scholarly journals T Cell Costimulation through CD28 Depends on Induction of the Bcl-xγ Isoform

2002 ◽  
Vol 196 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Qunrui Ye ◽  
Barry Press ◽  
Stephan Kissler ◽  
Xiao-Feng Yang ◽  
Linrong Lu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Proteolipid Protein ◽  
Autoimmune Encephalomyelitis ◽  
Activated T Cells ◽  
Impaired Memory ◽  
Cytokine Responses ◽  
Costimulatory Signals ◽  
Dependent Signaling Pathway ◽  
Experimental Autoimmune

The molecular basis of CD28-dependent costimulation of T cells is poorly understood. Bcl-xγ is a member of the Bcl-x family whose expression is restricted to activated T cells and requires CD28-dependent ligation for full expression. We report that Bcl-xγ–deficient (Bcl-xγ−/−) T cells display defective proliferative and cytokine responses to CD28-dependent costimulatory signals, impaired memory responses to proteolipid protein peptide (PLP), and do not develop PLP-induced experimental autoimmune encephalomyelitis (EAE). In contrast, enforced expression of Bcl-xγ largely replaces the requirement for B7-dependent ligation of CD28. These findings identify the Bcl-xγ cytosolic protein as an essential downstream link in the CD28-dependent signaling pathway that underlies T cell costimulation.

scholarly journals Priming of Myelin-Specific T Cells in the Absence of Dendritic Cells Results in Accelerated Development of Experimental Autoimmune Encephalomyelitis

2020 ◽  
Author(s):  
Thaiphi Luu ◽  
Julie F. Cheung ◽  
Hanspeter Waldner
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Experimental Autoimmune Encephalomyelitis ◽  
T Cell Responses ◽  
Proteolipid Protein ◽  
Cell Receptor ◽  
Autoimmune Encephalomyelitis ◽  
Cell Responses ◽  
Experimental Autoimmune

AbstractExperimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS), is predominantly mediated by pro-inflammatory CD4+ T cell responses to CNS antigens, including myelin proteolipid protein (PLP). Dendritic cells (DCs) are considered critical for inducing T cell responses against infectious agents, but the importance of DCs in priming self-reactive CD4+ T cells in autoimmune disease such as MS has been unclear.To determine the requirement of DCs in PLP-specific CD4+ T cell responses and EAE, we genetically deleted CD11c+ DCs in PLP T cell receptor (TCR) transgenic SJL mice constitutively. DC deficiency did not impair the development, selection or the pathogenic function of PLP-specific CD4+ T cells in these mice, and resulted in accelerated spontaneous EAE compared to DC sufficient controls. In addition, using a genetic approach to ablate DCs conditionally in SJL mice, we show that CD11c+ DCs were dispensable for presenting exogenous or endogenous myelin antigen to PLP-specific T cells and for promoting pro-inflammatory T cell responses and severe EAE. Our findings demonstrate that constitutive or conditional ablation of CD11c+ DCs diminished self-tolerance to PLP autoantigen. They further show that in the absence of DCs, non-DCs can efficiently present CNS myelin antigens such as PLP to self-reactive T cells, resulting in accelerated onset of spontaneous or induced EAE.

scholarly journals Priming of myelin-specific T cells in the absence of dendritic cells results in accelerated development of Experimental Autoimmune Encephalomyelitis

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250340
Author(s):  
Thaiphi Luu ◽  
Julie F. Cheung ◽  
Jennifer Baccon ◽  
Hanspeter Waldner
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Experimental Autoimmune Encephalomyelitis ◽  
T Cell Responses ◽  
Proteolipid Protein ◽  
Cell Receptor ◽  
Autoimmune Encephalomyelitis ◽  
Cell Responses ◽  
Experimental Autoimmune

