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1.
Proc Natl Acad Sci U S A ; 121(10): e2309957121, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38422022

RESUMEN

Hypoxia signaling influences tumor development through both cell-intrinsic and -extrinsic pathways. Inhibiting hypoxia-inducible factor (HIF) function has recently been approved as a cancer treatment strategy. Hence, it is important to understand how regulators of HIF may affect tumor growth under physiological conditions. Here we report that in aging mice factor-inhibiting HIF (FIH), one of the most studied negative regulators of HIF, is a haploinsufficient suppressor of spontaneous B cell lymphomas, particular pulmonary B cell lymphomas. FIH deficiency alters immune composition in aged mice and creates a tumor-supportive immune environment demonstrated in syngeneic mouse tumor models. Mechanistically, FIH-defective myeloid cells acquire tumor-supportive properties in response to signals secreted by cancer cells or produced in the tumor microenvironment with enhanced arginase expression and cytokine-directed migration. Together, these data demonstrate that under physiological conditions, FIH plays a key role in maintaining immune homeostasis and can suppress tumorigenesis through a cell-extrinsic pathway.


Asunto(s)
Linfoma de Células B , Proteínas Represoras , Animales , Ratones , Hipoxia/metabolismo , Oxigenasas de Función Mixta/metabolismo , Proteínas Represoras/metabolismo , Microambiente Tumoral
2.
BMJ Open Gastroenterol ; 11(1)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38302475

RESUMEN

OBJECTIVE: Coeliac disease (CD) diagnosis generally depends on histological examination of duodenal biopsies. We present the first study analysing the concordance in examination of duodenal biopsies using digitised whole-slide images (WSIs). We further investigate whether the inclusion of immunoglobulin A tissue transglutaminase (IgA tTG) and haemoglobin (Hb) data improves the interobserver agreement of diagnosis. DESIGN: We undertook a large study of the concordance in histological examination of duodenal biopsies using digitised WSIs in an entirely virtual reporting setting. Our study was organised in two phases: in phase 1, 13 pathologists independently classified 100 duodenal biopsies (40 normal; 40 CD; 20 indeterminate enteropathy) in the absence of any clinical or laboratory data. In phase 2, the same pathologists examined the (re-anonymised) WSIs with the inclusion of IgA tTG and Hb data. RESULTS: We found the mean probability of two observers agreeing in the absence of additional data to be 0.73 (±0.08) with a corresponding Cohen's kappa of 0.59 (±0.11). We further showed that the inclusion of additional data increased the concordance to 0.80 (±0.06) with a Cohen's kappa coefficient of 0.67 (±0.09). CONCLUSION: We showed that the addition of serological data significantly improves the quality of CD diagnosis. However, the limited interobserver agreement in CD diagnosis using digitised WSIs, even after the inclusion of IgA tTG and Hb data, indicates the importance of interpreting duodenal biopsy in the appropriate clinical context. It further highlights the unmet need for an objective means of reproducible duodenal biopsy diagnosis, such as the automated analysis of WSIs using artificial intelligence.


Asunto(s)
Enfermedad Celíaca , Humanos , Enfermedad Celíaca/diagnóstico , Transglutaminasas , Inteligencia Artificial , Variaciones Dependientes del Observador , Inmunoglobulina A
3.
Biomolecules ; 13(12)2023 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-38136579

RESUMEN

Coeliac disease (CeD) is a T-cell mediated enteropathy triggered by dietary gluten which remains substantially under-diagnosed around the world. The diagnostic gold-standard requires histological assessment of intestinal biopsies taken at endoscopy while consuming a gluten-containing diet. However, there is a lack of concordance between pathologists in histological assessment, and both endoscopy and gluten challenge are burdensome and unpleasant for patients. Identification of gluten-specific T-cell receptors (TCRs) in the TCR repertoire could provide a less subjective diagnostic test, and potentially remove the need to consume gluten. We review published gluten-specific TCR sequences, and develop an interpretable machine learning model to investigate their diagnostic potential. To investigate this, we sequenced the TCR repertoires of mucosal CD4+ T cells from 20 patients with and without CeD. These data were used as a training dataset to develop the model, then an independently published dataset of 20 patients was used as the testing dataset. We determined that this model has a training accuracy of 100% and testing accuracy of 80% for the diagnosis of CeD, including in patients on a gluten-free diet (GFD). We identified 20 CD4+ TCR sequences with the highest diagnostic potential for CeD. The sequences identified here have the potential to provide an objective diagnostic test for CeD, which does not require the consumption of gluten.


