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1.
Obes Facts ; 17(3): 243-254, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38316112

RESUMO

INTRODUCTION: School-based exercise interventions targeted at reducing obesity are often successful in the short term, but they are resource-heavy and do not always lead to long-lasting behaviour changes. This study investigated the effect of reducing sedentary time, rather than increasing exercise, on physical activity (PA) behaviours and obesity in primary school children. METHODS: Thirty UK state primary schools participated in this cluster-controlled intervention study (IDACI score = 0.15 ± 0.07, free school meals = 26 ± 9%). Twenty-six intervention and 4 control schools (intervention = 3,529, control = 308 children) completed the Physical Activity Questionnaire for Children (PAQ-C) in terms 1 and 3. Three intervention and 3 control schools (intervention = 219, control = 152 children) also measured waist-to-height ratio (WTHR). The Active Movement Intervention is a school-based programme which integrates non-sedentary behaviours such as standing and walking in the classroom. Data were analysed via ANCOVAs and multiple linear regressions. RESULTS: WTHR was reduced by 8% in the intervention group only (F(2, 285) = 11.387, p < 0.001), and sport participation increased by 10% in the intervention group only (F(1, 232) = 6.982, p = 0.008). Other PAQ-C measures increased significantly in the intervention group, but there was no group*time interaction. Changes in PAQ-C did not predict reductions in WTHR. Instead, the amount of change in WTHR was predicted by intervention group and by baseline WTHR of the pupil, where children with higher baseline WTHR showed greater reductions (F(2, 365) = 77.21, p < 0.001, R2 = 0.30). Socio-economic status (SES), age, or gender did not mediate any of the changes in the PAQ-C or WTHR. CONCLUSION: Reducing sedentary behaviours during school time can be an effective obesity reduction strategy for primary school children who are overweight. The lack of demographic effects suggests that this method can be effective regardless of the school's SES, pupil age, or gender.


Assuntos
Exercício Físico , Obesidade Infantil , Instituições Acadêmicas , Comportamento Sedentário , Humanos , Criança , Masculino , Feminino , Obesidade Infantil/prevenção & controle , Inquéritos e Questionários , Reino Unido , Serviços de Saúde Escolar , Razão Cintura-Estatura , Caminhada
2.
Nat Immunol ; 24(3): 487-500, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36759711

RESUMO

The T cell repertoire of healthy mice and humans harbors self-reactive CD4+ conventional T (Tconv) cells capable of inducing autoimmunity. Using T cell receptor profiling paired with in vivo clonal analysis of T cell differentiation, we identified Tconv cell clones that are recurrently enriched in non-lymphoid organs following ablation of Foxp3+ regulatory T (Treg) cells. A subset of these clones was highly proliferative in the lymphoid organs at steady state and exhibited overt reactivity to self-ligands displayed by dendritic cells, yet were not purged by clonal deletion. These clones spontaneously adopted numerous hallmarks of follicular helper T (TFH) cells, including expression of Bcl6 and PD-1, exhibited an elevated propensity to localize within B cell follicles at steady state, and produced interferon-γ in non-lymphoid organs following sustained Treg cell depletion. Our work identifies a naturally occurring population of self-reactive TFH-like cells and delineates a previously unappreciated fate for self-specific Tconv cells.


Assuntos
Linfócitos T CD4-Positivos , Células T Auxiliares Foliculares , Linfócitos T Reguladores , Animais , Humanos , Camundongos , Autoimunidade , Diferenciação Celular , Células Clonais , Fenótipo , Linfócitos T Auxiliares-Indutores , Linfócitos T CD4-Positivos/imunologia
3.
Br J Cancer ; 126(3): 361-370, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34876674

RESUMO

Head and neck squamous cell carcinoma (HNSCC) is a molecularly heterogeneous disease, with a 5-year survival rate that still hovers at ~60% despite recent advancements. The advanced stage upon diagnosis, limited success with effective targeted therapy and lack of reliable biomarkers are among the key factors underlying the marginally improved survival rates over the decades. Prevention, early detection and biomarker-driven treatment adaptation are crucial for timely interventions and improved clinical outcomes. Liquid biopsy, analysis of tumour-specific biomarkers circulating in bodily fluids, is a rapidly evolving field that may play a striking role in optimising patient care. In recent years, significant progress has been made towards advancing liquid biopsies for non-invasive early cancer detection, prognosis, treatment adaptation, monitoring of residual disease and surveillance of recurrence. While these emerging technologies have immense potential to improve patient survival, numerous methodological and biological limitations must be overcome before their implementation into clinical practice. This review outlines the current state of knowledge on various types of liquid biopsies in HNSCC, and their potential applications for diagnosis, prognosis, grading treatment response and post-treatment surveillance. It also discusses challenges associated with the clinical applicability of liquid biopsies and prospects of the optimised approaches in the management of HNSCC.