Experimental autoimmune encephalomyelitis (EAE) is an established animal model of multiple sclerosis (MS). Inflammatory CD4+ T cell responses directed against CNS antigens, including myelin proteolipid protein (PLP), are key mediators of EAE. Dendritic cells (DCs) are critical for the induction of T cell responses against infectious agents. However, the importance of DCs in priming self-reactive CD4+ T cells in autoimmune disease such as MS has been unclear. To determine the requirement of DCs in PLP-specific CD4+ T cell responses and EAE, we genetically deleted CD11c+ DCs in PLP T cell receptor (TCR) transgenic SJL mice constitutively. DC deficiency did not impair the development, selection or the pathogenic function of PLP-specific CD4+ T cells in these mice, and resulted in accelerated spontaneous EAE compared to DC sufficient controls. In addition, using a genetic approach to ablate DCs conditionally in SJL mice, we show that CD11c+ DCs were dispensable for presenting exogenous or endogenous myelin antigen to PLP-specific T cells and for promoting pro-inflammatory T cell responses and severe EAE. Our findings demonstrate that constitutive or conditional ablation of CD11c+ DCs diminished self-tolerance to PLP autoantigen. They further show that in the absence of DCs, non-DCs can efficiently present CNS myelin antigens such as PLP to self-reactive T cells, resulting in accelerated onset of spontaneous or induced EAE.

scholarly journals Mechanisms of acquired thymic tolerance in experimental autoimmune encephalomyelitis: thymic dendritic-enriched cells induce specific peripheral T cell unresponsiveness in vivo.

1995 ◽  
Vol 182 (2) ◽  
pp. 357-366 ◽  
Author(s):  
S J Khoury ◽  
L Gallon ◽  
W Chen ◽  
K Betres ◽  
M E Russell ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Autoimmune Encephalomyelitis ◽  
Activated T Cells ◽  
Lewis Rats ◽  
Intrathymic Injection ◽  
Experimental Autoimmune

Experimental autoimmune encephalomyelitis (EAE), an experimental model for the study of multiple sclerosis, is an autoimmune disease of the central nervous system that can be induced in a number of species by immunization with myelin basic protein (MBP). MBP-reactive CD4+ T cells, predominantly expressing the V beta 8.2 T cell receptor (TCR), migrate from the peripheral lymphoid organs and initiate the inflammatory response in the brain. We have previously shown that a single intrathymic injection of MBP or its major encephalitogenic peptide (p71-90), but not a nonencephalitogenic peptide (p21-40), induces antigen-specific systemic tolerance and inhibits the induction of EAE in Lewis rats. In this study, we investigated the mechanisms of induction and maintenance of acquired thymic tolerance in this model. First, we investigated which thymic cell is responsible for "induction" of systemic tolerance. Thymic dendritic-enriched cells, isolated by plastic adherence, when incubated in vitro with p71-90 and injected intravenously into Lewis rats, were capable of preventing the development of EAE, but his protection was lost in thymectomized recipients. In addition, intravenous injection of thymic dendritic cells isolated from animals that had been previously injected intrathymically with p71-90 but not p21-40 also prevented the development of EAE. Second, to determine the "effector" mechanisms involved in acquired thymic tolerance, we compared TCR expression in the brains of animals with actively induced EAE with TCR expression in animals that received intrathymic injection of p71-90 or p21-40. Using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) technique, we found increased expression of CD4 and V beta 8.2 message in brains of immunized animals compared with those of naive animals. In animals intrathymically injected with p71-90 but not p21-40, CD4 and V beta 8.2 transcript levels were significantly reduced compared with immunized controls. Immunohistologic studies of brain tissue and spleens with specific V beta 8.2 and control V beta 10 monoclonal antibodies confirmed these observations in vivo. These findings, taken together with recent data demonstrating that activated T cells circulate through the thymus, suggest that interaction of thymic dendritic cells with specific TCR of activated peripheral T cells can lead to inactivation of these antigen-specific cells and confirm the role of V beta 8.2-expressing T cells in EAE.

scholarly journals Mgat5 Deficiency in T Cells and Experimental Autoimmune Encephalomyelitis

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ani Grigorian ◽  
Michael Demetriou
Keyword(s):  
T Cells ◽  
T Cell ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Demyelinating Disease ◽  
Cell Receptor ◽  
Protein Glycosylation ◽  
Autoimmune Encephalomyelitis ◽  
Glycosylation Pathway ◽  
Experimental Autoimmune ◽  
Surface Glycoproteins

