Germinal center (GC) B cells cycle between two states, the light zone (LZ) and the dark zone (DZ), and in the latter they proliferate and hypermutate their immunoglobulin genes. How this functional transition takes place is still controversial. In this study, we demonstrate that ablation of Foxo1 after GC development led to the loss of the DZ GC B cells and disruption of the GC architecture. Mechanistically, even upon provision of adequate T cell help, Foxo1-deficient GC B cells showed less proliferative expansion than controls. Moreover, we found that the transcription factor BATF was transiently induced in LZ GC B cells in a Foxo1-dependent manner and that deletion of BATF similarly led to GC disruption. Thus, our results are consistent with a model where the switch from the LZ to the DZ is triggered after receipt of T cell help, and suggest that Foxo1-mediated BATF up-regulation is at least partly involved in this switch. Overall design: mRNA profiles of wild-type DZ, LZ, and Foxo1-deficient GC B cells were generated by deep sequencing in triplicate, using Illumina HiSeq 1500.
The transcription factor Foxo1 controls germinal center B cell proliferation in response to T cell help.
Specimen part, Subject
View SamplesDespite the importance of memory B cells for protection from recurrent infection, how these cells are selected during germinal center (GC) reactions remains unclear. We show here that light zone (LZ) GC B cells with lower affinity BCRs express a less CD40 signature and relatively high levels of Bach2, being prone to enter the memory B cell pool. We also find that Bach2 contributes to memory B cell generation in a Blimp-1 independent manner and that its higher expression confers on LZ GC cells a more advantage for entering the memory B cell compartment. Thus, our data support an instructive model in which weak T cell help keeps Bach2 expression relatively high, thereby being predisposed to enter the memory pool. Overall design: mRNA expression profiles of NP specific high and low affinity IgG1 LZ GC B cells were generated by deep sequencing using Illumina HiSeq 1500
Regulated selection of germinal-center cells into the memory B cell compartment.
Specimen part, Cell line, Subject
View SamplesDespite the importance of memory B cells for protection from recurrent infection, how these cells are selected during germinal center (GC) reactions remains unclear. We show here that light zone (LZ) GC B cells with lower affinity BCRs express a less CD40 signature and relatively high levels of Bach2, being prone to enter the memory B cell pool. We also find that Bach2 contributes to memory B cell generation in a Blimp-1-independent manner and that its higher expression confers on LZ GC cells a more advantage for entering the memory B cell compartment. Thus, our data support an instructive model in which weak T cell help keep Bach2 expression relatively high, thereby being predisposed to enter the memory pool. Overall design: mRNA expression profiles of Bach2-tdRFP low and high expression NP-specific IgG1 light zone GC B cells were generated by deep sequencing using Illumina HiSeq 1500.
Regulated selection of germinal-center cells into the memory B cell compartment.
Specimen part, Subject
View Samplesgene expression data from wild-type and Bcl6-/- regulatory T cells
Bcl6 controls the Th2 inflammatory activity of regulatory T cells by repressing Gata3 function.
Specimen part
View SamplesWe investigated transcriptional changes in CD4CD8aa and CD4 intraepthelial lymphocytes.
Transcriptional reprogramming of mature CD4⁺ helper T cells generates distinct MHC class II-restricted cytotoxic T lymphocytes.
Specimen part
View SamplesWe found that CITED2 is highly expressed in metastatic prostate cancer, and its expression is correlated with poor survival in pateints. In this study, we used an siRNA to decrease CITED2 expression in PC3 cells. A RNA-seq approach was utilized in order to determine global gene expression changes in CITED2 knockdown cells compared to control cells. Overall design: PC3 cells transfected with control siRNAs were used as controls. Cells transfected with siRNAs targeting CITED2 were used as experimental group. Cells were transfected for 72 hr and the analyses were done.
Aberrant expression of CITED2 promotes prostate cancer metastasis by activating the nucleolin-AKT pathway.
Cell line, Subject
View SamplesWe conditionally inactivated mouse Cdx2, a dominant regulator of intestinal development, and mapped its genome occupancy in adult intestinal villi. Although homeotic transformation, observed in Cdx2-null embryos, was absent in mutant adults, gene expression and cell morphology were vitally compromised. Lethality was accelerated in mice lacking both Cdx2 and its homolog Cdx1, with exaggeration of defects in crypt cell replication and enterocyte differentiation. Cdx2 occupancy correlated with hundreds of transcripts that fell but not with equal numbers that rose with Cdx loss, indicating a predominantly activating role at intestinal cis-regulatory regions. Integrated consideration of a mutant phenotype and cistrome hence reveals the continued and distinct requirement in adults of a master developmental regulator that activates tissue-specific genes.
