scholarly journals T Cell Receptor-induced Activation and Apoptosis In Cycling Human T Cells Occur throughout the Cell Cycle

1999 ◽  
Vol 10 (12) ◽  
pp. 4441-4450 ◽  
Author(s):  
Michael Karas ◽  
Tal Z. Zaks ◽  
Liu JL ◽  
Derek LeRoith
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Fas Ligand ◽  
Cell Receptor ◽  
Receptor Activation ◽  
Activation Induced Cell Death ◽  
Human T Cells

Previous studies have found conflicting associations between susceptibility to activation-induced cell death and the cell cycle in T cells. However, most of the studies used potentially toxic pharmacological agents for cell cycle synchronization. A panel of human melanoma tumor-reactive T cell lines, a CD8+ HER-2/neu-reactive T cell clone, and the leukemic T cell line Jurkat were separated by centrifugal elutriation. Fractions enriched for the G0–G1, S, and G2–M phases of the cell cycle were assayed for T cell receptor-mediated activation as measured by intracellular Ca2+flux, cytolytic recognition of tumor targets, and induction of Fas ligand mRNA. Susceptibility to apoptosis induced by recombinant Fas ligand and activation-induced cell death were also studied. None of the parameters studied was specific to a certain phase of the cell cycle, leading us to conclude that in nontransformed human T cells, both activation and apoptosis through T cell receptor activation can occur in all phases of the cell cycle.

scholarly journals Fas ligand mediates activation-induced cell death in human T lymphocytes.

1995 ◽  
Vol 181 (1) ◽  
pp. 71-77 ◽  
Author(s):  
M R Alderson ◽  
T W Tough ◽  
T Davis-Smith ◽  
S Braddy ◽  
B Falk ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Fas Ligand ◽  
Significant Proportion ◽  
Cell Receptor ◽  
Target Cells ◽  
Activated T Cells ◽  
Activation Induced Cell Death ◽  
Fas L

A significant proportion of previously activated human T cells undergo apoptosis when triggered through the CD3/T cell receptor complex, a process termed activation-induced cell death (AICD). Ligation of Fas on activated T cells by either Fas antibodies or recombinant human Fas-ligand (Fas-L) also results in cytolysis. We demonstrate that these two pathways of apoptosis are causally related. Stimulation of previously activated T cells resulted in the expression of Fas-L mRNA and lysis of Fas-positive target cells. Fas-L antagonists inhibited AICD of T cell clones and staphylococcus enterotoxin B (SEB)-specific T cell lines. The data indicate AICD in previously stimulated T cells is mediated by Fas/Fas-L interactions.

scholarly journals The Caspase 8 Inhibitor c-FLIPL Modulates T-Cell Receptor-Induced Proliferation but Not Activation-Induced Cell Death of Lymphocytes

2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Death Receptor ◽  
Cell Receptor ◽  
Caspase 8 ◽  
Activation Induced Cell Death

ABSTRACT The caspase 8 inhibitor c-FLIPL can act in vitro as a molecular switch between cell death and growth signals transmitted by the death receptor Fas (CD95). To elucidate its function in vivo, transgenic mice were generated that overexpress c-FLIPL in the T-cell compartment (c-FLIPL Tg mice). As anticipated, FasL-induced apoptosis was inhibited in T cells from the c-FLIPL Tg mice. In contrast, activation-induced cell death of T cells in c-FLIPL Tg mice was unaffected, suggesting that this deletion process can proceed in the absence of active caspase 8. Accordingly, c-FLIPL Tg mice differed from Fas-deficient mice by showing no accumulation of B220+ CD4− CD8− T cells. However, stimulation of T lymphocytes with suboptimal doses of anti-CD3 or antigen revealed increased proliferative responses in T cells from c-FLIPL Tg mice. Thus, a major role of c-FLIPL in vivo is the modulation of T-cell proliferation by decreasing the T-cell receptor signaling threshold.

scholarly journals Inhibition of Superoxide Generation upon T-Cell Receptor Engagement Rescues Mart-127-35–Reactive T Cells from Activation-Induced Cell Death

