Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Immunity ; 45(3): 610-625, 2016 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-27612641

RESUMEN

The nature of gut intraepithelial lymphocytes (IELs) lacking antigen receptors remains controversial. Herein we showed that, in humans and in mice, innate intestinal IELs expressing intracellular CD3 (iCD3(+)) differentiate along an Id2 transcription factor (TF)-independent pathway in response to TF NOTCH1, interleukin-15 (IL-15), and Granzyme B signals. In NOTCH1-activated human hematopoietic precursors, IL-15 induced Granzyme B, which cleaved NOTCH1 into a peptide lacking transcriptional activity. As a result, NOTCH1 target genes indispensable for T cell differentiation were silenced and precursors were reprogrammed into innate cells with T cell marks including intracellular CD3 and T cell rearrangements. In the intraepithelial lymphoma complicating celiac disease, iCD3(+) innate IELs acquired gain-of-function mutations in Janus kinase 1 or Signal transducer and activator of transcription 3, which enhanced their response to IL-15. Overall we characterized gut T cell-like innate IELs, deciphered their pathway of differentiation and showed their malignant transformation in celiac disease.


Asunto(s)
Enfermedad Celíaca/inmunología , Interleucina-15/inmunología , Intestinos/inmunología , Linfoma/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Complejo CD3/inmunología , Diferenciación Celular/inmunología , Células Cultivadas , Granzimas/inmunología , Humanos , Proteína 2 Inhibidora de la Diferenciación/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Receptor Notch1/inmunología , Factor de Transcripción STAT3/inmunología , Transducción de Señal/inmunología , Transcripción Genética/inmunología
2.
PLoS Genet ; 11(5): e1005239, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26000857

RESUMEN

In vitro disease modeling based on induced pluripotent stem cells (iPSCs) provides a powerful system to study cellular pathophysiology, especially in combination with targeted genome editing and protocols to differentiate iPSCs into affected cell types. In this study, we established zinc-finger nuclease-mediated genome editing in primary fibroblasts and iPSCs generated from a mouse model for radiosensitive severe combined immunodeficiency (RS-SCID), a rare disorder characterized by cellular sensitivity to radiation and the absence of lymphocytes due to impaired DNA-dependent protein kinase (DNA-PK) activity. Our results demonstrate that gene editing in RS-SCID fibroblasts rescued DNA-PK dependent signaling to overcome radiosensitivity. Furthermore, in vitro T-cell differentiation from iPSCs was employed to model the stage-specific T-cell maturation block induced by the disease causing mutation. Genetic correction of the RS-SCID iPSCs restored T-lymphocyte maturation, polyclonal V(D)J recombination of the T-cell receptor followed by successful beta-selection. In conclusion, we provide proof that iPSC-based in vitro T-cell differentiation is a valuable paradigm for SCID disease modeling, which can be utilized to investigate disorders of T-cell development and to validate gene therapy strategies for T-cell deficiencies. Moreover, this study emphasizes the significance of designer nucleases as a tool for generating isogenic disease models and their future role in producing autologous, genetically corrected transplants for various clinical applications.


Asunto(s)
Diferenciación Celular , Proteína Quinasa Activada por ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Quinasas/metabolismo , Transducción de Señal , Linfocitos T/citología , Animales , Proteína Quinasa Activada por ADN/deficiencia , Proteína Quinasa Activada por ADN/genética , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Modelos Animales de Enfermedad , Fibroblastos/citología , Fibroblastos/metabolismo , Genoma , Técnicas de Genotipaje , Células HEK293 , Humanos , Células Madre Pluripotentes Inducidas/citología , Masculino , Ratones , Células 3T3 NIH , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Fenotipo , Proteínas Quinasas/genética , Linfocitos T/metabolismo , Dedos de Zinc
4.
J Infect Dis ; 208(2): 235-43, 2013 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-23559464

RESUMEN

BACKGROUND: The genotoxicity of zidovudine has been established in experimental models. The objective of the study was to identify genotoxicity markers in cord blood cells from newborns exposed in utero to antiretroviral (ARV) combinations containing zidovudine. METHODS: Cells were investigated by karyotyping and gene expression analysis of the CD34(+) hematopoietic stem/progenitor cell (HPC) compartment. RESULTS: Karyotyping of the cord blood cells from 15 ARV-exposed newborns and 12 controls revealed a higher proportion of aneuploid cells in the exposed group (median, 18.8% [interquartile range, 10.0%-26.7%] vs 6.6% [interquartile range, 3.1%-11.7%]; P < .001). All chromosomes were involved, with a random distribution of these alterations. Gene expression profiling of CD34(+) HPCs from 7 ARV-exposed and 6 control newborns revealed that >300 genes were significantly upregulated or downregulated by at least 1.5-fold in the exposed group (P < .05 for all comparisons). Significant alterations of genes involved in cell cycle control, mitotic checkpoints, and DNA repair were identified. Although this study does not allow discrimination between the roles of each of the 3 drugs, both cytogenetic and transcriptional findings are similar to those in cellular experiments that used zidovudine alone. CONCLUSIONS: The cord blood cells, including hematopoietic stem cells, from newborns exposed in utero to a zidovudine-based ARV combination present cytogenetic and transcriptional abnormalities compatible with DNA damage.


