RESUMEN
ABSTRACT: Natural killer (NK) cells represent the cytotoxic member within the innate lymphoid cell (ILC) family that are important against viral infections and cancer. Although the NK cell emergence from hematopoietic stem and progenitor cells through multiple intermediate stages and the underlying regulatory gene network has been extensively studied in mice, this process is not well characterized in humans. Here, using a temporal in vitro model to reconstruct the developmental trajectory of NK lineage, we identified an ILC-restricted oligopotent stage 3a CD34-CD117+CD161+CD45RA+CD56- progenitor population, that exclusively gave rise to CD56-expressing ILCs in vitro. We also further investigated a previously nonappreciated heterogeneity within the CD56+CD94-NKp44+ subset, phenotypically equivalent to stage 3b population containing both group-1 ILC and RORγt+ ILC3 cells, that could be further separated based on their differential expression of DNAM-1 and CD161 receptors. We confirmed that DNAM-1hi S3b and CD161hiCD117hi ILC3 populations distinctively differed in their expression of effector molecules, cytokine secretion, and cytotoxic activity. Furthermore, analysis of lineage output using DNA-barcode tracing across these stages supported a close developmental relationship between S3b-NK and S4-NK (CD56+CD94+) cells, whereas distant to the ILC3 subset. Cross-referencing gene signatures of culture-derived NK cells and other noncytotoxic ILCs with publicly available data sets validated that these in vitro stages highly resemble transcriptional profiles of respective in vivo ILC counterparts. Finally, by integrating RNA velocity and gene network analysis through single-cell regulatory network inference and clustering we unravel a network of coordinated and highly dynamic regulons driving the cytotoxic NK cell program, as a guide map for future studies on NK cell regulation.
Asunto(s)
Células Asesinas Naturales , Análisis de la Célula Individual , Humanos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Análisis de la Célula Individual/métodos , Linaje de la Célula , Inmunidad Innata , Diferenciación CelularRESUMEN
The emerging notion of hematopoietic stem and progenitor cells (HSPCs) as a low-primed cloud without sharply demarcated gene expression programs raises the question on how cellular-fate options emerge and at which stem-like stage lineage priming is initiated. Here, we investigate single-cell chromatin accessibility of Lineage-, cKit+, and Sca1+ (LSK) HSPCs spanning the early differentiation landscape. Application of a signal-processing algorithm to detect transition points corresponding to massive alterations in accessibility of 571 transcription factor motifs reveals a population of LSK FMS-like tyrosine kinase 3 (Flt3)intCD9high cells that concurrently display stem-like and lineage-affiliated chromatin signatures, pointing to a simultaneous gain of both lympho-myeloid and megakaryocyte-erythroid programs. Molecularly and functionally, these cells position between stem cells and committed progenitors and display multi-lineage capacity in vitro and in vivo but lack self-renewal activity. This integrative molecular analysis resolves the heterogeneity of cells along hematopoietic differentiation and permits investigation of chromatin-mediated transition between multipotency and lineage restriction.
Asunto(s)
Cromatina , Células Madre Hematopoyéticas , Diferenciación Celular , Linaje de la Célula , Cromatina/metabolismo , Regulación de la Expresión Génica , Células Madre Hematopoyéticas/metabolismo , MegacariocitosRESUMEN
The process of hematopoiesis is subject to substantial ontogenic remodeling that is accompanied by alterations in cellular fate during both development and disease. We combine state-of-the-art mass spectrometry with extensive functional assays to gain insight into ontogeny-specific proteomic mechanisms regulating hematopoiesis. Through deep coverage of the cellular proteome of fetal and adult lympho-myeloid multipotent progenitors (LMPPs), common lymphoid progenitors (CLPs), and granulocyte-monocyte progenitors (GMPs), we establish that features traditionally attributed to adult hematopoiesis are conserved across lymphoid and myeloid lineages, whereas generic fetal features are suppressed in GMPs. We reveal molecular and functional evidence for a diminished granulocyte differentiation capacity in fetal LMPPs and GMPs relative to their adult counterparts. Our data indicate an ontogeny-specific requirement of myosin activity for myelopoiesis in LMPPs. Finally, we uncover an ontogenic shift in the monocytic differentiation capacity of GMPs, partially driven by a differential expression of Irf8 during fetal and adult life.
