The Ets family transcription factor PU.1 is essential for the development and maintenance of several hematopoietic lineages. In the thymus, PU.1 is expressed only in the early ETP/DN1, DN2a and DN2b stages of development. While PU.1 deletion in multipotent precursors leads to a complete block in T-cell development its function in the intrathymic stages in which it is expressed remains undetermined. The goal of this expression profiling study was to determine if PU.1 regulates the expression of T-lineage genes during the early stages of development. To do this, we generated the PU.1-Eng construct which expresses a fusion protein containing the DNA binding ETS domain of PU.1 (aas 159-260) fused to the obligate repressor domain (aas 1-298) of the Drosophila engrailed protein. The PU.1-ETS construct only expresses the ETS domain of PU.1 (aas 159-260) and serves as a control. Fetal liver precursors were isolated from e14.5 embryos and co-cultured with OP9-DL1 cells in the presence of IL-7 and Flt3L (5 ng/ml each) for 4 days to obtain FLDN1, DN2a and DN2b cells. These were infected with vector only, PU.1-ETS and the PU.1-Eng constructs and DN2 cells were sorted after 20 hours of infection. Total RNA was isolated from these cells and polyA+ fraction was used to prepare libraries for high throughput sequencing. Libraries prepared from 2 independent sets of samples were subjected to non-strand specific single-end sequencing. Overall design: Two sets of samples generated from fetal liver precursor derived DN2 cells expressing PU.1-ETS and PU.1-Eng constructs were used for expression profiling. The LZRS retroviral vector, without any insert, was used to generate the vector control dataset.
Regulation of early T-lineage gene expression and developmental progression by the progenitor cell transcription factor PU.1.
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View SamplesThe chromatin regulator Aiolos and the transcriptional coactivator OBF-1 have been implicated in regulating aspects of B cell maturation and activation. Mice lacking either of these factors have a largely normal early B cell development. However, when both factors are eliminated simultaneously a block is uncovered at the transition between pre-B and immature B cells, indicating that these proteins exert a critical function in developing B lymphocytes. In mice deficient for Aiolos and OBF-1, the numbers of immature B cells are reduced, small pre-BII cells are increased and a significant impairment in immunoglobulin light chain DNA rearrangement is observed. We identified genes whose expression is deregulated in the pre-B cell compartment of these mice. In particular, we found that components of the pre-BCR, such as the surrogate light chain genes l5l5 and VpreB, fail to be efficiently silenced in double-mutant mice. Strikingly, developmentally regulated nuclear repositioning of the l5l5 gene is impaired in pre-B cells lacking OBF-1 and Aiolos. These studies uncover a novel role for OBF-1 and Aiolos in controlling the transcription and nuclear organization of genes involved in pre-BCR function.
Silencing and nuclear repositioning of the lambda5 gene locus at the pre-B cell stage requires Aiolos and OBF-1.
No sample metadata fields
View SamplesInterleukin-21 (IL-21) is a pleiotropic cytokine that induces expression of transcription factor BLIMP1 (encoded by Prdm1), which regulates plasma cell differentiation and T cell homeostasis. We identified an IL-21 response element downstream of Prdm1 that binds the transcription factors STAT3 and IRF4, which are required for optimal Prdm1 expression. Genome-wide ChIP-Seq mapping of STAT3- and IRF4-binding sites showed that most regions with IL-21-induced STAT3 binding also bound IRF4 in vivo, and furthermore, revealed that the noncanonical TTCnnnTAA GAS motif critical in Prdm1 was broadly used for STAT3 binding. Comparing genome-wide expression array data to binding sites revealed that most IL-21-regulated genes were associated with combined STAT3-IRF4 sites rather than pure STAT3 sites. Correspondingly, ChIP-Seq analysis of Irf4_/_ T cells showed greatly diminished STAT3 binding after IL-21 treatment, and Irf4_/_ mice showed impaired IL- 21-induced Tfh cell differentiation in vivo. These results reveal broad cooperative gene regulation by STAT3 and IRF4.
