTS: We observed a high variability in FGFR2 expression between the different tumour samples. There was a subset of ACC with comparatively high nuclear expression of FGFR2. We did not find a clear association between the CTNNB1 mutational status or clinical features and the FGFR2 expression. We conclude that FGFR signalling plays a role in adrenocortical carcinoma. Our data encourages further investigations of FGFR signalling in ACC, especially since new inhibitors of FGFR signalling are already entering clinical trials for the treatment of other cancer types.


Assuntos
Neoplasias do Córtex Suprarrenal/metabolismo , Carcinoma Adrenocortical/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , beta Catenina/genética , Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Genótipo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Projetos Piloto
5.
Horm Metab Res ; 51(6): 341-346, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31207654

RESUMO

A rapid and fully automated chemiluminescent immunoassay for the detection of thyrotropin receptor autoantibodies (TSHR-Ab) based on a bridge technology was compared with two bioassays that measure either stimulating (TSAb) or blocking (TBAb) antibodies for the detection and differentiation of TSHR-Ab. A total of 229 patients with various thyroid disorders [151 with Graves' disease (GD), 35 with Hashimoto's thyroiditis (HT), 32 with nodular goiter, and 11 with thyroid cancer] were included. The bridge immunoassay was performed according to the manufacturer's instructions (cut-off>0.55 IU/l). TSAb and TBAb were measured with reporter bioassays. Blocking activity was defined as percent inhibition of luciferase expression relative to induction with bovine TSH alone (cut-off>34% inhibition). TSAb was reported as percentage of specimen-to-reference ratio (> 140 SRR%). The 3 TSHR-Ab assays were negative in all patients with benign euthyroid nodular goiter and differentiated thyroid cancer. In contrast, in all patients with GD, irrespective of the disease duration, TSHR-Ab positivity was present in 127 of 151 (84%) and 140 (93%) for the bridge assay and TSAb bioassay, respectively (p<0.001). Fifteen of 151 (10%) GD samples were positive in the TSAb bioassay but negative in the bridge assay. The bridge assay and the TSAb bioassay correlated positively (r=0.39, p<0.0001) in patients with GD. Both assays detected TSHR-Ab in all ten untreated hyperthyroid patients with GD. In GD patients with a duration of less than six months, 27/29 (93%) and 28 (97%) were TSHR-Ab positive with the bridge and TSAb bioassay, respectively. In comparison, TSHR-Ab were present in two of 35 (6%) and five (14%) HT patients with the bridge and TSAb bio-assay, respectively. TSHR blocking antibodies were present in one (3%) patient with HT and in two (1%) patients with GD; these two GD patients were also bridge assay positive but TSAb bioassay negative. In conclusion, the bridge immunoassay and both bioassays are highly sensitive for the detection of TSHR-Ab. The bridge assay is, however, also positive in the presence of TSHR blocking antibodies detected in a TBAb bioassay.


Assuntos
Anticorpos/imunologia , Doença de Graves/diagnóstico , Doença de Hashimoto/diagnóstico , Imunoensaio/métodos , Imunoglobulinas Estimuladoras da Glândula Tireoide/sangue , Receptores da Tireotropina/imunologia , Neoplasias da Glândula Tireoide/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Diferenciação Celular , Feminino , Bócio Nodular/sangue , Bócio Nodular/diagnóstico , Bócio Nodular/imunologia , Doença de Graves/sangue , Doença de Graves/imunologia , Doença de Hashimoto/sangue , Doença de Hashimoto/imunologia , Humanos , Imunoglobulinas Estimuladoras da Glândula Tireoide/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias da Glândula Tireoide/sangue , Neoplasias da Glândula Tireoide/imunologia , Adulto Jovem
6.
Front Biosci (Landmark Ed) ; 24(1): 35-47, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30468646

RESUMO

Graves' disease (GD) is the most common cause for hyperthyroidism in iodine-replete areas. The disease is caused by the appearance of stimulating TSH receptor autoantibodies (TRAb) leading to hyperthyroidism. Blocking and neutral TRAb have, however, also been described. TRAb can be measured either by competition assays, assays using a bridge technology or bioassays (for discriminating stimulating vs. blocking antibodies). Therapy of GD with antithyroid drugs belonging to the group of thionamides is the first-line treatment to be continued for 12 up to 18 months. In case of relapse, thyroid ablative therapy including radioiodine therapy or thyroidectomy, respectively, should be performed. Risk factors for relapse are a large thyroid volume, persistence of high TRAb serum titer, smoking, and others. Within this review, we will give insights into the pathogenesis of GD including the pathogenesis of Graves' ophthalmopathy. We also describe recent developments of TRAb measurement, which is used for the diagnosis of GD as well as for outcome prediction. Finally, we discuss therapy aspects as well as the important issue of GD and pregnancy.