Asunto(s)
Linaje de la Célula , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Proteómica , Células Madre Adultas/citología , Células Madre Adultas/metabolismo , Animales , Diferenciación Celular , Feto/citología , Granulocitos/citología , Células HEK293 , Humanos , Inmunofenotipificación , Factores Reguladores del Interferón/metabolismo , Cinética , Células Progenitoras Linfoides/citología , Células Progenitoras Linfoides/metabolismo , Ratones Endogámicos C57BL , Monocitos/citología , Monocitos/metabolismo , Células Progenitoras Mieloides/citología , Células Progenitoras Mieloides/metabolismo , Proteoma/metabolismo , Quinasas Asociadas a rho/antagonistas & inhibidores , Quinasas Asociadas a rho/metabolismoRESUMEN
The ß-catenin/Wnt signaling pathway plays an important role in all stages of T cell development. Nemo-like kinase (NLK) is an evolutionary conserved serine/threonine kinase and a negative regulator of the Wnt signaling pathway. NLK can directly phosphorylate histone deacetylase 1 (HDAC1), as well as T cell factor/lymphoid enhancer-binding factor (TCF/LEF), causing subsequent repression of target gene transcription. By engineering mice lacking NLK in early stages of T cell development, we set out to characterize the role NLK plays in T cell development and found that deletion of NLK does not affect mouse health or lymphoid tissue development. Instead, these mice harbored a reduced number of single-positive (SP) CD8+ thymocytes without any defects in the SP CD4+ thymocyte population. The decrease in SP CD8+ thymocytes was not caused by a block in differentiation from double-positive CD4+CD8+ cells. Neither TCR signaling nor activation was altered in the absence of NLK. Instead, we observed a significant increase in cell death and reduced phosphorylation of LEF1 as well as HDAC1 among NLK-deleted SP CD8+ cells. Thus, NLK seems to play an important role in the survival of CD8+ thymocytes. Our data provide evidence for a new function for NLK with regard to its involvement in T cell development and supporting survival of SP CD8+ thymocytes.
Asunto(s)
Linfocitos T CD8-positivos/fisiología , Proteínas Serina-Treonina Quinasas/metabolismo , Subgrupos de Linfocitos T/fisiología , Timocitos/fisiología , Animales , Diferenciación Celular , Supervivencia Celular , Histona Desacetilasa 1/metabolismo , Activación de Linfocitos , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Proteínas Wnt/metabolismoRESUMEN
Maf transcription factors are critical regulators of beta-cell function. We have previously shown that reduced MafA expression in human and mouse islets is associated with a pro-inflammatory gene signature. Here, we investigate if the loss of Maf transcription factors induced autoimmune processes in the pancreas. Transcriptomics analysis showed expression of pro-inflammatory as well as immune cell marker genes. However, clusters of CD4+ T and B220+ B cells were associated primarily with adult MafA-/-MafB+/-, but not MafA-/- islets. MafA expression was detected in the thymus, lymph nodes and bone marrow suggesting a novel role of MafA in regulating immune-cell function. Analysis of pancreatic lymph node cells showed activation of CD4+ T cells, but lack of CD8+ T cell activation which also coincided with an enrichment of naïve CD8+ T cells. Further analysis of T cell marker genes revealed a reduction of T cell receptor signaling gene expression in CD8, but not in CD4+ T cells, which was accompanied with a defect in early T cell receptor signaling in mutant CD8+ T cells. These results suggest that loss of MafA impairs both beta- and T cell function affecting the balance of peripheral immune responses against islet autoantigens, resulting in local inflammation in pancreatic islets.