Asunto(s)
Fármacos Anti-VIH/efectos adversos , Sangre Fetal/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Zidovudina/efectos adversos , Adulto , Antígenos CD34/genética , Antígenos CD34/metabolismo , Ciclo Celular/genética , Reparación del ADN/genética , Combinación de Medicamentos , Femenino , Sangre Fetal/citología , Sangre Fetal/fisiología , Perfilación de la Expresión Génica/métodos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , Infecciones por VIH/metabolismo , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Humanos , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Cariotipificación/métodos , Intercambio Materno-Fetal/fisiología , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/metabolismo , Complicaciones Infecciosas del Embarazo/virología , Efectos Tardíos de la Exposición Prenatal , Células Madre/metabolismo , Transcriptoma/genética , Adulto Joven , Zidovudina/farmacocinética
5.
Neuro Oncol ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38919026

RESUMEN

BACKGROUND: Outcome of children with medulloblastoma (MB) and Fanconi Anemia (FA), an inherited DNA repair deficiency, has not been described systematically. Treatment is complicated by high vulnerability to treatment-associated side effects, yet structured data are lacking. This study aims at giving a comprehensive overview about clinical and molecular characteristics of pediatric FA MB patients. METHODS: Clinical data including detailed information on treatment and toxicities of six previously unreported FA MB patients were supplemented with data of 16 published cases. RESULTS: We identified 22 cases of children with FA and MB with clinical data available. All MBs with subgroup reporting were SHH-activated (n=9), confirmed by methylation profiling in five patients. FA MB patients exclusively belonged to complementation groups FA-D1 (n=16) or FA-N (n=3). Patients were treated with postoperative chemotherapy only (50%) or radiotherapy (RT)±chemotherapy (27%). 23% did not receive adjuvant therapy. Excessive treatment-related toxicities were frequent. Severe hematological toxicity occurred in 91% of patients treated with alkylating chemotherapy, while non-alkylating agents and RT were less toxic. Median overall survival (OS) was 1 year (95%CI 0.3-1.8). 1-year-progression-free-survival (PFS) was 26.3±10.1% and 1-year-OS was 42.1±11.3%. Adjuvant therapy prolonged survival (1y-OS/1y-PFS 0%/0% without adjuvant therapy vs. 53.3±12.9%/33.3±12.2% with adjuvant therapy, p=0.006/p=0.086). CONCLUSIONS: MB in FA patients is strongly associated with SHH activation and FA-D1/FA-N. Despite the dismal prognosis, adjuvant therapy may prolong survival. Non-alkylating chemotherapy and RT are feasible in selected patients with careful monitoring of toxicities and dose adjustments. Curative therapy for FA MB-SHH remains an unmet medical need.

6.
Stem Cells ; 30(8): 1771-80, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22689616

RESUMEN

Slow T-cell reconstitution is a major clinical concern after transplantation of cord blood (CB)-derived hematopoietic stem cells. Adoptive transfer of in vitro-generated T-cell progenitors has emerged as a promising strategy for promoting de novo thymopoiesis and thus accelerating T-cell reconstitution. Here, we describe the development of a new culture system based on the immobilized Notch ligand Delta-like-4 (DL-4). Culture of human CD34(+) CB cells in this new DL-4 system enabled the in vitro generation of large amounts of T-cell progenitor cells that (a) displayed the phenotypic and molecular signatures of early thymic progenitors and (b) had high T lymphopoietic potential. When transferred into NOD/SCID/γc(-/-) (NSG) mice, DL-4 primed T-cell progenitors migrated to the thymus and developed into functional, mature, polyclonal αß T cells that subsequently left the thymus and accelerated T-cell reconstitution. T-cell reconstitution was even faster and more robust when ex vivo-manipulated and nonmanipulated CB samples were simultaneously injected into NSG mice (i.e., a situation reminiscent of the double CB transplant setting). This work provides further evidence of the ability of in vitro-generated human T-cell progenitors to accelerate T-cell reconstitution and also introduces a feeder-cell-free culture technique with the potential for rapid, safe transfer to a clinical setting.


