scholarly journals Fas transduces activation signals in normal human T lymphocytes.

1993 ◽  
Vol 178 (6) ◽  
pp. 2231-2235 ◽  
Author(s):  
M R Alderson ◽  
R J Armitage ◽  
E Maraskovsky ◽  
T W Tough ◽  
E Roux ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Interleukin 2 ◽  
Tumor Necrosis Factor Receptor ◽  
Lymphoid Cells ◽  
Culture Vessel ◽  
Cell Surface Molecule ◽  
Transformed Cell ◽  
Transformed Cell Lines

The Fas gene encodes a cell surface molecule that is a member of the the nerve growth factor/tumor necrosis factor receptor family of proteins and can mediate programmed cell death (apoptosis) in certain transformed cell lines. To characterize further the biological function of Fas, particularly with regard to its function in normal cells, a panel of monoclonal antibodies (mAbs) was generated against the extracellular portion of human Fas. Some of these mAbs induced apoptosis in transformed cell lines expressing Fas, but only when immobilized on the culture vessel. One of the new Fas mAbs (M38) was used for studies on normal lymphoid cells and found to stimulate the proliferation of purified human T cells and thymocytes when immobilized on culture wells along with CD3 antibody. T cell proliferation induced by Fas mAb was largely interleukin 2 independent and was demonstrated to be due to a direct effect on the precursor T cell. Thus, the data demonstrate that in addition to a role in the induction of apoptosis in certain transformed cell lines, the Fas protein may also play an important role in the activation and proliferation of normal T cells.

scholarly journals Nonmalignant T cells stimulate growth of T-cell lymphoma cells in the presence of bacterial toxins

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3325-3332 ◽  
Author(s):  
Anders Woetmann ◽  
Paola Lovato ◽  
Karsten W. Eriksen ◽  
Thorbjørn Krejsgaard ◽  
Tord Labuda ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Mhc Class Ii ◽  
Interleukin 2 ◽  
Class Ii ◽  
Bacterial Toxins ◽  
Dependent Manner ◽  
Malignant Cells ◽  
T Cell Lines

AbstractBacterial toxins including staphylococcal enterotoxins (SEs) have been implicated in the pathogenesis of cutaneous T-cell lymphomas (CTCLs). Here, we investigate SE-mediated interactions between nonmalignant T cells and malignant T-cell lines established from skin and blood of CTCL patients. The malignant CTCL cells express MHC class II molecules that are high-affinity receptors for SE. Although treatment with SE has no direct effect on the growth of the malignant CTCL cells, the SE-treated CTCL cells induce vigorous proliferation of the SE-responsive nonmalignant T cells. In turn, the nonmalignant T cells enhance proliferation of the malignant cells in an SE- and MHC class II–dependent manner. Furthermore, SE and, in addition, alloantigen presentation by malignant CTCL cells to irradiated nonmalignant CD4+ T-cell lines also enhance proliferation of the malignant cells. The growth-promoting effect depends on direct cell-cell contact and soluble factors such as interleukin-2. In conclusion, we demonstrate that SE triggers a bidirectional cross talk between nonmalignant T cells and malignant CTCL cells that promotes growth of the malignant cells. This represents a novel mechanism by which infections with SE-producing bacteria may contribute to pathogenesis of CTCL.

scholarly journals Inhibition of p53 Transactivation Function by the Human T-Cell Lymphotropic Virus Type 1 Tax Protein

1998 ◽  
Vol 72 (2) ◽  
pp. 1165-1170 ◽  
Author(s):  
Cynthia A. Pise-Masison ◽  
Kyeong-Sook Choi ◽  
Michael Radonovich ◽  
Jürgen Dittmer ◽  
Seong-Jin Kim ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Lines ◽  
Virus Type ◽  
Primary Role ◽  
Wild Type ◽  
Transformed Cell ◽  
Human T Cell ◽  
Wild Type P53 ◽  
Transformed Cell Lines