Asunto(s)
Enfermedad Celíaca , Humanos , Enfermedad Celíaca/diagnóstico , Glútenes , Linfocitos T/patología , Receptores de Antígenos de Linfocitos T/genética , Dieta
4.
J Exp Med ; 219(12)2022 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-36178457

RESUMEN

Natural killer (NK) cells are critical to immune surveillance against infections and cancer. Their role in immune surveillance requires that NK cells are present within tissues in a quiescent state. Mechanisms by which NK cells remain quiescent in tissues are incompletely elucidated. The transcriptional repressor BACH2 plays a critical role within the adaptive immune system, but its function within innate lymphocytes has been unclear. Here, we show that BACH2 acts as an intrinsic negative regulator of NK cell maturation and function. BACH2 is expressed within developing and mature NK cells and promotes the maintenance of immature NK cells by restricting their maturation in the presence of weak stimulatory signals. Loss of BACH2 within NK cells results in accumulation of activated NK cells with unrestrained cytotoxic function within tissues, which mediate augmented immune surveillance to pulmonary cancer metastasis. These findings establish a critical function of BACH2 as a global negative regulator of innate cytotoxic function and tumor immune surveillance by NK cells.


Asunto(s)
Antineoplásicos , Neoplasias , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Humanos , Inmunidad Innata , Células Asesinas Naturales
5.
J Exp Med ; 219(6)2022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35551368

RESUMEN

Inborn errors of immunity (IEIs) unveil regulatory pathways of human immunity. We describe a new IEI caused by mutations in the GTPase of the immune-associated protein 6 (GIMAP6) gene in patients with infections, lymphoproliferation, autoimmunity, and multiorgan vasculitis. Patients and Gimap6-/- mice show defects in autophagy, redox regulation, and polyunsaturated fatty acid (PUFA)-containing lipids. We find that GIMAP6 complexes with GABARAPL2 and GIMAP7 to regulate GTPase activity. Also, GIMAP6 is induced by IFN-γ and plays a critical role in antibacterial immunity. Finally, we observed that Gimap6-/- mice died prematurely from microangiopathic glomerulosclerosis most likely due to GIMAP6 deficiency in kidney endothelial cells.


Asunto(s)
GTP Fosfohidrolasas , Síndromes de Inmunodeficiencia , Animales , Autofagia , Células Endoteliales/metabolismo , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Humanos , Inflamación , Ratones
6.
Diagnostics (Basel) ; 12(5)2022 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-35626377

RESUMEN

Measuring immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), can rely on antibodies, reactive T cells and other factors, with T-cell-mediated responses appearing to have greater sensitivity and longevity. Because each T cell carries an essentially unique nucleic acid sequence for its T-cell receptor (TCR), we can interrogate sequence data derived from DNA or RNA to assess aspects of the immune response. This review deals with the utility of bulk, rather than single-cell, sequencing of TCR repertoires, considering the importance of study design, in terms of cohort selection, laboratory methods and analysis. The advances in understanding SARS-CoV-2 immunity that have resulted from bulk TCR repertoire sequencing are also be discussed. The complexity of sequencing data obtained by bulk repertoire sequencing makes analysis challenging, but simple descriptive analyses, clonal analysis, searches for specific sequences associated with immune responses to SARS-CoV-2, motif-based analyses, and machine learning approaches have all been applied. TCR repertoire sequencing has demonstrated early expansion followed by contraction of SARS-CoV-2-specific clonotypes, during active infection. Maintenance of TCR repertoire diversity, including the maintenance of diversity of anti-SARS-CoV-2 response, predicts a favourable outcome. TCR repertoire narrowing in severe COVID-19 is most likely a consequence of COVID-19-associated lymphopenia. It has been possible to follow clonotypic sequences longitudinally, which has been particularly valuable for clonotypes known to be associated with SARS-CoV-2 peptide/MHC tetramer binding or with SARS-CoV-2 peptide-induced cytokine responses. Closely related clonotypes to these previously identified sequences have been shown to respond with similar kinetics during infection. A possible superantigen-like effect of the SARS-CoV-2 spike protein has been identified, by means of observing V-segment skewing in patients with severe COVID-19, together with structural modelling. Such a superantigen-like activity, which is apparently absent from other coronaviruses, may be the basis of multisystem inflammatory syndrome and cytokine storms in COVID-19. Bulk TCR repertoire sequencing has proven to be a useful and cost-effective approach to understanding interactions between SARS-CoV-2 and the human host, with the potential to inform the design of therapeutics and vaccines, as well as to provide invaluable pathogenetic and epidemiological insights.