Assuntos
Autoanticorpos/imunologia , Doença de Graves/imunologia , Imunoglobulinas Estimuladoras da Glândula Tireoide/imunologia , Receptores da Tireotropina/imunologia , Antitireóideos/uso terapêutico , Doença de Graves/patologia , Doença de Graves/terapia , Humanos , Radioisótopos do Iodo/uso terapêutico , Receptores da Tireotropina/metabolismo , Recidiva , Tireoidectomia
7.
Horm Metab Res ; 50(8): 602-608, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30081408

RESUMO

Circulating tumor cells (CTCs) have been shown to be a valuable prognostic marker for different solid cancers. Within the present study we quantified CTCs in thyroid cancer (TC) patients. Special focus was given to disease-free PTC patients with undetectable serum thyroglobulin (Tg) levels. Altogether, 67 TC patients (33 papillary, 20 follicular, 14 medullary) were included in the study. CTC numbers, which were normalized to 3.3×105 peripheral blood mononuclear cells, were correlated with clinical outcome. TC patients had significantly higher CTC numbers compared to controls. The number of CTCs correlated to the initial tumor stage. Importantly, in comparison to controls, differentiated TC patients with serum Tg levels<0.3 ng/ml (no evidence of tumor recurrence) revealed a significantly higher amount of CTCs, also associated to their former tumor stage. Regarding the tumor-free papillary TC (PTC) patients the number of CTCs additionally correlated to the time point of radioiodine (RI) therapy: PTC patients with RI therapies>8 years before CTC measurement had significantly higher CTC numbers compared to those with RI therapy<8 years ago. We found a clear correlation between the number of CTCs and the tumor stage. Importantly, PTC patients who are in remission may still have increased numbers of CTCs. Follow-up analyses in these patients will reveal whether these data will have a clinical impact.


Assuntos
Células Neoplásicas Circulantes/patologia , Neoplasias da Glândula Tireoide/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/sangue , Carcinoma Papilar/patologia , Contagem de Células , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/patologia
8.
Minerva Endocrinol ; 43(3): 323-332, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29265783

RESUMO

TSH receptor antibodies (TRAbs) are characteristic indicators for the common autoimmune thyroid disease Graves disease (GD). In almost all patients stimulating TRAbs are found leading to hyperthyroidism as these antibodies act in an agonistic manner to TSH. Besides stimulating TRAbs, other TRAbs are also frequently found leading to inhibition of TSH receptor signaling (blocking TRAbs) or to the activation of different signaling cascades resulting in e.g. thyrocyte apoptosis (cleavage antibodies). Patients' sera may contain all three types of TRAbs. Dependent on the activity of these particular TSHR autoantibodies clinical symptoms might change. Within this review we summarize current genetic and environmental factors that are generally accepted for GD's etiology. Binding sides to the TSH receptor as well as the resulting signaling cascades are described just as the current used assay methods for TRAb measurement. Finally, we illustrate the clinical impact of TRAbs in the follow-up of GD patients with special focus on GD patients suffering from Graves' ophthalmopathy.


Assuntos
Autoanticorpos/análise , Doença de Graves/imunologia , Doença de Graves/fisiopatologia , Receptores da Tireotropina/imunologia , Doença de Graves/diagnóstico , Oftalmopatia de Graves/imunologia , Oftalmopatia de Graves/fisiopatologia , Humanos
9.
Horm Metab Res ; 50(1): 23-28, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29169190

RESUMO

Calcitonin (CT), a tumor marker for medullary thyroid cancer (MTC), can be stimulated with pentagastrin or calcium. Because of the unavailability of pentagastrin, basal CT measurement is frequently used for the preoperative diagnosis of MTC. The aim of the study was to define basal serum calcitonin (bCT) cut-off thresholds for diagnosing MTC. Within a retrospective analysis, 114 patients (51 males) were included fulfilling the criteria of an increased preoperative bCT level (>10 pg/ml) and the criteria of an available postoperative histology analysis. Based on a ROC plot analysis, the cut-off values for the diagnosis of MTC vs. non-malignancy (C cell hyperplasia and goiter) were identified. The most precise bCT thresholds for the identification of MTC were ≥46 pg/ml for males (sensitivity: 93.6%, specificity: 95.0%, PPV: 97%, NPV: 90%) and ≥35 pg/ml for females (sensitivity: 87.3%, specificity: 87.5%, PPV: 98%, NPV: 50%). Using these cut-offs, only 6% of male patients were not identified of having MTC, whereas 5% were false positive (having instead C cell hyperplasia). In females, the discrepancy was higher since 13% of female MTC patients were false negative by using the cut-off of ≥35 pg/ml, and 13% had false positive results (suffering from C cell hyperplasia). Gender-specific bCT cut-offs for the identification of MTC vs. C cell hyperplasia and non-malignancy were defined, which can be used in clinical routine. In female patients, however, the accuracy is much lower compared to males.