Assuntos
Biomarcadores Tumorais/análise , Detecção Precoce de Câncer/métodos , Neoplasias de Cabeça e Pescoço/diagnóstico , Biópsia Líquida/métodos , Células Neoplásicas Circulantes/patologia , Animais , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos
4.
Int J Cancer ; 150(3): 450-460, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34569064

RESUMO

Oral cavity squamous cell carcinoma (OSCC) affects more than 30 000 individuals in the United States annually, with smoking and alcohol consumption being the main risk factors. Management of early-stage tumors usually includes surgical resection followed by postoperative radiotherapy in certain cases. The cervical lymph nodes (LNs) are the most common site for local metastasis, and elective neck dissection is usually performed if the primary tumor thickness is greater than 3.5 mm. However, postoperative histological examination often reveals that many patients with early-stage disease are negative for neck nodal metastasis, posing a pressing need for improved risk stratification to either avoid overtreatment or prevent the disease progression. To this end, we aimed to identify a primary tumor gene signature that can accurately predict cervical LN metastasis in patients with early-stage OSCC. Using gene expression profiles from 189 samples, we trained K-top scoring pairs models and identified six gene pairs that can distinguish primary tumors with nodal metastasis from those without metastasis. The signature was further validated on an independent cohort of 35 patients using real-time polymerase chain reaction (PCR) in which it achieved an area under the receiver operating characteristic (ROC) curve and accuracy of 90% and 91%, respectively. These results indicate that such signature holds promise as a quick and cost effective method for detecting patients at high risk of developing cervical LN metastasis, and may be potentially used to guide the neck treatment regimen in early-stage OSCC.


Assuntos
Neoplasias Bucais/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/genética , Invasividade Neoplásica , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Transcriptoma
5.
Cell Rep Med ; 2(9): 100399, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34622236

RESUMO

Immune suppression by CD4+FOXP3+ regulatory T (Treg) cells and tumor infiltration by CD8+ effector T cells represent two major factors impacting response to cancer immunotherapy. Using deconvolution-based transcriptional profiling of human papilloma virus (HPV)-negative oral squamous cell carcinomas (OSCCs) and other solid cancers, we demonstrate that the density of Treg cells does not correlate with that of CD8+ T cells in many tumors, revealing polarized clusters enriched for either CD8+ T cells or CD4+ Treg and conventional T cells. In a mouse model of carcinogen-induced OSCC characterized by CD4+ T cell enrichment, late-stage Treg cell ablation triggers increased densities of both CD4+ and CD8+ effector T cells within oral lesions. Notably, this intervention does not induce tumor regression but instead induces rapid emergence of invasive OSCCs via an effector T cell-dependent process. Thus, induction of a T cell-inflamed phenotype via therapeutic manipulation of Treg cells may trigger unexpected tumor-promoting effects in OSCC.


Assuntos
Carcinoma de Células Escamosas/imunologia , Neoplasias Bucais/imunologia , Linfócitos T Reguladores/imunologia , 4-Nitroquinolina-1-Óxido , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Carcinógenos , Carcinoma de Células Escamosas/patologia , Células Clonais , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Contagem de Linfócitos , Depleção Linfocítica , Camundongos Endogâmicos C57BL , Neoplasias Bucais/patologia , Invasividade Neoplásica , Peptídeos/química , Quinolonas , Linfócitos T Reguladores/efeitos dos fármacos
6.
Front Oncol ; 11: 677051, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336664

