PI3K signaling and FOXO transcription factors play opposing roles at several B cell developmental stages. We show here abundant nuclear FOXO1 expression in the proliferative compartment of the germinal center (GC), its dark zone (DZ), and PI3K activity, downregulating FOXO1, in the GC light zone (LZ), where cells are selected for further differentiation. However, here FOXO1 is expressed in c-Myc+ cells destined for DZ reentry. Upon FOXO1 ablation by genetic means or induction of PI3K activity GCs become devoid of their DZ, due at least partly to the downregulation of the chemokine receptor CXCR4. While this is known to prevent proper cyclic selection of cells expressing high-affinity antibodies, the initiation of immunoglobulin switching is essentially dependent on FOXO1 activity.
PI3 Kinase and FOXO1 Transcription Factor Activity Differentially Control B Cells in the Germinal Center Light and Dark Zones.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Vitamin C supplementation modulates gene expression in peripheral blood mononuclear cells specifically upon an inflammatory stimulus: a pilot study in healthy subjects.
Specimen part
View SamplesA role of vitamin C (ascorbic acid) as an antioxidant molecule has been recognized, largely based on in vitro studies. However, more recently, the concept of antioxidant molecule has been reconsidered and its biological function is no longer considered to be simply due to its ability to act as electron donors, rather, it appears to act by modulating signaling and gene expression.
Vitamin C supplementation modulates gene expression in peripheral blood mononuclear cells specifically upon an inflammatory stimulus: a pilot study in healthy subjects.
Specimen part
View SamplesNucleotides triphosphates are extracellular messengers binding to specific plasma membrane receptors (P2Rs) that modulate responses as different as proliferation, differentiation, migration or cell death on several cell types including hematopoietic stem cells. Little and controversial information is available on the role of extracellular nucleotides in human mesenchimal stem cells (hMSCs). In this study, we assessed whether P2Rs are expressed and functional in bone marrow-derived hMSCs. Our results demonstrated, at the mRNA and protein level, the expression of all P2X and P2Y receptor subtypes identified so far. P2R activation by their natural ligands adenosine triphosphate (ATP) and uridine triphosphate (UTP) induced in hMSCs, intracellular Ca2+ concentration changes, plasma membrane depolarization and permeabilization. hMSCs were resistant to the cytotoxic effects of high dose ATP despite the expression of permeabilizing P2Rs as demonstrated by the lack of morphological changes, significant release of intracellular markers of cell death or modification of the mitochondrial network. Gene expression profiling revealed the down-regulation of cell proliferation genes whereas genes involved in cell migration and cytokine production were strongly up-regulated by ATP. Functional studies confirmed the inhibitory activity of ATP on proliferation of hMSCs and clonogenic progenitors. Moreover, ATP exerted a chemotactic effect on hMSCs and increased their migration in response to the chemokine CXCL12. Finally, whereas ATP did not affect T-cell inhibitory activity of hMSCs, the nucleotide increased the production of pro-inflammatory cytokines by hMSCs. Thus, our data show that purinergic signaling modulates hMSC functions and point to a role for extracellular nucleotides on hMSCs biology.
Purinergic stimulation of human mesenchymal stem cells potentiates their chemotactic response to CXCL12 and increases the homing capacity and production of proinflammatory cytokines.
No sample metadata fields
View SamplesBitter taste receptors (T2Rs) are typical G-protein coupled receptors expressed in various tissue where they are involved in the regulation of physiological processes, thus suggesting a wider function in sensing microenvironment. We analyzed their expression and role in acute myeloid leukemia (AML). AML cells express functional T2Rs and their stimulation with the agonist, denatonium benzoate, substantially modified the AML cell transcriptomic profile and functions. GEP analysis identified relevant cellular processes affected by denatonium treatment in AML, including cell cycle, survival, migration and metabolism. More precisely, T2R activation reduced proliferation by inducing cell cycle arrest in G0/G1 phase or induced apoptosis via caspase cascade activation; impaired AML cell motility and migratory capacity; inhibited cellular respiration by decreasing glucose uptake and oxidative phosphorylation.
