Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Cancer Discov ; 11(11): 2924-2943, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34103328

RESUMEN

Acute leukemias are systemic malignancies associated with a dire outcome. Because of low immunogenicity, leukemias display a remarkable ability to evade immune control and are often resistant to checkpoint blockade. Here, we discover that leukemia cells actively establish a suppressive environment to prevent immune attacks by co-opting a signaling axis that skews macrophages toward a tumor-promoting tissue repair phenotype, namely the GAS6/AXL axis. Using aggressive leukemia models, we demonstrate that ablation of the AXL receptor specifically in macrophages, or its ligand GAS6 in the environment, stimulates antileukemic immunity and elicits effective and lasting natural killer cell- and T cell-dependent immune response against naïve and treatment-resistant leukemia. Remarkably, AXL deficiency in macrophages also enables PD-1 checkpoint blockade in PD-1-refractory leukemias. Finally, we provide proof-of-concept that a clinical-grade AXL inhibitor can be used in combination with standard-of-care therapy to cure established leukemia, regardless of AXL expression in malignant cells. SIGNIFICANCE: Alternatively primed myeloid cells predict negative outcome in leukemia. By demonstrating that leukemia cells actively evade immune control by engaging AXL receptor tyrosine kinase in macrophages and promoting their alternative priming, we identified a target which blockade, using a clinical-grade inhibitor, is vital to unleashing the therapeutic potential of myeloid-centered immunotherapy.This article is highlighted in the In This Issue feature, p. 2659.


Asunto(s)
Leucemia , Humanos , Inmunoterapia , Leucemia/terapia , Macrófagos , Transducción de Señal
2.
Nat Commun ; 11(1): 586, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31996681

RESUMEN

The endothelial to haematopoietic transition (EHT) is the process whereby haemogenic endothelium differentiates into haematopoietic stem and progenitor cells (HSPCs). The intermediary steps of this process are unclear, in particular the identity of endothelial cells that give rise to HSPCs is unknown. Using single-cell transcriptome analysis and antibody screening, we identify CD44 as a marker of EHT enabling us to isolate robustly the different stages of EHT in the aorta-gonad-mesonephros (AGM) region. This allows us to provide a detailed phenotypical and transcriptional profile of CD44-positive arterial endothelial cells from which HSPCs emerge. They are characterized with high expression of genes related to Notch signalling, TGFbeta/BMP antagonists, a downregulation of genes related to glycolysis and the TCA cycle, and a lower rate of cell cycle. Moreover, we demonstrate that by inhibiting the interaction between CD44 and its ligand hyaluronan, we can block EHT, identifying an additional regulator of HSPC development.


Asunto(s)
Biomarcadores , Endotelio/metabolismo , Células Madre Hematopoyéticas/metabolismo , Receptores de Hialuranos/metabolismo , Transcriptoma , Animales , Aorta , Arterias , Ciclo Celular , Ciclo del Ácido Cítrico/genética , Biología Computacional , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Regulación hacia Abajo , Glucólisis/genética , Gónadas , Hematopoyesis/fisiología , Receptores de Hialuranos/sangre , Receptores de Hialuranos/genética , Ácido Hialurónico , Mesonefro , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor de Crecimiento Transformador beta/metabolismo
3.
Cytometry A ; 97(2): 156-167, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31603610

RESUMEN

Single-cell sequencing experiments are a new mainstay in biology and have been advancing science especially in the biomedical field. The high pressure to integrate the technology into daily laboratory live requires solid knowledge with respect to potential limitations and precautions to be taken care of before applying it to complex research questions. In the past, we have identified two issues with quality measures neglected by the growing community involving SmartSeq and droplet or micro-well-based scRNASeq methods (1) how to ensure that only single cells are introduced without biasing on light scattering when handling complex cell mixtures and organ preparations or (2) how best to control for (pro-)apoptotic cell contaminations in single-cell sequencing approaches. Sighting of concurrent literature involving single-cell sequencing technologies revealed that these topics are generally neglected or simply approached in silico but not at the bench before generating single-cell data sets. We fear that those important quality aspects are overlooked due to reduced awareness of their importance for guaranteeing the quality of experiments. In this Cytometry rigor issue, we provide experimentally supported guidance on how to circumvent those critical shortcomings in order to promote a better use of the fantastic single-cell sequencing toolbox in biology. © 2019 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.


