scholarly journals Multi-level remodelling of chromatin underlying activation of human T cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naiara G. Bediaga ◽  
Hannah D. Coughlan ◽  
Timothy M. Johanson ◽  
Alexandra L. Garnham ◽  
Gaetano Naselli ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Chromatin Accessibility ◽  
Chromatin Architecture ◽  
Chromatin Interactions ◽  
Human T Cells ◽  
Multi Level

AbstractRemodelling of chromatin architecture is known to regulate gene expression and has been well characterized in cell lineage development but less so in response to cell perturbation. Activation of T cells, which triggers extensive changes in transcriptional programs, serves as an instructive model to elucidate how changes in chromatin architecture orchestrate gene expression in response to cell perturbation. To characterize coordinate changes at different levels of chromatin architecture, we analyzed chromatin accessibility, chromosome conformation and gene expression in activated human T cells. T cell activation was characterized by widespread changes in chromatin accessibility and interactions that were shared between activated CD4+ and CD8+ T cells, and with the formation of active regulatory regions associated with transcription factors relevant to T cell biology. Chromatin interactions that increased and decreased were coupled, respectively, with up- and down-regulation of corresponding target genes. Furthermore, activation was associated with disruption of long-range chromatin interactions and with partitioning of topologically associating domains (TADs) and remodelling of their TAD boundaries. Newly formed/strengthened TAD boundaries were associated with higher nucleosome occupancy and lower accessibility, linking changes in lower and higher order chromatin architecture. T cell activation exemplifies coordinate multi-level remodelling of chromatin underlying gene transcription.

scholarly journals Activation-induced re-organization of chromatin in human T cells

2020 ◽  
Author(s):  
Naiara G. Bediaga ◽  
Hannah D. Coughlan ◽  
Timothy M. Johanson ◽  
Alexandra L. Garnham ◽  
Gaetano Naselli ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Genes ◽  
Nucleosome Occupancy ◽  
Chromatin Accessibility ◽  
Chromatin Architecture ◽  
Chromatin Interactions ◽  
Human T Cells

ABSTRACTRemodelling of chromatin architecture is known to regulate gene expression and has been well characterized in cell lineage development but less so in response to cell perturbation. Activation of T cells, which triggers extensive changes in transcriptional programs, serves as an instructive model to elucidate how changes in genome organization orchestrate gene expression in response to cell perturbation. To characterize coordinate changes at different levels of chromatin architecture, we analysed chromatin accessibility, chromosome conformation and gene expression after activation of human T cells. T cell activation led to widespread changes in chromatin interactions and accessibility that were mostly shared between CD4+ and CD8+ T cells. Differential chromatin interactions were associated with upregulation or downregulation of linked target genes. Moreover, activation was associated with the formation of shorter chromatin interactions, partitioning of topologically associating domains (TADs) and acquisition of new TAD boundaries characterized by higher nucleosome occupancy, and lower chromatin accessibility and gene expression. These findings render an integrated and multiscale characterization of activation-induced re-organization of chromatin architecture underlying gene transcription in human T cells.

scholarly journals Nanoconfinement of Microvilli Alters Gene Expression and Boosts T cell Activation

2021 ◽  
Author(s):  
Morteza Aramesh ◽  
Diana Stoycheva ◽  
Ioana Sandu ◽  
Stephan J. Ihle ◽  
Tamara Zund ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Cell Signaling ◽  
T Cell Activation ◽  
Cell Activation ◽  
Local Environment ◽  
T Cell Signaling ◽  
Sense And Respond ◽  
Altered Gene

T cells sense and respond to their local environment at the nanoscale by forming small actin-rich protrusions, called microvilli, which play critical roles in signaling and antigen recognition, particularly at the interface with the antigen presenting cells. However, the mechanisms by which microvilli contribute to cell signaling and activation is largely unknown. Here, we present a tunable engineered system that promotes microvilli formation and T cell signaling via physical stimuli. We discovered that nanoporous surfaces favored microvilli formation, and markedly altered gene expression in T cells and promoted their activation. Mechanistically, confinement of microvilli inside of nanopores leads to size-dependent sorting of membrane-anchored proteins, specifically segregating CD45 phosphatases and T cell receptors (TCR) from the tip of the protrusions when microvilli are confined in 200 nm pores, but not in 400 nm pores. Consequently, formation of TCR nanoclustered hotspots within 200 nm pores, allows sustained and augmented signaling that prompts T cell activation even in the absence of TCR agonists. The synergistic combination of mechanical and biochemical signals on porous surfaces presents a straightforward strategy to investigate the role of microvilli in T cell signaling as well as to boost T cell activation and expansion for application in the growing field of adoptive immunotherapy.

