1.67 Interaction between fibroblasts and T lymphocytes is needed for IL-17 secretion and Th17 differentiation requires T cell activation

2014 ◽  
Vol 73 (Suppl 1) ◽  
pp. A29.1-A29 ◽  
Author(s):  
Mélissa Noack ◽  
N’Diémé Thiam ◽  
Pierre Miossec
Keyword(s):  
T Cell ◽  
T Lymphocytes ◽  
T Cell Activation ◽  
Cell Activation ◽  
Th17 Differentiation

Abstract MP05: The Mechanism Of The Pvat Pro-inflammatory Micro-environment Formation During The Development Of High Fat Diet-induced Hypertension

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Yining Jin ◽  
Omar Kana ◽  
Ramya Kumar ◽  
Rance Nault ◽  
Hannah Garver ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
High Fat Diet ◽  
Cell Activation ◽  
Control Diet ◽  
Rna Seq ◽  
High Fat ◽  
Induced Hypertension ◽  
Th17 Differentiation

There is considerable evidence for a causative role for T cells in hypertension, including studies with immunosuppressive drugs and T cell-deficient models. Our previous studies showed that soluble mediators from mesenteric perivascular adipose tissue (mPVAT) modulate T cell function. Specifically, conditioned media from mPVAT (mPVAT-CM) from Dahl S rats on a high fat diet (HFD) promoted expression of the pro-inflammatory cytokines, IFNg, IL-17a and GM-CSF, by activated T cells. Furthermore, the Dahl S rats on HFD will later develop hypertension. Hypothesis: mPVAT is stimulated to produce immunomodulatory mediators that promotes Th1/17 differentiation preceding the development of HFD-induced hypertension. We conducted bulk RNA-seq on activated splenocytes cultured in mPVAT-CM from Dahl S rats on either control or HFD for 10 weeks. In accordance with our previous studies, PVAT-CM from HFD-fed rats significantly upregulated many genes associated with IFNg/IL-17 induction, including Mpeg1, Lyz2 and Tnfsf4 (5.0±1.78, 3.70±0.53 and 1.78±0.42 fold over Control diet, respectively). In contrast, Th2/Treg-associated genes, such as Ctla2a (-0.27±0.02) and Ccr4 (-0.41±0.03) were downregulated. We also performed single cell (sc) RNA-seq on the PVAT stromal vascular fraction (SVF) and found that acute inflammatory genes were enriched in the HFD group. Together with the bulk RNA-seq on mPVAT, these data strongly suggest that the pro-inflammatory mPVAT micro-environment may promote Th1/Th17 differentiation. To identify mediators in PVAT-CM that may induce Th1/Th17 differentiation, we compared the bulk RNA-seq on splenocytes cultured in PVAT-CM with bulk RNA-seq conducted on the whole mPVAT itself. We found that a T cell co-stimulatory receptor DPP4 (CD26), which is closely associated with T cell activation was significantly increased in mPVAT from HFD-fed rats (33.4±2.3 HFD vs. 15.3±1.8 Control diet). We also observed an increase in DPP4 global expression from mPVAT SVF in HFD-fed rats, as determined by scRNA-seq. Conclusion: The data suggest that HFD promotes the IFNg and IL-17a pathways in PVAT, which precedes hypertension in Dahl S rats and correlates with an increase in expression of DPP-4, a gene that promotes T cell activation. (NIH P01 HL070687).

scholarly journals Immune function of the blood-brain barrier: incomplete presentation of protein (auto-)antigens by rat brain microvascular endothelium in vitro.