Asunto(s)
Regulación de la Expresión Génica , Islotes Pancreáticos/patología , Factores de Transcripción Maf de Gran Tamaño/metabolismo , Factor de Transcripción MafB/metabolismo , Animales , Células Presentadoras de Antígenos/metabolismo , Autoinmunidad , Linfocitos B/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Técnicas de Inactivación de Genes , Inflamación/genética , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/patología , Islotes Pancreáticos/inmunología , Factores de Transcripción Maf de Gran Tamaño/deficiencia , Factores de Transcripción Maf de Gran Tamaño/genética , Factor de Transcripción MafB/deficiencia , Factor de Transcripción MafB/genética , Ratones , Mutación , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de SeñalRESUMEN
Within the hematopoietic system, the Notch pathway is critical for promoting thymic T cell development and suppressing the B and myeloid lineage fates; however, its impact on NK lymphopoiesis is less understood. To study the role of Notch during NK cell development in vivo, we investigated different NK cell compartments and function in Rbp-Jkfl/flVav-Cretg/+ mice, in which Rbp-Jk, the major transcriptional effector of canonical Notch signaling, was specifically deleted in all hematopoietic cells. Peripheral conventional cytotoxic NK cells in Rbp-Jk-deleted mice were significantly reduced and had an activated phenotype. Furthermore, the pool of early NK cell progenitors in the bone marrow was decreased, whereas immature NK cells were increased, leading to a block in NK cell maturation. These changes were cell intrinsic as the hematopoietic chimeras generated after transplantation of Rbp-Jk-deficient bone marrow cells had the same NK cell phenotype as the Rbp-Jk-deleted donor mice, whereas the wild-type competitors did not. The expression of several crucial NK cell regulatory pathways was significantly altered after Rbp-Jk deletion. Together, these results demonstrate the involvement of canonical Notch signaling in regulation of multiple stages of NK cell development.
Asunto(s)
Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/genética , Células Asesinas Naturales/fisiología , Células Progenitoras Linfoides/fisiología , Linfopoyesis , Receptores Notch/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Quimera , Citotoxicidad Inmunológica , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de SeñalRESUMEN
ETV6-RUNX1 is associated with childhood acute B-lymphoblastic leukemia (cALL) functioning as a first-hit mutation that initiates a clinically silent pre-leukemia in utero. Because lineage commitment hierarchies differ between embryo and adult, and the impact of oncogenes is cell-context dependent, we hypothesized that the childhood affiliation of ETV6-RUNX1 cALL reflects its origins in a progenitor unique to embryonic life. We characterize the first emerging B cells in first-trimester human embryos, identifying a developmentally restricted CD19-IL-7R+ progenitor compartment, which transitions from a myeloid to lymphoid program during ontogeny. This developmental series is recapitulated in differentiating human pluripotent stem cells (hPSCs), thereby providing a model for the initiation of cALL. Genome-engineered hPSCs expressing ETV6-RUNX1 from the endogenous ETV6 locus show expansion of the CD19-IL-7R+ compartment, show a partial block in B lineage commitment, and produce proB cells with aberrant myeloid gene expression signatures and potential: features (collectively) consistent with a pre-leukemic state.
