scholarly journals Metabolic turnover and dynamics of RNA modifications by 13C labelling

2021 ◽  
Author(s):  
Paulo A Gameiro ◽  
Iosifina P Foskolou ◽  
Vesela Encheva ◽  
Mariana Silva dos Santos ◽  
James I MacRae ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Ribosomal Rna ◽  
Cell Activation ◽  
Metabolic Stress ◽  
Rna Modifications ◽  
Isotopic Labelling ◽  
Dynamic Modulation ◽  
13C Labelling ◽  
Stationary Conditions ◽  
Kinetics Of

Abstract RNA methylation regulates various aspects of RNA metabolism, and dynamic modulation ofRNA modifications has emerged as a major effector in cellular transitions. Yet, we lack quantitativemethods to comprehensively assess methylation dynamics, its features and regulatory inputs, acrossRNA modifications. We developed 13C-dynamods, an isotopic labelling approach using [13C-methyl]-methionine, to quantify the turnover of base modifications in newly synthesized RNA. This turnover-basedapproach resolved the contributions of mRNA vs. ncRNA modifications within polyadenylatedRNA and uncovered the distinct kinetics of N6-methyladenosine (m6A) and 7-methylguanosine (m7G)in mRNA. Moreover, we obtained converging evidence indicating presence of N6,N6-dimethyladenosine (m62A) in non-ribosomal RNA, in particular tRNA and rapidly decaying RNAs.Finally, we showed that mRNA methylation dynamics is coordinated with ribonucleotide biosynthesisduring T-cell activation, and revealed post-transcriptional lability of m6A upon metabolic stress. Thus,13C-dynamods enables studies of origin, maintenance and regulation of RNA modifications understeady-state and non-stationary conditions.

scholarly journals Metabolic turnover and dynamics of RNA modifications by 13C labelling

2021 ◽  
Author(s):  
Paulo A Gameiro ◽  
Iosifina Foskolou ◽  
Vesela Encheva ◽  
Mariana Silva dos Santos ◽  
James MacRae ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Mammalian Cells ◽  
Quantitative Methods ◽  
Cell Activation ◽  
Metabolic Stress ◽  
Rna Modifications ◽  
Biological Regulation ◽  
Rna Methylation ◽  
Ribonucleoprotein Complexes ◽  
Kinetics Of

Abstract RNA methylation is essential for appropriate assembly of ribonucleoprotein complexes. Dynamics of RNA methylation is thus important, but we lack quantitative methods to comprehensively assess it. We developed 13C-dynamods, an isotopic labelling approach using 13C-methyl-methionine, to quantify the turnover of base modifications in newly synthesized RNA, which is effective in distinguishing modifications in mRNAs from those in ncRNAs. This approach detected the presence of N6,N6-dimethyladenosine (m62A) in mRNA and tRNA in mammalian cells, and uncovered distinct kinetics of N-6-methyladenosine (m6A) and N-7-methylguanosine (m7G) in mRNA. Moreover, by assessing RNA metabolism during T-cell activation, we showed how methylation dynamics is coordinated with ribonucleotide biosynthesis. Finally, by quantification of methylation turnover and ribonucleoside abundance, we uncover the post-transcriptional lability of m6A in response to metabolic stress. Thus, 13C-dynamods enables studies of the origin, maintenance and biological regulation of RNA modifications under steady-state and non-stationary conditions.

Controlling receptor-ligand contact to examine kinetics of T cell activation

1997 ◽  
Vol 25 (6) ◽  
pp. 1072-1080 ◽  
Author(s):  
S. M. Patrick ◽  
H. An ◽  
M. B. Harris ◽  
I. B. Ivanov ◽  
N. S. Braunstein ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Receptor Ligand ◽  
Kinetics Of

Kinetics of T Cell Activation Are Altered in the Presence of Cancer

2010 ◽  
Vol 158 (2) ◽  
pp. 400-401
Author(s):  
A.J. Russ ◽  
L. Wentworth ◽  
C.S. Cho
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Kinetics Of

scholarly journals Metabolic stress and disease-stage specific basigin expression of peripheral blood immune cell subsets in COVID-19 patients

2020 ◽  
Author(s):  
Peter J. Siska ◽  
Katrin Singer ◽  
Jana Klitzke ◽  
Nathalie Kauer ◽  
Sonja-Maria Decking ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Metabolic Stress ◽  
Recovery Phase ◽  
Disease Stage ◽  
Immune Cell Subsets ◽  
Ros Accumulation