RESUMO

Despite recent advancements, the 5 year survival of head and neck squamous cell carcinoma (HNSCC) hovers at 60%. DCLK1 has been shown to regulate epithelial-to-mesenchymal transition as well as serving as a cancer stem cell marker in colon, pancreatic and renal cancer. Although it was reported that DCLK1 is associated with poor prognosis in oropharyngeal cancers, very little is known about the molecular characterization of DCLK1 in HNSCC. In this study, we performed a comprehensive transcriptome-based computational analysis on hundreds of HNSCC patients from TCGA and GEO databases, and found that DCLK1 expression positively correlates with NOTCH signaling pathway activation. Since NOTCH signaling has a recognized role in HNSCC tumorigenesis, we next performed a series of in vitro experiments in a collection of HNSCC cell lines to investigate the role of DCLK1 in NOTCH pathway regulation. Our analyses revealed that DCLK1 inhibition, using either a pharmacological inhibitor or siRNA, resulted in substantially decreased proliferation, invasion, migration, and colony formation. Furthermore, these effects paralleled downregulation of active NOTCH1, and its downstream effectors, HEY1, HES1 and HES5, whereas overexpression of DCLK1 in normal keratinocytes, lead to an upregulation of NOTCH signaling associated with increased proliferation. Analysis of 233 primary and 40 recurrent HNSCC cancer biopsies revealed that high DCLK1 expression was associated with poor prognosis and showed a trend towards higher active NOTCH1 expression in tumors with elevated DCLK1. Our results demonstrate the novel role of DCLK1 as a regulator of NOTCH signaling network and suggest its potential as a therapeutic target in HNSCC.

7.
Sci Rep ; 11(1): 12425, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127708

RESUMO

Saliva has significant advantages as a test medium for detection of SARS-CoV-2 infection in patients, such as ease of collection, minimal requirement of supplies and trained personnel, and safety. Comprehensive validation in a large cohort of prospectively collected specimens with unknown SARS-CoV-2 status should be performed to evaluate the potential and limitations of saliva-based testing. We developed a saliva-based testing pipeline for detection of SARS-CoV-2 nucleic acids using real-time reverse transcription PCR (RT-PCR) and droplet digital PCR (ddPCR) readouts, and measured samples from 137 outpatients tested at a curbside testing facility and 29 inpatients hospitalized for COVID-19. These measurements were compared to the nasal swab results for each patient performed by a certified microbiology laboratory. We found that our saliva testing positively detects 100% (RT-PCR) and 93.75% (ddPCR) of curbside patients that were identified as SARS-CoV-2 positive by the Emergency Use Authorization (EUA) certified nasal swab testing assay. Quantification of viral loads by ddPCR revealed an extremely wide range, with 1 million-fold difference between individual patients. Our results demonstrate for both community screening and hospital settings that saliva testing reliability is on par with that of the nasal swabs in detecting infected cases, and has potential for higher sensitivity when combined with ddPCR in detecting low-abundance viral loads that evade traditional testing methods.


Assuntos
COVID-19/diagnóstico , SARS-CoV-2/genética , Saliva/virologia , Adulto , COVID-19/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/análise , RNA Viral/genética , RNA Viral/metabolismo , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/isolamento & purificação , Carga Viral
8.
Cell ; 184(15): 3981-3997.e22, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34157301

RESUMO

A fraction of mature T cells can be activated by peripheral self-antigens, potentially eliciting host autoimmunity. We investigated homeostatic control of self-activated T cells within unperturbed tissue environments by combining high-resolution multiplexed and volumetric imaging with computational modeling. In lymph nodes, self-activated T cells produced interleukin (IL)-2, which enhanced local regulatory T cell (Treg) proliferation and inhibitory functionality. The resulting micro-domains reciprocally constrained inputs required for damaging effector responses, including CD28 co-stimulation and IL-2 signaling, constituting a negative feedback circuit. Due to these local constraints, self-activated T cells underwent transient clonal expansion, followed by rapid death ("pruning"). Computational simulations and experimental manipulations revealed the feedback machinery's quantitative limits: modest reductions in Treg micro-domain density or functionality produced non-linear breakdowns in control, enabling self-activated T cells to subvert pruning. This fine-tuned, paracrine feedback process not only enforces immune homeostasis but also establishes a sharp boundary between autoimmune and host-protective T cell responses.