Asunto(s)
Linfocitos B/patología , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Desarrollo Embrionario , Regulación Leucémica de la Expresión Génica , Células Madre Pluripotentes Inducidas/patología , Células Mieloides/patología , Proteínas de Fusión Oncogénica/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Enfermedad Aguda , Linfocitos B/metabolismo , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Femenino , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Modelos Biológicos , Células Mieloides/metabolismo , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Embarazo , Primer Trimestre del Embarazo , Receptores de Interleucina-7 , TranscriptomaRESUMEN
Given that FLT3 expression is highly restricted on lymphoid progenitors, it is possible that the established role of FLT3 in the regulation of B and T lymphopoiesis reflects its high expression and role in regulation of lymphoid-primed multipotent progenitors (LMPPs) or common lymphoid progenitors (CLPs). We generated a Flt3 conditional knock-out (Flt3fl/fl) mouse model to address the direct role of FLT3 in regulation of lymphoid-restricted progenitors, subsequent to turning on Rag1 expression, as well as potentially ontogeny-specific roles in B and T lymphopoiesis. Our studies establish a prominent and direct role of FLT3, independently of the established role of FLT3 in regulation of LMPPs and CLPs, in regulation of fetal as well as adult early B cell progenitors, and the early thymic progenitors (ETPs) in adult mice but not in the fetus. Our findings highlight the potential benefit of targeting poor prognosis acute B-cell progenitor leukaemia and ETP leukaemia with recurrent FLT3 mutations using clinical FLT3 inhibitors.
Asunto(s)
Células de la Médula Ósea/metabolismo , Diferenciación Celular , Células Progenitoras Linfoides/metabolismo , Linfopoyesis , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Células de la Médula Ósea/patología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Progenitoras Linfoides/patología , Ratones , Ratones Noqueados , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Timo/metabolismo , Timo/patología , Tirosina Quinasa 3 Similar a fms/genéticaRESUMEN
BACKGROUND: Mesenchymal stromal cells (MSCs) are currently being evaluated in numerous pre-clinical and clinical cell-based therapy studies. Furthermore, there is an increasing interest in exploring alternative uses of these cells in disease modelling, pharmaceutical screening, and regenerative medicine by applying reprogramming technologies. However, the limited availability of MSCs from various sources restricts their use. Term amniotic fluid has been proposed as an alternative source of MSCs. Previously, only low volumes of term fluid and its cellular constituents have been collected, and current knowledge of the MSCs derived from this fluid is limited. In this study, we collected amniotic fluid at term using a novel collection system and evaluated amniotic fluid MSC content and their characteristics, including their feasibility to undergo cellular reprogramming. METHODS: Amniotic fluid was collected at term caesarean section deliveries using a closed catheter-based system. Following fluid processing, amniotic fluid was assessed for cellularity, MSC frequency, in-vitro proliferation, surface phenotype, differentiation, and gene expression characteristics. Cells were also reprogrammed to the pluripotent stem cell state and differentiated towards neural and haematopoietic lineages. RESULTS: The average volume of term amniotic fluid collected was approximately 0.4 litres per donor, containing an average of 7 million viable mononuclear cells per litre, and a CFU-F content of 15 per 100,000 MNCs. Expanded CFU-F cultures showed similar surface phenotype, differentiation potential, and gene expression characteristics to MSCs isolated from traditional sources, and showed extensive expansion potential and rapid doubling times. Given the high proliferation rates of these neonatal source cells, we assessed them in a reprogramming application, where the derived induced pluripotent stem cells showed multigerm layer lineage differentiation potential. CONCLUSIONS: The potentially large donor base from caesarean section deliveries, the high yield of term amniotic fluid MSCs obtainable, the properties of the MSCs identified, and the suitability of the cells to be reprogrammed into the pluripotent state demonstrated these cells to be a promising and plentiful resource for further evaluation in bio-banking, cell therapy, disease modelling, and regenerative medicine applications.