Essential and redundant functions of caudal family proteins in activating adult intestinal genes.
Specimen part
View SamplesAs Trypanosoma cruzi, the etiological agent of Chagas disease, multiplies in the cytoplasm of nucleated host cells, infection with this parasite is highly likely to affect host cells. We performed an exhaustive transcriptome analysis of T. cruzi-infected HeLa cells using an oligonucleotide microarray containing probes for greater than 47,000 human gene transcripts. In comparison with uninfected cells, those infected with T. cruzi showed greater than threefold up-regulation of 41 genes and greater than threefold down-regulation of 23 genes. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of selected, differentially expressed genes confirmed the microarray data. Many of these up- and down-regulated genes were related to cellular proliferation, including seven up-regulated genes encoding proliferation inhibitors and three down-regulated genes encoding proliferation promoters, strongly suggesting that T. cruzi infection inhibits host cell proliferation, which may allow more time for T. cruzi to replicate and produce its intracellular nests. These findings provide new insight into the molecular mechanisms by which intracellular T. cruzi infection influences the host cell, leading to pathogenicity.
Transcriptome profile of Trypanosoma cruzi-infected cells: simultaneous up- and down-regulation of proliferation inhibitors and promoters.
No sample metadata fields
View SamplesEpstein-Barr Virus (EBV) Latent Membrane Protein 1 (LMP1) transforms rodent fibroblasts and is expressed in most EBV-associated malignancies. LMP1 Transformation Effector Site 2 (TES2)/C-Terminal Activation Region 2 (CTAR2) activates NF-kappaB, p38, JNK, ERK and IRF7 pathways. We have investigated LMP1 TES2 genome-wide RNA effects at 4 time points after LMP1 TES2 expression in HEK 293 cells. Using a False Discovery Rate (FDR) of < 0.001 after correction for multiple hypotheses, LMP1 TES2 caused > 2-fold changes in 1916 mRNAs; 1479 RNAs were up-regulated and 437 down-regulated. In contrast to TNFalpha stimulation, which transiently up-regulates many target genes, LMP1 TES2 maintained most RNA effects through the time course, despite robust and sustained induction of negative feedback regulators, such as IkappaBalpha and A20. LMP1 TES2 regulated RNAs encode many NF-kappaB signaling proteins and secondary interacting proteins. Consequently, many LMP1 TES2-regulated RNAs encode proteins that form an extensive interactome. Gene Set Enrichment Analyses found LMP1 TES2 up-regulated genes to be significantly enriched for Pathways in Cancer, B-and T-cell receptor signaling, and Toll-like receptor signaling. Surprisingly, LMP1 TES2 and IkappaBalpha super-repressor co-expression decreased LMP1 TES2 RNA effects to only 5 RNAs with FDR<0.001 and >2 fold change. Thus, canonical NF-kappaB activation is critical for almost all LMP1 TES2 RNA effects in HEK-293 cells and a more significant therapeutic target than previously appreciated.
Canonical NF-kappaB activation is essential for Epstein-Barr virus latent membrane protein 1 TES2/CTAR2 gene regulation.
Specimen part
View SamplesDNA methylation plays critical roles in the nervous system and has been traditionally considered to be restricted to CpG dinucleotides in metazoan genomes. Here we show that the single-base resolution neuronal DNA methylome from the adult mouse dentate gyrus consists of both CpG (~75%) and CpH (~25%) methylation (H = A/C/T). Neuronal CpH methylation is conserved in human brains, enriched in low CpG-density regions, depleted at protein-DNA interaction sites, and anti-correlated with gene expression. Functionally, both mCpGs and mCpHs can repress transcription in vitro and are recognized by MeCP2 in vivo. Unlike most CpG methylation, CpH methylation is established de novo during neuronal maturation and requires DNMT3A for active maintenance in post-mitotic neurons. These characteristics of CpH methylation suggest a significantly expanded proportion of the neuronal genome under cytosine methylation regulation and provide a new framework for understanding the roles of this key epigenetic modification in neuronal identity, maturation, plasticity and neurological disorders. Overall design: Three biological replicates (dentate gyrus samples from C57Black6 mice) were analyzed by mRNA-seq
Distribution, recognition and regulation of non-CpG methylation in the adult mammalian brain.
No sample metadata fields
View Samples