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.

Mechanism of Interleukin-10 Inhibition of T-Helper Cell Activation by Superantigen at the Level of the Cell Cycle

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 208-216 ◽  
Author(s):  
George Q. Perrin ◽  
Howard M. Johnson ◽  
Prem S. Subramaniam
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Inhibitory Protein ◽  
Cell Functions

Abstract We have analyzed the effects of interleukin-10 (IL-10) on the entry of quiescent CD4+ T cells into the cell cycle upon stimulation with the superantigen staphylococcal enterotoxin B (SEB). IL-10 arrested cells at G0/G1. IL-10 treatment prevented the downregulation of p27Kip1, an inhibitory protein that controls progression out of the G0 phase of the cell cycle. IL-10 also prevented the upregulation of the G1 cyclins D2 and D3, proteins necessary for entry and progression through the G1 phase of the cell cycle. Associated with the inhibition of the cell cycle, IL-10 suppressed SEB induction of interleukin-2 (IL-2). Addition of exogenous IL-2 to IL-10–treated cells significantly reversed the antiproliferative effects of IL-10. Moreover, IL-10 effects on the early G1proteins p27Kip1 and cyclin D2 were similarly reversed by exogenous IL-2. Although this reversal by IL-2 was pronounced, it was not complete, suggesting that IL-10 may have some effects not directly related to the suppression of IL-2 production. Cell separation experiments suggest that IL-10 can effect purified CD4+ T cells directly, providing functional evidence for the presence of IL-10 receptors on CD4+ T cells. IL-10 also inhibited expression of IL-2 transcriptional regulators c-fos and c-jun, which also inhibit other cell functions. Our studies show that the mechanism of IL-10 regulation of quiescent CD4+ T-cell activation is mainly by blocking induction of IL-2 that is critical to downregulation of p27Kip1 and upregulation of D cyclins in T-cell activation and entry into the cell cycle.

Mechanism of Interleukin-10 Inhibition of T-Helper Cell Activation by Superantigen at the Level of the Cell Cycle

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 208-216
Author(s):  
George Q. Perrin ◽  
Howard M. Johnson ◽  
Prem S. Subramaniam
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Inhibitory Protein ◽  
Cell Functions

We have analyzed the effects of interleukin-10 (IL-10) on the entry of quiescent CD4+ T cells into the cell cycle upon stimulation with the superantigen staphylococcal enterotoxin B (SEB). IL-10 arrested cells at G0/G1. IL-10 treatment prevented the downregulation of p27Kip1, an inhibitory protein that controls progression out of the G0 phase of the cell cycle. IL-10 also prevented the upregulation of the G1 cyclins D2 and D3, proteins necessary for entry and progression through the G1 phase of the cell cycle. Associated with the inhibition of the cell cycle, IL-10 suppressed SEB induction of interleukin-2 (IL-2). Addition of exogenous IL-2 to IL-10–treated cells significantly reversed the antiproliferative effects of IL-10. Moreover, IL-10 effects on the early G1proteins p27Kip1 and cyclin D2 were similarly reversed by exogenous IL-2. Although this reversal by IL-2 was pronounced, it was not complete, suggesting that IL-10 may have some effects not directly related to the suppression of IL-2 production. Cell separation experiments suggest that IL-10 can effect purified CD4+ T cells directly, providing functional evidence for the presence of IL-10 receptors on CD4+ T cells. IL-10 also inhibited expression of IL-2 transcriptional regulators c-fos and c-jun, which also inhibit other cell functions. Our studies show that the mechanism of IL-10 regulation of quiescent CD4+ T-cell activation is mainly by blocking induction of IL-2 that is critical to downregulation of p27Kip1 and upregulation of D cyclins in T-cell activation and entry into the cell cycle.

scholarly journals Differential Interleukin-2 Transcription Kinetics Render Mouse but Not Human T Cells Vulnerable to Splicing Inhibition Early after Activation