Assuntos
Calcitonina/sangue , Carcinoma Neuroendócrino/sangue , Carcinoma Neuroendócrino/diagnóstico , Neoplasias da Glândula Tireoide/sangue , Neoplasias da Glândula Tireoide/diagnóstico , Feminino , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Curva ROC , Valores de Referência , Sensibilidade e Especificidade
10.
J Clin Endocrinol Metab ; 102(7): 2154-2161, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27860539

RESUMO

Context: Papillary thyroid cancer (PTC) is characterized by a lymphocytic infiltration. PTC patients with lymphocytic infiltration may have a better clinical outcome. Objective: Characterization of tumor epitope-specific immunity and correlation analyses with the clinical outcome. Patients: 150 PTC patients; 40 Hashimoto thyroiditis (HT) patients; 21 healthy controls; 27,239 healthy whites (for HLA typing). Main Outcome Measures: HLA class I restricted thyroperoxidase (TPO) and thyroglobulin (Tg) epitope-specific T cells (tetramer analyses), correlation analyses between HLA class II phenotypes, T cell immunity, and the clinical course. Results: The frequency of TPO- and Tg-specific CD8+ T cells in PTC patients was largely increased compared with healthy controls (TPO and Tg, P < 0.005 and P < 0.005) and was similar to those in HT patients. HLA-DQB1*03-positive PTC patients had a significantly lower risk [risk ratio (RR), 0.170; 95% confidence interval (CI), 0.037 to 0.755; P < 0.05] and HLA-DRB1*03-positive and HLA-DQB1*02-positive PTC patients a significantly higher risk (HLA-DRB1*03: RR, 4.400; 95% CI, 1.378 to 14.05; P < 0.05; HLA-DQB1*02: RR, 3.692; 95% CI, 1.102 to 12.38; P < 0.05) for distant metastases, compared with patients with other haplotypes. HLA-DQB1*03-positive PTC patients revealed an increased responsiveness of tumor epitopes in vitro. These tumor epitope-specific CD8+ T cells were also found in lymph node metastases of HLA-DQB1*03-positive PTC patients. Conclusion: We demonstrate a tumor epitope-specific immunity in PTC patients and the protective role of HLA-DQB1*03 against metastatic spread. These results have direct implications for new treatment options with immune checkpoint inhibitors.


Assuntos
Antígenos de Neoplasias/imunologia , Carcinoma/imunologia , Epitopos de Linfócito T/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias da Glândula Tireoide/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD8-Positivos/imunologia , Carcinoma/patologia , Carcinoma/secundário , Carcinoma Papilar , Estudos de Casos e Controles , Epitopos/imunologia , Feminino , Doença de Hashimoto/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Teste de Histocompatibilidade/métodos , Humanos , Imunidade Celular , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Prognóstico , Subpopulações de Linfócitos T/imunologia , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/secundário , Adulto Jovem
11.
Trends Endocrinol Metab ; 25(12): 656-64, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25306886

RESUMO

Hashimoto's thyroiditis (HT) is the most common autoimmune disease in humans frequently leading to hypothyroidism. HT is characterized by a cellular immune response with lymphatic infiltration of the thyroid gland by T and B cells, as well as by a humoral immune response leading to specific antibody production. The synchronous appearance of HT and papillary thyroid cancer (PTC) indicates an immunological link between the two entities. Three different pathomechanisms may be postulated, including preexisting autoimmunity leading to malignancy due to inflammation, immunity towards preexisiting tumor cells leading to specific autoimmunity, and immune tolerance leading to malignancy despite (auto)immunity. In this article we review data describing these potential mechanisms that might lead to the synchronous appearance of HT and PTC.