Coronavirus disease 2019 (COVID-19) is driven by dysregulated immune responses yet the role of immunometabolism in COVID-19 pathogenesis remains unclear. By investigating 47 patients with confirmed SARS-CoV-2 infection and 16 uninfected controls, we found an immunometabolic dysregulation specific for patients with progressed disease that was reversible in the recovery phase. Specifically, T cells and monocytes exhibited increased mitochondrial mass, accumulated intracellular ROS and these changes were accompanied by disrupted mitochondrial architecture. Basigin (CD147), but not established markers of T cell activation, was up-regulated on T cells from progressed COVID-19 patients and correlated with ROS accumulation, reflected in the transcriptome. During recovery, basigin and ROS decreased to match the uninfected controls. In vitro analyses confirmed the correlation and showed a down-regulation of ROS by dexamethasone treatment. Our findings provide evidence of a basigin-related and reversible immunometabolic dysregulation in COVID-19.

scholarly journals Functional and metabolic fitness of human CD4+ T lymphocytes during metabolic stress

2021 ◽  
Vol 4 (12) ◽  
pp. e202101013
Author(s):  
Lisa Holthaus ◽  
Virag Sharma ◽  
Daniel Brandt ◽  
Anette-Gabriele Ziegler ◽  
Martin Jastroch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Metabolic Stress ◽  
Sirtuin 1 ◽  
Interferon Response ◽  
Oligoadenylate Synthetase ◽  
Cell Functions

Human CD4+ T cells are essential mediators of immune responses. By altering the mitochondrial and metabolic states, we defined metabolic requirements of human CD4+ T cells for in vitro activation, expansion, and effector function. T-cell activation and proliferation were reduced by inhibiting oxidative phosphorylation, whereas early cytokine production was maintained by either OXPHOS or glycolytic activity. Glucose deprivation in the presence of mild mitochondrial stress markedly reduced all three T-cell functions, contrasting the exposure to resveratrol, an antioxidant and sirtuin-1 activator, which specifically inhibited cytokine production and T-cell proliferation, but not T-cell activation. Conditions that inhibited T-cell activation were associated with the down-regulation of 2′,5′-oligoadenylate synthetase genes via interferon response pathways. Our findings indicate that T-cell function is grossly impaired by stressors combined with nutrient deprivation, suggesting that correcting nutrient availability, metabolic stress, and/or the function of T cells in these conditions will improve the efficacy of T-cell–based therapies.

scholarly journals Sequential expression of genes involved in human T lymphocyte growth and differentiation.

1985 ◽  
Vol 161 (6) ◽  
pp. 1593-1598 ◽  
Author(s):  
M Krönke ◽  
W J Leonard ◽  
J M Depper ◽  
W C Greene
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Transferrin Receptor ◽  
Transcriptional Activity ◽  
Cell Activation ◽  
Receptor Gene ◽  
Ifn Gamma ◽  
Transient Event ◽  
Genes Encoding ◽  
Kinetics Of

Nuclear transcription assays were performed with isolated nuclei from human peripheral blood T lymphocytes stimulated with phytohemagglutinin and phorbol myristate acetate to determine the kinetics of transcriptional activity of various genes occurring in T cell activation. Although silent in resting T cells, the genes encoding c-myc and the interleukin 2 (IL-2) receptor were induced early, preceding gamma interferon (IFN-gamma), IL-2, and transferrin receptor gene transcription. Transcriptional activity of these genes fell after their respective peaks, indicating that the expression of these genes is a transient event during T cell activation. With the exception of the transferrin receptor gene, the kinetics of induction of these genes were not altered by concentrations of cycloheximide that inhibited protein synthesis. These data indicate that the induction of genes encoding c-myc, IL-2, IL-2 receptor, and IFN-gamma occur independently of the sequential production of the proteins they encode.

scholarly journals The role of β2 integrin in dendritic cell migration during infection

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Tarfa Altorki ◽  
Werner Muller ◽  
Andrew Brass ◽  
Sheena Cruickshank
Keyword(s):  
T Cell ◽  
Lymph Nodes ◽  
T Cell Activation ◽  
Cell Activation ◽  
Leukocyte Adhesion ◽  
Trichuris Muris ◽  
Dendritic Cell Migration ◽  
And Function ◽  
Kinetics Of

