scholarly journals Modulation of LIGHT-HVEM Costimulation Prolongs Cardiac Allograft Survival

2002 ◽  
Vol 195 (6) ◽  
pp. 795-800 ◽  
Author(s):  
Qunrui Ye ◽  
Christopher C. Fraser ◽  
Wei Gao ◽  
Liqing Wang ◽  
Samantha J. Busfield ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Allograft Rejection ◽  
Cell Activation ◽  
Cardiac Allograft ◽  
Allograft Survival ◽  
Activated T Cells ◽  
Cardiac Allograft Rejection ◽  
Ifn Γ

LIGHT (TNFSF14), a tumor necrosis factor superfamily member expressed by activated T cells, binds to herpes virus entry mediator (HVEM) which is constitutively expressed by T cells and costimulates T cell activation in a CD28-independent manner. Given interest in regulating the effector functions of T cells in vivo, we examined the role of LIGHT-HVEM costimulation in a murine cardiac allograft rejection model. Normal hearts lacked LIGHT or HVEM mRNA expression, but allografts showed strong expression of both genes from day 3 after transplant, and in situ hybridization and immunohistology-localized LIGHT and HVEM to infiltrating leukocytes. To test the importance of LIGHT expression on allograft survival, we generated LIGHT−/− mice by homologous recombination. The mean survival of fully major histocompatibility complex–mismatched vascularized cardiac allografts in LIGHT−/− mice (10 days, P < 0.05) or cyclosporine A (CsA)-treated LIGHT+/+ mice (10 days, P < 0.05) was only slightly prolonged compared with LIGHT+/+ mice (7 days). However, mean allograft survival in CsA-treated LIGHT−/− allograft recipients (30 days) was considerably enhanced (P < 0.001) compared with the 10 days of mean survival in either untreated LIGHT−/− mice or CsA-treated LIGHT+/+ controls. Molecular analyzes showed that the beneficial effects of targeting of LIGHT in CsA-treated recipients were accompanied by decreased intragraft expression of interferon (IFN)-γ, plus IFN-γ–induced chemokine, inducible protein-10, and its receptor, CXCR3. Treatment of LIGHT+/+ allograft recipients with HVEM-Ig plus CsA also enhanced mean allograft survival (21 days) versus wild-type controls receiving HVEM-Ig (mean of 7 days) or CsA alone (P < 0.001). Our data suggest that T cell to T cell–mediated LIGHT/HVEM-dependent costimulation is a significant component of the host response leading to cardiac allograft rejection.

scholarly journals T-cell activation by the CD28 ligand B7 is required for cardiac allograft rejection in vivo.

1992 ◽  
Vol 89 (22) ◽  
pp. 11102-11105 ◽  
Author(s):  
L. A. Turka ◽  
P. S. Linsley ◽  
H. Lin ◽  
W. Brady ◽  
J. M. Leiden ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Allograft Rejection ◽  
Cell Activation ◽  
Cardiac Allograft ◽  
Cardiac Allograft Rejection

scholarly journals Critical role for perforin and Fas-dependent killing of dendritic cells in the control of inflammation

Blood ◽  
2012 ◽  
Vol 119 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Min Chen ◽  
Kumar Felix ◽  
Jin Wang
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Cell Types ◽  
Activated T Cells ◽  
Ifn Γ

AbstractAfter stimulation of antigen-specific T cells, dendritic cell (DCs) are susceptible to killing by these activated T cells that involve perforin and Fas-dependent mechanisms. Fas-dependent DC apoptosis has been shown to limit DC accumulation and prevent the development of autoimmunity. However, a role for perforin in the maintenance of DC homeostasis for immune regulation remains to be determined. Here we show that perforin deficiency in mice, together with the deletion of Fas in DCs (perforin−/−DC-Fas−/−), led to DC accumulation, uncontrolled T-cell activation, and IFN-γ production by CD8+ T cells, resulting in the development of lethal hemophagocytic lymphohistiocytosis. Consistently, adoptive transfer of Fas−/− DCs induced over-activation and IFN-γ production in perforin−/− CD8+ T cells. Neutralization of IFN-γ prevented the spreading of inflammatory responses to different cell types and protected the survival of perforin−/−DC-Fas−/− mice. Our data suggest that perforin and Fas synergize in the maintenance of DC homeostasis to limit T cell activation, and prevent the initiation of an inflammatory cascade.

scholarly journals Requirement of the Chemokine Receptor CXCR3 for Acute Allograft Rejection