7.
Blood ; 139(16): 2471-2482, 2022 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-35134130

RESUMEN

The accessibility of cell surface proteins makes them tractable for targeting by cancer immunotherapy, but identifying suitable targets remains challenging. Here we describe plasma membrane profiling of primary human myeloma cells to identify an unprecedented number of cell surface proteins of a primary cancer. We used a novel approach to prioritize immunotherapy targets and identified a cell surface protein not previously implicated in myeloma, semaphorin-4A (SEMA4A). Using knock-down by short-hairpin RNA and CRISPR/nuclease-dead Cas9 (dCas9), we show that expression of SEMA4A is essential for normal myeloma cell growth in vitro, indicating that myeloma cells cannot downregulate the protein to avoid detection. We further show that SEMA4A would not be identified as a myeloma therapeutic target by standard CRISPR/Cas9 knockout screens because of exon skipping. Finally, we potently and selectively targeted SEMA4A with a novel antibody-drug conjugate in vitro and in vivo.


Asunto(s)
Mieloma Múltiple , Semaforinas , Membrana Celular/metabolismo , Humanos , Factores Inmunológicos , Inmunoterapia , Proteínas de la Membrana , Mieloma Múltiple/genética , Mieloma Múltiple/terapia , Proteómica , Semaforinas/genética , Semaforinas/metabolismo
8.
Diagnostics (Basel) ; 11(9)2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34574044

RESUMEN

A high prevalence of hepatic pathology (in 17 of 19 cases) was reported in post-mortem (PM) examinations of COVID-19 patients, undertaken between March 2020 and February 2021 by a single autopsy pathologist in two English Coronial jurisdictions. The patients in our cohort demonstrated high levels of recognised COVID-19 risk factors, including hypertension (8/16, 50%), type 2 diabetes mellitus (8/16, 50%) and evidence of arteriopathy 6/16 (38%). Hepatic abnormalities included steatosis (12/19; 63%), moderate to severe venous congestion (5/19; 26%) and cirrhosis (4/19; 21%). A subsequent literature review indicated a significantly increased prevalence of steatosis (49%), venous congestion (34%) and cirrhosis (9.3%) in COVID-19 PM cases, compared with a pre-pandemic PM cohort (33%, 16%, and 2.6%, respectively), likely reflecting an increased mortality risk in SARS-CoV-2 infection for patients with pre-existing liver disease. To corroborate this observation, we retrospectively analysed the admission liver function test (LFT) results of 276 consecutive, anonymised COVID-19 hospital patients in our centre, for whom outcome data were available. Of these patients, 236 (85.5%) had significantly reduced albumin levels at the time of admission to hospital, which was likely indicative of pre-existing chronic liver or renal disease. There was a strong correlation between patient outcome (length of hospital admission or death) and abnormal albumin at the time of hospital admission (p = 0.000012). We discuss potential mechanisms by which our observations of hepatic dysfunction are linked to a risk of COVID-19 mortality, speculating on the importance of recently identified anti-interferon antibodies.