Asunto(s)
Apoptosis , Humanos , Control de Calidad
4.
Eur J Immunol ; 49(10): 1457-1973, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31633216

RESUMEN

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.


Asunto(s)
Alergia e Inmunología/normas , Separación Celular/métodos , Separación Celular/normas , Citometría de Flujo/métodos , Citometría de Flujo/normas , Consenso , Humanos , Fenotipo
5.
In Vivo ; 32(6): 1323-1331, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30348684

RESUMEN

BACKGROUND/AIM: Vascular anomalies encompass different vascular malformations [arteriovenous (AVM), lymphatic (LM), venous lymphatic (VLM), venous (VM)] and vascular tumors such as hemangiomas (HA). The pathogenesis of vascular anomalies is still poorly understood. Viral infection was speculated as a possible underlying cause. MATERIALS AND METHODS: A total of 13 human vascular anomalies and three human skin control tissues were used for viral analysis. RNA derived from AVM (n=4) and normal skin control (n=3) tissues was evaluated by RNA sequencing. The Virome Capture Sequencing Platform for Vertebrate Viruses (VirCapSeq-VERT) was deployed on 10 tissues with vascular anomalies (2×AVM, 1×HA, 1×LM, 2×VLM, 4×VM). RESULTS: RNA sequencing did not show any correlation of AVM with viral infection. By deploying VirCapSeq-VERT, no consistent viral association was seen in the tested tissues. CONCLUSION: The analysis does not point to the presence of an active viral infection in vascular anomalies. However, transient earlier viral infections, e.g. during pregnancy, cannot be excluded with this approach.


Asunto(s)
Malformaciones Vasculares/diagnóstico , Malformaciones Vasculares/etiología , Virosis/complicaciones , Virosis/virología , Regulación Viral de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , ARN Viral , Virus/genética
6.
Elife ; 72018 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-29555020

RESUMEN

Recent advances in single-cell transcriptomics techniques have opened the door to the study of gene regulatory networks (GRNs) at the single-cell level. Here, we studied the GRNs controlling the emergence of hematopoietic stem and progenitor cells from mouse embryonic endothelium using a combination of single-cell transcriptome assays. We found that a heptad of transcription factors (Runx1, Gata2, Tal1, Fli1, Lyl1, Erg and Lmo2) is specifically co-expressed in an intermediate population expressing both endothelial and hematopoietic markers. Within the heptad, we identified two sets of factors of opposing functions: one (Erg/Fli1) promoting the endothelial cell fate, the other (Runx1/Gata2) promoting the hematopoietic fate. Surprisingly, our data suggest that even though Fli1 initially supports the endothelial cell fate, it acquires a pro-hematopoietic role when co-expressed with Runx1. This work demonstrates the power of single-cell RNA-sequencing for characterizing complex transcription factor dynamics.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Hematopoyesis/genética , Células Madre Hematopoyéticas/metabolismo , Células Madre Embrionarias de Ratones/metabolismo , Análisis de la Célula Individual/métodos , Factores de Transcripción/genética , Animales , Análisis por Conglomerados , Subunidades alfa del Factor de Unión al Sitio Principal/genética , Endotelio/citología , Endotelio/embriología , Endotelio/metabolismo , Redes Reguladoras de Genes , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteína Proto-Oncogénica c-fli-1/genética
7.
Nucleic Acids Res ; 43(20): 9680-93, 2015 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-26476451

RESUMEN

Dendritic cells (DC) are professional antigen presenting cells that develop from hematopoietic stem cells through successive steps of lineage commitment and differentiation. Multipotent progenitors (MPP) are committed to DC restricted common DC progenitors (CDP), which differentiate into specific DC subsets, classical DC (cDC) and plasmacytoid DC (pDC). To determine epigenetic states and regulatory circuitries during DC differentiation, we measured consecutive changes of genome-wide gene expression, histone modification and transcription factor occupancy during the sequel MPP-CDP-cDC/pDC. Specific histone marks in CDP reveal a DC-primed epigenetic signature, which is maintained and reinforced during DC differentiation. Epigenetic marks and transcription factor PU.1 occupancy increasingly coincide upon DC differentiation. By integrating PU.1 occupancy and gene expression we devised a transcription factor regulatory circuitry for DC commitment and subset specification. The circuitry provides the transcription factor hierarchy that drives the sequel MPP-CDP-cDC/pDC, including Irf4, Irf8, Tcf4, Spib and Stat factors. The circuitry also includes feedback loops inferred for individual or multiple factors, which stabilize distinct stages of DC development and DC subsets. In summary, here we describe the basic regulatory circuitry of transcription factors that drives DC development.