ABSTRACT Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia. HTLV-1 transforms lymphocytes, and there is increasing evidence that the virus-encoded protein, Tax, plays a primary role in viral transformation. We have shown that wild-type p53 in HTLV-1-transformed cells is stabilized. This study was initiated to directly analyze whether the p53 in HTLV-1-transformed cell lines was transcriptionally active and to identify the viral gene product responsible for stabilization and inactivation. Transfection experiments using a p53-responsive reporter plasmid and γ-irradiation studies demonstrate that the wild-type p53 in HTLV-1-transformed cell lines is not fully active. Further, we demonstrate that the HTLV-1-transforming protein, Tax, stabilizes and inactivates p53 function. Cotransfection of Tax with p53 results in a greater than 10-fold reduction in p53 transcription activity. Using Gal4-p53 fusion proteins, we demonstrate that Tax inhibition of p53 transactivation function is independent of sequence-specific DNA binding. Moreover, Tax inhibits p53 function by interfering with the activity of the N-terminal activation domain (amino acids 1 to 52). We conclude that Tax is involved in the inactivation of p53 function and stabilization of p53 in HTLV-1-infected cells. The functional interference of p53 function by Tax may be important for transformation and leukemogenesis.

scholarly journals Interleukin 2 induces antigen-reactive T cell lines to secrete BCGF-I.

1983 ◽  
Vol 158 (6) ◽  
pp. 2024-2039 ◽  
Author(s):  
M Howard ◽  
L Matis ◽  
T R Malek ◽  
E Shevach ◽  
W Kell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Interleukin 2 ◽  
Activated T Lymphocytes ◽  
T Cell Lines ◽  
Activated B Cells

Antigen-activated T lymphocytes produce within 24 h of stimulation a factor that is indistinguishable biochemically and functionally from the B cell co-stimulating growth factor, BCGF-I, originally identified in induced EL4 supernatants: Supernatants from antigen-stimulated T cell lines are not directly mitogenic for resting B cells, but synergize in an H-2-unrestricted manner with anti-Ig activated B cells to produce polyclonal proliferation but not antibody-forming-cell development; biochemical studies reveal the B cell co-stimulating factor present in antigen-stimulated T cell line supernatants is identical by phenyl Sepharose chromatography and isoelectric focusing (IEF) to EL4 supernatant BCGF-I. We thus conclude that normal T cells produce BCGF-I in response to antigenic stimulation. Analysis of the mechanism of BCGF-I production by antigen-stimulated T cells showed that optimum amounts of BCGF-I were obtained as quickly as 24 h post-stimulation, and that the factor producing cells in the T cell line investigated bore the Lyt-1+2- phenotype. As few as 10(4) T cells produced sufficient BCGF-I to support the proliferation of 5 X 10(4) purified anti-Ig activated B cells. Finally, the activation of normal T cell lines to produce BCGF-I required either antigen presented in the context of syngeneic antigen-presenting cells (APC) or interleukin 2 (IL-2).

Only the CD45RA+ subpopulation of CD4+CD25high T cells gives rise to homogeneous regulatory T-cell lines upon in vitro expansion

Blood ◽  
2006 ◽  
Vol 108 (13) ◽  
pp. 4260-4267 ◽  
Author(s):  
Petra Hoffmann ◽  
Ruediger Eder ◽  
Tina J. Boeld ◽  
Kristina Doser ◽  
Biserka Piseshka ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Lines ◽  
Cytotoxic T Lymphocyte ◽  
Interleukin 2 ◽  
Solid Organ ◽  
Cell Therapies ◽  
In Vitro Expansion

Abstract Thymus-derived CD4+CD25+ regulatory T cells suppress autoreactive CD4+ and CD8+ T cells and thereby protect from autoimmunity. In animal models, adoptive transfer of CD4+CD25+ regulatory T cells has been shown to prevent and even cure autoimmune diseases as well as pathogenic alloresponses after solid organ and stem-cell transplantations. We recently described methods for the efficient in vitro expansion of human regulatory T cells for clinical applications. We now demonstrate that only CCR7- and L-selectin (CD62L)–coexpressing cells within expanded CD4+CD25high T cells maintain phenotypic and functional characteristics of regulatory T cells. Further analysis revealed that these cells originate from CD45RA+ naive cells within the CD4+CD25high T-cell compartment, as only this subpopulation homogeneously expressed CD62L, CCR7, cytotoxic T lymphocyte–associated antigen-4 (CTLA-4), and forkhead box P3 (FOXP3), produced no inflammatory cytokines and maintained robust suppressive activity after expansion. In contrast, cell lines derived from CD45RA– memory-type CD4+CD25high T cells lost expression of lymph node homing receptors CCR7 and CD62L, contained interleukin-2 (IL-2) and interferon-γ (IFN-γ) as well as IL-10–secreting cells, showed only moderate suppression and, most importantly, did not maintain FOXP3 expression. Based on these unexpected findings, we suggest that isolation and expansion of CD45RA+ naive CD4+ CD25high T cells is the best strategy for adoptive regulatory T (Treg)–cell therapies.