Assuntos
Carcinoma/imunologia , Doença de Hashimoto/imunologia , Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/imunologia , Carcinoma Papilar , Humanos , Imunidade Celular/fisiologia , Câncer Papilífero da Tireoide
12.
Thyroid ; 24(5): 888-96, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24460670

RESUMO

BACKGROUND: The impact of excessive iodine intake on the development of autoimmune thyroiditis (AIT) is still under debate. Transgenic, antibody-devoid TAZ10 mice spontaneously develop AIT due to autoreactive thyroperoxidase-specific T cells. In this model, development of AIT is determined by a T cell infiltration of the thyroid gland leading to an elevation of serum thyrotropin (TSH) levels and significant weight gain. In the present study we investigated the impact of moderate and high iodine supplementation on the course of disease in these mice, which are immunologically prone to AIT. METHODS: In addition to normal nutrition, mice were supplemented for 20 weeks with 2.5 µg versus 5 µg iodine per milliliter drinking water, which corresponds to a human daily iodine supplementation of 150 µg, 315 µg, and 615 µg iodine. AIT-defining parameters (weight gain, elevation of serum TSH levels, cellular infiltration of the thyroid) and immunologic effects were analyzed. RESULTS: No significant differences were displayed when comparing weight and serum TSH levels in the iodine-supplemented versus control groups. Increased thyroid infiltrates with CD8⁺ T cells were detected by fluorescein-activated cell sorter (FACS) and immunofluorescence staining in mice supplemented with elevated iodine amounts (315 µg and 615 µg iodine per day, respectively). Immunologic monitoring revealed selective changes in immune cell frequencies (CD8⁺ and regulatory T cells, natural killer [NK] cells) and cytokine production (interferon-γ, interleukin-1α, and interleukin-17), however, without affecting the overall immune balance. CONCLUSION: Our results demonstrate that elevated iodine supplementation has no physical impact on the course of disease in transgenic, antibody-devoid TAZ10 mice, which are immunologically prone to AIT.


Assuntos
Suplementos Nutricionais , Imunidade Celular , Fatores Imunológicos/uso terapêutico , Iodo/uso terapêutico , Células Th1/imunologia , Glândula Tireoide/imunologia , Tireoidite Autoimune/dietoterapia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Citocinas/sangue , Citocinas/metabolismo , Feminino , Fatores Imunológicos/administração & dosagem , Iodo/administração & dosagem , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/patologia , Masculino , Camundongos Transgênicos , Tamanho do Órgão , Organismos Livres de Patógenos Específicos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/patologia , Células Th1/metabolismo , Células Th1/patologia , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia , Tireoidite Autoimune/imunologia , Tireoidite Autoimune/metabolismo , Tireoidite Autoimune/patologia , Tireotropina/sangue , Aumento de Peso
13.
J Mol Endocrinol ; 50(1): 31-42, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23125459

RESUMO

Progressive loss of pancreatic ß-cell mass is a crucial feature of type 2 diabetes mellitus. As ß-cells express very low amounts of the antioxidant enzymes catalase and glutathione peroxidase (GPx), they appear to be particularly vulnerable to oxidative damage in the pathogenesis of diabetes. Here, we investigated the pancreatic expression pattern and regulation of selenoprotein P (Sepp1), which may serve as an additional antioxidant enzyme inside and outside of cells. Sepp1 was detected in rodent pancreas by immunofluorescence and real-time RT-PCR. Regulation of Sepp1 biosynthesis in INS-1 rat insulinoma cells was investigated by real-time RT-PCR, luciferase gene reporter assay, and immunoblotting. Sepp1 and Gpx1 gene expressions in rat pancreas were 58 and 22% respectively of the liver values. Pancreatic Sepp1 expression was restricted to the endocrine tissue, with Sepp1 being present in the α- and ß-cells of mouse islets. In INS-1 insulinoma cells, Sepp1 expression was stimulated by the selenium compound sodium selenate and diminished in the presence of high glucose (16.7 vs 5  mM) concentrations. Sepp1 mRNA stability was also lowered at 16.7  mM glucose. Moreover, Sepp1 mRNA levels were decreased in isolated murine islets cultured in high-glucose (22  mM) medium compared with normal glucose (5.5  mM) medium. Pancreatic Sepp1 expression was elevated upon treatment of mice with the ß-cell toxin streptozotocin. This study shows that pancreatic islets express relatively high levels of Sepp1 that may fulfill a function in antioxidant protection of ß-cells. Downregulation of Sepp1 expression by high glucose might thus contribute to glucotoxicity in ß-cells.