Assuntos
Retroalimentação Fisiológica , Homeostase/imunologia , Ativação Linfocitária/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoantígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Proliferação de Células , Interleucina-2/metabolismo , Microdomínios da Membrana/metabolismo , Camundongos Endogâmicos C57BL , Modelos Imunológicos , Comunicação Parácrina , Transdução de Sinais
9.
J Exp Med ; 218(6)2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33914024

RESUMO

For the large array of self-peptide/MHC class II (pMHC-II) complexes displayed in the body, it is unclear whether CD4+ T cell tolerance must be imparted for each individual complex or whether pMHC-II-nonspecific bystander mechanisms are sufficient to confer tolerance by acting broadly on T cells reactive to multiple self-pMHC-II ligands. Here, via reconstitution of T cell-deficient mice, we demonstrate that altered T cell selection on a single prostate-specific self-pMHC-II ligand renders recipient mice susceptible to prostate-specific T cell infiltration. Mechanistically, this self-pMHC-II complex is required for directing antigen-specific cells into the Foxp3+ regulatory T cell lineage but does not induce clonal deletion to a measurable extent. Thus, our data demonstrate that polyclonal T reg cells are unable to functionally compensate for a breach in tolerance to a single self-pMHC-II complex in this setting, revealing vulnerabilities in antigen-nonspecific bystander mechanisms of immune tolerance.


Assuntos
Linfócitos T Reguladores/imunologia , Animais , Antígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linhagem Celular , Células Dendríticas/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Tolerância Imunológica/imunologia , Insetos , Ligantes , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/imunologia
10.
Nat Immunol ; 21(5): 567-577, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32284593

RESUMO

Unprimed mice harbor a substantial population of 'memory-phenotype' CD8+ T cells (CD8-MP cells) that exhibit hallmarks of activation and innate-like functional properties. Due to the lack of faithful markers to distinguish CD8-MP cells from bona fide CD8+ memory T cells, the developmental origins and antigen specificities of CD8-MP cells remain incompletely defined. Using deep T cell antigen receptor (TCR) sequencing, we found that the TCRs expressed by CD8-MP cells are highly recurrent and distinct from the TCRs expressed by naive-phenotype CD8+ T cells. CD8-MP clones exhibited reactivity to widely expressed self-ligands. T cell precursors expressing CD8-MP TCRs showed upregulation of the transcription factor Eomes during maturation in the thymus, prior to induction of the full memory phenotype, which is suggestive of a unique program triggered by recognition of self-ligands. Moreover, CD8-MP cells infiltrate oncogene-driven prostate tumors and express high densities of PD-1, which suggests potential roles in antitumor immunity and the response to immunotherapy.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias da Próstata/imunologia , Receptores de Antígenos de Linfócitos T/genética , Proteínas com Domínio T/metabolismo , Timo/fisiologia , Animais , Autoantígenos/imunologia , Diferenciação Celular , Seleção Clonal Mediada por Antígeno , Células Clonais , Memória Imunológica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptor de Morte Celular Programada 1/metabolismo , Proteínas com Domínio T/genética , Regulação para Cima
11.
Annu Rev Immunol ; 38: 421-453, 2020 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-31990619

RESUMO

Foxp3-expressing CD4+ regulatory T (Treg) cells play key roles in the prevention of autoimmunity and the maintenance of immune homeostasis and represent a major barrier to the induction of robust antitumor immune responses. Thus, a clear understanding of the mechanisms coordinating Treg cell differentiation is crucial for understanding numerous facets of health and disease and for developing approaches to modulate Treg cells for clinical benefit. Here, we discuss current knowledge of the signals that coordinate Treg cell development, the antigen-presenting cell types that direct Treg cell selection, and the nature of endogenous Treg cell ligands, focusing on evidence from studies in mice. We also highlight recent advances in this area and identify key unanswered questions.


Assuntos
Diferenciação Celular/imunologia , Linfopoese/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Apresentação de Antígeno/imunologia , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Biomarcadores , Diferenciação Celular/genética , Deleção Clonal , Seleção Clonal Mediada por Antígeno , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Linfopoese/genética , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/citologia , Timo/citologia , Timo/imunologia , Timo/metabolismo
12.
Oral Oncol ; 96: 77-88, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31422218