9.
Cell Rep Med ; 2(2): 100192, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33495756

RESUMEN

The identification of SARS-CoV-2-specific T cell receptor (TCR) sequences is critical for understanding T cell responses to SARS-CoV-2. Accordingly, we reanalyze publicly available data from SARS-CoV-2-recovered patients who had low-severity disease (n = 17) and SARS-CoV-2 infection-naive (control) individuals (n = 39). Applying a machine learning approach to TCR beta (TRB) repertoire data, we can classify patient/control samples with a training sensitivity, specificity, and accuracy of 88.2%, 100%, and 96.4% and a testing sensitivity, specificity, and accuracy of 82.4%, 97.4%, and 92.9%, respectively. Interestingly, the same machine learning approach cannot separate SARS-CoV-2 recovered from SARS-CoV-2 infection-naive individual samples on the basis of B cell receptor (immunoglobulin heavy chain; IGH) repertoire data, suggesting that the T cell response to SARS-CoV-2 may be more stereotyped and longer lived. Following validation in larger cohorts, our method may be useful in detecting protective immunity acquired through natural infection or in determining the longevity of vaccine-induced immunity.


Asunto(s)
COVID-19/inmunología , Aprendizaje Automático , Linfocitos T/metabolismo , Secuencia de Aminoácidos , COVID-19/patología , COVID-19/virología , Análisis por Conglomerados , Regiones Determinantes de Complementariedad/química , Regiones Determinantes de Complementariedad/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Análisis de Componente Principal , Receptores de Antígenos de Linfocitos B/química , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/metabolismo , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , Análisis de Secuencia de ADN , Linfocitos T/inmunología
10.
Am J Clin Nutr ; 113(3): 622-629, 2021 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-33184625

RESUMEN

BACKGROUND: The number of gluten-free diet followers without celiac disease (CD) is increasing. However, little is known about the characteristics of these individuals. OBJECTIVES: We address this issue by investigating a wide range of genetic and phenotypic characteristics in association with following a gluten-free diet. METHODS: The cross-sectional association between lifestyle and health-related characteristics and following a gluten-free diet was investigated in 124,447 women and men aged 40-69 y from the population-based UK Biobank study. A genome-wide association study (GWAS) of following a gluten-free diet was performed. RESULTS: A total of 1776 (1.4%) participants reported following a gluten-free diet. Gluten-free diet followers were more likely to be women, nonwhite, highly educated, living in more socioeconomically deprived areas, former smokers, have lost weight in the past year, have poorer self-reported health, and have made dietary changes as a result of illness. Conversely, these individuals were less likely to consume alcohol daily, be overweight or obese, have hypertension, or use cholesterol-lowering medication. Participants with hospital inpatient diagnosed blood and immune mechanism disorders (OR: 1.62; 95% CI: 1.18, 2.21) and non-CD digestive system diseases (OR: 1.58; 95% CI: 1.42, 1.77) were more likely to follow a gluten-free diet. The GWAS demonstrated that no genetic variants were associated with being a gluten-free diet follower. CONCLUSIONS: Gluten-free diet followers have a better cardiovascular risk profile than non-gluten-free diet followers but poorer self-reported health and a higher prevalence of blood and immune disorders and digestive conditions. Reasons for following a gluten-free diet warrant further investigation.


Asunto(s)
Dieta Sin Gluten , Estudio de Asociación del Genoma Completo , Estilo de Vida , Adulto , Anciano , Recolección de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reino Unido
11.
J Pathol ; 253(3): 279-291, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33225446

RESUMEN

In coeliac disease (CeD), immune-mediated small intestinal damage is precipitated by gluten, leading to variable symptoms and complications, occasionally including aggressive T-cell lymphoma. Diagnosis, based primarily on histopathological examination of duodenal biopsies, is confounded by poor concordance between pathologists and minimal histological abnormality if insufficient gluten is consumed. CeD pathogenesis involves both CD4+ T-cell-mediated gluten recognition and CD8+ and γδ T-cell-mediated inflammation, with a previous study demonstrating a permanent change in γδ T-cell populations in CeD. We leveraged this understanding and explored the diagnostic utility of bulk T-cell receptor (TCR) sequencing in assessing duodenal biopsies in CeD. Genomic DNA extracted from duodenal biopsies underwent sequencing for TCR-δ (TRD) (CeD, n = 11; non-CeD, n = 11) and TCR-γ (TRG) (CeD, n = 33; non-CeD, n = 21). We developed a novel machine learning-based analysis of the TCR repertoire, clustering samples by diagnosis. Leave-one-out cross-validation (LOOCV) was performed to validate the classification algorithm. Using TRD repertoire, 100% (22/22) of duodenal biopsies were correctly classified, with a LOOCV accuracy of 91%. Using TCR-γ (TRG) repertoire, 94.4% (51/54) of duodenal biopsies were correctly classified, with LOOCV of 87%. Duodenal biopsy TRG repertoire analysis permitted accurate classification of biopsies from patients with CeD following a strict gluten-free diet for at least 6 months, who would be misclassified by current tests. This result reflects permanent changes to the duodenal γδ TCR repertoire in CeD, even in the absence of gluten consumption. Our method could complement or replace histopathological diagnosis in CeD and might have particular clinical utility in the diagnostic testing of patients unable to tolerate dietary gluten, and for assessing duodenal biopsies with equivocal features. This approach is generalisable to any TCR/BCR locus and any sequencing platform, with potential to predict diagnosis or prognosis in conditions mediated or modulated by the adaptive immune response. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Enfermedad Celíaca/diagnóstico , Enfermedad Celíaca/inmunología , Aprendizaje Automático , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Adulto , Dieta Sin Gluten , Femenino , Humanos , Intestino Delgado/inmunología , Masculino , Persona de Mediana Edad
12.
Nat Commun ; 11(1): 307, 2020 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-31949142

