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 Human T cell activation. IV. T cell activation and proliferation via the early activation antigen EA 1.

1989 ◽  
Vol 169 (3) ◽  
pp. 677-689 ◽  
Author(s):  
S Nakamura ◽  
S S Sung ◽  
J M Bjorndahl ◽  
S M Fu
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Early Activation ◽  
Human T Cell ◽  
Accessory Cells ◽  
Activation Antigen

A new mAb G38 was generated against purified EA 1, an early activation antigen. In immunoprecipitation, it was reactive with the same complex precipitated by the initial anti-EA 1 mAb P8. mAb G38 augmented PMA-induced proliferation of PBMC. It was shown to be mitogenic for purified T cells in collaboration with PMA in a dose-dependent manner. This effect was independent of monocytes and other accessory cells. mAb G38 augmented PMA-induced IL-2-R expression. In conjunction with PMA, it induced IL-2 synthesis and secretion. Its effects on IL-2-R and IL-2 expression were documented at both protein and mRNA levels. Both anti-EA 1 mAbs did not induce Ca2+ influx by themselves in PMA-treated T cells. However, the addition of second anti-mouse Ig antibodies induced readily detectable increases in [Ca2+]i. Ca2+-mediated pathways may be utilized as the transduction signal mechanisms. mAb Leu-23 was shown to be reactive with EA 1. mAb Leu-23 was also mitogenic for T cells in the presence of PMA. These findings provide evidence for a functional role for EA 1 in T cell activation and proliferation.

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 Human T cell activation. III. Rapid induction of a phosphorylated 28 kD/32 kD disulfide-linked early activation antigen (EA 1) by 12-o-tetradecanoyl phorbol-13-acetate, mitogens, and antigens.

1986 ◽  
Vol 164 (6) ◽  
pp. 1988-2005 ◽  
Author(s):  
T Hara ◽  
L K Jung ◽  
J M Bjorndahl ◽  
S M Fu
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Activated T Cells ◽  
Early Activation ◽  
Human T Cell ◽  
Activated Monocytes ◽  
Activation Antigen

With human T cells activated by 12-o-tetradecanoyl phorbol-13-acetate (TPA) as immunogen, an IgG2a mAb, early activation antigen 1 (EA 1), was generated against a 60-kD protein with disulfide-linked 28-kD and 32-kD subunits. Both subunits were phosphorylated. The antigen, EA 1, was readily detected on approximately 60% of isolated and cryopreserved thymocytes, as determined by indirect immunofluorescence. A low level of EA 1 expression was detectable on 6-7% of blood lymphocytes. TPA-activated T cells expressed EA 1 as early as 30 min after activation. By 1 h, 85-90% of the T cells stained with mAb EA 1. By 3-4 h, the expression of EA 1 was detected in greater than 95% of the T cells. Although the percentages of EA 1+ T cells did not change, the intensity of staining increased slightly. After 18-24 h, both the percentage of EA 1+ cells and the intensity of staining decreased gradually. TPA-induced EA 1 expression was independent of monocytes. EA 1 expression was slightly delayed in T cells that were isolated without the rosette selection and treated with TPA. Nevertheless, greater than 85% of these T cells expressed EA 1 within 1 h, and the maximal number of EA 1+ T cells was also detected at 3-4 h. In T cell populations with 1-2% monocytes, about 50-90% of the PHA- or Con A-activated T cells expressed EA 1 with a slower kinetics. EA 1 expression preceded that of IL-2-R in these activation processes. Similarly, T cells activated by soluble antigens (tetanus toxoid and PPD) and alloantigens in MLR also expressed EA 1 after a longer incubation. Approximately 20% of the T cells stained for EA 1 at day 6. EA 1 expression was not limited to activated T cells. B cells activated by TPA or anti-IgM antibody plus B cell growth factor expressed EA 1. The kinetics of EA 1 expression was markedly slower and the staining was less intense. Repeated attempts to detect EA 1 on resting and TPA-activated monocytes and granulocytes have not been successful. However, the detection of EA 1 in nonlymphoid cell lines would indicate that EA 1 may have a broader cell distribution. EA 1 expression was due to de novo synthesis, as the induction of EA 1 was blocked by cycloheximide and actinomycin D.(ABSTRACT TRUNCATED AT 400 WORDS)

Methimazole therapy in Graves' disease influences the abnormal expression of CD69 (early activation antigen) on T cells

1997 ◽  
Vol 155 (3) ◽  
pp. 491-500 ◽  
Author(s):  
JJ Corrales ◽  
A Lopez ◽  
J Ciudad ◽  
MT Mories ◽  
JM Miralles ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Graves Disease ◽  
Early Activation ◽  
Activation Antigen