RESUMO

OBJECTIVES: In this study we describe the tumor microenvironment, the signaling pathways and genetic alterations associated with the presence or absence of CD8+ T-cell infiltration in primary squamous cell carcinoma of the head and neck (SCCHN) tumors. MATERIALS AND METHODS: Two SCCHN multi-analyte cohorts were utilized, the Cancer Genome Atlas (TCGA) and the Chicago Head and Neck Genomics (CHGC) cohort. A well-established chemokine signature classified SCCHN tumors into high and low CD8+ T-cell inflamed phenotypes (TCIP-H, TCIP-L respectively). Gene set enrichment and iPANDA analyses were conducted to dissect differences in signaling pathways, somatic mutations and copy number aberrations for TCIP-H versus TCIP-L tumors, stratified by HPV status. RESULTS: TCIP-H SCCHN tumors were enriched in multiple immune checkpoints irrespective of HPV-status. HPV-positive tumors were enriched in markers of T-regulatory cells (Tregs) and HPV-negative tumors in protumorigenic M2 macrophages. TCIP-L SCCHN tumors were enriched for the ß-catenin/WNT and Hedgehog signaling pathways, had frequent mutations in NSD1, amplifications in EGFR and YAP1, as well as CDKN2A deletions. TCIP-H SCCHN tumors were associated with the MAPK/ERK, JAK/STAT and mTOR/AKT signaling pathways, and were enriched in CASP8, EP300, EPHA2, HRAS mutations, CD274, PDCD1LG2, JAK2 amplifications. CONCLUSIONS: Our findings support that combinatorial immune checkpoint blockade and depletion strategies targeting Tregs in HPV-positive and M2 macrophages in HPV-negative tumors may lead to improved antitumor immune responses in patients with TCIP-H SCCHN. We highlight novel pathways and genetic events that may serve as candidate biomarkers and novel targeted therapies to enhance the efficacy of immunotherapy in SCCHN patients.


Assuntos
Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Microambiente Tumoral
13.
J Immunol ; 202(9): 2628-2635, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902900

RESUMO

Deletion of CD8+ T cells by dendritic cells (DCs) is recognized as a critical mechanism of immune tolerance to self-antigens. Although DC-mediated peripheral deletion of autoreactive CD8+ T cells has been demonstrated using T cells reactive to model Ags, its role in shaping the naturally occurring polyclonal CD8+ T cell repertoire has not been defined. Using Batf3-/- mice lacking cross-presenting CD8α+ and CD103+ DCs (also known as type 1 conventional [cDC1]), we demonstrate that peripheral deletion of CD8+ T cells reactive to a model tissue Ag is dependent on cDC1. However, endogenous CD8+ T cells from the periphery of Batf3-/- mice do not exhibit heightened self-reactivity, and deep TCR sequencing of CD8+ T cells from Batf3-/- and Batf3+/+ mice reveals that cDC1 have a minimal impact on shaping the peripheral CD8+ T cell repertoire. Thus, although evident in reductionist systems, deletion of polyclonal self-specific CD8+ T cells by cDC1 plays a negligible role in enforcing tolerance to natural self-ligands.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Tolerância Imunológica , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Antígenos CD8/genética , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/citologia , Células Dendríticas/citologia , Cadeias alfa de Integrinas/genética , Cadeias alfa de Integrinas/imunologia , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Proteínas Repressoras/genética , Proteínas Repressoras/imunologia
14.
J Clin Invest ; 129(2): 902-914, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30667372

RESUMO

Graft-versus-host disease (GVHD) is a complication of hematopoietic stem cell transplantation (HSCT) that affects multiple organs. GVHD-associated intestinal damage can be separated into two distinct phases, initiation and propagation, which correspond to conditioning-induced damage and effector T cell activation and infiltration, respectively. Substantial evidence indicates that intestinal damage induced by pretransplant conditioning is a key driver of GVHD initiation. Here, we aimed to determine the impact of dysregulated intestinal permeability on the subsequent GVHD propagation phase. The initiation phase of GVHD was unchanged in mice lacking long MLCK (MLCK210), an established regulator of epithelial tight junction permeability. However, MLCK210-deficient mice were protected from sustained barrier loss and exhibited limited GVHD propagation, as indicated by reduced histopathology, fewer CD8+ effector T cells in the gut, and improved overall survival. Consistent with these findings, intestinal epithelial MLCK210 expression and enzymatic activity were similarly increased in human and mouse GVHD biopsies. Intestinal epithelial barrier loss mediated by MLCK210 is therefore a key driver of the GVHD propagation. These data suggest that inhibition of MLCK210-dependent barrier regulation may be an effective approach to limiting GVHD progression.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Mucosa Intestinal/imunologia , Quinase de Cadeia Leve de Miosina/imunologia , Junções Íntimas/imunologia , Aloenxertos , Animais , Linfócitos T CD8-Positivos/patologia , Feminino , Doença Enxerto-Hospedeiro/patologia , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos BALB C , Junções Íntimas/patologia
15.
J Immunol ; 200(2): 415-421, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29311383

