CD4+ T lymphocytes are key to immunological memory, but little is known about the lifestyle of memory CD4+ T lymphocytes. We showed that in the memory phase of specific immune responses to antigens, most of the memory CD4+ T lymphocytes relocated into the bone marrow (BM) within 3-8 weeks after their generation, a process involving integrin a2. Antigen-specific memory CD4+ T lymphocytes expressed Ly-6C to a high degree, unlike most splenic CD44hiCD62L- CD4+ T lymphocytes. In adult mice, more than 80% of Ly-6Chi CD44hiCD62L- memory CD4+ T lymphocytes were in the BM. In the BM, they are located next to IL-7-expressing VCAM-1+ stroma cells, and were in a resting state. Upon challenge with antigen, they rapidly expressed cytokines and CD154 and induced the production of high-affinity antibodies, indicating their functional activity in vivo and marking them as professional memory T helper cells
Professional memory CD4+ T lymphocytes preferentially reside and rest in the bone marrow.
Specimen part
View SamplesWe used microarray analysis to identify specific molecular mechanisms controlling IL-5 transcription in memory Th2 cells.
Eomesodermin controls interleukin-5 production in memory T helper 2 cells through inhibition of activity of the transcription factor GATA3.
Specimen part
View SamplesWe performed RNA-Seq and compared expression levels of genes of reactivated LCMV.GP66-77 specific CD4 T cells isolated from bone marrow (BM) and spleen of LCMV.GP61-80 primed C57BL/6 mice. Cells were isolated 3 days after antigenic re-challenge Overall design: C57BL/6 mice were primed at day 0 with LCMV.GP61-80-NP-MSA + poly(I:C) and immunized again at day 14 with LCMV.GP61-80 + poly(I:C). 60 days later, C57BL/6 mice were boosted with LCMV.GP61-80-NP-MSA + poly(I:C) and 3 days after the boost, LCMV specific CD4 T cells were isolated from BM and spleen
Nonfollicular reactivation of bone marrow resident memory CD4 T cells in immune clusters of the bone marrow.
Age, Specimen part, Cell line, Subject
View SamplesFollowing antigen encounter by CD4 T cells, polarizing cytokines induce the expression of master regulators that control differentiation. Inactivation of the histone methyltransferase Ezh2 was found to specifically enhance T-helper (Th)1 and Th2 cell differentiation and plasticity. Ezh2 directly bound and facilitated correct expression of Tbx21 and Gata3 in differentiating Th1 and Th2 cells, accompanied by substantial tri-methylation at lysine 27 of histone 3 (H3K27-Me3). In addition, Ezh2 deficiency resulted in spontaneous generation of discrete IFN- and Th2 cytokine-producing populations in non-polarizing cultures, and under these conditions IFN- expression was largely dependent on enhanced expression of the transcription factor Eomesodermin. In vivo, Loss of Ezh2 caused increased pathology in a model of allergic asthma and resulted in progressive accumulation of memory phenotype Th2 cells. This study establishes a functional link between Ezh2 and transcriptional regulation of lineage-specifying genes in terminally differentiated CD4 T cells.
The polycomb protein Ezh2 regulates differentiation and plasticity of CD4(+) T helper type 1 and type 2 cells.
Specimen part
View SamplesTo understand differences between resting and activated memory CD8+ T cells, we compared the global gene expression of ex vivo isolated naive and spleen and BM memory cells to in vitro activated spleen and BM memory cells.
Memory CD8(+) T cells colocalize with IL-7(+) stromal cells in bone marrow and rest in terms of proliferation and transcription.
Sex, Specimen part
View SamplesTo compare human memory CD4+ T cell subsets in peripheral blood (PB) and bone marrow (BM) of healthy individuals at transcriptional level, we analyzed the global gene expression of ex vivo PB CD69- as well as BM CD69- and CD69+ memory CD4+ T cells from 4 paired PB and BM samples. The gene expression of these subsets was additionally compared to the transcriptional profile of 8 PB samples taken ex vivo or stimulated with phorbol myristate acetate (PMA) and Ionomycin for 3 hours.
Human memory T cells from the bone marrow are resting and maintain long-lasting systemic memory.
Specimen part
View SamplesThe effect of cyclic mecanical stretch on cardiac gene expression was studied in neonatal rat ventricular myocytes (NRVMs).
Mechanical stretch induced transcriptomic profiles in cardiac myocytes.