1990 ◽  
Vol 110 (5) ◽  
pp. 1757-1766 ◽  
Author(s):  
W Risau ◽  
B Engelhardt ◽  
H Wekerle
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Rat Brain ◽  
Blood Brain Barrier ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ifn Gamma

The endothelial blood-brain barrier (BBB) has a critical role in controlling lymphocyte traffic into the central nervous system (CNS), both in physiological immunosurveillance, and in its pathological aberrations. The intercellular signals that possibly could induce lymphocytes to cross the BBB include immunogenic presentation of protein (auto-)antigens by BBB endothelia to circulating T lymphocytes. This concept has raised much, though controversial, attention. We approached this problem by analyzing in vitro immunospecific interactions between clonal rat T lymphocyte lines with syngeneic, stringently purified endothelial monolayer cultures from adult brain micro-vessels. The rat brain endothelia (RBE) were established from rat brain capillaries using double collagenase digestion, density gradient fractionation and selective cytolysis of contaminating pericytes by anti-Thy 1.1 antibodies and complement. Incubation with interferon-gamma in most of the brain-derived endothelial cells induced Ia-antigens in the cytoplasm and on the cell surface in some of the cells. Before the treatment, the cells were completely Ia-negative. Pericytes were unresponsive to IFN-gamma treatment. When confronted with syngeneic T cell lines specific for protein (auto-)antigens (e.g., ovalbumin and myelin basic protein, MBP), RBE were completely unable to induce antigen-specific proliferation of syngeneic T lymphocytes irrespective of pretreatment with IFN-gamma and of cell density. RBE were inert towards the T cells, and did not suppress T cell activation induced by other "professional" antigen presenting cells (APC) such as thymus-derived dendritic cells or macrophages. IFN-gamma-treated RBE were, however, susceptible to immunospecific T cell killing. They were lysed by MBP-specific T cells in the presence of the specific antigen or Con A. Antigen dependent lysis was restricted by the appropriate (MHC) class II product. We conclude that the interaction of brain endothelial cells with encephalitogenic T lymphocytes may involve recognition of antigen in the molecular context of relevant MHC products, but that this interaction per se is insufficient to initiate the full T cell activation program.

Abstract P347: γδ T Cells Drive CD4 + And CD8 + T Cell Activation In Hypertension

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Pierre Paradis ◽  
Ernesto L Schiffrin
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Vascular Injury ◽  
T Cell Activation ◽  
Cell Activation ◽  
Γδ T Cells ◽  
Ang Ii ◽  
Adaptive Immune Cells ◽  
Induced Hypertension

Objective: Both innate (monocyte/macrophages) and adaptive immune cells (T lymphocytes) have been shown to play a role in the development of vascular injury in hypertension. Recently, we demonstrated that a small subset of “innate-like” T lymphocytes, expressing the γ/δ T cell receptor (TCR) rather than the αβ TCR, plays a key role in hypertension and vascular injury. We demonstrated an increased number and activation (CD69 + ) of γδ T cells during the development of hypertension caused by angiotensin (Ang) II infusion, and that deficiency in γδ T cells prevented Ang II-induced hypertension, resistance artery endothelial dysfunction and spleen T-cell activation in mice. We hypothesized that γδ T cells mediate activation of other T cells in hypertension. Method and Results: Fourteen to 15-week old male C57BL/6 wild-type (WT) mice were infused with Ang II (490 ng/kg/min, SC) for 3, 7 and 14 days (n=5-7) and spleen T cell profile was determined by flow cytometry. A correlation was demonstrated between the frequency (FREQ) and the number (#) of activated CD69 + γδ T cells and CD4 + CD69 + T cells (FREQ: r=0.41, P <0.05 and #: r=0.58, P <0.001) and CD8 + CD69 + T cells (FREQ: r=0.36, P <0.05 and #: r=0.50, P <0.01). We also demonstrated a high correlation between the # of CD69 + γδ T cells expressing CD27, a marker of interferon-γ expressing cells and a member of the T-T interaction molecules, with CD4 + CD69 + (r=0.88, P <0.001) and CD8 + CD69 + (r=0.81, P <0.01) T cells after 7 days of Ang II infusion. Conclusion: This study demonstrated an association between CD27 + CD69 + γδ T cells and activated T cells. These results suggest that γδ T cells drive activation of other T cells in Ang II-induced hypertension. Targeting γδ T cells may contribute to reduce inflammation in hypertension.

p38 MAPK Mediates Inhibition of Activation Induced Cell Death in T Lymphocytes Via Upregulation of Bcl-xL and FLIPshort upon Ligation of CD137/4-1BB or CD28.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3320-3320
Author(s):  
Christian Scholz ◽  
Lilian Stärck ◽  
Mario Lehmann ◽  
Bernd Dörken ◽  
Peter T. Daniel
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Protein Kinase ◽  
T Lymphocytes ◽  
Family Member ◽  
P38 Mapk ◽  
T Cell Activation ◽  
Cell Activation ◽  
Activation Induced Cell Death ◽  
Costimulatory Signals