RESUMO

Regulatory T (Treg) cells are found at elevated densities in many human cancers and are thought to be a major barrier to the generation of robust antitumor T cell responses. In this review, we discuss recent advances in the understanding of tumor-associated Treg cell diversity and function. Emerging evidence indicates that the transcriptional program of Treg cells infiltrating human cancers may represent a composite program blending a tissue-associated expression signature with an additional tumor-specific signature common to Treg cells from multiple cancer types. Studies in mouse models have defined unique molecular pathways required for Treg cell function in the tumor context that can be manipulated to selectively dampen intratumoral Treg cell activity. Finally, an expanding body of work has revealed diverse functions for Treg cells in nonlymphoid tissues that are unrelated to immune suppression, suggesting a need to explore functions of intratumoral Treg cells beyond the regulation of antitumor immunity.


Assuntos
Linfócitos do Interstício Tumoral/imunologia , Neoplasias/imunologia , Linfócitos T Reguladores/imunologia , Animais , Citotoxicidade Imunológica , Humanos , Imunomodulação , Ativação Linfocitária/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Linfócitos T Reguladores/metabolismo , Evasão Tumoral/imunologia , Microambiente Tumoral
16.
Diabetes Obes Metab ; 20(1): 14-24, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28493515

RESUMO

The Restoring Insulin Secretion (RISE) study was initiated to evaluate interventions to slow or reverse the progression of ß-cell failure in type 2 diabetes (T2D). To design the RISE study, we undertook an evaluation of methods for measurement of ß-cell function and changes in ß-cell function in response to interventions. In the present paper, we review approaches for measurement of ß-cell function, focusing on methodologic and feasibility considerations. Methodologic considerations included: (1) the utility of each technique for evaluating key aspects of ß-cell function (first- and second-phase insulin secretion, maximum insulin secretion, glucose sensitivity, incretin effects) and (2) tactics for incorporating a measurement of insulin sensitivity in order to adjust insulin secretion measures for insulin sensitivity appropriately. Of particular concern were the capacity to measure ß-cell function accurately in those with poor function, as is seen in established T2D, and the capacity of each method for demonstrating treatment-induced changes in ß-cell function. Feasibility considerations included: staff burden, including time and required methodological expertise; participant burden, including time and number of study visits; and ease of standardizing methods across a multicentre consortium. After this evaluation, we selected a 2-day measurement procedure, combining a 3-hour 75-g oral glucose tolerance test and a 2-stage hyperglycaemic clamp procedure, augmented with arginine.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Modelos Biológicos , Projetos de Pesquisa , Arginina/administração & dosagem , Biomarcadores/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 2/terapia , Técnica Clamp de Glucose , Teste de Tolerância a Glucose/tendências , Humanos , Infusões Intravenosas , Resistência à Insulina , Secreção de Insulina , Células Secretoras de Insulina/patologia , Período Pós-Prandial , Projetos de Pesquisa/tendências
17.
Endocr Pract ; 23(10): 1232-1253, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28816530