Asunto(s)
Líquido Amniótico/citología , Tratamiento Basado en Trasplante de Células y Tejidos , Reprogramación Celular , Células Madre Mesenquimatosas/citología , Adipogénesis , Adhesión Celular , Diferenciación Celular , Línea Celular , Linaje de la Célula , Proliferación Celular , Separación Celular , Células Epiteliales/citología , Femenino , Fibroblastos/citología , Hematopoyesis , Humanos , Recién Nacido , Neuronas/citología , Osteogénesis , Células Madre Pluripotentes/citología , EmbarazoRESUMEN
Hematopoietic stem cells (HSCs) undergo a functional switch in neonatal mice hallmarked by a decrease in self-renewing divisions and entry into quiescence. Here, we investigated whether the developmental attenuation of B-1a cell output is a consequence of a shift in stem cell state during ontogeny. Using cellular barcoding for in vivo single-cell fate analyses, we found that fetal liver definitive HSCs gave rise to both B-1a and B-2 cells. Whereas B-1a potential diminished in all HSCs with time, B-2 output was maintained. B-1a and B-2 plasticity could be reinitiated in a subset of adult HSCs by ectopic expression of the RNA binding protein LIN28B, a key regulator of fetal hematopoiesis, and this coincided with the clonal reversal to fetal-like elevated self-renewal and repopulation potential. These results anchor the attenuation of B-1a cell output to fetal HSC behavior and demonstrate that the developmental decline in regenerative potential represents a reversible HSC state.
Asunto(s)
Linfocitos B/fisiología , Proteínas de Unión al ADN/metabolismo , Células Madre Hematopoyéticas/fisiología , Hígado/fisiología , Subgrupos Linfocitarios/fisiología , Animales , Animales Recién Nacidos , Diferenciación Celular/genética , Plasticidad de la Célula , Autorrenovación de las Células , Células Clonales , Proteínas de Unión al ADN/genética , Femenino , Hematopoyesis/genética , Inmunofenotipificación , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas de Unión al ARN , Análisis de la Célula IndividualRESUMEN
Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported.
Asunto(s)
Linaje de la Célula/fisiología , Feto/metabolismo , Linfopoyesis/fisiología , Células Precursoras de Linfocitos B/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Animales , Feto/citología , Ratones , Ratones Noqueados , Células Precursoras de Linfocitos B/citología , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genéticaRESUMEN
According to current models of hematopoiesis, lymphoid-primed multi-potent progenitors (LMPPs) (Lin(-)Sca-1(+)c-Kit(+)CD34(+)Flt3(hi)) and common myeloid progenitors (CMPs) (Lin(-)Sca-1(+)c-Kit(+)CD34(+)CD41(hi)) establish an early branch point for separate lineage-commitment pathways from hematopoietic stem cells, with the notable exception that both pathways are proposed to generate all myeloid innate immune cell types through the same myeloid-restricted pre-granulocyte-macrophage progenitor (pre-GM) (Lin(-)Sca-1(-)c-Kit(+)CD41(-)FcγRII/III(-)CD150(-)CD105(-)). By single-cell transcriptome profiling of pre-GMs, we identified distinct myeloid differentiation pathways: a pathway expressing the gene encoding the transcription factor GATA-1 generated mast cells, eosinophils, megakaryocytes and erythroid cells, and a pathway lacking expression of that gene generated monocytes, neutrophils and lymphocytes. These results identify an early hematopoietic-lineage bifurcation that separates the myeloid lineages before their segregation from other hematopoietic-lineage potential.
Asunto(s)
Diferenciación Celular , Linaje de la Célula , Linfocitos/fisiología , Células Mieloides/fisiología , Células Progenitoras Mieloides/fisiología , Animales , Antígenos CD/metabolismo , Células Cultivadas , Biología Computacional , Factor de Transcripción GATA1/genética , Factor de Transcripción GATA1/metabolismo , Hematopoyesis , Inmunidad Innata , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Análisis de Matrices Tisulares , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
Natural killer (NK) cells are cytotoxic lymphocytes and play a vital role in controlling viral infections and cancer. In contrast to B and T lymphopoiesis where cellular and regulatory pathways have been extensively characterized, the cellular stages of early human NK cell commitment remain poorly understood. Here we demonstrate that a Lin(-)CD34(+)CD38(+)CD123(-)CD45RA(+)CD7(+)CD10(+)CD127(-) population represents a NK lineage-restricted progenitor (NKP) in fetal development, umbilical cord blood, and adult tissues. The newly identified NKP has robust NK cell potential both in vitro and in vivo, generates functionally cytotoxic NK cells, and lacks the ability to produce T cells, B cells, myeloid cells, and innate lymphoid-like cells (ILCs). Our findings identify an early step to human NK cell commitment and provide new insights into the human hematopoietic hierarchy.