Asunto(s)
Células Madre Hematopoyéticas/citología , Péptidos y Proteínas de Señalización Intercelular/inmunología , Linfocitos T/citología , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas de Unión al Calcio , Diferenciación Celular/fisiología , Trasplante de Células Madre Hematopoyéticas/métodos , Células Madre Hematopoyéticas/inmunología , Humanos , Inmunoterapia , Péptidos y Proteínas de Señalización Intercelular/genética , Linfopoyesis/fisiología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Linfocitos T/inmunología
7.
Materials (Basel) ; 16(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36676394

RESUMEN

Hypereutectic Al-high Si alloys are of immense interest for applications in the automotive, space or electronic industries, due their low weight, low thermal expansion, and excellent mechanical and tribological properties. Additionally, their production by laser powder bed fusion (LPBF) technology provides high flexibility in geometrical design and alloy composition. Since, most of the alloy properties could be improved by increasing the Si content, there is much interest in discovering the maximum that could be realized in LBPF Al-high Si alloys, without the appearance of any material failure. For this reason, in this work the production of Al-high Si alloys with extremely high silicon content of up to 70 wt.% was fundamentally investigated with respect to microstructure and mechanical properties. Highly dense (99.3%) and crack-free AlSi50 samples (5 × 5 × 5 mm3), with excellent hardness (225 HV5) and compressive strength (742 MPa), were successfully produced. Further, for the first time, AlSi70 LBPF samples of high density (98.8%) without cracks were demonstrated, using moderate scanning velocities. Simultaneously, the hardness and the compressive strength in the AlSi70 alloys were significantly improved to 350 HV5 and 935 MPa, as a result of the formation of a continuous Si network in the microstructure of the alloy. With respect to the powder source, it was found that the application of powder blends resulted in similar alloy properties as if pre-alloyed powders were used, enabling higher flexibility in prospective application-oriented alloy development.

9.
ACS Appl Mater Interfaces ; 13(40): 47912-47920, 2021 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-34586775

RESUMEN

Silicon waste (SW), a byproduct from the photovoltaic industry, can be a prospective and environmentally friendly source for silicon in the field of thermoelectric (TE) materials. While thermoelectricity is not as sensitive toward impurities as other semiconductor applications, the impurities within the SW still impede the enhancement of the thermoelectric figure of merit, zT. Besides, the high thermal conductivity of silicon limits its applications as a TE material. In this work, we employ traditionally metallurgical methods in industry reducing the impurities in SW to an extremely low level in an environmentally friendly and economical way, and then the thermal conductivity of purified silicon is greatly reduced due to the implementation of multiscale phonon scattering without degrading the power factor seriously. Benefiting from these strategies, from 323 to 1123 K, for the sample made from purified silicon waste, the average zT, relevant for engineering application, is increased to 0.32, higher than that of the state-of-the-art n-type Ge-free bulk silicon materials made from commercially available silicon, but the total cost of our samples is negligible.

10.
Blood Adv ; 3(3): 461-475, 2019 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-30755435

RESUMEN

T cells represent a valuable tool for treating cancers and infectious and inherited diseases; however, they are mainly short-lived in vivo. T-cell therapies would strongly benefit from gene transfer into long-lived persisting naive T cells or T-cell progenitors. Here we demonstrate that baboon envelope glycoprotein pseudotyped lentiviral vectors (BaEV-LVs) far outperformed other LV pseudotypes for transduction of naive adult and fetal interleukin-7-stimulated T cells. Remarkably, BaEV-LVs efficiently transduced thymocytes and T-cell progenitors generated by culture of CD34+ cells on Delta-like ligand 4 (Dll4). Upon NOD/SCIDγC-/- engraftment, high transduction levels (80%-90%) were maintained in all T-cell subpopulations. Moreover, T-cell lineage reconstitution was accelerated in NOD/SCIDγC-/- recipients after T-cell progenitor injection compared with hematopoietic stem cell transplantation. Furthermore, γC-encoding BaEV-LVs very efficiently transduced Dll4-generated T-cell precursors from a patient with X-linked severe combined immunodeficiency (SCID-X1), which fully rescued T-cell development in vitro. These results indicate that BaEV-LVs are valuable tools for the genetic modification of naive T cells, which are important targets for gene therapy. Moreover, they allowed for the generation of gene-corrected T-cell progenitors that rescued SCID-X1 T-cell development in vitro. Ultimately, the coinjection of LV-corrected T-cell progenitors and hematopoietic stem cells might accelerate T-cell reconstitution in immunodeficient patients.


