Apoptotic elimination of peripheral T lymphocytes in patients with primary intracranial tumors

1999 ◽  
Vol 91 (6) ◽  
pp. 935-946 ◽  
Author(s):  
Lorri A. Morford ◽  
Amy R. Dix ◽  
William H. Brooks ◽  
Thomas L. Roszman

Object. Patients with gliomas exhibit severe T lymphopenia during the course of the disease. This study was conducted to determine the mechanism(s) responsible for the lymphopenia.Methods. Using two-color fluorescent staining techniques, the authors show that significant numbers of T cells undergo apoptosis in the peripheral blood of patients with gliomas. To determine whether a glioma-derived factor(s) induces this apoptosis, rosette-purified T cells obtained from healthy donors were treated with glioma cell culture supernatant (GCCS) and examined for apoptosis. It is demonstrated that treatment of normal T cells with GCCS induced apoptosis only with concurrent stimulation of the T-cell receptor/CD3 complex. The addition of neutralizing antibodies to interleukin (IL)-10, IL-4, transforming growth factor-α, or tumor necrosis factor-β (lymphotoxin) did not rescue these T cells from apoptosis. Experiments were also conducted in which the degree of monocyte involvement in the induction of T-cell apoptosis was explored. The U937 cells were pretreated for 20 hours with a 1:20 dilution of GCCS. After the removal of GCCS, the U937 cells were cultured in transwell assays with stimulated T cells. Although control U937 cells did not induce apoptosis of the activated T cells, GCCS-pretreated U937 cells induced appreciable apoptosis in normal, stimulated T-cell cultures.Conclusions. These data indicate that one mechanism by which gliomas cause immunosuppressive effects is the induction of monocytes to release soluble factors that promote activated T-cell apoptosis. The loss of activated T cells leads to T lymphopenia and contributes to the deficiencies in cell-mediated immunity that have been observed during testing of glioma patients' immune function.

2009 ◽  
Vol 206 (7) ◽  
pp. 1515-1523 ◽  
Author(s):  
Divya Purushothaman ◽  
Apurva Sarin

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Jinyun Chen ◽  
Qian Wang ◽  
Xuebing Feng ◽  
Zhuoya Zhang ◽  
Linyu Geng ◽  
...  

Aberrant autophagy played an important role in the pathogenesis of autoimmune diseases, especially in systemic lupus erythematosus (SLE). In this study, we showed that T cells from SLE patients had higher autophagic activity than that from healthy controls. A correlation between autophagic activity and apoptotic rate was observed in activated T cells. Moreover, activation of autophagy with rapamycin increased T cell apoptosis, whereas inhibition of autophagy with 3-MA decreased T cell apoptosis. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) could inhibit respiratory mitochondrial biogenesis in activated T cells to downregulate autophagy and consequently decrease T cell apoptosis through mitochondrial transfer and thus may play an important role in SLE treatment.


Science ◽  
2021 ◽  
Vol 372 (6543) ◽  
pp. eaba4220 ◽  
Author(s):  
Tao Yue ◽  
Xiaoming Zhan ◽  
Duanwu Zhang ◽  
Ruchi Jain ◽  
Kuan-wen Wang ◽  
...  

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.


2011 ◽  
Vol 18 (5) ◽  
pp. 717-723 ◽  
Author(s):  
Karen L. Wozniak ◽  
Mattie L. Young ◽  
Floyd L. Wormley