Analysis of interleukin-21-induced Prdm1 gene regulation reveals functional cooperation of STAT3 and IRF4 transcription factors.
Specimen part
View SamplesHomeostasis of the gut microbiota is pivotal to the survival of the host. Intestinal T cells and Innate Lymphoid cells (ILCs) control the composition of the microbiota and respond to its perturbations. Interleukin 22 (IL-22) plays a pivotal role in the immune control of gut commensal and pathogenic bacteria and is secreted by a heterogeneous population of intestinal T cells, NCR- ILC3 and NCR+ILC3. Expression of NCR by ILC3 is believed to define an irreversible effector ILC3 end-state fate in which these cells are key to control of bacterial infection via their production of IL-22. Here we identify the core transcriptional signature that drives the differentiation of NCR- ILC3 into NCR+ ILC3 and reveal that NCR+ILC3 exhibit more plasticity than originally thought, as NCR+ ILC3 can revert to NCR- ILC3. Contrary to the prevailing understanding of NCR+ ILC3 genesis and function, in vivo analyses of mice conditionally deleted of the key ILC3 genes Stat3, Il22, Tbet and Mcl1 demonstrated that NCR+ ILC3 were not essential for the control of colonic infections in the presence of T cells. However, NCR+ ILC3 were mandatory for homeostasis of the caecum. Our data identify that the interplay of intestinal T cells and ILC3 results in robust complementary fail-safe mechanisms that ensure gut homeostasis. Overall design: Transcriptional profiling of wild-type and T-bet knockout innate lymphoid cells (ILC3) using RNA sequencing
Complementarity and redundancy of IL-22-producing innate lymphoid cells.
Specimen part, Cell line, Subject
View SamplesUntreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. While each of the three stages has well-known clinical, virologic and immunological characteristics, much less is known of the molecular mechanisms underlying each stage. Here we report lymphatic tissue microarray analyses revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that while there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene-expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g.MDA-5, TLR-7 and -8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the pro-apoptotic Fas-Fas-L pathway. Yet, quite strikingly, the expression of nearly all acute-stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific, gene-expression signatures provide new insights into the molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection.
Microarray analysis of lymphatic tissue reveals stage-specific, gene expression signatures in HIV-1 infection.
Sex, Age, Specimen part, Disease, Disease stage, Race, Subject
View SamplesThe inhibitor of DNA binding 2 (Id2) is essential for NK cell development with its canonical role in this pathway being to antagonize E-proteins, silencing E-box gene expression and subsequent commitment to the T and B cell lineages. However, how E-box genes prevent NK cell development and homeostasis remains enigmatic. Here we identify a key role for Id2 in regulating the threshold for IL-15 receptor signaling and homeostasis of NK cells by repressing multiple E-protein target genes including Socs3. Deletion of Id2 in mature NK cells was incompatible with their homeostasis due to impaired IL-15 receptor signaling. Id2-null NK cells displayed impaired IL-15 mediated JAK1/STAT5 phosphorylation, compromised metabolic function and enhanced apoptosis. Remarkably, Id2-null NK cell homeostasis could be fully rescued in vivo by IL-15 receptor stimulation and partially rescued by genetic ablation of Socs3. During normal NK cell maturation we observed an inverse correlation between the expression levels of E-protein target genes and Id2. These results shift the current paradigm on the role of Id2, indicating that it is not only required to antagonize E-proteins during NK cell commitment, but constantly required to titrate E-protein activity to regulate NK cell fitness and responsiveness to IL-15. Overall design: Transcriptional profiling of wild type and Id2-null natural killer (NK) cells using RNA sequencing
The Helix-Loop-Helix Protein ID2 Governs NK Cell Fate by Tuning Their Sensitivity to Interleukin-15.
Specimen part, Cell line, Subject
View Samples10 day old seedlings were treated with 5uM of the cytokinin Benzyladenine(BA)or DMSO at 15min, 45min, 120min, 480min and 1440min
Expression profiling of cytokinin action in Arabidopsis.