scholarly journals Proliferation Response to Interleukin-2 and Jak/Stat Activation of T Cells Immortalized by Human T-Cell Lymphotropic Virus Type 1 Is Independent of Open Reading Frame I Expression

1999 ◽  
Vol 73 (11) ◽  
pp. 9642-9649 ◽  
Author(s):  
Nathaniel D. Collins ◽  
Celine D’Souza ◽  
Björn Albrecht ◽  
Michael D. Robek ◽  
Lee Ratner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Virus Type ◽  
Interleukin 2 ◽  
Receptor Expression ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Human T Cell

ABSTRACT Human T-cell lymphotropic virus type 1 (HTLV-1), a complex retrovirus, encodes a hydrophobic 12-kD protein from pX open reading frame (ORF) I that localizes to cellular endomembranes and contains four minimal SH3 binding motifs (PXXP). We have demonstrated the importance of ORF I expression in the establishment of infection and hypothesize that p12I has a role in T-cell activation. In this study, we tested interleukin-2 (IL-2) receptor expression, IL-2-mediated proliferation, and Jak/Stat activation in T-cell lines immortalized with either wild-type or ORF I mutant clones of HTLV-1. All cell lines exhibited typical patterns of T-cell markers and maintained mutation fidelity. No significant differences between cell lines were observed in IL-2 receptor chain (α, β, or γc) expression, in IL-2-mediated proliferation, or in IL-2-induced phosphorylated forms of Stat3, Stat5, Jak1, or Jak3. The expression of ORF I is more likely to play a role in early HTLV-1 infection, such as in the activation of quiescent T cells in vivo.

Rapid selection of antigen-specific T lymphocytes by retroviral transduction

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Guenther Koehne ◽  
Humilidad F. Gallardo ◽  
Michel Sadelain ◽  
Richard J. O'Reilly
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cytotoxic T Lymphocyte ◽  
Interleukin 2 ◽  
Retroviral Vectors ◽  
Retroviral Transduction ◽  
Alloreactive T Cells ◽  
T Cell Lines ◽  
Selection Of

Abstract Infusions of donor peripheral blood T cells can induce durable remissions of Epstein-Barr virus (EBV) lymphomas complicating marrow grafts, but they contain alloreactive T cells capable of inducing graft-versus-host disease. EBV-specific T-cell lines or clones avoid this problem but require 30 to 40 days of culture to establish. To accelerate the generation of EBV-specific T cells, we tested whether retroviral vectors, which only integrate in dividing cells, could be used to transduce and select antigen-reactive T cells early after sensitization to autologous EBV-transformed B cells. T cells were transduced with a dicistronic retroviral vector, NIT, which encodes low-affinity nerve growth factor receptor as an immunoselectable marker and herpes simplex virus thymidine kinase as a suicide gene, at different time points after sensitization. EBV-specific cytotoxic T lymphocyte precursor (CTLp) frequencies in purified NIT+T-cell fractions transduced on day 8 of culture were comparable to those of EBV-specific T-cell lines cultured for 30 days or more. Alloreactive CTLp frequencies were markedly reduced in the NIT+ fraction relative to the untransduced T-cell population. NIT+ fractions transduced on day 8 possessed more CD4+ T cells than the cell lines at day 30 and exhibited the same selective pattern of reactivity against immunodominant antigens presented by specific HLA alleles. In contrast, T cells transduced with NIT 5 days after stimulation with mitogen and interleukin-2 were relatively depleted of T cells specific for autologous EBV-transformed cells. Thus, retroviral vectors may be used for rapid selection of viral antigen-reactive T cells depleted of alloreactive T cells.