Assuntos
Ilhotas Pancreáticas/metabolismo , Selenoproteína P/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Regulação para Baixo , Imunofluorescência , Genes Reporter , Glucose/administração & dosagem , Camundongos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Selenoproteína P/biossíntese , Selenoproteína P/genética , Estreptozocina/farmacologia
15.
Endocrinology ; 153(9): 4367-79, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22733969

RESUMO

Natural killer (NK) cells belong to the innate immune system. Besides their role in antitumor immunity, NK cells also regulate the activity of other cells of the immune system, including dendritic cells, macrophages, and T cells, and may, therefore, be involved in autoimmune processes. The aim of the present study was to clarify the role of NK cells within this context. Using two mouse models for type 1 diabetes mellitus, a new subset of NK cells with regulatory function was identified. These cells were generated from conventional NK cells by incubation with IL-18 and are characterized by the expression of the surface markers CD117 (also known as c-Kit, stem cell factor receptor) and programmed death (PD)-ligand 1. In vitro analyses demonstrated a direct lysis activity of IL-18-stimulated NK cells against activated insulin-specific CD8(+) T cells in a PD-1/PD-ligand 1-dependent manner. Flow cytometry analyses revealed a large increase of splenic and lymphatic NK1.1(+)/c-Kit(+) NK cells in nonobese diabetic mice at 8 wk of age, the time point of acceleration of adaptive cytotoxic immunity. Adoptive transfer of unstimulated and IL-18-stimulated NK cells into streptozotocin-treated mice led to a delayed diabetes development and partial disease prevention in the group treated with IL-18-stimulated NK cells. Consistent with these data, mild diabetes was associated with increased numbers of NK1.1(+)/c-Kit(+) NK cells within the islets. Our results demonstrate a direct link between innate and adaptive immunity in autoimmunity with newly identified immunoregulatory NK cells displaying a potential role as immunosuppressors.


Assuntos
Autoimunidade/imunologia , Antígenos CD8/metabolismo , Células Matadoras Naturais/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Apoptose/fisiologia , Células Cultivadas , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/metabolismo , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Microscopia de Fluorescência , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
J Clin Endocrinol Metab ; 97(4): 1347-54, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22259066

RESUMO

CONTEXT: Hashimoto's thyroiditis (HT) is a common autoimmune disease leading to thyroid destruction due to lymphocytic infiltration. Only rare data are available regarding the recognition of specific cellular antigens, e.g. of thyroperoxidase (TPO) and thyroglobulin (Tg). OBJECTIVE: The aim of this study was to quantify and characterize TPO- and Tg-epitope-specific CD8-positive T cells of HT patients. DESIGN: Six different human leukocyte antigen (HLA)-A2 restricted, TPO- or Tg-specific tetramers were synthesized and used for measuring CD8-positive T cells in HT patients and controls. RESULTS: The frequency of peripheral TPO- and Tg-specific CD8-positive T cells was significantly higher in HLA-A2-positive HT patients (2.8 ± 9.5%) compared with HLA-A2-negative HT patients (0.5 ± 0.7%), HLA-A2-positive nonautoimmune goiter patients (0.2 ± 0.4%), and HLA-A2-positive healthy controls (0.1 ± 0.2%). The frequency of Tg-specific T cells (3.0%) was very similar to those of TPO-specific CD8-positive T cells (2.9%). Subgroup analyses revealed a steady increase of the number of epitope-specific CD8-positive T cells from 0.6 ± 1.0% at initial diagnosis up to 9.4 ± 18.3% in patients with long-lasting disease. Analyses of the number of thyroid-infiltrating cells as well as the cytotoxic capacity revealed a similar picture for TPO- and Tg-specific T cells. CONCLUSION: We here report for the first time that both antigens, TPO and Tg, are recognized by CD8-positive T cells and are involved in the thyroid destruction process leading to clinical disease manifestation.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos , Autoanticorpos/análise , Doença de Hashimoto/imunologia , Imunidade Celular , Iodeto Peroxidase/antagonistas & inibidores , Proteínas de Ligação ao Ferro/antagonistas & inibidores , Tireoglobulina/antagonistas & inibidores , Glândula Tireoide/imunologia , Adulto , Idoso , Especificidade de Anticorpos , Autoanticorpos/química , Autoantígenos/química , Biópsia por Agulha Fina , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Epitopos/análise , Epitopos/química , Feminino , Bócio/imunologia , Bócio/metabolismo , Bócio/patologia , Antígeno HLA-A2/metabolismo , Doença de Hashimoto/metabolismo , Doença de Hashimoto/patologia , Humanos , Iodeto Peroxidase/química , Proteínas de Ligação ao Ferro/química , Masculino , Pessoa de Meia-Idade , Tireoglobulina/química , Glândula Tireoide/patologia , Adulto Jovem
17.
Mol Cell Endocrinol ; 337(1-2): 52-61, 2011 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-21291954