scholarly journals Single-cell transcriptomics of human T cells reveals tissue and activation signatures in health and disease

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Peter A. Szabo ◽  
Hanna Mendes Levitin ◽  
Michelle Miron ◽  
Mark E. Snyder ◽  
Takashi Senda ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interferon Response ◽  
Functional Responses ◽  
Multiple Tumor ◽  
Human T Cell ◽  
Human T Cells

Abstract Human T cells coordinate adaptive immunity in diverse anatomic compartments through production of cytokines and effector molecules, but it is unclear how tissue site influences T cell persistence and function. Here, we use single cell RNA-sequencing (scRNA-seq) to define the heterogeneity of human T cells isolated from lungs, lymph nodes, bone marrow and blood, and their functional responses following stimulation. Through analysis of >50,000 resting and activated T cells, we reveal tissue T cell signatures in mucosal and lymphoid sites, and lineage-specific activation states across all sites including distinct effector states for CD8+ T cells and an interferon-response state for CD4+ T cells. Comparing scRNA-seq profiles of tumor-associated T cells to our dataset reveals predominant activated CD8+ compared to CD4+ T cell states within multiple tumor types. Our results therefore establish a high dimensional reference map of human T cell activation in health for analyzing T cells in disease.

scholarly journals Non-voltage-gated L-type Ca2+Channels in Human T Cells

2004 ◽  
Vol 279 (19) ◽  
pp. 19566-19573 ◽  
Author(s):  
Leanne Stokes ◽  
John Gordon ◽  
Gillian Grafton
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Splice Variants ◽  
Antigen Receptor ◽  
Dominant Form ◽  
Voltage Gated ◽  
Antigen Receptor Signaling ◽  
Human T Cells

In T lymphocytes, engagement of the antigen receptor leads to a biphasic Ca2+flux consisting of a mobilization of Ca2+from intracellular stores followed by a lower but sustained elevation that is dependent on extracellular Ca2+. The prolonged Ca2+flux is required for activation of transcription factors and for subsequent activation of the T cell. Ca2+influx requires as yet unidentified Ca2+channels, which potentially play a role in T cell activation. Here we present evidence that human T cells express a non-voltage-gated Ca2+channel related to L-type voltage-gated Ca2+channels. Drugs that block classical L-type channels inhibited the initial phase of the antigen receptor-induced Ca2+flux and could also inhibit the sustained phase of the Ca2+signal suggesting a role for the L-type Ca2+channel in antigen receptor signaling. T cells expressed transcripts for the α11.2 and α11.3 pore-forming subunits of L-type voltage-gated Ca2+channels and transcripts for all four known β-subunits including several potential new splice variants. Jurkat T leukemia cells expressed a small amount of full-length α11.2 protein but the dominant form was a truncated protein identical in size to a truncated α11.2 protein known to be expressed in B lymphocytes. They further expressed a truncated form of the α11.3 subunit and auxiliary β1- and β3-subunit proteins. Our data strongly suggest that functional but non-voltage-gated L-type Ca2+channels are expressed at the plasma membrane in T cells and play a role in the antigen receptor-mediated Ca2+flux in these cells.

Lysophosphatidic acid enhances interleukin-13 gene expression and promoter activity in T cells

2006 ◽  
Vol 290 (1) ◽  
pp. L66-L74 ◽  
Author(s):  
Joshua Rubenfeld ◽  
Jia Guo ◽  
Nitat Sookrung ◽  
Rongbing Chen ◽  
Wanpen Chaicumpa ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Lysophosphatidic Acid ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Regulatory Elements ◽  
Jurkat Cells

Lysophosphatidic acid (LPA) is a membrane-derived lysophospholipid with wide-ranging effects on multiple lung cells including airway epithelial and smooth muscle cells. LPA can augment migration and cytokine synthesis in lymphocytes, but its potential effects on Th2 cytokines have not been well studied. We examined the effects of physiological concentrations of LPA on IL-13 gene expression in human T cells. The Jurkat T cell line and human peripheral blood CD4+ T cells were incubated with LPA alone or with 1) pharmacological agonists of different signaling pathways, or 2) antibodies directed against the T cell receptor complex and costimulatory molecules. Luciferase-based reporter constructs driven by different lengths of the human IL-13 promoter were transfected by electroporation in Jurkat cells treated with and without LPA. The effects of LPA on IL-13 mRNA stability were examined using actinomycin D to halt ongoing transcription. Expression of mRNA encoding LPA2and LPP-1 increased with T cell activation. LPA augmented IL-13 secretion under conditions of submaximal T cell activation. This was observed using pharmacological agonists activating intracellular calcium-, PKC-, and cAMP-dependent signaling pathways, as well as antibodies directed against CD3 and CD28. LPA only slightly prolonged IL-13 mRNA half-life in submaximally stimulated Jurkat cells. In contrast, LPA significantly enhanced transcriptional activation of the IL-13 promoter via regulatory elements contained within proximal 312 bp. The effects of LPA on IL-13 promoter activation appeared to be distinct from those mediated by GATA-3. LPA can augment IL-13 gene expression in T cells, especially under conditions of submaximal activation.

