Search results for "Regulatory"

Regulation of the sea urchin early H2A histone gene expression depends on the modulator element and on sequences located near the 3' end

1999

Abstract Transcription of the sea urchin early histone genes occurs transiently during early cleavage, reaching the maximum at the morula stage and declining to an undetectable level at the gastrula stage. To identify the regulatory elements responsible for the timing and the levels of transcription of the H2A gene, we used promoter binding studies in nuclear extracts and microinjection of a CAT transgene driven by the early H2A promoter. We found that morula and gastrula nuclear proteins produced indistinguishable DNase I footprint patterns on the H2A promoter. Two sites of interactions, centred on the modulator/enhancer and on the CCAAT box respectively, were detected. Deletion of the mod…

Major orchestration of shikimate, early phenylpropanoid and stilbenoid pathways by Subgroup 2 R2R3-MYBs in grapevine

2021

AbstractThe stilbenoid pathway is responsible for the production of resveratrol and its derivatives in grapevine. A few transcription factors (TFs) have been previously identified as regulators of this pathway but the extent of this control is yet to be fully understood. Here we demonstrate how DNA affinity purification sequencing (DAP-Seq) allows for genome-wide TF binding site interrogation in a non-model species. We obtained 5,190 and 4,443 binding events assigned to 4,041 and 3,626 genes for MYB14 and MYB15, respectively (around 40% of peaks being located within -10kb of transcription start sites). DAP-Seq of MYB14 and MYB15 was combined with aggregate gene centred co-expression network…

Resolving the transcriptional transitions associated with oligodendrocyte generation from adult neural stem cells by single cell sequencing

2020

AbstractThe subventricular zone (SVZ) is the largest neurogenic niche in the adult forebrain. Notably, neural stem cells (NSCs) of the SVZ generate not only neurons, but also oligodendrocytes, the myelin-forming cells of the central nervous system. Transcriptomic studies have provided detailed knowledge of the molecular events that regulate neurogenesis, but little is understood about adult oligodendrogenesis from SVZ-NSCs. To address this, we performed in-depth single-cell transcriptomic analyses to resolve the major differences in neuronal and oligodendroglial lineages derived from the adult SVZ. A hallmark of adult oligodendrogenesis was the stage-specific expression of transcriptional m…

Release of dendritic cells from cognate CD4 + T-cell recognition results in impaired peripheral tolerance and fatal cytotoxic T-cell mediated autoimm…

2012

Resting dendritic cells (DCs) induce tolerance of peripheral T cells that have escaped thymic negative selection and thus contribute significantly to protection against autoimmunity. We recently showed that CD4 + Foxp3 + regulatory T cells (Tregs) are important for maintaining the steady-state phenotype of DCs and their tolerizing capacity in vivo. We now provide evidence that DC activation in the absence of Tregs is a direct consequence of missing DC–Treg interactions rather than being secondary to generalized autoimmunity in Treg-less mice. We show that DCs that lack MHC class II and thus cannot make cognate interactions with CD4 + T cells are completely unable to induce peripheral CD8 +…

Regulatory T Cells More Effectively Suppress Th1-Induced Airway Inflammation Compared with Th2

2011

Abstract Asthma is a syndrome with different inflammatory phenotypes. Animal models have shown that, after sensitization and allergen challenge, Th2 and Th1 cells contribute to the development of allergic airway disease. We have previously demonstrated that naturally occurring regulatory T cells (nTregs) can only marginally suppress Th2-induced airway inflammation and airway hyperresponsiveness. In this study, we investigated nTreg-mediated suppression of Th2-induced and Th1-induced acute allergic airway disease. We demonstrate in vivo that nTregs exert their suppressive potency via cAMP transfer on Th2- and Th1-induced airway disease. A comparison of both phenotypes revealed that, despite …

Interleukin-7 matures suppressive CD127(+) forkhead box P3 (FoxP3)(+) T cells into CD127(-) CD25(high) FoxP3(+) regulatory T cells.

2011

We have identified a novel interleukin (IL)-7-responsive T cell population [forkhead box P3 (FoxP3(+) ) CD4(+) CD25(+) CD127(+) ] that is comparably functionally suppressive to conventional FoxP3(+) CD4(+) CD25(+) regulatory T cells (T(regs) ). Although IL-2 is the most critical cytokine for thymic development of FoxP3(+) T(regs) , in the periphery other cytokines can be compensatory. CD25(+) CD127(+) T cells treated with IL-7 phenotypically 'matured' into the known 'classical' FoxP3(+) CD4(+) CD25(high) CD127(-) FoxP3(+) T(regs) . In freshly isolated splenocytes, the highest level of FoxP3 expression was found in CD127(+) CD25(+) T cells when compared with CD127(-) CD25(+) or CD127(+) CD25…

Regulatory (suppressor) T cells in peripheral allograft tolerance and graft-versus-host reaction.

2004

Among the mechanisms capable of inducing peripheral tolerance, regulatory (suppressor) T cells (Treg) probably play a key role in the control of both reactivity to self-antigens and alloimmune response. Augmentation or manipulation of Treg could improve organ allograft survival or control graft-versus-host disease, thus resulting in operational tolerance. The role of this immunomanipulation as one method of inducing tolerance has yet to be clearly defined.

Immune regulation by regulatory T cells: implications for transplantation.

2003

Item does not contain fulltext The induction of antigen-specific T cell tolerance and its maintenance in the periphery are critical for the immune system to prevent autoaggressive immune responses. Our current state of knowledge about the immunoregulatory mechanisms responsible for T cell tolerance in the periphery offers new possibilities for immunomodulation to prevent transplant rejection as well as to diminish autoimmune reaction or chronic allergy. There is growing evidence that dendritic cells, besides their well-known T cell stimulatory functions, also maintain and regulate T cell tolerance in the periphery. This control function is exerted by certain maturation stages and subsets of…

Distinct subsets of intrathyroidal regulatory CD4+CD25+ and CD8+CD25+ T cells in Hashimoto's thyroiditis: Potential role in the neoplastic cell growt…

2005

Plasmacytoid dendritic cells are inefficient in activation of human regulatory T cells

2011

BACKGROUND: Dendritic cells (DC) play a key role in initiation and regulation of immune responses. Plasmacytoid DC (pDC), a small subset of DC, characterized as type-I interferon producing cells, are critically involved in anti-viral immune responses, but also mediate tolerance by induction of regulatory T cells (Treg). In this study, we compared the capacity of human pDC and conventional DC (cDC) to modulate T cell activity in presence of Foxp3(+) Treg. PRINCIPAL FINDINGS: In coculture of T effector cells (Teff) and Treg, activated cDC overcome Treg anergy, abrogate their suppressive function and induce Teff proliferation. In contrast, pDC do not break Treg anergy but induce Teff prolifera…