scholarly journals Role of Death Receptor Pathway in Estradiol-Induced T-Cell Apoptosis in Vivo

2002 ◽  
Vol 70 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Y. Do
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Death Receptor ◽  
Death Receptor Pathway ◽  
T Cell Apoptosis

scholarly journals TDAG51 Is Not Essential for Fas/CD95 Regulation and Apoptosis In Vivo

2001 ◽  
Vol 21 (24) ◽  
pp. 8365-8370 ◽  
Author(s):  
Jaerang Rho ◽  
Shiaoching Gong ◽  
Nacksung Kim ◽  
Yongwon Choi
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Northern Blotting ◽  
Lymphoid Organs ◽  
Developmental Abnormalities ◽  
T Cell Apoptosis ◽  
Secondary Lymphoid Organs

ABSTRACT Fas/CD95 is a key regulator of apoptotic signaling, which is crucial for the maintenance of homeostasis in peripheral lymphoid organs. TDAG51 has been shown to play critical roles in the up-regulation of Fas gene expression and T-cell apoptosis in vitro. In order to identify the role of TDAG51 in vivo, we generated TDAG51-deficient (TDAG51−/−) mice. Northern blotting revealed no expression of TDAG51 in TDAG51−/− mice, indicating that the TDAG51 gene was successfully targeted. TDAG51−/− mice were healthy and showed no gross developmental abnormalities. While Fas-deficient mice display marked lymphadenopathy, splenomegaly, and lymphocytosis, TDAG51−/− mice had no apparent defects in secondary lymphoid organs. Although TDAG51 is required for up-regulation of Fas expression in T-cell hybridomas, TDAG51−/− mice expressed normal levels of Fas and had normal T-cell apoptosis. Therefore, we conclude that TDAG51 is not essential for Fas up-regulation and T-cell apoptosis in vivo. There are several known homologs of TDAG51, and these homologs may substitute for TDAG51 in TDAG51−/−mice.

scholarly journals SATB1 Cleavage by Caspase 6 Disrupts PDZ Domain-Mediated Dimerization, Causing Detachment from Chromatin Early in T-Cell Apoptosis

2001 ◽  
Vol 21 (16) ◽  
pp. 5591-5604 ◽  
Author(s):  
Sanjeev Galande ◽  
Liliane A. Dickinson ◽  
I. Saira Mian ◽  
Marianna Sikorska ◽  
Terumi Kohwi-Shigematsu
Keyword(s):  
T Cell ◽  
Dna Binding ◽  
Cell Apoptosis ◽  
Pdz Domain ◽  
Dna Binding Domains ◽  
T Cell Apoptosis ◽  
Binding Domains ◽  
Caspase 6 ◽  
Loop Domains

ABSTRACT SATB1 is expressed primarily in thymocytes and orchestrates temporal and spatial expression of a large number of genes in the T-cell lineage. SATB1 binds to the bases of chromatin loop domains in vivo, recognizing a special DNA context with strong base-unpairing propensity. The majority of thymocytes are eliminated by apoptosis due to selection processes in the thymus. We investigated the fate of SATB1 during thymocyte and T-cell apoptosis. Here we show that SATB1 is specifically cleaved by a caspase 6-like protease at amino acid position 254 to produce a 65-kDa major fragment containing both a base-unpairing region (BUR)-binding domain and a homeodomain. We found that this cleavage separates the DNA-binding domains from amino acids 90 to 204, a region which we show to be a dimerization domain. The resulting SATB1 monomer loses its BUR-binding activity, despite containing both its DNA-binding domains, and rapidly dissociates from chromatin in vivo. We found this dimerization region to have sequence similarity to PDZ domains, which have been previously shown to be involved in signaling by conferring protein-protein interactions. SATB1 cleavage during Jurkat T-cell apoptosis induced by an anti-Fas antibody occurs concomitantly with the high-molecular-weight fragmentation of chromatin of ∼50-kb fragments. Our results suggest that mechanisms of nuclear degradation early in apoptotic T cells involve efficient removal of SATB1 by disrupting its dimerization and cleavage of genomic DNA into loop domains to ensure rapid and efficient disassembly of higher-order chromatin structure.