Abstract Costimulation is essential for the induction of proliferation in naive T cells and for the inhibition of activation induced cell death (AICD) in activated T lymphocytes. While costimulatory signals mediated through the immunglobulin family member CD28 play a prominent role during primary T cell activation, ligation of the tumor necrosis factor receptor family member CD137/4-1BB is more important during late primary and secondary T cell activation. Signals mediated through either costimulatory protein block AICD. Inhibition of AICD through ligation of CD137/4-1BB or CD28 involves upregulation of Bcl-xL and FLIPshort (Eur J Immunol 2005, 35: 1257–66). We further demonstrated that costimulatory signals mediated through CD137/4-1BB or CD28 depend on the activity of phosphatidylinositol 3-kinase and AKT/protein kinase B, two kinases that had formerly been implied in CD28-induced signaling, indicating that CD28- and CD137/4-1BB-mediated signals share downstream signaling pathways. Here, we demonstrate that p38 mitogen-activated protein kinase (MAPK) mediates CD137/4-1BB-induced as well as CD28-mediated costimulation of cell proliferation and inhibition of AICD. This coincides with upregulation of Bcl-xL and FLIPshort. Inhibition of p38 MAPK abrogates T cell receptor induced proliferation and antagonizes costimulation mediated survival. Thus, p38 MAPK, which was previously thought to be primarily involved in CD137/4-1BB-mediated signaling, is similarly important for CD28-induced costimulation and survival. This indicates that, while involving different protein families, signal transduction by CD28 and CD137/4-1BB depends on a common upstream and downstream network of survival kinases.

scholarly journals Activation of virus replication after vaccination of HIV-1-infected individuals.

1995 ◽  
Vol 182 (6) ◽  
pp. 1727-1737 ◽  
Author(s):  
S I Staprans ◽  
B L Hamilton ◽  
S E Follansbee ◽  
T Elbeik ◽  
P Barbosa ◽  
...  
Keyword(s):  
T Cells ◽  
Steady State ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Activation ◽  
Cell Activation ◽  
Vaccine Antigens ◽  
Steady State Levels ◽  
Hiv 1

Little is known about the factors that govern the level of HIV-1 replication in infected individuals. Recent studies (using potent antiviral drugs) of the kinetics of HIV-1 replication in vivo have demonstrated that steady-state levels of viremia are sustained by continuous rounds of de novo infection and the associated rapid turnover of CD4+ T lymphocytes. However, no information is available concerning the biologic variables that determine the size of the pool of T cells that are susceptible to virus infection or the amount of virus produced from infected cells. Furthermore, it is not known whether all CD4+ T lymphocytes are equally susceptible to HIV-1 infection at a given time or whether the infection is focused on cells of a particular state of activation or antigenic specificity. Although HIV-1 replication in culture is known to be greatly facilitated by T cell activation, the ability of specific antigenic stimulation to augment HIV-1 replication in vivo has not been studied. We sought to determine whether vaccination of HIV-1-infected adults leads to activation of virus replication and the targeting of vaccine antigen-responsive T cells for virus infection and destruction. Should T cell activation resulting from exposure to environmental antigens prove to be an important determinant of the steady-state levels of HIV-1 replication in vivo and lead to the preferential loss of specific populations of CD4+ T lymphocytes, it would have significant implications for our understanding of and therapeutic strategies for HIV-1 disease. To begin to address these issues, HIV-1-infected individuals and uninfected controls were studied by measurement of immune responses to influenza antigens and quantitation of virion-associated plasma HIV-1 RNA levels at baseline and at intervals after immunization with the trivalent influenza vaccine. Influenza vaccination resulted in readily demonstrable but transient increases in plasma HIV-1 RNA levels, indicative of activation of viral replication, in HIV-1-infected individuals with preserved ability to immunologically respond to vaccine antigens. Activation of HIV-1 replication by vaccination was more often seen and of greater magnitude in individuals who displayed a T cell proliferative response to vaccine antigens at baseline and in those who mounted a significant serologic response after vaccination. The fold increase in viremia, as well as the rates of increase of HIV-1 in plasma after vaccination and rates of viral decline after peak viremia, were higher in individuals with higher CD4+ T cell counts.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Modulation of KV1.3 channels by protein kinase A I in T lymphocytes is mediated by the disc large 1-tyrosine kinase Lck complex