RESUMEN

Autophagy is an important cellular degradation pathway with a central role in metabolism as well as basic quality control, two processes inextricably linked to ageing. A decrease in autophagy is associated with increasing age, yet it is unknown if this is causal in the ageing process, and whether autophagy restoration can counteract these ageing effects. Here we demonstrate that systemic autophagy inhibition induces the premature acquisition of age-associated phenotypes and pathologies in mammals. Remarkably, autophagy restoration provides a near complete recovery of morbidity and a significant extension of lifespan; however, at the molecular level this rescue appears incomplete. Importantly autophagy-restored mice still succumb earlier due to an increase in spontaneous tumour formation. Thus, our data suggest that chronic autophagy inhibition confers an irreversible increase in cancer risk and uncovers a biphasic role of autophagy in cancer development being both tumour suppressive and oncogenic, sequentially.


Asunto(s)
Envejecimiento/fisiología , Autofagia/efectos de los fármacos , Autofagia/fisiología , Longevidad/fisiología , Neoplasias , Envejecimiento/genética , Animales , Autofagia/genética , Proteína 5 Relacionada con la Autofagia/genética , Trasplante de Médula Ósea , Modelos Animales de Enfermedad , Femenino , Inflamación , Longevidad/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Músculos , Fenotipo , Proteína Sequestosoma-1/metabolismo , Piel/patología
13.
Cancer Cell ; 33(2): 274-291.e8, 2018 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-29438697

RESUMEN

Lympho-myeloid restricted early thymic progenitors (ETPs) are postulated to be the cell of origin for ETP leukemias, a therapy-resistant leukemia associated with frequent co-occurrence of EZH2 and RUNX1 inactivating mutations, and constitutively activating signaling pathway mutations. In a mouse model, we demonstrate that Ezh2 and Runx1 inactivation targeted to early lymphoid progenitors causes a marked expansion of pre-leukemic ETPs, showing transcriptional signatures characteristic of ETP leukemia. Addition of a RAS-signaling pathway mutation (Flt3-ITD) results in an aggressive leukemia co-expressing myeloid and lymphoid genes, which can be established and propagated in vivo by the expanded ETPs. Both mouse and human ETP leukemias show sensitivity to BET inhibition in vitro and in vivo, which reverses aberrant gene expression induced by Ezh2 inactivation.


Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Leucemia Mieloide Aguda/genética , Mutación/genética , Animales , Regulación Leucémica de la Expresión Génica , Ratones Noqueados , Células Mieloides/metabolismo , Transducción de Señal/genética , Células Madre
14.
Endocrinology ; 158(3): 503-515, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28001444