ABSTRACTIndividuals with defects in T cell-mediated immunity (CMI) are highly susceptible to infection withCryptococcus neoformans. The purpose of these studies was to determine if protection against experimental pulmonary cryptococcosis can be generated in T cell-deficient hosts. BALB/c mice were depleted of CD4+and/or CD8+T cells or given an isotype control antibody prior to vaccination with aC. neoformansstrain, designated H99γ, previously shown to induce protection againstC. neoformansinfection in immunocompetent mice. Mice depleted of CD4+or CD8+T cells, but not both subsets, survived an acute pulmonary infection withC. neoformansstrain H99γ and a subsequent second challenge with wild-typeC. neoformansstrain H99. We observed a significant increase in the percentage of CD4+and CD8+T cells expressing the activation marker CD69 in the lungs of mice immunized withC. neoformansstrain H99γ prior to a secondary challenge with wild-type cryptococci. CD4+T cells within the lungs of immunized mice also appeared to acquire a predominantly activated effector memory cell phenotype (CD69+CD44+CCR7−CD45RB−CD62L−) following a second pulmonary challenge with wild-typeC. neoformans, compared to CD4+T cells from naïve mice. Lastly, immunization of immunocompetent mice withC. neoformansstrain H99γ prior to depletion of CD4+and/or CD8+T cells resulted in significant protection against a second challenge with wild-typeC. neoformans. Our studies demonstrate that protective immunity against pulmonary cryptococcosis can be generated in immunosuppressed hosts, thus supporting the development of cryptococcal vaccines.


2009 ◽  
Vol 184 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Nagendra Singh ◽  
Mutsumi Yamamoto ◽  
Mariko Takami ◽  
Yoichi Seki ◽  
Mayuko Takezaki ◽  
...  

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3832-3839 ◽  
Author(s):  
Ming-Tseh Lin ◽  
Li-Hui Tseng ◽  
Haydar Frangoul ◽  
Ted Gooley ◽  
Ji Pei ◽  
...  

Lymphopenia and immune deficiency are significant problems following allogeneic hematopoietic cell transplantation (HCT). It is largely assumed that delayed immune reconstruction is due to a profound decrease in thymus-dependent lymphopoiesis, especially in older patients, but apoptosis is also known to play a significant role in lymphocyte homeostasis. Peripheral T cells from patients who received HCT were studied for evidence of increased cell death. Spontaneous apoptosis was measured in CD3+ T cells following a 24-hour incubation using 7-amino-actinomycin D in conjunction with the dual staining of cell surface antigens. Apoptosis was significantly greater among CD3+ T cells taken from patients 19-23 days after transplantation (30.4% ± 12.5%,P < .05), and 1 year after transplantation (9.7% ± 2.8%, P < .05) compared with healthy controls (4.0% ± 1.5%). Increased apoptosis occurred preferentially in HLA (human leukocyte antigen)-DR positive cells and in both CD3+/CD4+ and CD3+/CD8+ T-cell subsets, while CD56+/CD3− natural killer cells were relatively resistant to apoptosis. The extent of CD4+T-cell apoptosis was greater in patients with grade II-IV acute graft-versus-host disease (GVHD) (33.9% ± 11.3%) compared with grade 0-I GVHD (14.6 ± 6.5%, P < .05). T-cell apoptosis was also greater in patients who received transplantations from HLA-mismatched donors (39.5% ± 10.4%,P < .05) or HLA-matched unrelated donors (32.1% ± 11.4%, P < .05) compared with patients who received transplantations from HLA-identical siblings (19.6% ± 6.7%). The intensity of apoptosis among CD4+ T cells was significantly correlated with a lower CD4+ T-cell count. Together, these observations suggest that activation of T cells in vivo, presumably by alloantigens, predisposes the cells to spontaneous apoptosis, and this phenomenon is associated with lymphopenia. Activation-induced T-cell apoptosis may contribute to delayed immune reconstitution following HCT.


2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Xiaoxie Xu ◽  
Jun Huang ◽  
Mei Zhao ◽  
Huanpeng Chen ◽  
Jinhua Mo ◽  
...  

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.


Blood ◽  
2008 ◽  
Vol 112 (5) ◽  
pp. 1759-1766 ◽  
Author(s):  
Peter N. Lalli ◽  
Michael G. Strainic ◽  
Min Yang ◽  
Feng Lin ◽  
M. Edward Medof ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tianzhu Tao ◽  
Lulong Bo ◽  
Teng Li ◽  
Longbao Shi ◽  
Hui Zhang ◽  
...  