2000 ◽  
Vol 192 (10) ◽  
pp. 1515-1520 ◽  
Author(s):  
Wayne W. Hancock ◽  
Bao Lu ◽  
Wei Gao ◽  
Vilmos Csizmadia ◽  
Kerrie Faia ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Chemokine Receptor ◽  
Allograft Rejection ◽  
Cell Activation ◽  
Acute Allograft Rejection ◽  
Activated T Cells ◽  
In Vivo Models ◽  
Ifn Γ

Chemokines provide signals for activation and recruitment of effector cells into sites of inflammation, acting via specific G protein–coupled receptors. However, in vitro data demonstrating the presence of multiple ligands for a given chemokine receptor, and often multiple receptors for a given chemokine, have led to concerns of biologic redundancy. Here we show that acute cardiac allograft rejection is accompanied by progressive intragraft production of the chemokines interferon (IFN)-γ–inducible protein of 10 kD (IP-10), monokine induced by IFN-γ (Mig), and IFN-inducible T cell α chemoattractant (I-TAC), and by infiltration of activated T cells bearing the corresponding chemokine receptor, CXCR3. We used three in vivo models to demonstrate a role for CXCR3 in the development of transplant rejection. First, CXCR3-deficient (CXCR3−/−) mice showed profound resistance to development of acute allograft rejection. Second, CXCR3−/− allograft recipients treated with a brief, subtherapeutic course of cyclosporin A maintained their allografts permanently and without evidence of chronic rejection. Third, CXCR+/+ mice treated with an anti-CXCR3 monoclonal antibody showed prolongation of allograft survival, even if begun after the onset of rejection. Taken in conjunction with our findings of CXCR3 expression in rejecting human cardiac allografts, we conclude that CXCR3 plays a key role in T cell activation, recruitment, and allograft destruction.

scholarly journals Antigen Presenting Cells from Tumor and Colon of Colorectal Cancer Patients Are Distinct in Activation and Functional Status, but Comparably Responsive to Activated T Cells

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5247
Author(s):  
Frank Liang ◽  
Azar Rezapour ◽  
Louis Szeponik ◽  
Samuel Alsén ◽  
Yvonne Wettergren ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Functional Status ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Activated T Cells ◽  
Ifn Γ ◽  
Colorectal Cancer Patients

Although mouse models of CRC treatments have demonstrated robust immune activation, it remains unclear to what extent CRC patients’ APCs and TILs interact to fuel or quench treatment-induced immune responses. Our ex vivo characterization of tumor and adjacent colon cell suspensions suggest that contrasting environments in these tissues promoted inversed expression of T cell co-stimulatory CD80, and co-inhibitory programmed death (PD)-ligand1 (PD-L1) on intratumoral vs. colonic APCs. While putative tumor-specific CD103+CD39+CD8+ TILs expressed lower CD69 (early activation marker) and higher PD-1 (extended activation/exhaustion marker) than colonic counterparts, the latter had instead higher CD69 and lower PD-1 levels. Functional comparisons showed that intratumoral APCs were inferior to colonic APCs regarding protein uptake and upregulation of CD80 and PD-L1 after protein degradation. Our attempt to model CRC treatment-induced T cell activation in vitro showed less interferon (IFN)-γ production by TILs than colonic T cells. In this model, we also measured APCs’ CD80 and PD-L1 expression in response to activated co-residing T cells. These markers were comparable in the two tissues, despite higher IFN- γ exposure for colonic APCs. Thus, APCs within distinct intratumoral and colonic milieus showed different activation and functional status, but were similarly responsive to signals from induced T cell activation.

scholarly journals CCL19 enhances CD8+ T-cell responses and accelerates HBV clearance

2021 ◽  
Author(s):  
Yan Yan ◽  
Wei Zhao ◽  
Wei Liu ◽  
Yan Li ◽  
Xu Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Crucial Role ◽  
Cell Activation ◽  
Hbv Infection ◽  
Host Immune System ◽  
Tnf Α ◽  
Ifn Γ ◽  
High Level

Abstract Background Chemokine (C–C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8+ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear. Methods We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C–C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation. Results From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ+ CD8+ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8+ T-cell proportion, decreased frequency of PD-1+ CD8+ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8+ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8+ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8+ regulatory T (Treg) cells were observed. Conclusions Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.

scholarly journals Novel self-amplificatory loop between T cells and tenocytes as a driver of chronicity in tendon disease

2021 ◽  
pp. annrheumdis-2020-219335
Author(s):  
Emma Garcia-Melchor ◽  
Giacomo Cafaro ◽  
Lucy MacDonald ◽  
Lindsay A N Crowe ◽  
Shatakshi Sood ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
T Cell ◽  
Inflammatory Cytokines ◽  
T Cell Activation ◽  
Cell Activation ◽  
Conditioned Media ◽  
Tissue Remodelling ◽  
Activated T Cells ◽  
T Cell Migration