RESUMO

OBJECTIVE: To determine the prevalence of Hispanic/Latino adults with diabetes who meet target hemoglobin A1c, blood pressure (BP), and low-density-lipoprotein cholesterol (LDL-C) recommendations, and angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blocker (ARB) and statin medication use by heritage and sociodemographic and diabetes-related characteristics. METHODS: Data were cross-sectional, collected between 2008 and 2011, and included adults age 18 to 74 years who reported a physician diagnosis of diabetes in the Hispanic Community Health Study/Study of Latinos (N = 2,148). Chi-square tests compared the prevalence of hemoglobin A1c, BP, and LDL-C targets and ACE/ARB and statin use across participant characteristics. Predictive margins regression was used to determine the prevalence adjusted for sociodemographic characteristics. RESULTS: The overall prevalence of A1c <7.0% (53 mmol/mol), BP <130/80 mm Hg, and LDL-C <100 mg/dL was 43.0, 48.7, and 36.6%, respectively, with 8.4% meeting all three targets. Younger adults aged 18 to 39 years with diabetes were less likely to have A1c <7.0% (53 mmol/mol) or LDL-C <100 mg/dL compared to those aged 65 to 74 years; younger adults were more likely to have BP <130/80 mm Hg (P<.05 for all). Individuals of Mexican heritage were significantly less likely to have A1c <7.0% (53 mmol/mol) compared to those with Cuban heritage, but they were more likely to have BP <130/80 mm Hg compared to those with Dominican, Cuban, or Puerto Rican heritage (P<.05 for all); there was no difference in LDL-C by heritage. Overall, 38.2% of adults with diabetes were taking a statin, and 50.5% were taking ACE/ARB medications. CONCLUSION: Hemoglobin A1c, BP, and LDL-C control are suboptimal among Hispanic/Latinos with diabetes living in the U.S. With 8.4% meeting all three recommendations, substantial opportunity exists to improve diabetes control in this population. ABBREVIATIONS: A1c = hemoglobin A1c; ABC = hemoglobin A1c, blood pressure, low-density-lipoprotein cholesterol; ACE = angiotensin-converting enzyme; ADA = American Diabetes Association; ARB = angiotensin receptor blocker; BMI = body mass index; BP = blood pressure; CHD = coronary heart disease; CVD = cardiovascular disease; HCHS/SOL = Hispanic Community Health Study/Study of Latinos; LDL-C = low-density-lipoprotein cholesterol; NHANES = National Health and Nutrition Examination Survey; PAD = peripheral artery disease.


Assuntos
Pressão Sanguínea , LDL-Colesterol/sangue , Diabetes Mellitus/etnologia , Hemoglobinas Glicadas/metabolismo , Hispânico ou Latino/estatística & dados numéricos , Adolescente , Adulto , Idoso , Estudos Transversais , Diabetes Mellitus/sangue , Diabetes Mellitus/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Estados Unidos/epidemiologia , Adulto Jovem
18.
Immunity ; 47(1): 107-117.e8, 2017 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-28709804

RESUMO

Regulatory T (Treg) cells expressing the transcription factor Foxp3 are critical for the prevention of autoimmunity and the suppression of anti-tumor immunity. The major self-antigens recognized by Treg cells remain undefined, representing a substantial barrier to the understanding of immune regulation. Here, we have identified natural Treg cell ligands in mice. We found that two recurrent Treg cell clones, one prevalent in prostate tumors and the other associated with prostatic autoimmune lesions, recognized distinct non-overlapping MHC-class-II-restricted peptides derived from the same prostate-specific protein. Notably, this protein is frequently targeted by autoantibodies in experimental models of prostatic autoimmunity. On the basis of these findings, we propose a model in which Treg cell responses at peripheral sites converge on those self-proteins that are most susceptible to autoimmune attack, and we suggest that this link could be exploited as a generalizable strategy for identifying the Treg cell antigens relevant to human autoimmunity.


Assuntos
Autoantígenos/metabolismo , Epitopos de Linfócito T/metabolismo , Neoplasias da Próstata/imunologia , Linfócitos T Reguladores/imunologia , Timo/fisiologia , Animais , Autoanticorpos/metabolismo , Autoantígenos/genética , Autoantígenos/imunologia , Diferenciação Celular , Células Clonais , Mapeamento de Epitopos , Fatores de Transcrição Forkhead/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Ativação Linfocitária , Masculino , Camundongos
19.
Prev Med ; 95: 110-118, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27956225