Denatonium as a Bitter Taste Receptor Agonist Modifies Transcriptomic Profile and Functions of Acute Myeloid Leukemia Cells.
Specimen part, Cell line, Treatment
View SamplesIn the present study, we investigated whether, and to what extent, P2Rs and their ligands are involved in the regulation of AML cells. Our findings show that AML blasts express several receptors belonging to the P2X and P2Y family. Although different samples respond differently to ATP and UTP stimulation (reflecting the variability intrinsic to the group of acute myeloid leukemias), all the tested samples appear to be responsive to purinergic signalling, as demonstrated by intracellular calcium mobilization.
Purinergic signaling inhibits human acute myeloblastic leukemia cell proliferation, migration, and engraftment in immunodeficient mice.
Specimen part
View SamplesPrevious studies identified a role for latent herpesvirus infection in cross-protection to infection and exacerbation of chronic inflammatory diseases. Here, we compared the gene expression signature from livers, spleens and brains of mice infected with wild-type gammaherpesvirus 68 (MHV68), a mutant virus defective in the establishment of latency (ORF73.stop) or mockulum. We identified over 600 genes differentially expressed in organs of mice latently infected with MHV68 and found distinct sets of genes linked to different pathways were altered in spleen compared to liver. Several of the most differentially expressed latency-specific genes (e.g. IFN, Cxcl9, Ccl5) are associated with known latency-specific phenotypes.
Latent gammaherpesvirus 68 infection induces distinct transcriptional changes in different organs.
Specimen part
View SamplesMicroRNA (miRNA) and endogenous siRNA (endo-siRNA) are two essential classes of small noncoding RNAs (sncRNAs) in eukaryotic organisms. The class of miRNA is diverse and there exist noncanonical miRNAs that bypass the canonical miRNA biogenesis pathway. In order to identify noncanonical miRNAs and endo-siRNAs responding to virus infection and study their potential function, we sequenced small-RNA species from cells lytically infected with murine gammaherpesvirus 68. In addition to 3 novel canonical miRNAs in mouse, two antisense miRNAs in virus and 25 novel noncanonical miRNAs, including miRNAs derived from tRNAs, snoRNAs and introns, in the host were identified. These noncanonical miRNAs exhibited features distinct from canonical miRNAs in the lengths and structures of miRNA hairpins as well as base pairings and first nucleotide preference. Many of the novel miRNAs are conserved in mammals. In addition to several known murine endo-siRNAs detected by the sequencing profiling, a novel locus in the mouse genome was identified to give rise to endo-siRNAs. This novel endo-siRNA locus is comprised of two tandem inverted B4 short interspersed nuclear elements (SINEs). Unexpectedly, the SINE-derived endo-siRNAs were found in a variety of sequencing data as well as virus-infected cells. Moreover, a murine miRNA was up-regulated more than 35 fold in infected than in mock-treated cells. The putative target genes of the viral and the up-regulated murine miRNAs were potentially involved in processes of gene transcription and protein phosphorylation and localized to membranes, suggesting their role in manipulating the host basal immune system during lytic infection. Our results extended the number of noncanonical miRNAs in mammals and shed new lights on their potential functions of lytic infection of MHV68. Overall design: Mouse NIH 3T12 cells infectd with MHV68 (3 samples) and mock-treated (2 samples) were examined. Noncanonical microRNAs and endogenous siRNAs discovery in lytic infection of murine gammaherpesvirus MHV68 (NC_001826.2).
Identification of novel microRNA-like molecules generated from herpesvirus and host tRNA transcripts.
Specimen part, Cell line, Subject
View SamplesWe tested the effects of co-infection on vaccine response to YFV-17D.
Sequential Infection with Common Pathogens Promotes Human-like Immune Gene Expression and Altered Vaccine Response.
Specimen part
View SamplesAutophagy genes play an important role in the T cell activation and proliferation. We examined the role of ATG7 during the process of CD8 T cell memory formation. In the absence of ATG7, antigen-specific CD8 T cells failed to survive past the contraction phase and failed to give rise to memory cells.
Autophagy is essential for effector CD8(+) T cell survival and memory formation.
Specimen part
View Samples