2019 ◽  
Vol 39 (16) ◽  
Author(s):  
Debojit Bose ◽  
Alexander Neumann ◽  
Bernd Timmermann ◽  
Stefan Meinke ◽  
Florian Heyd
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Time Window ◽  
Interleukin 2 ◽  
Adaptive Immune Response ◽  
Human T Cells ◽  
Splicing Efficiency

ABSTRACTT cells are nodal players in the adaptive immune response against pathogens and malignant cells. Alternative splicing plays a crucial role in T cell activation, which is analyzed mainly at later time points upon stimulation. Here we have discovered a 2-h time window early after stimulation where optimal splicing efficiency or, more generally, gene expression efficiency is crucial for successful T cell activation. Reducing the splicing efficiency at 4 to 6 h poststimulation significantly impaired murine T cell activation, which was dependent on the expression dynamics of the Egr1–Nab2–interleukin-2 (IL-2) pathway. This time window overlaps the time of peak IL-2de novotranscription, which, we suggest, represents a permissive time window in which decreased splicing (or transcription) efficiency reduces mature IL-2 production, thereby hampering murine T cell activation. Notably, the distinct expression kinetics of the Egr1–Nab2–IL-2 pathway between mouse and human render human T cells refractory to this vulnerability. We propose that the rational temporal modulation of splicing or transcription during peakde novoexpression of key effectors can be used to fine-tune stimulation-dependent biological outcomes. Our data also show that critical consideration is required when extrapolating mouse data to the human system in basic and translational research.

scholarly journals Simultaneous flow cytometric analysis of human T cell activation antigen expression and DNA content.

1983 ◽  
Vol 157 (2) ◽  
pp. 461-472 ◽  
Author(s):  
T Cotner ◽  
J M Williams ◽  
L Christenson ◽  
H M Shapiro ◽  
T B Strom ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Flow Cytometric Analysis ◽  
Early Activation ◽  
Activation Antigens ◽  
Activation Antigen

Cell-surface antigens that are induced to appear on T cells activated by the lectin phytohemagglutinin-P (PHA) can be classified both on the basis of the kinetics of their appearance and on their growth-association properties. Seven distinct T cell activation antigens, defined by monoclonal antibodies, were classified as early, intermediate, or late antigens based on their temporal appearance relative to DNA synthesis. Four antigens, the transferrin receptor, the T cell activation antigen Tac, the 4F2 antigen, and the 49.9 antigen were early antigens, whereas the OKT10 antigen appeared at intermediate times and both HLA-DR and antigen 19.2 appeared late. The use of a dye, Hoechst 33342, which stains DNA stoichiometrically, allowed the simultaneous analysis of immunofluorescence and cell cycle position of individual cells. This analysis unexpectedly revealed that essentially all cells in the proliferative phase of the cell cycle expressed each of the four early-activation antigens. The correlation between expression of the four early-activation antigens and T cell proliferation suggests that these molecules are important for the growth of all T cells. The relationship of two of these activation antigens, known to be the receptors for transferrin and interleukin 2, a T cell growth factor, is discussed with special reference to the roles of their ligands in supporting the growth of T cells.

scholarly journals A negative role for the interleukin-2-inducible T-cell kinase (ITK) in human Foxp3+ TREG differentiation

2018 ◽  
Author(s):  
Polina Mamontov ◽  
Ryan A. Eberwine ◽  
Jackie Perrigoue ◽  
Anuk Das ◽  
Joshua R. Friedman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Kinase Inhibitor ◽  
Interleukin 2 ◽  
Tec Kinases ◽  
Human T Cells ◽  
Inducible T Cell Kinase