RESUMO

The objectives of this analysis were to compare the ability of fasting plasma glucose (FPG), post oral load plasma glucose (2hPG), and hemoglobin A1c (HbA1c) to identify U.S. Hispanic/Latino individuals with prediabetes, and to assess its cardiovascular risk factor correlates. This is a cross-sectional analysis of baseline data from 15,507 adults without self-reported diabetes mellitus from six Hispanic/Latino heritage groups, enrolled in the Hispanic Community Health Study/Study of Latinos, which takes place in four U.S. communities. The prevalence of prediabetes was determined according to individual or combinations of ADA-defined cut points: FPG=5.6-7.0mmol/L, 2hPG=7.8-11.1mmol/L, and HbA1c=5.7%-6.4% (39-46mmol/mol). The sensitivity of these criteria to detect prediabetes was estimated. The prevalence ratios (PRs) for selected cardiovascular risk factors were compared among alternative categories of prediabetes versus normoglycemia [FPG<5.6mmol/L and 2hPG<7.8mmol/L and HbA1c<5.7% (39mmol/mol)]. Approximately 36% of individuals met any of the ADA prediabetes criteria. Using 2hPG as the gold standard, the sensitivity of FPG was 40.1%, HbA1c was 45.6%, and that of HbA1c+FPG was 62.2%. The number of significant PRs for cardiovascular risk factors was higher among individuals with isolated 2hPG=7.8-11.1mmol/L, FPG=5.6-7.0mmol/L+HbA1c=5.7%-6.4%, or those who met the three prediabetes criteria. Assessing FPG, HbA1c, and cardiovascular risk factors in Hispanics/Latinos at risk might enhance the early prevention of diabetes mellitus and cardiovascular complications in this young and growing population, independent of their heritage group.


Assuntos
Cultura , Teste de Tolerância a Glucose/métodos , Hispânico ou Latino , Estado Pré-Diabético/sangue , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Hemoglobinas Glicadas/análise , Humanos , Hipertensão , Prevalência , Fatores de Risco , Inquéritos e Questionários
20.
Endocr Pract ; 22(10): 1151-1160, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27295013

RESUMO

OBJECTIVE: The aim of this study was to compare the ability of American Diabetes Association (ADA) diagnostic criteria to identify U.S. Hispanics/Latinos from diverse heritage groups with probable diabetes mellitus and assess cardiovascular risk factor correlates of those criteria. METHODS: Cross-sectional analysis of data from 15,507 adults from 6 Hispanic/Latino heritage groups, enrolled in the Hispanic Community Health Study/Study of Latinos. The prevalence of probable diabetes mellitus was estimated using individual or combinations of ADA-defined cut points. The sensitivity and specificity of these criteria at identifying diabetes mellitus from ADA-defined prediabetes and normoglycemia were evaluated. Prevalence ratios of hypertension, abnormal lipids, and elevated urinary albumin-creatinine ratio for unrecognized diabetes mellitus-versus prediabetes and normoglycemia-were calculated. RESULTS: Among Hispanics/Latinos (mean age, 43 years) with diabetes mellitus, 39.4% met laboratory test criteria for probable diabetes, and the prevalence varied by heritage group. Using the oral glucose tolerance test as the gold standard, the sensitivity of fasting plasma glucose (FPG) and hemoglobin A1c-alone or in combination-was low (18, 23, and 33%, respectively) at identifying probable diabetes mellitus. Individuals who met any criterion for probable diabetes mellitus had significantly higher (P<.05) prevalence of most cardiovascular risk factors than those with normoglycemia or prediabetes, and this association was not modified by Hispanic/Latino heritage group. CONCLUSION: FPG and hemoglobin A1c are not sensitive (but are highly specific) at detecting probable diabetes mellitus among Hispanics/Latinos, independent of heritage group. Assessing cardiovascular risk factors at diagnosis might prompt multitarget interventions and reduce health complications in this young population. ABBREVIATIONS: 2hPG = 2-hour post-glucose load plasma glucose ADA = American Diabetes Association BMI = body mass index CV = cardiovascular FPG = fasting plasma glucose HbA1c = hemoglobin A1c HCHS/SOL = Hispanic Community Health Study/Study of Latinos HDL-C = high-density-lipoprotein cholesterol NGT = normal glucose tolerance NHANES = National Health and Nutrition Examination Survey OGTT = oral glucose tolerance test TG = triglyceride UACR = urine albumin-creatinine ratio.


Assuntos
Diabetes Mellitus/diagnóstico , Diabetes Mellitus/etnologia , Hispânico ou Latino , Adolescente , Adulto , Idoso , Doenças Cardiovasculares/etnologia , Cidades/epidemiologia , Serviços de Saúde Comunitária , Estudos Transversais , Feminino , Hispânico ou Latino/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Estados Unidos/epidemiologia , Adulto Jovem
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