Lack of control of T cell apoptosis under HAART. Influence of therapy regimen in vivo and in vitro

AIDS ◽  
2002 ◽  
Vol 16 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Luzia Maria de Oliveira Pinto ◽  
Hervé Lecoeur ◽  
Eric Ledru ◽  
Christophe Rapp ◽  
Olivier Patey ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Therapy Regimen ◽  
T Cell Apoptosis ◽  
Lack Of Control

scholarly journals Cytokine-dependent regulation of NADPH oxidase activity and the consequences for activated T cell homeostasis

2009 ◽  
Vol 206 (7) ◽  
pp. 1515-1523 ◽  
Author(s):  
Divya Purushothaman ◽  
Apurva Sarin
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nadph Oxidase ◽  
Cell Apoptosis ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Activated T Cells ◽  
T Cell Apoptosis ◽  
Mitochondrial Superoxide ◽  
Activated T Cell

Cellular dependence on growth factors for survival is developmentally programmed and continues in adult metazoans. Antigen-activated T cell apoptosis in the waning phase of the immune response is thought to be triggered by depletion of cytokines from the microenvironment. T cell apoptosis resulting from cytokine deprivation is mediated by reactive oxygen species (ROS), but their source and position in the apoptotic cascade is poorly understood. RNA interference approaches implicated the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in neglect-induced apoptosis in T cells. Using mice deficient for the catalytic subunit gp91phox to characterize the molecular link to activated T cell apoptosis, we show that gp91phox-deficient T (T−/−) cells generated mitochondrial superoxide but had diminished hydrogen peroxide production in response to neglect, which, in turn, regulated Jun N-terminal kinase–dependent Bax activation and apoptosis. Activated T−/− cells were distinguished by improved survival after activation by superantigens in vivo, adoptive transfers into congenic hosts, and higher recall responses after immunization. Thus, the NADPH oxidase may regulate adaptive immunity in addition to its previously well-characterized role in the innate response.

The role of T cell apoptosis in transplantation tolerance

2000 ◽  
Vol 12 (5) ◽  
pp. 522-527 ◽  
Author(s):  
Xian Chang Li ◽  
Andrew D Wells ◽  
Terry B Strom ◽  
Laurence A Turka
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Transplantation Tolerance ◽  
T Cell Apoptosis

Progression of intracranial glioma disrupts thymic homeostasis and induces T-cell apoptosis in vivo

2008 ◽  
Vol 57 (12) ◽  
pp. 1807-1816 ◽  
Author(s):  
Abdeljabar El Andaloussi ◽  
Yu Han ◽  
Maciej S. Lesniak
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
T Cell Apoptosis

scholarly journals Stabilizedβ-Catenin Ameliorates ALPS-Like Symptoms of B6/lprMice

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Xiaoxie Xu ◽  
Jun Huang ◽  
Mei Zhao ◽  
Huanpeng Chen ◽  
Jinhua Mo ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Potential Role ◽  
Activated T Cells ◽  
Apoptotic Pathway ◽  
T Cell Apoptosis ◽  
Incurable Disease ◽  
Lymphoproliferative Syndrome ◽  
Proinflammatory Factors

Autoimmune lymphoproliferative syndrome (ALPS) is an incurable disease mainly caused by the defect of Fas-mediated apoptosis and characterized by nonmalignant autoimmune lymphoproliferation. Stabilizedβ-catenin could not only potentiate Fas-mediated T cell apoptosis via upregulating the expression of Fas on activated T cells, but also potentiate T cell apoptosis via intrinsic apoptotic pathway. In the present study, we introducedβ-catTgintolpr/lprmice and aimed to explore the potential role of stabilizedβ-catenin (β-catTg) in the development of ALPS-like phenotypes oflpr/lprmice. We found that the total splenocyte cells and some compositions were slightly downregulated inβ-catTglpr/lprmice, especially the CD4 and CD8 TEMcells were significantly reduced. Meanwhile, stabilizedβ-catenin obviously decreased the numbers of spleen TCRβ+CD4−CD8−T (DNT) cells, and the levels of some serum proinflammatory factors also were lowered inβ-catTglpr/lprmice. Beyond that, stabilizedβ-catenin slightly lowered the levels of the serum autoantibodies and the scores of kidney histopathology ofβ-catTglpr/lprmice compared withlpr/lprmice. Our study suggested that stabilizedβ-catenin ameliorated some ALPS-like symptoms oflpr/lprmice by potentiating Fas-independent signal-mediated T cell apoptosis, which might uncover a potential novel therapeutic direction for ALPS.