RESUMO

Lymphatic infiltration is a well known phenomenon in different tumors including endocrine malignancies. However, little is known about the role of antigen-presenting cells and T cell activation in this context. The aim of our study was to investigate the quantity and function of CD14+/CD56+ monocytes in tumor patients including endocrine malignancies. First, these cells were characterized in peripheral blood of endocrine and non-endocrine cancer patients as well as in tumor tissue samples. Cancer patients had in mean 3.7 times more CD14+/CD56+ monocytes in the peripheral blood compared to healthy controls (p≤0.0001), while the highest frequencies were seen in patients with heavy tumor load. Importantly, these cells additionally expressed several NK cell markers. A proof of CD14+/CD56+ infiltrations into papillary thyroid carcinoma was shown by immunohistochemical analyses. Functional analyses revealed an apoptosis inducing capacity in vitro after IFN-α re-stimulation. Our data indicate the importance of tumor-lysing monocytes in antitumor immunity.


Assuntos
Linfócitos do Interstício Tumoral/citologia , Neoplasias/patologia , Neoplasias da Glândula Tireoide/patologia , Adulto , Idoso , Apoptose , Biomarcadores Tumorais/metabolismo , Complexo CD3/metabolismo , Antígeno CD56/metabolismo , Carcinoma , Carcinoma Papilar , Estudos de Casos e Controles , Contagem de Células , Feminino , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Ativação Linfocitária , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Neoplasias/metabolismo , Fenótipo , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/metabolismo , Adulto Jovem
18.
Mol Cell Endocrinol ; 335(1): 69-77, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20600588

RESUMO

Currently, no effective treatment for malignant pheochromocytoma exists. The aim of our study was to investigate the role of chromogranin A (CgA) as a specific target molecule for immunotherapy in a murine model for pheochromocytoma. Six amino acid-modified and non-modified CgA peptides were used for dendritic cell vaccination. Altogether, 50 mice received two different CgA vaccination protocols; another 20 animals served as controls. In vitro tetramer analyses revealed large increases of CgA-specific cytotoxic T cells (CTL) in CgA-treated mice. Tumors of exogenous applied pheochromocytoma cells showed an extensive infiltration by CD8+ T cells. In vitro, CTL of CgA-treated mice exhibited strong MHC I restricted lysis capacities towards pheochromocytoma cells. Importantly, these mice showed strongly diminished outgrowth of liver tumors of applied pheochromocytoma cells. Our data clearly demonstrate that CgA peptide-based immunotherapy induces a cytotoxic immune response in experimental pheochromocytoma, indicating potential for therapeutic applications in patients with malignant pheochromocytoma.


Assuntos
Neoplasias das Glândulas Suprarrenais/terapia , Vacinas Anticâncer/administração & dosagem , Cromogranina A/imunologia , Peptídeos/imunologia , Feocromocitoma/terapia , Neoplasias das Glândulas Suprarrenais/imunologia , Neoplasias das Glândulas Suprarrenais/patologia , Sequência de Aminoácidos , Animais , Células da Medula Óssea/imunologia , Linhagem Celular Tumoral , Células Dendríticas/imunologia , Células Dendríticas/transplante , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Linfonodos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Feocromocitoma/imunologia , Feocromocitoma/patologia , Baço/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
19.
J Oncol ; 2010: 179491, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20671939

RESUMO

Up to now, there are no curative therapies available for the subset of metastasized undifferentiated/anaplastic thyroid carcinomas. This review describes the possible use of immunocompetent cells which may help to restore the antitumor immune recognition for treating an existing tumor or preventing its recurrence. The most prominent experimental strategy is the use of dendritic cells (DCs) which are highly potent in presenting tumor antigens. Activated DCs subsequently migrate to draining lymph nodes where they present antigens to naïve lymphocytes and induce cytotoxic T cells (CTL). Alternatively to DC therapy, adoptive cell transfer may be performed by either using natural killer cells or ex vivo maturated CTLs. Within this review article we will focus on recent advances in the understanding of anti-tumor immune responses, for example, in thyroid carcinomas including the advances which have been made for the identification of potential tumor antigens in thyroid malignancies.

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