Abstract Background Dendritic cells (DCs) play a key role in shaping T cell responses. To do this, DCs must be able to migrate to the site of the infection and the lymph nodes to prime T cells and initiate the appropriate immune response. Integrins such as β2 integrin play a key role in leukocyte adhesion, migration, and cell activation. However, the role of β2 integrin in DC migration and function in the context of infection-induced inflammation in the gut is not well understood. This study looked at the role of β2 integrin in DC migration and function during infection with the nematode worm Trichuris muris. Itgb2tm1Bay mice lacking functional β2 integrin and WT littermate controls were infected with T. muris and the response to infection and kinetics of the DC response was assessed. Results In infection, the lack of functional β2 integrin significantly reduced DC migration to the site of infection but not the lymph nodes. The lack of functional β2 integrin did not negatively impact T cell activation in response to T. muris infection. Conclusions This data suggests that β2 integrins are important in DC recruitment to the infection site potentially impacting the initiation of innate immunity but is dispensible for DC migration to lymph nodes and T cell priming in the context of T. muris infection.

scholarly journals Alterations in the Human Plasma Lipidome in Response to Tularemia Vaccination

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 414
Author(s):  
Kristal M. Maner-Smith ◽  
Johannes B. Goll ◽  
Manoj Khadka ◽  
Travis L. Jensen ◽  
Jennifer K. Colucci ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Cell Activation ◽  
Lipid Classes ◽  
Human Response ◽  
Vaccine Response ◽  
Post Vaccination ◽  
Serum Cytokines ◽  
Lipid Species ◽  
Tularemia Vaccine ◽  
Kinetics Of

Tularemia is a highly infectious and contagious disease caused by the bacterium Francisella tularensis. To better understand human response to a live-attenuated tularemia vaccine and the biological pathways altered post-vaccination, healthy adults were vaccinated, and plasma was collected pre- and post-vaccination for longitudinal lipidomics studies. Using tandem mass spectrometry, we fully characterized individual lipid species within predominant lipid classes to identify changes in the plasma lipidome during the vaccine response. Separately, we targeted oxylipins, a subset of lipid mediators involved in inflammatory pathways. We identified 14 differentially abundant lipid species from eight lipid classes. These included 5-hydroxyeicosatetraenoic acid (5-HETE) which is indicative of lipoxygenase activity and, subsequently, inflammation. Results suggest that 5-HETE was metabolized to a dihydroxyeicosatrienoic acid (DHET) by day 7 post-vaccination, shedding light on the kinetics of the 5-HETE-mediated inflammatory response. In addition to 5-HETE and DHET, we observed pronounced changes in 34:1 phosphatidylinositol, anandamide, oleamide, ceramides, 16:1 cholesteryl ester, and other glycerophospholipids; several of these changes in abundance were correlated with serum cytokines and T cell activation. These data provide new insights into alterations in plasma lipidome post-tularemia vaccination, potentially identifying key mediators and pathways involved in vaccine response and efficacy.

scholarly journals Microclusters as T Cell Signaling Hubs: Structure, Kinetics, and Regulation

2021 ◽  
Vol 8 ◽  
Author(s):  
Lakshmi Balagopalan ◽  
Kumarkrishna Raychaudhuri ◽  
Lawrence E. Samelson
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cell Activation ◽  
Vesicular Trafficking ◽  
Image Resolution ◽  
Live Cells ◽  
Cell Surface Signaling ◽  
Kinetics Of

When T cell receptors (TCRs) engage with stimulatory ligands, one of the first microscopically visible events is the formation of microclusters at the site of T cell activation. Since the discovery of these structures almost 20 years ago, they have been studied extensively in live cells using confocal and total internal reflection fluorescence (TIRF) microscopy. However, due to limits in image resolution and acquisition speed, the spatial relationships of signaling components within microclusters, the kinetics of their assembly and disassembly, and the role of vesicular trafficking in microcluster formation and maintenance were not finely characterized. In this review, we will summarize how new microscopy techniques have revealed novel insights into the assembly of these structures. The sub-diffraction organization of microclusters as well as the finely dissected kinetics of recruitment and disassociation of molecules from microclusters will be discussed. The role of cell surface molecules in microcluster formation and the kinetics of molecular recruitment via intracellular vesicular trafficking to microclusters is described. Finally, the role of post-translational modifications such as ubiquitination in the downregulation of cell surface signaling molecules is also discussed. These results will be related to the role of these structures and processes in T cell activation.

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