Multiple sclerosis (MS) is an inflammatory demyelinating and neurodegenerative disease initiated by autoreactive T cells. Mgat5, a gene in the Asn (N-) linked protein glycosylation pathway, associates with MS severity and negatively regulates experimental autoimmune encephalomyelitis (EAE) and spontaneous inflammatory demyelination in mice. N-glycan branching by Mgat5 regulates interaction of surface glycoproteins with galectins, forming a molecular lattice that differentially controls the concentration of surface glycoproteins. T-cell receptor signaling, T-cell proliferation, TH1 differentiation, and CTLA-4 endocytosis are inhibited by Mgat5 branching. Non-T cells also contribute to MS pathogenesis and express abundant Mgat5 branched N-glycans. Here we explore whether Mgat5 deficiency in myelin-reactive T cells is sufficient to promote demyelinating disease. Adoptive transfer of myelin-reactive Mgat5−/− T cells into Mgat5+/+ versus Mgat5−/− recipients revealed more severe EAE in the latter, suggesting that Mgat5 branching deficiency in recipient naive T cells and/or non-T cells contribute to disease pathogenesis.

scholarly journals Priming of T cells to Fas-mediated proliferative signals by interleukin-7

Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1195-1204 ◽  
Author(s):  
Bence Rethi ◽  
Nancy Vivar ◽  
Stefano Sammicheli ◽  
Caroline Fluur ◽  
Nicolas Ruffin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocyte ◽  
Cell Receptor ◽  
Cell Depletion ◽  
Activated T Cells ◽  
T Cell Depletion ◽  
Interleukin 7 ◽  
Costimulatory Signals ◽  
Opposing Effects

Abstract T-cell depletion associated with HIV infection or cytoreductive therapies triggers potential T-cell regenerative mechanisms such as peripheral T-lymphocyte expansion to weak antigenic stimuli and the increased availability of interleukin-7 (IL-7), a cytokine with potent antiapoptotic and proliferative activities. Deleterious mechanisms also associated with lymphopenia, such as increased Fas expression and apoptosis of T cell, however, may result in opposing effects. In this study, we show that Fas molecules, primarily associated with T-cell depletion in lymphopenic settings, may also contribute to compensatory T-cell expansion through transmitting costimulatory signals to suboptimally activated T cells. Proliferation of T lymphocytes in response to concomitant Fas and T-cell receptor (TCR) triggering was shown to be increased in HIV-infected individuals compared with noninfected controls. As IL-7 levels are often elevated in lymphopenic individuals in association with increased Fas expression, we analyzed whether IL-7 would influence Fas-mediated proliferative signals in T cells. We show that IL-7 is able to increase the efficacy of Fas to induce proliferation of suboptimally activated T cells. Thus, high IL-7 levels associated with lymphopenic conditions may simultaneously induce sensitivity to Fas-mediated apoptosis in nonactivated T cells and increase Fas-induced costimulatory signals in T cells recognizing low-affinity antigens.

A shift in encephalitogenic T cell cytokine pattern is associated with suppression of EAE by intravenous immunoglobulins (IVIg)

1997 ◽  
Vol 3 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Anastas Pashov ◽  
Blanche Bellon ◽  
Srini V Kaveri ◽  
Michel D Kazatchkine
Keyword(s):  
T Cells ◽  
T Cell ◽  
Intravenous Immunoglobulins ◽  
Ivig Treatment ◽  
Autoimmune Encephalomyelitis ◽  
Proliferative Effect ◽  
Kinetics Of ◽  
Experimental Autoimmune

Pooled human polyspecific IgG preparations for intravenous use (IVIg) have been used in a number of antibody mediated autoimmune diseases and recently in some T cell mediated disorders including multiple sclerosis, birdshot retinopathy and rheumatoid arthritis. Furthermore, IVIg has been proven beneficial in the corresponding animal models, i.e. experimental autoimmune encephalomyelitis (EAE), experimental autoimmune uveoretinitis and adjuvant arthritis respectively. The exact mechanisms for IVIg adion in T cell mediated disorders are still poorly understood. There is evidence that IVIg treatment in vitro and in vivo decreases or changes the kinetics of the secretion by normal PBMC of a number of cytokines and anti-proliferative effect of IVIg on T cells in vitro and in vivo has also been reported. It remains unclear though to what extent the IVIg effects in T cell mediated autoimmunity are related only to non-specifc T cell suppression and whether it also reshapes the autoimmune T cell cytokine profile. In this study we demonstrate that IVIg protects against EAE and that this beneficial effed is associated with a decreased proli feration of T cells specific for the immunizing antigen. Moreover, we show that these antigen-specific cells produce low amount of Th /-type cytokines and transfer an attenuated EAE