scholarly journals Interleukin-2-dependent phosphorylation of the retinoblastoma-susceptibility-gene product p110-115RB in human T-cells

1992 ◽  
Vol 282 (3) ◽  
pp. 759-764 ◽  
Author(s):  
G A Evans ◽  
L M Wahl ◽  
W L Farrar
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
Gene Transcription ◽  
T Cell Activation ◽  
Cell Activation ◽  
Susceptibility Gene ◽  
Interleukin 2 ◽  
Human T Cells ◽  
Rb Phosphorylation

The state of phosphorylation of the retinoblastoma-susceptibility gene product, p110-115RB, is thought to have fundamental importance in controlling the progression of the cell through the cell cycle. We have studied RB phosphorylation in human T-cells in the context of T-cell activation, stimulated by phytohaemagglutinin (PHA) and interleukin-2 (IL-2). We show that, of the signals associated with T-cell activation, only signals that directly lead to movement into S phase of the cell cycle are capable of stimulating RB phosphorylation. Cyclosporin A (CsA), a potent inhibitor of IL-2 synthesis and cellular proliferation, blocked RB phosphorylation, and this was recovered with exogenous IL-2, indicating a direct involvement of IL-2 in controlling RB phosphorylation. We found that PHA did not stimulate RB phosphorylation within 10 h of treatment, but IL-2 could effectively stimulate RB phosphorylation within 2 h, and this approached a maximum within 8-10 h of IL-2 treatment. Further, by using actinomycin D to inhibit new gene transcription following IL-2 stimulation, we found that early-cell-cycle phosphorylation of RB required IL-2-stimulated gene transcription. From these data we conclude that, in human T-cells, RB phosphorylation is not directly associated with T-cell receptor-mediated events, but requires the interaction of IL-2 and new gene transcription following IL-2 stimulation.

scholarly journals The immunobiology of CD27 and OX40 and their potential as targets for cancer immunotherapy

Blood ◽  
2018 ◽  
Vol 131 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Sarah L. Buchan ◽  
Anne Rogel ◽  
Aymen Al-Shamkhani
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
High Profile ◽  
Cell Immunity ◽  
Human T Cells ◽  
Checkpoint Receptors ◽  
Tumor Types

In recent years, monoclonal antibodies (mAbs) able to reinvigorate antitumor T-cell immunity have heralded a paradigm shift in cancer treatment. The most high profile of these mAbs block the inhibitory checkpoint receptors PD-1 and CTLA-4 and have improved life expectancy for patients across a range of tumor types. However, it is becoming increasingly clear that failure of some patients to respond to checkpoint inhibition is attributable to inadequate T-cell priming. For full T-cell activation, 2 signals must be received, and ligands providing the second of these signals, termed costimulation, are often lacking in tumors. Members of the TNF receptor superfamily (TNFRSF) are key costimulators of T cells during infection, and there has been an increasing interest in harnessing these receptors to augment tumor immunity. We here review the immunobiology of 2 particularly promising TNFRSF target receptors, CD27 and OX40, and their respective ligands, CD70 and OX40L, focusing on their role within a tumor setting. We describe the influence of CD27 and OX40 on human T cells based on in vitro studies and on the phenotypes of several recently described individuals exhibiting natural deficiencies in CD27/CD70 and OX40. Finally, we review key literature describing progress in elucidating the efficacy and mode of action of OX40- and CD27-targeting mAbs in preclinical models and provide an overview of current clinical trials targeting these promising receptor/ligand pairings in cancer.

scholarly journals HIV infection of primary human T cells is determined by tunable thresholds of T cell activation

2004 ◽  
Vol 34 (6) ◽  
pp. 1705-1714 ◽  
Author(s):  
Kyra Oswald-Richter ◽  
Stacy M. Grill ◽  
Mindy Leelawong ◽  
Derya Unutmaz
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human T Cells
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