Rapid selection of antigen-specific T lymphocytes by retroviral transduction

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Guenther Koehne ◽  
Humilidad F. Gallardo ◽  
Michel Sadelain ◽  
Richard J. O'Reilly
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cytotoxic T Lymphocyte ◽  
Interleukin 2 ◽  
Retroviral Vectors ◽  
Retroviral Transduction ◽  
Alloreactive T Cells ◽  
T Cell Lines ◽  
Selection Of

Infusions of donor peripheral blood T cells can induce durable remissions of Epstein-Barr virus (EBV) lymphomas complicating marrow grafts, but they contain alloreactive T cells capable of inducing graft-versus-host disease. EBV-specific T-cell lines or clones avoid this problem but require 30 to 40 days of culture to establish. To accelerate the generation of EBV-specific T cells, we tested whether retroviral vectors, which only integrate in dividing cells, could be used to transduce and select antigen-reactive T cells early after sensitization to autologous EBV-transformed B cells. T cells were transduced with a dicistronic retroviral vector, NIT, which encodes low-affinity nerve growth factor receptor as an immunoselectable marker and herpes simplex virus thymidine kinase as a suicide gene, at different time points after sensitization. EBV-specific cytotoxic T lymphocyte precursor (CTLp) frequencies in purified NIT+T-cell fractions transduced on day 8 of culture were comparable to those of EBV-specific T-cell lines cultured for 30 days or more. Alloreactive CTLp frequencies were markedly reduced in the NIT+ fraction relative to the untransduced T-cell population. NIT+ fractions transduced on day 8 possessed more CD4+ T cells than the cell lines at day 30 and exhibited the same selective pattern of reactivity against immunodominant antigens presented by specific HLA alleles. In contrast, T cells transduced with NIT 5 days after stimulation with mitogen and interleukin-2 were relatively depleted of T cells specific for autologous EBV-transformed cells. Thus, retroviral vectors may be used for rapid selection of viral antigen-reactive T cells depleted of alloreactive T cells.

scholarly journals The significance of low bcl-2 expression by CD45RO T cells in normal individuals and patients with acute viral infections. The role of apoptosis in T cell memory.

1993 ◽  
Vol 178 (2) ◽  
pp. 427-438 ◽  
Author(s):  
A N Akbar ◽  
N Borthwick ◽  
M Salmon ◽  
W Gombert ◽  
M Bofill ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Infections ◽  
Apoptotic Cell ◽  
Interleukin 2 ◽  
Lymphoid Cells ◽  
T Cell Memory ◽  
Varicella Zoster Virus Infection ◽  
Cell Memory ◽  
Activated T Cells

The bcl-2 gene product has been shown to prevent apoptotic cell death. We have now investigated the bcl-2 protein expression by resting and activated mature T cell populations. Freshly isolated CD45RO+ T cells within CD4+ and CD8+ subsets expressed significantly less bcl-2 than CD45RO- (CD45RA+) T cells (p < 0.001). When CD45RA+ T cells within both CD4+ and CD8+ subsets were activated in vitro, the transition to CD45RO phenotype was associated with a decrease in bcl-2 expression. Patients with acute viral infections such as infectious mononucleosis caused by Epstein-Barr virus infections or chickenpox, resulting from varicella zoster virus infection, had circulating populations of activated CD45RO+ T cells which also showed low bcl-2 expression. In these patients, a significant correlation was seen between low bcl-2 expression by activated T cells and their apoptosis in culture (r = 0.94, p < 0.001). These results suggest that the primary activation of T cells leads to the expansion of a population that is destined to perish unless rescued by some extrinsic event. Thus the suicide of CD45RO+ T cells could be prevented by the addition of interleukin 2 to the culture medium which resulted in a concomitant increase in the bcl-2 expression of these cells. Alternatively, apoptosis was also prevented by coculturing the activated T lymphocytes with fibroblasts, which maintained the viability of lymphoid cells in a restinglike state but with low bcl-2 expression. The paradox that the CD45RO+ population contains the primed/memory T cell pool yet expresses low bcl-2 and is susceptible to apoptosis can be reconciled by the observations that maintenance of T cell memory may be dependent on the continuous restimulation of T cells, which increases their bcl-2 expression. Furthermore, the propensity of CD45RO+ T cells to extravasate may facilitate encounter with fibroblast-like cells in tissue stroma and thus be an important additional factor which promotes the survival of selected primed/memory T cells in vivo.

scholarly journals Fetal liver T cell receptor gamma/delta+ T cells as cytotoxic T lymphocytes specific for maternal alloantigens.

