This SuperSeries is composed of the SubSeries listed below.
An integrated approach to dissecting oncogene addiction implicates a Myb-coordinated self-renewal program as essential for leukemia maintenance.
Specimen part, Treatment
View SamplesTo explore oncogene addiction programs in a genetically defined leukemia context we developed an AML mouse model driven by a conditional MLL-AF9 allele together with oncogenic Ras, which enabled us to examine the consequences of MLL-AF9 inhibition in established disease. In order to produce a tightly regulated system that was easy to monitor, we constructed two retroviral vectors containing dsRed-linked MLL-AF9 under control of a tetracycline response element promoter, and KrasG12D or NrasG12D linked to the Tet-off tet-transactivator, which activates TRE expression in a doxycycline repressible manner. Leukemias were generated by retroviral cotransduction of both vectors into hematopoietic stem and progenitor cells, which were transplanted into syngeneic mice. Cells harboring both constructs induced aggressive myelomonocytic leukemia. Five independent primary leukemia cell lines were established from bone marrow of terminal mice. Treatment of these lines with doxycycline rapidly turned off MLL-AF9 expression, and induced terminal myeloid differentiation and complete disease remission in vivo.
An integrated approach to dissecting oncogene addiction implicates a Myb-coordinated self-renewal program as essential for leukemia maintenance.
Specimen part, Treatment
View SamplesUsing an integrative approach combining a Tet-off conditional AML mouse model, global expression profiling following suppression of the driving MLL-AF9 oncogene, and a new Tet-on conditional shRNA expression system we have identified Myb as critical mediator of addiction to MLL-AF9. Suppression of Myb in established AML in vivo terminates aberrant self-renewal and triggers a terminal myeloid differentiation program that precisely phenocopies the effects of suppressing MLL-AF9. Remarkably, suppressing Myb effectively eradicates aggressive and chemotherapy resistant AML.
An integrated approach to dissecting oncogene addiction implicates a Myb-coordinated self-renewal program as essential for leukemia maintenance.
Specimen part
View SamplesGene expression profile of joint tissue from C3H and interval specific congenic mouse lines (ISCL) following infection with Borrelia burgdorferi
Interval-specific congenic lines reveal quantitative trait Loci with penetrant lyme arthritis phenotypes on chromosomes 5, 11, and 12.
Specimen part
View SamplesThe major myeloid blood cell lineages, including erythrocytes, platelets, granulocytes and macrophages, are generated from hematopoietic stem cells (HSC) by differentiation through a series of increasingly more committed progenitor cells. Precise phenotypic identification and functional characterization of such intermediate progenitors has important consequences for understanding fundamental differentiation processes and is clinically relevant since such events become dysregulated in various disease settings, including leukemia. While previous studies have suggested a hierarchy for myeloid differentiation involving a common progenitor through which all myeloid lineages are derived, several recent studies have suggested that such a developmental intermediate might not be an absolute requirement. Here, we evaluated the functional in vitro and in vivo potentials of a range of prospectively isolated myeloid precursors with differential expression of CD150, Endoglin and CD41. Our studies reveal a complex hierarchy of myeloerythroid progenitors with distinct and developmentally restricted lineage potentials. Global gene expression signatures of these cellular subsets revealed expression patterns consistent with their functional capacities, while hierarchical clustering analysis provides details on their lineage relationships. These data challenge existing models of hematopoietic differentiation, by suggesting that progenitors of the innate and adaptive immune system in the adult separate late, and to a large extent, following the divergence of megakaryocytic/erythroid potential.
Elucidation of the phenotypic, functional, and molecular topography of a myeloerythroid progenitor cell hierarchy.
No sample metadata fields
View SamplesGene expression profiling using microarray has been limited to profiling of differentially expressed genes at comparison setting since probesets for different genes have different sensitivities. We overcome this limitation by using a very large number of varied microarray datasets as a common reference, so that statistical attributes of each probeset, such as dynamic range or a threshold between low and high expression can be reliably discovered through meta-analysis. This strategy is implemented in web-based platform named Gene Expression Commons (http://gexc.stanford.edu/ ) with datasets of 39 distinct highly purified mouse hematopoietic stem/progenitor/functional cell populations covering almost the entire hematopoietic system. Since the Gene Expression Commons is designed as an open platform, any scientist can explore gene expression of any gene, search by expression pattern of interest, submit their own microarray datasets, and design their own working models.
Gene Expression Commons: an open platform for absolute gene expression profiling.
Sex, Age
View SamplesAlthough mast cells elicit proinflammatory and type I IFN responses upon VSV infection, in response to L.monocytogenes (L.m) or S. Typhimurium (S.t), such cells elicit a transcriptional program devoid of type I IFN response.
Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria.
Specimen part
View SamplesLactobacilli are probiotics that, among other health promoting effects, have been ascribed immunostimulating and virus preventive properties. Certain lactobacilli species have been shown to possess strong IL-12 inducing properties. As IL-12 production depends on the up-regulation of type I interferons, we hypothesized that the strong IL-12 inducing capacity of L. acidophilus NCFM in murine bone marrow derived DC is caused by an up-regulation of IFN-, which subsequently stimulates the induction of IL-12 and the dsRNA binding toll like receptor (TLR)-3. The expression of the genes encoding IFN-, IL-12, IL-10 and TLR-3 in DC upon stimulation with L. acidophilus NCFM was measured. L. acidophilus NCFM induced a much stronger expression of ifn-, il-12 and il-10 compared to the synthetic dsRNA ligand Poly I:C, whereas the levels of expressed tlr-3 were similar. By the use of whole genome microarray gene expression, we investigated whether other genes related to the viral defence were up-regulated in DC upon stimulation with L. acidophilus NCFM and found that various virus defence related genes, both early and late, were among the strongest up-regulated genes. The IFN- stimulating capability was also detected in another L. acidophilus strain, but was not a property of other probiotic bacteria tested (B. bifidum and E. coli nissle).The IFN- inducing capacity was markedly reduced in TLR-2 -/- DCs, dependent on endocytosis and the major cause of the induction of il-12 and tlr-3 in L. acidophilus NCFM stimulated cells. Collectively, our results reveal that certain lactobacilli trigger the expression of viral defence genes in DC in a TLR-2 manner through induction of IFN- .
Lactobacillus acidophilus induces virus immune defence genes in murine dendritic cells by a Toll-like receptor-2-dependent mechanism.
Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic chromatin states uniquely define the developmental plasticity of murine hematopoietic stem cells.
Specimen part
View SamplesAn investigation of the global gene expression signatures of murine hematopoietic stem cell differentiation during steady state hematopoiesis.
Epigenetic chromatin states uniquely define the developmental plasticity of murine hematopoietic stem cells.
Specimen part
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