Asunto(s)
Sangre Fetal/citología , Feto/citología , Hematopoyesis , Células Asesinas Naturales/fisiología , Células Progenitoras Linfoides/fisiología , Adulto , Antígenos CD/metabolismo , Diferenciación Celular , Linaje de la Célula , Citotoxicidad Inmunológica , Desarrollo Fetal , Hematopoyesis/inmunología , Humanos , Inmunidad Innata , InmunofenotipificaciónRESUMEN
Bone marrow-derived natural killer (NK) cells constitute the major subset of cytotoxic lymphocytes in peripheral blood. They provide innate defense against intracellular infection or malignancy and contribute to immune homeostasis. Large numbers of NK cells are also present in tissues, including the liver and uterus, where they can mediate immunosurveillance but also play important roles in tissue remodeling and vascularization. Here, we review the pathways involved in NK cell lineage commitment and differentiation, discussing relationships to other lymphocyte populations and highlighting genetic determinants. Characterizing NK cells from distinct tissues and during infections have revealed subset specializations, reflecting inherent cellular plasticity. In this context, we discuss how different environmental and inflammatory stimuli may shape NK cells. Particular emphasis is placed on genes identified as being critical for NK cell development, differentiation, and function from studies of model organisms or associations with disease. Such studies are also revealing important cellular redundancies. Here, we provide a view of the genetic framework constraining NK cell development and function, pinpointing molecules required for these processes but also underscoring plasticity and redundancy that may underlie robust immunological function. With this view, built in redundancy may highlight the importance of NK cells to immunity.
Asunto(s)
Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Animales , Diferenciación Celular/inmunología , Humanos , Inmunidad/fisiología , Células Asesinas Naturales/citologíaRESUMEN
In jawed vertebrates, development of an adaptive immune-system is essential for protection of the born organism against otherwise life-threatening pathogens. Myeloid cells of the innate immune system are formed early in development, whereas lymphopoiesis has been suggested to initiate much later, following emergence of definitive hematopoietic stem cells (HSCs). Herein, we demonstrate that the embryonic lymphoid commitment process initiates earlier than previously appreciated, prior to emergence of definitive HSCs, through establishment of a previously unrecognized entirely immune-restricted and lymphoid-primed progenitor. Notably, this immune-restricted progenitor appears to first emerge in the yolk sac and contributes physiologically to the establishment of lymphoid and some myeloid components of the immune-system, establishing the lymphomyeloid lineage restriction process as an early and physiologically important lineage-commitment step in mammalian hematopoiesis.
Asunto(s)
Células Madre Hematopoyéticas/citología , Animales , Diferenciación Celular/fisiología , Células Cultivadas , Femenino , Regulación del Desarrollo de la Expresión Génica/genética , Regulación del Desarrollo de la Expresión Génica/fisiología , Células Madre Hematopoyéticas/metabolismo , Linfocitos/citología , Linfocitos/metabolismo , Masculino , Ratones , Células Mieloides/citología , Células Mieloides/metabolismo , Reacción en Cadena de la PolimerasaRESUMEN
Whether signals mediated via growth factor receptors (GFRs) might influence lineage fate in multipotent progenitors (MPPs) is unclear. We explored this issue in a mouse knockin model of gain-of-function Flt3-ITD mutation because FLT3-ITDs are paradoxically restricted to acute myeloid leukemia even though Flt3 primarily promotes lymphoid development during normal hematopoiesis. When expressed in MPPs, Flt3-ITD collaborated with Runx1 mutation to induce high-penetrance aggressive leukemias that were exclusively of the myeloid phenotype. Flt3-ITDs preferentially expanded MPPs with reduced lymphoid and increased myeloid transcriptional priming while compromising early B and T lymphopoiesis. Flt3-ITD-induced myeloid lineage bias involved upregulation of the transcription factor Pu.1, which is a direct target gene of Stat3, an aberrantly activated target of Flt3-ITDs, further establishing how lineage bias can be inflicted on MPPs through aberrant GFR signaling. Collectively, these findings provide new insights into how oncogenic mutations might subvert the normal process of lineage commitment and dictate the phenotype of resulting malignancies.