Asunto(s)
Lentivirus/genética , Células Madre/metabolismo , Animales , Ratones , Ratones Endogámicos NOD , Ratones SCID , Papio
11.
FASEB J ; 16(13): 1811-3, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12223449

RESUMEN

The anemia of chronic inflammatory and malignant diseases is partly due to impaired synthesis of the hormone erythropoietin (Epo). The proinflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor a (TNF-alpha) suppress in vitro Epo gene expression and Epo protein secretion. However, the molecular mechanisms of this inhibition are poorly understood. The human Epo promoter and the 5' flanking region contain several recognition sequences for transcription factors acting either positively or negatively. Herein, we investigated the roles of the transcription factors GATA-2 and NF-kappaB in the modulation of Epo gene expression by IL-1beta and TNF-alpha in the human hepatoma cell line HepG2. Electrophoretic mobility shift assays revealed increased GATA-2 and NF-kappaB DNA binding in cells treated with IL-1beta or TNF-alpha. Reporter gene assays with a sequence from the Epo promoter in front of the firefly luciferase gene showed that the cytokines reduced Epo reporter gene activity. Functional inactivation of GATA-2 and NF-kappaB by oligo-decoy techniques prevented the inhibition of Epo production by IL-1beta and TNF-alpha. In HepG2 cells stably transfected with a dominant-negative form of IkappaBalpha, the activation of NF-kappaB was inhibited, while Epo mRNA levels and Epo secretion increased. Thus, both GATA-2 and NF-kappaB seem to be involved in the suppression of Epo gene expression by IL-1beta and TNF-alpha in vitro and may be responsible for impaired Epo synthesis in inflammatory diseases in vivo.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Eritropoyetina/genética , FN-kappa B/metabolismo , Factores de Transcripción/metabolismo , Northern Blotting , Hipoxia de la Célula/fisiología , Ensayo de Cambio de Movilidad Electroforética , Factor de Transcripción GATA2 , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-1/farmacología , Oligonucleótidos/metabolismo , Unión Proteica/efectos de los fármacos , ARN Mensajero/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/farmacología
12.
J Exp Med ; 211(9): 1821-32, 2014 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-25135298

RESUMEN

V(D)J recombination of TCR loci is regulated by chromatin accessibility to RAG1/2 proteins, rendering RAG1/2 targeting a potentially important regulator of lymphoid differentiation. We show that within the human TCR-α/δ locus, Dδ2-Dδ3 rearrangements occur at a very immature thymic, CD34(+)/CD1a(-)/CD7(+dim) stage, before Dδ2(Dδ3)-Jδ1 rearrangements. These strictly ordered rearrangements are regulated by mechanisms acting beyond chromatin accessibility. Importantly, direct Dδ2-Jδ1 rearrangements are prohibited by a B12/23 restriction and ordered human TCR-δ gene assembly requires RUNX1 protein, which binds to the Dδ2-23RSS, interacts with RAG1, and enhances RAG1 deposition at this site. This RUNX1-mediated V(D)J recombinase targeting imposes the use of two Dδ gene segments in human TCR-δ chains. Absence of this RUNX1 binding site in the homologous mouse Dδ1-23RSS provides a molecular explanation for the lack of ordered TCR-δ gene assembly in mice and may underlie differences in early lymphoid differentiation between these species.


Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Reordenamiento Génico de la Cadena delta de los Receptores de Antígenos de los Linfocitos T , Proteínas de Homeodominio/metabolismo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Secuencia de Bases , Sitios de Unión/genética , Diferenciación Celular , Línea Celular , ADN/genética , ADN/metabolismo , Células HEK293 , Humanos , Cinética , Linfopoyesis , Ratones , Datos de Secuencia Molecular , Especificidad de la Especie , Subgrupos de Linfocitos T/citología , VDJ Recombinasas/metabolismo
14.
Immunotherapy ; 2(4): 481-96, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20636003

RESUMEN

Although partially HLA-mismatched hematopoietic stem cell transplantation (HSCT) has become an important therapeutic option for children with primary immunodeficiencies, delayed reconstitution of the T-cell compartment remains a major clinical concern. Adoptive immunotherapies to provide recipients with a protective and diverse T-cell repertoire in the months following HSCT are warranted. In order to improve T-cell reconstitution after T-cell-depleted HSCT, different strategies are currently being studied. Some are based on administration of modified mature T cells (e.g., allodepleted T cells or pathogen-specific T cells). Others aim at accelerating de novo thymopoiesis from donor-derived hematopoietic stem cells in vivo via the administration of thymopoietic agents or the transfer of large numbers of T-cell precursors generated ex vivo. The present article will provide a brief summary of recent advances in the field of allodepletion and adoptive transfer of pathogen-specific T cells and a detailed discussion of strategies for enhancing thymopoiesis in vivo.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Inmunoterapia Adoptiva , Linfocitos T/inmunología , Prueba de Histocompatibilidad , Humanos , Inmunoterapia Adoptiva/tendencias , Linfocitos T/citología , Linfocitos T/trasplante
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA