To examine the impact of tumors on the immune system, we compared global gene expression profiles of peripheral blood T cells from previously untreated patients with B cell chronic lymphocytic leukemia (CLL) with those from age-matched healthy donors. Although the cells analyzed were not part of the malignant clone, analysis revealed differentially expressed genes, mainly involved in cell differentiation in CD4 cells and defects in cytoskeleton formation, vesicle trafficking, and cytotoxicity in CD8 cells of the CLL patients. In coculture experiments using CLL cells and T cells from healthy allogeneic donors, similar defects developed in both CD4 and CD8 cells. These changes were induced only with direct contact and were not cytokine mediated. Identification of the specific pathways perturbed in the T cells of cancer-bearing patients will allow us to assess steps to repair these defects, which will likely be required to enhance antitumor immunity.
Chronic lymphocytic leukemia cells induce changes in gene expression of CD4 and CD8 T cells.
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View SamplesImmune deficiency is common in cancer, but the biological basis for this and ways to reverse it remains elusive. Here we present a mouse model of B cell chronic lymphocytic leukemia (CLL) that recapitulates changes in the non-malignant circulating T cells seen in patients with this illness.1 To validate this model, we examined changes in T cell gene expression, protein expression and function in Em-TCL1 transgenic mice as they developed CLL 2,3 and demonstrate that development of CLL in these transgenic mice is associated with changes in impaired T cell function and in gene expression in CD4 and CD8 T cells similar to those observed in patients with this disease. Infusion of CLL cells into non-leukemia bearing Em-TCL1 mice rapidly induces these changes, demonstrating a causal relationship between leukemia and the induction of T cell changes. This model allows dissection of the molecular changes induced in CD4 and CD8 T cells by interaction with leukemia cells and further supports the concept that cancer results in complex abnormalities in the immune microenvironment.
E(mu)-TCL1 mice represent a model for immunotherapeutic reversal of chronic lymphocytic leukemia-induced T-cell dysfunction.
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View SamplesThe maintenance of immune homeostasis requires regulatory T cells (Tregs). Given their intrinsic self-reactivity, Tregs must stably maintain a suppressive phenotype to avoid autoimmunity. We report that impaired expression of the transcription factor (TF) Helios by FoxP3+ CD4 and Qa-1-restricted CD8 Tregs results in defective regulatory activity and autoimmunity in mice. Helios-deficient Treg develop an unstable phenotype during inflammatory responses characterized by reduced FoxP3 expression and increased effector cytokine expression secondary to diminished activation of the STAT5 pathway. CD8 Treg also require Helios-dependent STAT5 activation for survival and to prevent terminal T cell differentiation. Definition of Helios as a key transcription factor that stabilizes regulatory T-cells in the face of inflammatory responses provides a genetic explanation for a core property of regulatory T-cells.
Stable inhibitory activity of regulatory T cells requires the transcription factor Helios.
Specimen part
View SamplesIron is an essential component of the erythrocyte protein hemoglobin and is crucial to oxygen transport in vertebrates. In the steady state, erythrocyte production is in equilibrium with erythrocyte removal1. In various pathophysiological conditions, erythrocyte life span is severely compromised, which threatens the organism with anemia and iron toxicity 2,3. Here we identify anon-demand mechanism specific to the liver that clears erythrocytes and recycles iron. We showthat Ly-6Chigh monocytes ingest stressed and senescent erythrocytes, accumulate in the liver, and differentiate to ferroportin 1 (FPN1)-expressing macrophages that can deliver iron to hepatocytes. Monocyte-derived FPN1+ Tim-4neg macrophages are transient, reside alongside embryonically-derived Tim-4high Kuppfer cells, and depend on Csf1 and Nrf2. The spleenlikewise recruits iron-loaded Ly-6Chigh monocytes, but they do not differentiate into ironrecycling macrophages due to the suppressive action of Csf2, and are instead shuttled to the livervia coordinated chemotactic cues. Inhibiting this mechanism by preventing monocyte recruitment to the liver leads to kidney failure and liver damage. These observations identify the liver as the primary organ supporting emergency erythrocyte removal and iron recycling, and uncover a mechanism by which the body adapts to fluctuations in erythrocyte integrity.
On-demand erythrocyte disposal and iron recycling requires transient macrophages in the liver.