ABSTRACTThe Tec kinases ITK (interleukin-2-inducible T-cell kinase) and RLK (resting lymphocyte kinase) are critical components of the proximal TCR/CD3 signal transduction machinery, and data in mice suggest that ITK negatively regulates TREG differentiation. However, whether Tec kinases modulate TREG development and/or function in human T cells remains unknown. Using a novel self-delivery siRNA platform (sdRNA), we found that ITK knockdown in primary human naïve peripheral blood CD4 T cells increased Foxp3+ TREG differentiation under both TREG and T effector (Teff) cell priming conditions. ITK knockdown also enhanced the expression of the co-inhibitory receptor PD-1 on FoxP3+ T cells. TREGS differentiated in vitro (iTREG) after ITK knockdown displayed suppressive capacity against effector CD4+ T cell proliferation. ITK knockdown decreased IL-17A production in T cells primed under Th17 conditions and increased Th1 differentiation. Finally, a dual ITK/RLK Tec kinase inhibitor blocked TREG differentiation and T cell activation in general. Our data suggest that targeting ITK in human T cells may be an effective approach to boost TREG in the context of autoimmune diseases, but non-specific inhibition of other Tec family kinases may broadly inhibit T cell activation.

scholarly journals CD28-B7 interactions allow the induction of CD8+ cytotoxic T lymphocytes in the absence of exogenous help.

1993 ◽  
Vol 177 (6) ◽  
pp. 1791-1796 ◽  
Author(s):  
F A Harding ◽  
J P Allison
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytotoxic T Cells ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Histocompatibility Complex ◽  
Necessary And Sufficient ◽  
Additional Antigen

The activation requirements for the generation of CD8+ cytotoxic T cells (CTL) are poorly understood. Here we demonstrate that in the absence of exogenous help, a CD28-B7 interaction is necessary and sufficient for generation of class I major histocompatibility complex-specific CTL. Costimulation is required only during the inductive phase of the response, and not during the effector phase. Transfection of the CD28 counter receptor, B7, into nonstimulatory P815 cells confers the ability to elicit P815-specific CTL, and this response can be inhibited by anti-CD28 Fab or by the chimeric B7-binding protein CTLA4Ig. Anti-CD28 monoclonal antibody (mAb) can provide a costimulatory signal to CD8+ T cells when the costimulatory capacity of splenic stimulators is destroyed by chemical fixation. CD28-mediated signaling provokes the release of interleukin 2 (IL-2) from the CD8+ CTL precursors, as anti-CD28 mAb could be substituted for by the addition of IL-2, and an anti-IL-2 mAb can block the generation of anti-CD28-induced CTL. CD4+ cells are not involved in the costimulatory response in the systems examined. We conclude that CD8+ T cell activation requires two signals: an antigen-specific signal mediated by the T cell receptor, and an additional antigen nonspecific signal provided via a CD28-B7 interaction.

scholarly journals SLFN2 protection of tRNAs from stress-induced cleavage is essential for T cell–mediated immunity

Science ◽  
2021 ◽  
Vol 372 (6543) ◽  
pp. eaba4220 ◽  
Author(s):  
Tao Yue ◽  
Xiaoming Zhan ◽  
Duanwu Zhang ◽  
Ruchi Jain ◽  
Kuan-wen Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Cell Mediated Immunity ◽  
Activated T Cells ◽  
Granule Formation

Reactive oxygen species (ROS) increase in activated T cells because of metabolic activity induced to support T cell proliferation and differentiation. We show that these ROS trigger an oxidative stress response that leads to translation repression. This response is countered by Schlafen 2 (SLFN2), which directly binds transfer RNAs (tRNAs) to protect them from cleavage by the ribonuclease angiogenin. T cell–specific SLFN2 deficiency results in the accumulation of tRNA fragments, which inhibit translation and promote stress-granule formation. Interleukin-2 receptor β (IL-2Rβ) and IL-2Rγ fail to be translationally up-regulated after T cell receptor stimulation, rendering SLFN2-deficient T cells insensitive to interleukin-2’s mitogenic effects. SLFN2 confers resistance against the ROS-mediated translation-inhibitory effects of oxidative stress normally induced by T cell activation, permitting the robust protein synthesis necessary for T cell expansion and immunity.

Sign in / Sign up

Export Citation Format

Share Document