scholarly journals Locally produced C5a binds to T cell–expressed C5aR to enhance effector T-cell expansion by limiting antigen-induced apoptosis

Blood ◽  
2008 ◽  
Vol 112 (5) ◽  
pp. 1759-1766 ◽  
Author(s):  
Peter N. Lalli ◽  
Michael G. Strainic ◽  
Min Yang ◽  
Feng Lin ◽  
M. Edward Medof ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Apoptosis ◽  
Cell Expansion ◽  
Immune Cell ◽  
Regulatory Protein ◽  
T Cell Apoptosis ◽  
T Cell Expansion

Abstract Our recent studies have shown that immune cell–produced complement provides costimulatory and survival signals to naive CD4+ T cells. Whether these signals are similarly required during effector cell expansion and what molecular pathways link locally produced complement to T-cell survival were not clarified. To address this, we stimulated monoclonal and polyclonal T cells in vitro and in vivo with antigen-presenting cells (APCs) deficient in the complement regulatory protein, decay accelerating factor (DAF), and/or the complement component C3. We found that T-cell expansion induced by DAF-deficient APCs was augmented with diminished T-cell apoptosis, whereas T-cell expansion induced by C3−/− APCs was reduced because of enhanced T-cell apoptosis. These effects were traced to locally produced C5a, which through binding to T cell–expressed C5aR, enhanced expression of Bcl-2 and prevented Fas up-regulation. The results show that C5aR signal transduction in T cells is important to allow optimal T-cell expansion, as well as to maintain naive cell viability, and does so by suppressing programmed cell death.

A cytotoxic nitrido-osmium(vi) complex induces caspase-mediated apoptosis in HepG2 cancer cells

2020 ◽  
Vol 49 (47) ◽  
pp. 17173-17182
Author(s):  
Wan-Qiong Huang ◽  
Chuan-Xian Wang ◽  
Tao Liu ◽  
Zi-Xin Li ◽  
Chen Pan ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Hepg2 Cell ◽  
Cell Apoptosis ◽  
Death Receptor ◽  
Mitochondrial Pathway ◽  
Anticancer Activities ◽  
Death Receptor Pathway

A structurally fine-tuned nitridoosmium(vi) complex induces HepG2 cell apoptosis through activation of the mitochondrial pathway and death receptor pathway, showing promising in vitro and in vivo anticancer activities.

scholarly journals The Role of Galectins as Modulators of Metabolism and Inflammation

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Monica Fengsrud Brinchmann ◽  
Deepti Manjari Patel ◽  
Martin Haugmo Iversen
Keyword(s):  
T Cell ◽  
Metabolic Control ◽  
Cell Apoptosis ◽  
Subcellular Location ◽  
Tissue Specific ◽  
T Cell Apoptosis ◽  
Specific Distribution ◽  
Key Players ◽  
Glycosylated Proteins

Galectins areβ-galcotosid-binding lectins. The function of galectins varies with their tissue-specific and subcellular location, and their binding to carbohydrates makes them key players in several intra- and extracellular processes where they bind to glycosylated proteins and lipids. In humans, there are 12 identified galectins, some with tissue-specific distribution. Galectins are found inside cells and in the nucleus, cytosol, and organelles, as well as extracellularly. Galectin-1, -2, -3, -4, -7, -8, -9, and -12 can all induce T-cell apoptosis and modulate inflammation. In the context of metabolic control and loss of the same in, for example, diabetes, galectin-1, -2, -3, -9, and -12 are especially interesting. This review presents information on galectins relevant to the control of inflammation and metabolism and the potential to target galectins for therapeutic purposes.

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