With frequent fluctuations in global climate, plants often experience co-occurring dry-wet cycles and pathogen infection and this combination adversely affects plant survival. In the past, some studies indicated that morpho-physiological responses of plants to the combined stress are different from the individual stressed plants. However, interaction of drought stressed or drought recovered plants with pathogen has not been widely studied at molecular level. Such studies are important to understand the defense pathways that operate as part of combined stress tolerance mechanism. In this study, Arabidopsis plants were exposed to individual drought stress (soil drying at 40% FC, D), Pseudomonas syringae pv tomato DC3000 (PStDC3000), infection and their combination. Plants recovered from drought stress were also exposed to PStDC3000. Beside we have also infiltrated P. syringae pv tabaci (PSta, non-host pathogen) individually or in combination with drought stress. Using Affymetrix WT gene 1.0 ST array, global transcriptome profiling of plants leaves under individual drought stress and pathogen infection was compared with their combination. Results implicate that plants exposed to combined drought and pathogen stress experience a new state of stress where each combination of stressor and their timing defines the plant responses and thus should be studied explicitly.
Global Transcriptional Analysis Reveals Unique and Shared Responses in Arabidopsis thaliana Exposed to Combined Drought and Pathogen Stress.
Specimen part
View SamplesSV40 large T antigen (TAg) contributes to cell transformation, in part, by targeting two well characterized tumor suppressors, pRb and p53. TAg expression affects the transcriptional circuits controlled by Rb and by p53. We have performed a microarray analysis to examine the global change in gene expression induced by wild-type TAg and TAg-mutants, in an effort to link changes in gene expression to specific transforming functions. For this analysis we have used MEFs expressing TAg or infected by SV40. Our analysis indicates that TAg can induce interferon-stimulated genes in MEFs and that this induction depends upon the LXCXE motif and p53 binding.
Induction of interferon-stimulated genes by Simian virus 40 T antigens.
No sample metadata fields
View SamplesExpression profiling of isoflavone and 3,3-diindolylmethane treated C4-2B prostate cancer cells was conducted using Affymetrix Human Genome U133 Plus 2.0. Array
Targeting bone remodeling by isoflavone and 3,3'-diindolylmethane in the context of prostate cancer bone metastasis.
Cell line, Time
View SamplesImmune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection. However, despite heightened readiness to respond, memory cells exist in a functionally quiescent state. The paradigm is that memory cells remain inactive due to lack of TCR stimuli. Here we report a unique role of Tregs in orchestrating memory quiescence by inhibiting effector and proliferation programs through CTLA-4. Loss of Tregs resulted in activation of genome-wide transcriptional programs characteristic of potent effectors, and both developing and established memory quickly reverted to a terminally differentiated (KLRG-1hi/IL-7Rlo/GzmBhi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality and protective efficacy. CTLA-4, an inhibitory receptor overexpressed on Tregs, functionally replaced Tregs in trans to rescue Treg-less memory defects and restore homeostasis of secondary mediators as well. These studies present CD28-CTLA-4-CD80/CD86 axis as a novel target to potentially accelerate vaccine-induced immunity and improve T-cell memory quality in current cancer immunotherapies proposing transient Treg-depletion.
Quiescence of Memory CD8(+) T Cells Is Mediated by Regulatory T Cells through Inhibitory Receptor CTLA-4.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genomic impact of transient low-dose decitabine treatment on primary AML cells.
Sex, Age, Specimen part, Disease, Treatment
View SamplesAcute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples.
Genomic impact of transient low-dose decitabine treatment on primary AML cells.
Specimen part, Disease, Treatment
View SamplesUsing killer cell lectin-like receptor G1 as a marker to distinguish terminal effector cells from memory precursors, we found that despite their diverse cell fates both subsets possessed remarkably similar gene expression profiles and functioned as equally potent killer cells. However, only the memory precursors were capable of making IL-2 thus defining a novel effector cell that was cytotoxic, expressed granzyme B, and produced inflammatory cytokines in addition to IL-2. This effector population then differentiated into long-lived protective memory T cells capable of self-renewal and rapid re-call responses. Mechanistic studies showed that cells that continued to receive antigenic stimulation during the later stages of infection were more likely to become terminal effectors. Importantly, curtailing antigenic stimulation towards the tail-end of the acute infection enhanced the generation of memory cells. These studies support the decreasing potential model of memory differentiation and show that the duration of antigenic stimulation is a critical regulator of memory formation
Functional and genomic profiling of effector CD8 T cell subsets with distinct memory fates.
No sample metadata fields
View SamplesCD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells.
Prolonged interleukin-2Ralpha expression on virus-specific CD8+ T cells favors terminal-effector differentiation in vivo.
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 SamplesWe have determined that tenascin C (TNC) regulates the growth of human brain tumor initiating cells (BTICs). We have identified novel mechanisms by which TNC regulates BTIC growth. Analysis of the array data identified a number of genes that were altered with TNC treatment that could potentially regulate BTIC growth. The study provides the mechanistic basis for the regulation of BTIC growth with TNC.
Activation of NOTCH Signaling by Tenascin-C Promotes Growth of Human Brain Tumor-Initiating Cells.
Specimen part, Cell line, Treatment
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