Age, Compound, Time
View SamplesSystemic vaccination with the attenuated virus SIVmac239-Nef provides sterilizing or partial protection to rhesus monkeys challenged with WT SIV strains, providing important opportunities to study key immunological components of a protective host response. Here we show that intravenous vaccination with SIVmac239-Nef provides two potentially crucial immunological barriers localized at mucosal surfaces that correlate with the vaccines protective effects against WT SIVmac251 vaginal challenge: 1) a conditioned and coordinated response from the mucosal epithelium that blunts the early inflammatory and chemotactic signalling cascade that aids virus propagation and expansion; 2) early on-site generation/diversification of SIV-specific Abs from ectopic germinal center-like lymphoid aggregates. This unique host response to WT SIVmac251 in the female reproductive tract of SIVmac239-Nef-vaccinated animals points to a multi-layered strategy for a protective host response during immunodeficiency virus exposurerapid induction of humroal immunity at mucosal surfaces without the deleterious inflammatory side effects tied to innate recognition of virus. This vaccine-induced host response highlights potential key protective mechanisms needed for an effective HIV vaccine
Live simian immunodeficiency virus vaccine correlate of protection: immune complex-inhibitory Fc receptor interactions that reduce target cell availability.
Sex, Specimen part
View SamplesLectins are proteins present on cell surfaces or as shed extracellular proteins that function in innate immune defense as phagocytic receptors to recognize specific bacterial cell wall components. Based on the knowledge that cigarette smoking is associated with increased risk of bacterial infection, we hypothesized that cigarette smoking may modulate the expression of lectin genes in the airway epithelium. Affymetrix HG U133 Plus 2.0 microarrays were used to survey expression of lectin genes in large (3rd to 4th order bronchi) airway epithelium from 9 normal nonsmokers and 20 phenotypic normal smokers and small (10th to 12th order bronchi) airway epithelium from 13 normal nonsmokers and 20 phenotypic normal smokers. From the 72 lectin genes that were surveyed, there were no changes (>2-fold change, p<0.05) in gene expression in either large or small airway epithelium among normal smokers compared to nonsmokers except for a striking down regulation in both large and small airway epithelium of normal smokers of intelectin 1, a recently described lectin that participates in the innate immune response by recognizing and binding to galactofuranosyl residues in the cell walls of bacteria (large airway epithelium, p<0.003; small airway epithelium, p<0.002). TaqMan RT-PCR confirmed the observation that intelectin 1 was down-regulated in both large (p<0.05) and small airway epithelium (p<0.02) of normal smokers compared to normal nonsmokers. Immunohistochemistry assessment of biopsies of the large airway epithelium of normal nonsmokers demonstrated intelectin 1 was expressed in secretory cells, with qualitatively decreased expression in biopsies from normal smokers. Western analysis confirmed the decreased expression of intelectin 1 in airway epithelium of normal smokers compared to normal nonsmokers (p<0.02). Finally, compared to normal nonsmokers, intelectin 1 expression was decreased in small airway epithelium of smokers with early COPD (n= 13, p<0.001) and smokers with established COPD (n= 14, p<0.001), in a fashion similar to that of normal smokers. In the context that intelectin 1 is an epithelial molecule that likely plays a role in defense against bacteria, the down regulation of expression of intelectin 1 in response to cigarette smoking may contribute to the increase in susceptibility to infections observed in smokers, including those with COPD.
Decreased expression of intelectin 1 in the human airway epithelium of smokers compared to nonsmokers.
Sex, Age
View SamplesInflorescence stages 1 to 12 from mutants involved in Arabidopsis small RNA metabolism. Three biological replicates of each mutant comprising at least 9 independent plants were harvested, and the expression profiles were determined using Affymetrix ATH1 arrays. Comparisons among the sample groups allow the identification of genes regulated by small RNAs (microRNAs and siRNAs).
microRNA-directed phasing during trans-acting siRNA biogenesis in plants.
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