Asunto(s)
Células Dendríticas/metabolismo , Epigénesis Genética , Redes Reguladoras de Genes , Factores de Transcripción/metabolismo , Animales , Linaje de la Célula , Células Cultivadas , Células Madre Hematopoyéticas/metabolismo , Histonas/metabolismo , Ratones , Proteínas Proto-Oncogénicas/metabolismo , Transactivadores/metabolismo
9.
Nat Commun ; 5: 4868, 2014 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-25204769

RESUMEN

The emergence of new genes throughout evolution requires rewiring and extension of regulatory networks. However, the molecular details of how the transcriptional regulation of new gene copies evolves remain largely unexplored. Here we show how duplication of a transcription factor gene allowed the emergence of two independent regulatory circuits. Interestingly, the ancestral transcription factor was promiscuous and could bind different motifs in its target promoters. After duplication, one paralogue evolved increased binding specificity so that it only binds one type of motif, whereas the other copy evolved a decreased activity so that it only activates promoters that contain multiple binding sites. Interestingly, only a few mutations in both the DNA-binding domains and in the promoter binding sites were required to gradually disentangle the two networks. These results reveal how duplication of a promiscuous transcription factor followed by concerted cis and trans mutations allows expansion of a regulatory network.


Asunto(s)
Regulación Fúngica de la Expresión Génica , Proteínas de Transporte de Monosacáridos/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Factores de Transcripción/genética , alfa-Glucosidasas/genética , Secuencias de Aminoácidos , Sitios de Unión , Duplicación de Gen , Glucosidasas/genética , Regiones Promotoras Genéticas
10.
Nat Methods ; 10(11): 1093-5, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24056876

RESUMEN

Single-cell RNA-seq can yield valuable insights about the variability within a population of seemingly homogeneous cells. We developed a quantitative statistical method to distinguish true biological variability from the high levels of technical noise in single-cell experiments. Our approach quantifies the statistical significance of observed cell-to-cell variability in expression strength on a gene-by-gene basis. We validate our approach using two independent data sets from Arabidopsis thaliana and Mus musculus.


Asunto(s)
Análisis de Secuencia de ARN/métodos , Análisis de la Célula Individual
11.
Eur J Hum Genet ; 21(10): 1177-80, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23422942

RESUMEN

Most balanced chromosomal aberrations are not associated with a clinical phenotype, however, in some patients they may disrupt gene structure. With the development of various next-generation sequencing techniques, fast and specific analyses of the breakpoint regions of chromosomal rearrangements are possible. Here, we report on a 19-year-old woman with a de novo balanced translocation t(2;8)(p13.2;q22.1) and a severe clinical phenotype including intellectual disability, epilepsy, behavioral features resembling autism, and minor dysmorphic features. By next-generation sequencing, we defined the breakpoints and found disruption of the exocyst complex component 6B (EXOC6B) gene in intron 1 on chromosome 2p13.2 involving two Alu elements with a homology of 81%. No gene was found at the respective breakpoint on chromosome 8. Expression analysis of the EXOC6B in blood lymphocytes and buccal smear revealed reduced expression in the patient in comparison with the control. Our findings in combination with one recently published case and one other patient listed in DECIPHER v5.1 indicate EXOC6B as a gene relevant for intellectual development and electrophysiological stability.


Asunto(s)
Anomalías Múltiples/genética , Discapacidades del Desarrollo/genética , Epilepsia/genética , Proteínas de Unión al GTP/genética , Translocación Genética , Anomalías Múltiples/metabolismo , Puntos de Rotura del Cromosoma , Cromosomas Humanos Par 2/genética , Cromosomas Humanos Par 8/genética , Discapacidades del Desarrollo/metabolismo , Epilepsia/metabolismo , Femenino , Proteínas de Unión al GTP/metabolismo , Humanos , Linfocitos/metabolismo , Mucosa Bucal/metabolismo , Síndrome , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...