RESUMEN

Plasmablastic B-cell malignancies include plasmablastic lymphoma and subsets of multiple myeloma and diffuse large B-cell lymphomaDLBCL. These diseases can be difficult to diagnose and treat, and they lack well-characterized cell line models. Here, immunophenotyping and FOXP1 expression profiling identified plasmablastic characteristics in DLBCL cell lines HLY-1 and SU-DHL-9, associated with CTNNAL1, HPGD, RORA, IGF1, and/or vitamin D receptor (VDR) transcription. We demonstrated VDR protein expression in primary plasmablastic tumor cells and confirmed in cell lines expression of both VDR and the metabolic enzyme CYP27B1, which catalyzes active vitamin D3 production. Although Vdr and Cyp27b1 transcription in normal B cells were activated by interleukin 4 (IL-4) and CD40 signaling, respectively, unstimulated malignant plasmablastic cells lacking IL-4 expressed both VDR and CYP27B1. Positive autoregulation evidenced intact VDR function in all plasmablastic lines, and inhibition of growth by active vitamin D3 was both dependent on MYC protein inhibition and could be enhanced by cotreatment with a synthetic ROR ligand SR-1078. Furthermore, a VDR polymorphism, FOK1, was associated with greater vitamin D3-dependent growth inhibition. In summary, HLY-1 provides an important model of strongly plasmablastic lymphoma, and disruption of VDR pathway activity may be of therapeutic benefit in both plasmablastic lymphoma and myeloma.


Asunto(s)
Colecalciferol/uso terapéutico , Mieloma Múltiple/metabolismo , Linfoma Plasmablástico/metabolismo , Receptores de Calcitriol/metabolismo , Animales , Benzamidas , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Colecalciferol/farmacología , Femenino , Factores de Transcripción Forkhead/metabolismo , Humanos , Inmunofenotipificación , Ratones Endogámicos C57BL , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Linfoma Plasmablástico/tratamiento farmacológico , Linfoma Plasmablástico/genética , Receptores de Calcitriol/genética , Proteínas Represoras/metabolismo
15.
J Innate Immun ; 8(5): 517-28, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27423740

RESUMEN

Withdrawal of iron from serum (hypoferraemia) is a conserved innate immune antimicrobial strategy that can withhold this critical nutrient from invading pathogens, impairing their growth. Hepcidin (Hamp1) is the master regulator of iron and its expression is induced by inflammation. Mice lacking Hamp1 from birth rapidly accumulate iron and are susceptible to infection by blood-dwelling siderophilic bacteria such as Vibrio vulnificus. In order to study the innate immune role of hepcidin against a background of normal iron status, we developed a transgenic mouse model of tamoxifen-sensitive conditional Hamp1 deletion (termed iHamp1-KO mice). These mice attain adulthood with an iron status indistinguishable from littermate controls. Hamp1 disruption and the consequent decline of serum hepcidin concentrations occurred within hours of a single tamoxifen dose. We found that the TLR ligands LPS and Pam3CSK4 and heat-killed Brucella abortus caused an equivalent induction of inflammation in control and iHamp1-KO mice. Pam3CSK4 and B. abortus only caused a drop in serum iron in control mice, while hypoferraemia due to LPS was evident but substantially blunted in iHamp1-KO mice. Our results characterise a powerful new model of rapidly inducible hepcidin disruption, and demonstrate the critical contribution of hepcidin to the hypoferraemia of inflammation.


Asunto(s)
Brucella abortus/inmunología , Hepcidinas/metabolismo , Inflamación/inmunología , Trastornos del Metabolismo del Hierro/inmunología , Animales , Antígenos Bacterianos/inmunología , Genotipo , Hepcidinas/genética , Humanos , Inflamación/microbiología , Trastornos del Metabolismo del Hierro/microbiología , Lipopéptidos/inmunología , Lipopolisacáridos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Animales , Receptores Toll-Like/metabolismo
16.
Histopathology ; 69(6): 1066-1076, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27345622