Asunto(s)
Leucemia Mieloide Aguda/patología , Células Madre Multipotentes/citología , Células Mieloides/citología , Tirosina Quinasa 3 Similar a fms/fisiología , Animales , Diferenciación Celular/fisiología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Modelos Animales de Enfermedad , Citometría de Flujo/métodos , Expresión Génica , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Ratones , Análisis por Micromatrices , Células Madre Multipotentes/inmunología , Células Madre Multipotentes/metabolismo , Células Madre Multipotentes/patología , Células Mieloides/inmunología , Células Mieloides/metabolismo , Células Mieloides/patología , Transducción de Señal , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
Formation of the hematopoietic stem cell (HSC) niche in bone marrow (BM) is tightly associated with endochondral ossification, but little is known about the mechanisms involved. We used the oc/oc mouse, a mouse model with impaired endochondral ossification caused by a loss of osteoclast (OCL) activity, to investigate the role of osteoblasts (OBLs) and OCLs in the HSC niche formation. The absence of OCL activity resulted in a defective HSC niche associated with an increased proportion of mesenchymal progenitors but reduced osteoblastic differentiation, leading to impaired HSC homing to the BM. Restoration of OCL activity reversed the defect in HSC niche formation. Our data demonstrate that OBLs are required for establishing HSC niches and that osteoblastic development is induced by OCLs. These findings broaden our knowledge of the HSC niche formation, which is critical for understanding normal and pathological hematopoiesis.
Asunto(s)
Células Madre Hematopoyéticas/fisiología , Osteoclastos/fisiología , Nicho de Células Madre/fisiología , Animales , Secuencia de Bases , Células de la Médula Ósea/citología , Células de la Médula Ósea/fisiología , Diferenciación Celular/fisiología , Movimiento Celular/fisiología , Cartilla de ADN/genética , Femenino , Hematopoyesis/fisiología , Células Madre Hematopoyéticas/citología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Osteoblastos/citología , Osteoblastos/fisiología , Osteoclastos/citología , Osteogénesis/fisiología , Osteopetrosis/genética , Osteopetrosis/patología , Osteopetrosis/fisiopatología , Fenotipo , Embarazo , ATPasas de Translocación de Protón Vacuolares/genética , ATPasas de Translocación de Protón Vacuolares/fisiologíaRESUMEN
The earliest stages of natural killer (NK)-cell development are not well characterized. In this study, we investigated in different fetal hematopoietic tissues how NK-cell progenitors and their mature NK-cell progeny emerge and expand during fetal development. Here we demonstrate, for the first time, that the counterpart of adult BM Lin(-)CD122(+)NK1.1(-)DX5(-) NK-cell progenitor (NKP) emerges in the fetal liver at E13.5. After NKP expansion, immature NK cells emerge at E14.5 in the liver and E15.5 in the spleen. Thymic NK cells arise at E15.5, whereas functionally competent cytotoxic NK cells were present in the liver and spleen at E16.5 and E17.5, respectively. Fetal NKPs failed to produce B and myeloid cells but sustained combined NK- and T-lineage potential at the single-cell level. NKPs were also found in the fetal blood, spleen, and thymus. These findings show the emergence and expansion of bipotent NK/T-cell progenitor during fetal and adult lymphopoiesis, further supporting that NK/T-lineage restriction is taking place prethymically. Uncovering the earliest NK-cell developmental stages will provide important clues, helping to understand the origin of diverse NK-cell subsets, their progenitors, and key regulators.