Background. B7 family members and ligands have been identified as critical checkpoints in orchestrating the immune response during sepsis. V-domain Ig suppressor of T cell activation (VISTA) is a new inhibitory immune checkpoint involved in restraining T cell response. Previous studies demonstrated that VISTA engagement on T cells and myeloid cells could transmit inhibitory signals, resulting in reduced activation and function. The current study was designed to determine the potential therapeutic effects of a high-affinity anti-VISTA antibody (clone MH5A) in a murine model of sepsis. Methods. Polymicrobial sepsis was induced in male C57BL/6 mice via cecal ligation and puncture. Expression profiles of VISTA on T lymphocytes and macrophage were examined at 24 and 72 h postsurgery. The effects of anti-VISTA mAb on the 7-day survival, lymphocyte apoptosis, cytokine expression, bacterial burden, and vital organ damage were determined. Furthermore, the effects of anti-VISTA mAb on CD3+ T cell apoptosis and macrophage activation were determined in vitro. Results. VISTA was substantially expressed on T cells and macrophages in sham-operated mice; septic peritonitis did not induce significant changes in the expression profiles. Treatment with MH5A improved the survival of septic mice, accompanied by reduced lymphocyte apoptosis, decreased cytokine expression, and enhanced bacterial clearance. Engagement of VISTA receptor with MH5A mitigated CD3+ T cell apoptosis cultured from CLP mice and suppressed LPS-induced cytokine production by macrophage in vitro. Conclusion. The present study identified VISTA as a novel immune checkpoint in the regulation of T cell and macrophage response during sepsis. Modulation of the VISTA pathway might offer a promising opportunity in the immunotherapy for sepsis.


1995 ◽  
Vol 181 (6) ◽  
pp. 2029-2036 ◽  
Author(s):  
P D Katsikis ◽  
E S Wunderlich ◽  
C A Smith ◽  
L A Herzenberg ◽  
L A Herzenberg

Apoptosis (programmed cell death) of T lymphocytes has been proposed as a mechanism which plays an important role in the pathogenesis of human immunodeficiency virus (HIV) disease. Activation of Fas (CD95) can either result in costimulation of proliferation and cytokine production or in the induction of apoptosis of T lymphocytes. This raises the possibility that Fas is involved in the observed T cell apoptosis during HIV disease. In this report we show that peripheral blood CD4+ and CD8+ T lymphocytes from HIV-infected individuals undergo apoptosis in vitro in response to antibody stimulation (cross-linking) of Fas at a much higher frequency than from uninfected controls. This anti-Fas-induced T cell apoptosis is markedly higher than spontaneous T cell apoptosis in HIV-infected individuals. Antibodies against other members of the tumor necrosis factor (TNF)/nerve growth factor receptor family such as CD27, CD30, CD40, 4-1BB, p55 TNF receptor, p75 TNF receptor, and TNF receptor-related protein did not result in any increase of T cell apoptosis above that spontaneously observed in HIV+ individuals. Anti-Fas-induced apoptosis was much higher in symptomatic HIV-infected individuals; and the magnitude of anti-Fas-induced CD4+ T cell apoptosis correlated inversely with peripheral blood CD4+ T cell absolute counts. Surface expression of Fas on T cells was also found to be higher in HIV-infected individuals. Resting and activated CD4+ and CD8+ T cells both underwent apoptosis in response to anti-Fas antibody. L-Selectin positive memory CD4+ T cells were especially susceptible to anti-Fas-induced apoptosis. These findings show that CD4+ and CD8+ T lymphocytes in HIV-infected individuals are primed in vivo to undergo apoptosis in response to Fas stimulation, suggesting that Fas signaling may be responsible for the T lymphocyte functional defects and depletion observed in HIV disease.


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