Treatment
View SamplesThe circadian clock controls a wide variety of metabolic and homeostatic processes in a number of tissues, including the kidney. However, the role of the renal circadian clocks remains largely unknown. To address this question we performed transcriptomic analysis in mice with inducible and conditional ablation of the circadian clock system in the renal tubular cells (Bmal1lox/lox/Pax8-rtTA/LC1 mice). Deep sequencing of the renal transcriptome revealed significant changes in the expression of genes related to metabolic pathways and organic anion transport. In parallel, kidneys from Bmal1lox/lox/Pax8-rtTA/LC1 mice exhibited a significant decrease in the NAD+/NADH ratio suggesting an increased anaerobic glycolysis and/or decreased mitochondrial function. In-depth analysis of two selected pathways revealed (i) a significant increase in plasma urea levels correlating with increased renal arginase 2 (Arg2) activity, hyperargininemia and increase of the kidney arginine content; (ii) a significantly increased plasma creatinine concentration and reduced capacity of the kidney to secrete anionic drugs (furosemide), paralleled by a ~80% decrease in the expression levels of organic anion transporter OAT3 (SLC22a8). Collectively, these results indicate that the renal circadian clocks control a variety of metabolic/homeostatic processes at both the intra-renal and systemic levels and are involved in drug disposition. Overall design: Mice with a specific ablation of the Arntl gene encoding BMAL1 in the renal tubular cells were compared to wild-type littermate at ZT4 and ZT16 (ZT – Zeitgeber time units; ZT0 is the time of light on and ZT12 is the time of light off).
Nephron-Specific Deletion of Circadian Clock Gene Bmal1 Alters the Plasma and Renal Metabolome and Impairs Drug Disposition.
Specimen part, Subject, Time
View SamplesTo identify a novel target for the treatment of heart failure, we examined gene expression in the failing heart. Among the genes analyzed, 12/15 lipoxygenase (12/15-LOX) was markedly up-regulated in heart failure. To determine whether increased expression of 12/15-LOX causes heart failure, we established transgenic mice that overexpressed 12/15-LOX in cardiomyocytes. Echocardiography showed that 12/15-LOX transgenic mice developed systolic dysfunction. Cardiac fibrosis increased in 12/15-LOX transgenic mice with advancing age, and was associated with the infiltration of macrophages. Consistent with these observations, cardiac expression of monocyte chemoattractant protein-1 (Mcp-1) was up-regulated in 12/15-LOX transgenic mice compared with wild-type mice. Treatment with 12-hydroxy-eicosatetraenotic acid, a major metabolite of 12/15-LOX, increased MCP-1 expression in cardiac fibroblasts and endothelial cells, but not in cardiomyocytes. Inhibition of Mcp-1 reduced the infiltration of macrophages into the myocardium and prevented both systolic dysfunction and cardiac fibrosis in 12/15-LOX transgenic mice. Likewise, disruption of 12/15-LOX significantly reduced cardiac Mcp-1 expression and macrophage infiltration, thereby improving systolic dysfunction induced by chronic pressure overload. Our results suggest that cardiac 12/15-LOX is involved in the development of heart failure and that inhibition of 12/15-LOX could be a novel treatment for this condition.
Cardiac 12/15 lipoxygenase-induced inflammation is involved in heart failure.
Sex, Age
View SamplesPressure overload induces a transition from cardiac hypertrophy to heart failure, but its underlying mechanisms remain elusive. Here we reconstruct a trajectory of cardiomyocyte remodeling and clarify distinct cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure, by integrating single-cardiomyocyte transcriptome with cell morphology, epigenomic state and heart function. During early hypertrophy, cardiomyocytes activate mitochondrial translation/metabolism genes, whose expression is correlated with cell size and linked to ERK1/2 and NRF1/2 transcriptional networks. Persistent overload leads to a bifurcation into adaptive and failing cardiomyocytes, and p53 signaling is specifically activated in late hypertrophy. Cardiomyocyte-specific p53 deletion shows that cardiomyocyte remodeling is initiated by p53-independent mitochondrial activation and morphological hypertrophy, followed by p53-dependent mitochondrial inhibition, morphological elongation, and heart failure gene program activation. Human single-cardiomyocyte analysis validates the conservation of the pathogenic transcriptional signatures. Collectively, cardiomyocyte identity is encoded in transcriptional programs that orchestrate morphological and functional phenotypes. Overall design: Integrative analysis of single-cardiomyocyte RNA-seq of pressure-overload-induced heart failure model mice and heart failure patients with dilated cardiomyopathy, single-cell morphology, cardiac function and genetic perturbation
Cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure.
Subject
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