At present, the in vivo response of T, B and natural killer (NK) cells to antithyroid drug therapy remains largely unknown. In the present study, we have prospectively analyzed the in vivo effects of methimazole treatment on a large number of circulating T and NK cell subsets, some of them expressing cell surface activation antigens involved in the very early phase of the immune response, in a group of 17 hyperthyroid, untreated patients with Graves' disease (GD). As one of the first events during T cell activation is the expression of interleukin (IL) receptors, we also studied the binding of IL-2 and IL-6 to T cells. Patients with Graves' disease were sequentially studied at diagnosis/before treatment (day 0) and 7, 14, 30, 90 and 180 days after methimazole therapy. The results were compared with both a group of 19 age- and sex-matched control volunteers and a group of 20 untreated/euthyroid patients with Graves' disease in long-term remission. The combination of flow cytometry and three-color immunofluorescence revealed a clear (P < 0.01) decrease in the percentage of NK cells before and during the whole course of therapy with respect to both controls and patients with Graves' disease who were in long-term remission. Before therapy, a marked increase (P < 0.001) in the ratio of B to NK cells was also observed; thereafter, a slight decrease in this ratio was observed, although normal values were detected only in patients in long-term remission. Expression of the CD69 early activation antigen in the hyperthyroid untreated patients with Graves' disease was clearly increased (P < 0.01) with respect to both controls and patients with Graves' disease who were in long-term remission. This abnormal CD69 expression was found to be significantly reduced (P < 0.001) by methimazole therapy, and this represents a new effect of the drug. Expression of the low-affinity receptor for IL-2 (CD25)--another early T cell activation marker--was not altered in Graves' disease, but the binding of IL-2 and IL-6 to T cells exhibited a progressive and parallel increase during the first 30 days of therapy, decreasing thereafter. Our results show that methimazole therapy downregulates the abnormally high expression of the CD69 early activation antigen on T cells, being less effective on inducing changes in other T cell activation markers and in NK cells.

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.

scholarly journals Antigen-independent activation of naive and memory resting T cells by a cytokine combination.

1994 ◽  
Vol 180 (3) ◽  
pp. 1159-1164 ◽  
Author(s):  
D Unutmaz ◽  
P Pileri ◽  
S Abrignani
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Effector Function ◽  
Necrosis Factor Alpha ◽  
Naive T Cells ◽  
Naïve T Cells

We investigated whether human resting T cells could be activated to proliferate and display effector function in the absence of T cell receptor occupancy. We report that combination of interleukin 2 (IL-2), tumor necrosis factor alpha, and IL-6 activated highly purified naive (CD45RA+) and memory (CD45RO+) resting CD4+ T cells to proliferate. Under this condition, memory resting T cells could also display effector function as measured by lymphokine synthesis and help for immunoglobulin production by B cells. This novel Ag-independent pathway of T cell activation may play an important role in vivo in recruiting effector T cells at the site of immune response and in maintaining the clonal size of memory T cells in the absence of antigenic stimulation. Moreover, cytokines can induce proliferation of naive T cells without switch to memory phenotype and this may help the maintenance of the peripheral pool of naive T cells.

Effect of CD28 signal transduction on c-Rel in human peripheral blood T cells

1994 ◽  
Vol 14 (12) ◽  
pp. 7933-7942
Author(s):  
R G Bryan ◽  
Y Li ◽  
J H Lai ◽  
M Van ◽  
N R Rice ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Nuclear Translocation ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Cd28 Costimulation

Optimal T-cell activation requires both an antigen-specific signal delivered through the T-cell receptor and a costimulatory signal which can be delivered through the CD28 molecule. CD28 costimulation induces the expression of multiple lymphokines, including interleukin 2 (IL-2). Because the c-Rel transcription factor bound to and activated the CD28 response element within the IL-2 promoter, we focused our study on the mechanism of CD28-mediated regulation of c-Rel in human peripheral blood T cells. We showed that CD28 costimulation accelerated the kinetics of nuclear translocation of c-Rel (and its phosphorylated form), p50 (NFKB1), and p65 (RelA). The enhanced nuclear translocation of c-Rel correlated with the stimulation of Il-2 production and T-cell proliferation by several distinct anti-CD28 monoclonal antibodies. This is explained at least in part by the long-term downregulation of I kappa B alpha following CD28 signalling as opposed to phorbol myristate acetate alone. Furthermore, we showed that the c-Rel-containing CD28-responsive complex is enhanced by, but not specific to, CD28 costimulation. Our results indicate that c-Rel is one of the transcription factors targeted by CD28 signalling.

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