RESUMEN

AIMS: Richter's syndrome (RS) refers to high-grade transformation of B-cell chronic lymphocytic leukaemia (CLL), usually to diffuse large B-cell lymphoma, as assessed according to strict World Health Organization (WHO)-defined histological criteria. Although this is a relatively evidence-poor area, the recommended clinical management of high-grade transformation differs considerably from that of relapsed CLL. The 'CHOP-OR' trial was a single-arm, multicentre, non-randomized phase II National Cancer Research Institute trial in patients with newly diagnosed RS, recruited from across the UK from April 2011 to December 2014. Forty-three patients were enrolled, of whom 37 were ultimately evaluable for response. The aim was to verify the presence of RS in the trial patients and identify pitfalls in the diagnosis of RS. METHODS AND RESULTS: Two independent, specialist haematopathologists reviewed histological material from 40 available cases enrolled in the CHOP-OR trial to determine whether the submitted diagnosis of RS was correct. Three cases were unavailable for central review. This series represents the largest central review of RS within a prospective trial in the literature to date. Thirty-three of the 40 (82.5%) submitted cases showed features consistent with WHO-defined RS. Reasons for diagnostic uncertainty in discrepant cases included large proliferation centres, variably confluent and serpiginous proliferation centres, and an apparently high proliferation index, sometimes attributable to a thick section or associated normal bone marrow proliferation. CONCLUSIONS: We discuss the importance of high-quality histological and immunohistochemical sections and strict adherence to WHO criteria in the diagnosis of RS. This study further reinforces the importance of centralized review of cases of haematological malignancy.


Asunto(s)
Transformación Celular Neoplásica , Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células B Grandes Difuso/diagnóstico , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
Atherosclerosis ; 250: 95-105, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27187934

RESUMEN

BACKGROUND AND AIMS: Coronary artery disease (CAD) risk is associated with non-coding genetic variants at the phosphatase and actin regulating protein 1(PHACTR1) gene locus. The PHACTR1 gene encodes an actin-binding protein with phosphatase regulating activity. The mechanism whereby PHACTR1 influences CAD risk is unknown. We hypothesized that PHACTR1 would be expressed in human cell types relevant to CAD and regulated by atherogenic or genetic factors. METHODS AND RESULTS: Using immunohistochemistry, we demonstrate that PHACTR1 protein is expressed strongly in human atherosclerotic plaque macrophages, lipid-laden foam cells, adventitial lymphocytes and endothelial cells. Using a combination of genomic analysis and molecular techniques, we demonstrate that PHACTR1 is expressed as multiple previously uncharacterized transcripts in macrophages, foam cells, lymphocytes and endothelial cells. Immunoblotting confirmed a total absence of PHACTR1 in vascular smooth muscle cells. Real-time quantitative PCR showed that PHACTR1 is regulated by atherogenic and inflammatory stimuli. In aortic endothelial cells, oxLDL and TNF-alpha both upregulated an intermediate length transcript. A short transcript expressed only in immune cells was upregulated in macrophages by oxidized low-density lipoprotein, and oxidized phospholipids but suppressed by lipopolysaccharide or TNF-alpha. In primary human macrophages, we identified a novel expression quantitative trait locus (eQTL) specific for this short transcript, whereby the risk allele at CAD risk SNP rs9349379 is associated with reduced PHACTR1 expression, similar to the effect of an inflammatory stimulus. CONCLUSIONS: Our data demonstrate that PHACTR1 is a key atherosclerosis candidate gene since it is regulated by atherogenic stimuli in macrophages and endothelial cells and we identify an effect of the genetic risk variant on PHACTR1 expression in macrophages that is similar to that of an inflammatory stimulus.


Asunto(s)
Aterosclerosis/genética , Enfermedad de la Arteria Coronaria/genética , Interacción Gen-Ambiente , Macrófagos/metabolismo , Proteínas de Microfilamentos/metabolismo , Adulto , Anciano , Alelos , Aterosclerosis/diagnóstico , Enfermedad de la Arteria Coronaria/diagnóstico , Vasos Coronarios/patología , Células Endoteliales/citología , Regulación de la Expresión Génica , Genotipo , Humanos , Inflamación , Lipopolisacáridos/farmacología , Proteínas de Microfilamentos/genética , Persona de Mediana Edad , Músculo Liso Vascular/patología , Polimorfismo de Nucleótido Simple , Factor de Necrosis Tumoral alfa/farmacología , Adulto Joven
18.
Oncotarget ; 7(33): 52940-52956, 2016 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-27224915

