This SuperSeries is composed of the SubSeries listed below.
No associated publication
Specimen part
View SamplesRetinoblastoma-1 (RB1), and the RB1-related proteins p107 and p130, reside at a central node in the cell cycle regulatory network. RB1 is required for normal erythroid development in vitro, but is largely dispensable for erythropoiesis in vivo. The modest phenotype caused by RB1 deficiency in mice raises questions about redundancy within the RB1 family, and the role of RB1 in erythroid differentiation. Here we show that RB1 is the major pocket protein that regulates terminal erythroid differentiation. Erythroid cells lacking all pocket proteins exhibit the same cell cycle defects as those deficient for RB1 alone. Further, we show that RB1 broadly represses gene expression in erythroid cells, coincident with the transition from precursor to terminally differentiated cell. RB1-repressed genes are well expressed but downregulated at the final stage of erythroid development. By merging differential and time-dependent changes in expression, we define a group of approximately 800 RB1-repressed genes. As anticipated, these genes are enriched for terms such as cell cycle and DNA metabolic process, but also for terms such as mRNA processing, chromosome organization, and ubiquitin-mediated protein catabolic pro-cess. Our results suggest that RB1-mediated repression of genes involved in noncanonical processes has a central role in terminal erythroid differentiation.
No associated publication
Specimen part
View SamplesRetinoblastoma-1 (RB1), and the RB1-related proteins p107 and p130, reside at a central node in the cell cycle regulatory network. RB1 is required for normal erythroid development in vitro, but is largely dispensable for erythropoiesis in vivo. The modest phenotype caused by RB1 deficiency in mice raises questions about redundancy within the RB1 family, and the role of RB1 in erythroid differentiation. Here we show that RB1 is the major pocket protein that regulates terminal erythroid differentiation. Erythroid cells lacking all pocket proteins exhibit the same cell cycle defects as those deficient for RB1 alone. Further, we show that RB1 broadly represses gene expression in erythroid cells, coincident with the transition from precursor to terminally differentiated cell. RB1-repressed genes are well expressed but downregulated at the final stage of erythroid development. By merging differential and time-dependent changes in expression, we define a group of approximately 800 RB1-repressed genes. As anticipated, these genes are enriched for terms such as cell cycle and DNA metabolic process, but also for terms such as mRNA processing, chromosome organization, and ubiquitin-mediated protein catabolic pro-cess. Our results suggest that RB1-mediated repression of genes involved in noncanonical processes has a central role in terminal erythroid differentiation.
No associated publication
Specimen part
View SamplesLong recognized as an evolutionarily ancient cell type involved in tissue homeostasis and immune defense against pathogens, macrophages are being rediscovered as regulators of several diseases including cancer. Here we show that in mice, mammary tumor growth induces the accumulation of tumor-associated macrophages (TAMs) that are phenotypically and functionally distinct from mammary tissue macrophages (MTMs). TAMs express the adhesion molecule Vcam1 and proliferate upon their differentiation from inflammatory monocytes, but do not exhibit an alternatively activated phenotype. TAM differentiation depends on the transcriptional regulator of Notch signaling, RBPJ; and TAM, but not MTM, depletion restores tumor-infiltrating cytotoxic T cell responses and suppresses tumor growth. These findings reveal the ontogeny of TAMs and a discrete tumor-elicited inflammatory response, which may provide new opportunities for cancer immunotherapy.
The cellular and molecular origin of tumor-associated macrophages.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The transcription factor Foxo1 controls central-memory CD8+ T cell responses to infection.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Novel Foxo1-dependent transcriptional programs control T(reg) cell function.
Specimen part
View SamplesMemory T cells provide immunity against pathogen reinvasion, but mechanisms of their long-term maintenance is unclear. Here we show that mice with the deletion of the transcription factor Foxo1 in activated CD8+ T cells had defective secondary but not primary responses to Listeria monocytogenes infection. Compared to short-lived effector T cells, memory precursor effector T cells expressed higher amounts of Foxo1 that promoted their generation and maintenance. Gene expression profiling and chromatin immunoprecipitation sequencing experiments revealed the chemokine receptor CCR7 and the transcription factor TCF1 as novel Foxo1-bound target genes with critical functions in memory T cell trafficking and transcriptional regulation. These findings demonstrate that Foxo1 is selectively incorporated into the genetic program that regulates memory but not effector CD8+ T cell responses to infection.
The transcription factor Foxo1 controls central-memory CD8+ T cell responses to infection.
Specimen part
View SamplesRegulatory T (Treg) cells characterized by expression of the transcription factor forkhead box P3 (Foxp3) maintain immune homeostasis by suppressing self-destructive immune responses1-4. Foxp3 operates as a late acting differentiation factor controlling Treg cell homeostasis and function5, whereas the early Treg cell lineage commitment is regulated by the Akt kinase and the forkhead box O (Foxo) family of transcription factors6-10. However, whether Foxo proteins act beyond the Treg cell commitment stage to control Treg cell homeostasis and function remains largely unexplored. Here we show that Foxo1 is a pivotal regulator of Treg cell function. Treg cells express high amounts of Foxo1, and display reduced T-cell receptor-induced Akt activation, Foxo1 phosphorylation, and Foxo1 nuclear exclusion. Mice with Treg cell-specific deletion of Foxo1 develop a fatal inflammatory disorder similar in severity to Foxp3-deficient mice, but without the loss of Treg cells. Genome-wide analysis of Foxo1 binding sites reveals ~300 Foxo1-bound target genes, including the proinflammatory cytokine Ifng, that do not appear to be directly regulated by Foxp3. These findings demonstrate that the evolutionarily ancient Akt-Foxo1 signaling module controls a novel genetic program indispensable for Treg cell function.
Novel Foxo1-dependent transcriptional programs control T(reg) cell function.
Specimen part
View SamplesThe organs of multicellular species are comprised of cell types that must function together to perform specific tasks. One critical organ function is responding to internal or external change but little is known about how responses are tailored to specific cell types or coordinated among them on a global level. Here we use cellular profiling of five Arabidopsis root cell types in response to a limiting resource, nitrogen, to uncover a vast and predominantly cell-specific response that was largely undetectable using traditional methods. These methods reveal a new class of cell-specific nitrogen responses. As a proof-of-principle, we dissected one cell-specific response circuit that mediates nitrogen-induced changes in root branching from pericycle cells. Thus, cellular response profiling links gene modules to discrete functions in specific cell types.
Cell-specific nitrogen responses mediate developmental plasticity.
Specimen part
View SamplesTo identify potential transient interactions between a TF and its targets, we developed an approach that can identify primary targets based either on TF-induced regulation or TF-binding, assayed in the same samples. Our studies focused on the TF bZIP1 (BASIC LEUCINE ZIPPER 1), a central integrator of cellular and metabolic signaling.
Hit-and-run transcriptional control by bZIP1 mediates rapid nutrient signaling in Arabidopsis.
No sample metadata fields
View Samples