2009 ◽  
Vol 69 (15) ◽  
pp. 6282-6289 ◽  
Author(s):  
Håkan Norell ◽  
Telma Martins da Palma ◽  
Aaron Lesher ◽  
Navtej Kaur ◽  
Meenal Mehrotra ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Superoxide Generation ◽  
Activation Induced Cell Death

scholarly journals Bcl-2 Knockdown Accelerates T Cell Receptor-Triggered Activation-Induced Cell Death in Jurkat T Cells

2014 ◽  
Vol 18 (1) ◽  
pp. 73 ◽  
Author(s):  
Yun-Jung Lee ◽  
Tae Joon Won ◽  
Kyeong Eun Hyung ◽  
Mi Ji Lee ◽  
Young-hye Moon ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Jurkat T Cells ◽  
Activation Induced Cell Death

scholarly journals Induction of Fas Ligand Expression by HIV Involves the Interaction of Nef with the T Cell Receptor ζ Chain

1999 ◽  
Vol 189 (9) ◽  
pp. 1489-1496 ◽  
Author(s):  
Xiao-Ning Xu ◽  
Bernd Laffert ◽  
Gavin R. Screaton ◽  
Michael Kraft ◽  
Dietlinde Wolf ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Molecular Mechanism ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Fas Ligand ◽  
Cell Receptor ◽  
Fasl Expression ◽  
Hiv 1

During HIV/SIV infection, there is widespread programmed cell death in infected and, perhaps more importantly, uninfected cells. Much of this apoptosis is mediated by Fas–Fas ligand (FasL) interactions. Previously we demonstrated in macaques that induction of FasL expression and apoptotic cell death of both CD4+ and CD8+ T cells by SIV is dependent on a functional nef gene. However, the molecular mechanism whereby HIV-1 induces the expression of FasL remained poorly understood. Here we report a direct association of HIV-1 Nef with the ζ chain of the T cell receptor (TCR) complex and the requirement of both proteins for HIV-mediated upregulation of FasL. Expression of FasL through Nef depended upon the integrity of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the TCR ζ chain. Conformation for the importance of ζ for Nef-mediated signaling in T cells came from an independent finding. A single ITAM motif of ζ but not CD3ε was both required and sufficient to promote activation and binding of the Nef-associated kinase (NAK/p62). Our data imply that Nef can form a signaling complex with the TCR, which bypasses the requirement of antigen to initiate T cell activation and subsequently upregulation of FasL expression. Thus, our study may provide critical insights into the molecular mechanism whereby the HIV-1 accessory protein Nef contributes to the pathogenesis of HIV.

scholarly journals Characterization of human T cells reactive with the Mycoplasma arthritidis-derived superantigen (MAM): generation of a monoclonal antibody against V beta 17, the T cell receptor gene product expressed by a large fraction of MAM-reactive human T cells.

1991 ◽  
Vol 174 (4) ◽  
pp. 891-900 ◽  
Author(s):  
S M Friedman ◽  
M K Crow ◽  
J R Tumang ◽  
M Tumang ◽  
Y Q Xu ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Activity ◽  
Cell Receptor ◽  
Cytotoxic T Cell ◽  
Mycoplasma Arthritidis ◽  
Human T Cells

While all known microbial superantigens are mitogenic for human peripheral blood lymphocytes (PBL), the functional response induced by Mycoplasma arthritidis-derived superantigen (MAM) is unique in that MAM stimulation of PBL consistently results in T cell-dependent B cell activation characterized by polyclonal IgM and IgG production. These immunostimulatory effects of MAM on the humoral arm of the human immune system warranted a more precise characterization of MAM-reactive human T cells. Using an uncloned MAM reactive human T cell line as immunogen, we have generated a monoclonal antibody (mAb) (termed C1) specific for the T cell receptor V beta gene expressed by the major fraction of MAM-reactive human T cells, V beta 17. In addition, a V beta 17- MAM-reactive T cell population exists, assessed by MAM, induced T cell proliferation and cytotoxic T cell activity. mAb C1 will be useful in characterizing the functional properties of V beta 17+ T cells and their potential role in autoimmune disease.

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