RESUMEN

FOXP2 shares partially overlapping normal tissue expression and functionality with FOXP1; an established diffuse large B-cell lymphoma (DLBCL) oncogene and marker of poor prognosis. FOXP2 is expressed in the plasma cell malignancy multiple myeloma but has not been studied in DLBCL, where a poor prognosis activated B-cell (ABC)-like subtype display partially blocked plasma cell differentiation. FOXP2 protein expression was detected in ABC-DLBCL cell lines, and in primary DLBCL samples tumoral FOXP2 protein expression was detected in both germinal center B-cell-like (GCB) and non-GCB DLBCL. In biopsies from DLBCL patients treated with immunochemotherapy (R-CHOP), ≥ 20% nuclear tumoral FOXP2-positivity (n = 24/158) correlated with significantly inferior overall survival (OS: P = 0.0017) and progression-free survival (PFS: P = 0.0096). This remained significant in multivariate analysis against either the international prognostic index score or the non-GCB DLBCL phenotype (P < 0.05 for both OS and PFS). Expression of BLIMP1, a marker of plasmacytic differentiation that is commonly inactivated in ABC-DLBCL, did not correlate with patient outcome or FOXP2 expression in this series. Increased frequency of FOXP2 expression significantly correlated with FOXP1-positivity (P = 0.0187), and FOXP1 co-immunoprecipitated FOXP2 from ABC-DLBCL cells indicating that these proteins can co-localize in a multi-protein complex. FOXP2-positive DLBCL had reduced expression of HIP1R (P = 0.0348), which is directly repressed by FOXP1, and exhibited distinct patterns of gene expression. Specifically in ABC-DLBCL these were associated with lower expression of immune response and T-cell receptor signaling pathways. Further studies are warranted to investigate the potential functional cooperativity between FOXP1 and FOXP2 in repressing immune responses during the pathogenesis of high-risk DLBCL.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Factores de Transcripción Forkhead/metabolismo , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Línea Celular Tumoral , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Factores de Transcripción Forkhead/genética , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Ontología de Genes , Humanos , Estimación de Kaplan-Meier , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Masculino , Persona de Mediana Edad , Prednisona/administración & dosificación , Unión Proteica , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transducción de Señal/genética , Transcriptoma/genética , Vincristina/administración & dosificación , Adulto Joven
19.
J Pathol ; 238(2): 359-67, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26387837

RESUMEN

Animal models are essential research tools in modern biomedical research, but there are concerns about their lack of reproducibility and the failure of animal data to translate into advances in human medical therapy. A major factor in improving experimental reproducibility is thorough communication of research methodologies. The recently published ARRIVE guidelines outline basic information that should be provided when reporting animal studies. This paper builds on ARRIVE by providing the minimum information needed in reports to allow proper assessment of pathology data gathered from animal tissues. This guidance covers aspects of experimental design, technical procedures, data gathering, analysis, and presentation that are potential sources of variation when creating morphological, immunohistochemical (IHC) or in situ hybridization (ISH) datasets. This reporting framework will maximize the likelihood that pathology data derived from animal experiments can be reproduced by ensuring that sufficient information is available to allow for replication of the methods and facilitate inter-study comparison by identifying potential interpretative confounders.


Asunto(s)
Modelos Animales , Patología/métodos , Guías de Práctica Clínica como Asunto , Experimentación Animal , Animales , Humanos , Difusión de la Información , Publicaciones , Proyectos de Investigación , Investigación Biomédica Traslacional
20.
Cold Spring Harb Protoc ; 2015(9): pdb.top070391, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26330629

RESUMEN

Autophagy is a lysosomal catabolic pathway responsible for the degradation of cytoplasmic constituents. Autophagy is primarily a survival pathway for recycling cellular material in times of nutrient starvation, and in response to hypoxia, endoplasmic reticulum stress, and other stresses, regulated through the mammalian target of rapamycin pathway. The proteasomal pathway is responsible for degradation of proteins, whereas autophagy can degrade cytoplasmic material in bulk, including whole organelles such as mitochondria (mitophagy), bacteria (xenophagy), or lipids (lipophagy). Although signs of autophagy can be present during cell death, it remains controversial whether autophagy can execute cell death in vivo. Here, we will introduce protocols for detecting autophagy in mammalian primary cells by using western blots, immunofluorescence, immunohistochemistry, flow cytometry, and imaging flow cytometry.


Asunto(s)
Autofagia , Fenómenos Fisiológicos Celulares , Técnicas Citológicas/métodos , Animales , Células Cultivadas , Humanos , Mamíferos
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