This SuperSeries is composed of the SubSeries listed below.
Transcriptional reprogramming of CD11b+Esam(hi) dendritic cell identity and function by loss of Runx3.
Sex, Age, Specimen part
View SamplesCD4+ dendritic cells are part of the innate immunity essential for priming and activating of CD4+ T cells
Transcriptional reprogramming of CD11b+Esam(hi) dendritic cell identity and function by loss of Runx3.
Sex, Age
View SamplesEsam/CD4+ dendritic cells are part of the innate immunity essential for priming and activating of CD4+ T cells
Transcriptional reprogramming of CD11b+Esam(hi) dendritic cell identity and function by loss of Runx3.
Sex, Age
View SamplesMiRNAs have the potential to regulate cellular differentiation programs. However, miRNA-deficiency in primary hematopoietic stem cells (HSCs) results in HSC depletion in mice, leaving the question of whether miRNAs play a role in early-lineage decisions unanswered. To address this issue, we deleted Dicer1, which encodes an essential RNaseIII enzyme for miRNA biogenesis, in murine CCAAT/enhancer-binding protein alpha (C/EBPA)-positive myeloid-committed progenitors in vivo. In contrast to the results in HSCs, we found that miRNA depletion affected neither the number of myeloid progenitors nor the percentage of C/EBPA-positive progenitor cells. Analysis of gene-expression profiles from wild type and Dicer1-deficient granulocyte-macrophage progenitors (GMPs) revealed that 20 miRNA families were active in GMPs. Of the derepressed miRNA targets in Dicer1-null GMPs, 27% are normally exclusively expressed in HSCs or are specific for multi-potent progenitors and erythropoiesis, indicating an altered gene-expression landscape. Dicer1-deficient GMPs were defective in myeloid development in vitro and exhibited an increased replating capacity, indicating a regained self-renewal potential of these cells. In mice, Dicer1 deletion blocked monocytic differentiation, depleted macrophages and caused myeloid dysplasia with morphological features of Pelger-Hut anomaly. These results provide evidence for a miRNA-controlled switch for a cellular program of self-renewal and expansion towards myeloid differentiation in GMPs.
Dicer1 deletion in myeloid-committed progenitors causes neutrophil dysplasia and blocks macrophage/dendritic cell development in mice.
Specimen part
View SamplesC/EBPalpha is a transcription factor critically involved in myeloid development and indispensable for formation of granulocytes. To track the cellular fate of stem and progenitor (LSK) cells, which express C/EBPalpha, we developed a mouse model expressing Cre recombinase from the Cebpa promoter and an inducible EYFP allele. We show that Cebpa/EYFP+ cells represent a significant subset of LSK cells, which predominantly give rise to myeloid cells in steady state hematopoiesis.
Lineage-instructive function of C/EBPα in multipotent hematopoietic cells and early thymic progenitors.
Specimen part
View SamplesTo identify cellular and genetic abnormalities involved in interstrand cross link repair-deficient bone marrow failure and its transformation to leukemia, we used an Ercc1 hypomorphic mouse model (Ercc1 -/d).
ICL-induced miR139-3p and miR199a-3p have opposite roles in hematopoietic cell expansion and leukemic transformation.
Age, Specimen part
View SamplesRegulatory T cells (Tregs) expressing the transcription factor Foxp3 have a pivotal role in maintaining immunological self-tolerance1-5; yet, excessive Treg activities suppress anti-tumor immune responses6-8. Compared to resting phenotype Tregs (rTregs) in the secondary lymphoid organs, Tregs in non-lymphoid tissues including solid tumors exhibit an activated Treg (aTreg) phenotype9-11. However, aTreg function and whether its generation can be manipulated to promote tumor immunity without evoking autoimmunity are largely unexplored. Here we show that the transcription factor Foxo1, previously demonstrated to promote Treg suppression of lymphoproliferative diseases12,13, has an unexpected function in inhibiting aTreg-mediated immune tolerance. We found that aTregs turned over at a slower rate than rTregs, but were not locally maintained in tissues. Transcriptome analysis revealed that aTreg differentiation was associated with repression of Foxo1-dependent gene transcription, concomitant with reduced Foxo1 expression, cytoplasmic Foxo1 localization, and enhanced Foxo1 phosphorylation at sites of the Akt kinase. Treg-specific expression of an Akt-insensitive Foxo1 mutant prevented downregulation of lymphoid organ homing molecules, and impeded Treg homing to non-lymphoid organs, causing CD8+ T cell-mediated autoimmune diseases. Compared to Tregs from healthy tissues, tumor-infiltrating Tregs downregulated Foxo1 target genes more substantially. Expression of the Foxo1 mutant at a lower dose was sufficient to deplete tumor-associated Tregs, activate effector CD8+ T cells, and inhibit tumor growth without inflicting autoimmunity. Thus, Foxo1 inactivation is essential for the migration of aTregs that have a crucial function in suppressing CD8+ T cell responses; and the Foxo signaling pathway in Tregs can be titrated to preferentially break tumor immune tolerance. Overall design: Transcriptome of splenic rTreg (CD4+Foxp3+CD62LhiCD44lo) and aTreg (CD4+Foxp3+CD62LhiCD44lo) were compared. Duplicates from biologically independent animials were used.
Graded Foxo1 activity in Treg cells differentiates tumour immunity from spontaneous autoimmunity.
Specimen part, Subject
View SamplesThe Early Growth Response (Egr) family of transcription factors consists of 4 members (Egr1-4) that are expressed in a wide variety of cell types. A large body of evidence point to a role for Egr transcription factors in growth, survival, and differentiation. A major unanswered question is whether Egr transcription factors serve similar functions in diverse cell types by activating a common set of target genes. Signal transduction cascades in neurons and lymphocytes show striking parallels. Activation of either cell type activates the Ras-MAPK pathway and, in parallel, leads to increases in intracellular calcium stimulating the calcineurin-NFAT pathway. In both cell types, the strength of the activation signal affects the cellular outcomes and very strong stimuli lead to cell death. Notably both these pathways converge on the induction of Egr genes. We believe that downstream targets of Egr transcription factors in lymphocytes may also be activated by Egr factors in activated neurons. There is precedence for common target gene activation in these two cell types: apoptosis in both activated T cells and methamphetamine stimulated neurons occurs via FasL induction by NFAT transcription factors. We propose to use developing T lymphocytes (thymocytes) as a model system for discovery of Egr-dependent target genes for several reasons. First, we have observed a prominent survival defect in thymocytes from mice deficient in both Egr1 and Egr3 (1/3 DKO) and a partial differention block in the immature double negative (DN) stage. In addition, thymocytes are an easily manipulatable cell type, and the DN subpopulation affected in 1/3 DKO mice can be isolated to very high purity. We anticipate that 1/3 DKO thymocytes will provide an excellent experimental system that will provide insight into Egr-dependent transcription in neuronal development, activation, and death.
Redundant role for early growth response transcriptional regulators in thymocyte differentiation and survival.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Comparative Transcriptome Profiling Reveals Coding and Noncoding RNA Differences in NSCLC from African Americans and European Americans.
Sex, Age, Specimen part, Disease, Race, Subject
View SamplesTranslational Relevance
Comparative Transcriptome Profiling Reveals Coding and Noncoding RNA Differences in NSCLC from African Americans and European Americans.
Sex, Age, Race, Subject
View Samples