Specimen part
View SamplesYamoa is marketed and sold as a dietary supplement with anecdotal positive effects in asthma and hay fever. We determined that Yamoa (ground bark of Funtumia elastica tree) stimulated innate immunity in part by affecting gamma delta T cells. Yamoa had distinct priming effects, very similar to, but more robust than, that of lipopolysaccharide (LPS), on bovine, mouse and human gamma delta T cells. However, the optimal effect was dependent on the presence of accessory cells. Gene expression patterns in bovine gamma delta T cells and monocytes induced by Yamoa were very similar to those induced by ultrapure LPS, but the agonists in Yamoa did not signal entirely through TLR4. Yamoa stimulated human cells to produce cytokines involved innate protection. The bioactive component of Yamoa was delineated to a complex polysaccharide fraction (Yam-I). Intraperitoneal injection of Yamoa and very low doses of Yam-I in mice induced rapid increases peritoneal neutrophils directed by changes chemokine expression. Yamoa and Yam-I were effective as therapeutic treatments in mice with Salmonella enterica serotype Typhimurium (ST) induced enterocolitis that resulted in decreased bacterial counts in feces. This initial characterization of the immune stimulatory properties of polysaccharides derived from Yamoa suggests potential mechanisms for positive effects in asthma and that they have potential for application in infectious disease settings. .
Polysaccharides derived from Yamoa (Funtumia elastica) prime gammadelta T cells in vitro and enhance innate immune responses in vivo.
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View SamplesRibosome profiling of MDA-MB-231 cells treated with Silvestrol to monitor transcriptome wide, eIF4A-dependent changes in translation efficiency Overall design: Translation efficiency (TE) of mRNAs dervied from ribosome footprints was monitored in the presence or absence of 25 nM Silvestrol, an inhibitor of eukaryotic translation initiation factor 4A (eIF4A). Transcripts with reduced TE in the presence of Silvestrol were compare to transcripts with reduced TE in the presence of INK128, a catalytic mTOR inhbitor.
Transcriptome-wide characterization of the eIF4A signature highlights plasticity in translation regulation.
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View SamplesMicroglia are key regulators of inflammatory response after stroke and brain injury. Here we profiled the microglia transcriptome isolated from a spontaneously hypertensive rat model of focal cerebral ischemia.
Transcriptomic characterization of microglia activation in a rat model of ischemic stroke.
Sex, Age
View SamplesWe compared the prognostic significance of ectodomain isoforms of the epidermal growth factor receptor (EGFR), which lack the tyrosine kinase (TK) domain, with that of the full length receptor and its autophosphorylation status in cervical cancers treated with conventional chemoradiotherapy.
Membranous expression of ectodomain isoforms of the epidermal growth factor receptor predicts outcome after chemoradiotherapy of lymph node-negative cervical cancer.
Specimen part
View SamplesWe analyzed the transcriptome of dormant and after-ripened imbibed seeds of the Arabidopsis accession Cape verde Islands.
Dormant and after-Ripened Arabidopsis thaliana Seeds are Distinguished by Early Transcriptional Differences in the Imbibed State.
Specimen part, Time
View SamplesIron is essential for many cellular processes and is required by bacteria for replication. To acquire iron from the host, pathogenic Gram-negative bacteria secrete siderophores, including Enterobactin (Ent). However, Ent is bound by the host protein Lipocalin 2 (Lcn2), preventing bacterial reuptake of aferric or ferric Ent. In two experiments we treated A549 (lung cancer cell line) cells with Lcn2, Ent, and iron, alone and in combination. In experiment 1, biological duplicates of 4 conditions were used: PBS control, Lcn2, Lcn2+Ent, and Lcn2+Ent+iron. In experiment 2, 4 biological replicates of 4 conditions were used: PBS control, Ent, iron, and Ent+iron. Targets made from the samples were hybridized to Affymetrix Human Gene 1.0 ST arrays to measure transcript abundances. The RMA algorithm was used to estimate transcript levels. Replicate samples were exchangeable, so we fit one-way ANOVA models to log2-transformed data separately to each experiment, and tested for pairwise differences between groups in each experiment, as well as asking if the Ent vs. PBS differences were larger or smaller than the Ent+iron vs. iron differences (Ent by iron interactions). We report results for 29096 probe-sets that were not annotated as positive or negative controls on the array. A supplementary Excel workbook is provided that contains the estimated expression level, some probe-set annotation, and simple statistical analysis for each probe-set. It may be convenient for some users, however obtaining newer probe-set annotation may be advisable.
Bacterial siderophores that evade or overwhelm lipocalin 2 induce hypoxia inducible factor 1α and proinflammatory cytokine secretion in cultured respiratory epithelial cells.
Specimen part, Cell line
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