ObjectivesIncreasing evidence suggests that inflammatory mechanisms play a key role in chronic tendon disease. After observing T cell signatures in human tendinopathy, we explored the interaction between T cells and tendon stromal cells or tenocytes to define their functional contribution to tissue remodelling and inflammation amplification and hence disease perpetuation.MethodsT cells were quantified and characterised in healthy and tendinopathic tissues by flow cytometry (FACS), imaging mass cytometry (IMC) and single cell RNA-seq. Tenocyte activation induced by conditioned media from primary damaged tendon or interleukin-1β was evaluated by qPCR. The role of tenocytes in regulating T cell migration was interrogated in a standard transwell membrane system. T cell activation (cell surface markers by FACS and cytokine release by ELISA) and changes in gene expression in tenocytes (qPCR) were assessed in cocultures of T cells and explanted tenocytes.ResultsSignificant quantitative differences were observed in healthy compared with tendinopathic tissues. IMC showed T cells in close proximity to tenocytes, suggesting tenocyte–T cell interactions. On activation, tenocytes upregulated inflammatory cytokines, chemokines and adhesion molecules implicated in T cell recruitment and activation. Conditioned media from activated tenocytes induced T cell migration and coculture of tenocytes with T cells resulted in reciprocal activation of T cells. In turn, these activated T cells upregulated production of inflammatory mediators in tenocytes, while increasing the pathogenic collagen 3/collagen 1 ratio.ConclusionsInteraction between T cells and tenocytes induces the expression of inflammatory cytokines/chemokines in tenocytes, alters collagen composition favouring collagen 3 and self-amplifies T cell activation via an auto-regulatory feedback loop. Selectively targeting this adaptive/stromal interface may provide novel translational strategies in the management of human tendon disorders.

NFATc3 regulates the transcription of genes involved in T-cell activation and angiogenesis

Blood ◽  
2011 ◽  
Vol 118 (3) ◽  
pp. 795-803 ◽  
Author(s):  
Katia Urso ◽  
Arantzazu Alfranca ◽  
Sara Martínez-Martínez ◽  
Amelia Escolano ◽  
Inmaculada Ortega ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Genes ◽  
Gene Knockout ◽  
Activated T Cells ◽  
Knock Down ◽  
And Function

Abstract The nuclear factor of activated T cells (NFAT) family of transcription factors plays important roles in many biologic processes, including the development and function of the immune and vascular systems. Cells usually express more than one NFAT member, raising the question of whether NFATs play overlapping roles or if each member has selective functions. Using mRNA knock-down, we show that NFATc3 is specifically required for IL2 and cyclooxygenase-2 (COX2) gene expression in transformed and primary T cells and for T-cell proliferation. We also show that NFATc3 regulates COX2 in endothelial cells, where it is required for COX2, dependent migration and angiogenesis in vivo. These results indicate that individual NFAT members mediate specific functions through the differential regulation of the transcription of target genes. These effects, observed on short-term suppression by mRNA knock-down, are likely to have been masked by compensatory effects in gene-knockout studies.

T cells: a dedicated effector kinase pathways for every trait?

2021 ◽  
Vol 478 (6) ◽  
pp. 1303-1307
Author(s):  
Kriti Bahl ◽  
Jeroen P. Roose
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Spectrometric Analysis ◽  
Activated T Cells ◽  
Biological Responses ◽  
Extracellular Signal ◽  
Differentiation And Proliferation

Signaling pathways play critical roles in regulating the activation of T cells. Recognition of foreign peptide presented by MHC to the T cell receptor (TCR) triggers a signaling cascade of proximal kinases and adapter molecules that lead to the activation of Effector kinase pathways. These effector kinase pathways play pivotal roles in T cell activation, differentiation, and proliferation. RNA sequencing-based methods have provided insights into the gene expression programs that support the above-mentioned cell biological responses. The proteome is often overlooked. A recent study by Damasio et al. [Biochem. J. (2021) 478, 79–98. doi:10.1042/BCJ20200661] focuses on characterizing the effect of extracellular signal-regulated kinase (ERK) on the remodeling of the proteome of activated CD8+ T cells using Mass spectrometric analysis. Surprisingly, the Effector kinase ERK pathway is responsible for only a select proportion of the proteome that restructures during T cell activation. The primary targets of ERK signaling are transcription factors, cytokines, and cytokine receptors. In this commentary, we discuss the recent findings by Damasio et al. [Biochem. J. (2021) 478, 79–98. doi:10.1042/BCJ20200661] in the context of different Effector kinase pathways in activated T cells.

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.

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