2012 ◽  
Vol 302 (10) ◽  
pp. C1504-C1512 ◽  
Author(s):  
Zerrin Kuras ◽  
Vladimir Kucher ◽  
Scott M. Gordon ◽  
Lisa Neumeier ◽  
Ameet A. Chimote ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Tyrosine Kinase ◽  
Signaling Pathway ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Scaffolding Protein ◽  
T Cell Function

The cAMP/PKA signaling system constitutes an inhibitory pathway in T cells and, although its biochemistry has been thoroughly investigated, its possible effects on ion channels are still not fully understood. KV1.3 channels play an important role in T-cell activation, and their inhibition suppresses T-cell function. It has been reported that PKA modulates KV1.3 activity. Two PKA isoforms are expressed in human T cells: PKAI and PKAII. PKAI has been shown to inhibit T-cell activation via suppression of the tyrosine kinase Lck. The aim of this study was to determine the PKA isoform modulating KV1.3 and the signaling pathway underneath. 8-Bromoadenosine 3′,5′-cyclic monophosphate (8-BrcAMP), a nonselective activator of PKA, inhibited KV1.3 currents both in primary human T and in Jurkat cells. This inhibition was prevented by the PKA blocker PKI6–22. Selective knockdown of PKAI, but not PKAII, with siRNAs abolished the response to 8-BrcAMP. Additional studies were performed to determine the signaling pathway mediating PKAI effect on KV1.3. Overexpression of a constitutively active mutant of Lck reduced the response of KV1.3 to 8-Br-cAMP. Moreover, knockdown of the scaffolding protein disc large 1 (Dlg1), which binds KV1.3 to Lck, abolished PKA modulation of KV1.3 channels. Immunohistochemistry studies showed that PKAI, but not PKAII, colocalizes with KV1.3 and Dlg1 indicating a close proximity between these proteins. These results indicate that PKAI selectively regulates KV1.3 channels in human T lymphocytes. This effect is mediated by Lck and Dlg1. We thus propose that the KV1.3/Dlg1/Lck complex is part of the membrane pathway that cAMP utilizes to regulate T-cell function.

An emerging player in the adaptive immune response: microRNA-146a is a modulator of IL-2 expression and activation-induced cell death in T lymphocytes

Blood ◽  
2010 ◽  
Vol 115 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Graziella Curtale ◽  
Franca Citarella ◽  
Claudia Carissimi ◽  
Marina Goldoni ◽  
Nicoletta Carucci ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Activation Induced Cell Death

Abstract Activation of the T cell–mediated immune response has been associated with changes in the expression of specific microRNAs (miRNAs). However, the role of miRNAs in the development of an effective immune response is just beginning to be explored. This study focuses on the functional role of miR-146a in T lymphocyte–mediated immune response and provides interesting clues on the transcriptional regulation of miR-146a during T-cell activation. We show that miR-146a is low in human naive T cells and is abundantly expressed in human memory T cells; consistently, miR-146a is induced in human primary T lymphocytes upon T-cell receptor (TCR) stimulation. Moreover, we identified NF-kB and c-ETS binding sites as required for the induction of miR-146a transcription upon TCR engagement. Our results demonstrate that several signaling pathways, other than inflammation, are influenced by miR-146a. In particular, we provide experimental evidence that miR-146a modulates activation-induced cell death (AICD), acting as an antiapoptotic factor, and that Fas-associated death domain (FADD) is a target of miR-146a. Furthermore, miR-146a enforced expression impairs both activator protein 1 (AP-1) activity and interleukin-2 (IL-2) production induced by TCR engagement, thus suggesting a role of this miRNA in the modulation of adaptive immunity.

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