1992 ◽  
Vol 176 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Y Miyagawa ◽  
T Matsuoka ◽  
A Baba ◽  
T Nakamura ◽  
T Tsuno ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Lines ◽  
Fetal Liver ◽  
Cell Receptor ◽  
Lymphoid Cells ◽  
Gamma Delta T Cells ◽  
Gamma Delta ◽  
Killer Activity

We have established fetal liver-derived T cell receptor (TCR) gamma/delta+, CD3+ T cell lines that are cytotoxic for maternal T cells. Fetal liver-derived lymphoid progenitors yielded predominantly TCR-gamma/delta+ cell clusters when cultured on fetal bone marrow-derived stromal cells in the presence of a cytokine cocktail under magnetic force. These tightly adherent clusters were cloned by limiting dilution and the resulting cell lines analyzed for phenotype and function. Six of eight TCR-gamma/delta lines from 8-9.5-wk gestation fetuses were V delta 2+ as compared with zero of eight lines from later stages of gestation (10 and 15 wk), where all the lines were V delta 1+. In cytotoxicity assays, these TCR-gamma/delta+, CD3+, CD4-, and CD8+ or CD8- long-term cultured lymphoid cells (LLC) were killer cells active against the class I antigens on maternal T cells. Of the cell lines, the CD8+ TCR-gamma/delta+ LLC had the highest levels of killer activity. Thus fetal liver TCR-gamma/delta+ T cells may play a crucial role in protection against invading maternal T cells generated in the feto-maternal interaction.

scholarly journals Jasplakinolide Induces Apoptosis in Various Transformed Cell Lines by a Caspase-3-Like Protease-Dependent Pathway

2000 ◽  
Vol 7 (6) ◽  
pp. 947-952 ◽  
Author(s):  
Chikako Odaka ◽  
Miranda L. Sanders ◽  
Phillip Crews
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Lines ◽  
Caspase 3 ◽  
Dependent Manner ◽  
Jurkat T Cells ◽  
Transformed Cell ◽  
Induced Apoptosis ◽  
Transformed Cell Lines ◽  
Dependent Pathway

ABSTRACT To clarify the mechanisms underlying the antiproliferative effects of jasplakinolide, a cyclic depsipeptide from marine sponges, we examined whether jasplakinolide induces apoptosis in a variety of transformed and nontransformed cells. Jasplakinolide inhibited proliferation of human Jurkat T cells, resulting in cell death. This was accompanied by chromatin condensation and DNA cleavage at the linker regions between the nucleosomes. When caspase-3-like activity in the cytosolic extracts of Jurkat T cells was examined with a fluorescent substrate, DEVD-MAC (N-acetyl-Asp-Glu-Val-Asp-4-methyl-coumaryl-7-amide), the activity in the cells treated with jasplakinolide was remarkably increased in a time-dependent manner. Pretreatment of Jurkat T cells with the caspase inhibitor zVAD [benzyloxycarbonyl(Cbz)-Val-Ala-β-Asp(OMe)-fluoromethylketone] or DEVD-CHO (N-acetyl-Asp-Glu-Val-Asp-1-aldehyde) prevented the induction of apoptosis by jasplakinolide. Moreover, exposure of various murine transformed cell lines to jasplakinolide resulted in cell death, which was inhibited by zVAD. Although it has been well established that murine immature thymocytes are sensitive to apoptosis when exposed to various apoptotic stimuli, these cells as well as mature T lymphocytes were resistant to jasplakinolide-induced apoptosis. The results suggest that jasplakinolide induces apoptotic cell death through a caspase-3-like protease-dependent pathway. Another important outcome is that transformed cell lines were more susceptible to jasplakinolide-induced apoptosis than normal nontransformed cells.

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