Shedded neuronal ICAM-5 suppresses T-cell activation

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3615-3625 ◽  
Author(s):  
Li Tian ◽  
Jani Lappalainen ◽  
Matti Autero ◽  
Satu Hänninen ◽  
Heikki Rauvala ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Soluble Form ◽  
Mammalian Brain ◽  
Activated T Cells ◽  
Activation Markers ◽  
Costimulatory Signals

Abstract Intercellular adhesion molecules (ICAMs) bind to leukocyte β2 integrins, which, among other functions, provide costimulatory signals for T-cell activation. ICAM-5 (telencephalin) is expressed in the somadendritic region of neurons of the mammalian brain. The receptor for ICAM-5 is the integrin LFA-1, a major leukocyte integ-rin expressed in lymphocytes and microglia. In conditions of brain ischemia, epilepsy, and encephalitis, the soluble form of ICAM-5 (sICAM-5) has been detected in physiologic fluids. Here, we report that sICAM-5 attenuates the T-cell receptor-mediated activation of T cells as demonstrated by the decreased expression of the activation markers CD69, CD40L, and CD25 (IL-2R). This effect is most clearly seen in CD45ROLow (naive), and not in CD45ROHigh (memory) T cells, and is most effective early in priming, but not in the presence of strong costimulatory signals. Furthermore, sICAM-5 promotes the mRNA expression of the cytokines TGF-β1 and IFN-γ, but not TNF. The formation of sICAM-5 is promoted by activated T cells through the cleavage of ICAM-5 from neurons. This suggests that ICAM-5 is involved in immune privilege of the brain and acts as an anti-inflammatory agent.

scholarly journals Treatment of Experimental Autoimmune Encephalomyelitis with Genetically Modified Memory T Cells

1997 ◽  
Vol 186 (1) ◽  
pp. 159-164 ◽  
Author(s):  
Peter M. Mathisen ◽  
Min Yu ◽  
Justin M. Johnson ◽  
Judith A. Drazba ◽  
Vincent K. Tuohy
Keyword(s):  
T Cells ◽  
T Cell ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Demyelinating Disease ◽  
Memory T Cells ◽  
Vector System ◽  
Autoimmune Encephalomyelitis ◽  
T Cell Clones ◽  
Cell Clones ◽  
Experimental Autoimmune

The migratory properties of memory T cells provide a model vector system for site-specific delivery of therapeutic transgene factors to autoimmune inflammatory lesions. Lymph node cells from (SWR×SJL)F1 mice immunized with the p139–151 determinant of myelin proteolipid protein (PLP) were transfected with a DNA construct that placed the anti-inflammatory cytokine interleukin-10 (IL-10) cDNA under control of an antigen-inducible IL-2 promoter region. Isolated T cell clones demonstrated antigen-inducible expression of transgene IL-10 and expressed cell surface markers consistent with the phenotype of normal memory T cells. Upon adoptive transfer, transfected T cell clones were able to inhibit onset of experimental autoimmune encephalomyelitis (EAE) and to treat EAE animals therapeutically after onset of neurologic signs. Semiquantitative immunocytochemistry showed a significant correlation between decreased demyelination and treatment with the transfected T cells. Taken together, these data indicate the autoreactive T cells can be genetically designed to produce therapeutic factors in an antigen-inducible manner resulting in a decreased severity of clinical and histological autoimmune demyelinating disease.

Macrophage brain infiltration in experimental autoimmune encephalomyelitis is not completely compromised by suppressed T-cell invasion: in vivo magnetic resonance imaging illustration in effective anti-VLA-4 antibody treatment

2004 ◽  
Vol 10 (5) ◽  
pp. 540-548 ◽  
Author(s):  
Mathilde SA Deloire ◽  
Tarik Touil ◽  
Bruno Brochet ◽  
Vincent Dousset ◽  
Jean-Marie Caillé ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
T Cells ◽  
T Cell ◽  
Magnetic Resonance ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Disease Process ◽  
Resonance Imaging ◽  
Autoimmune Encephalomyelitis ◽  
Antibody Treatment ◽  
Experimental Autoimmune

Large inflammatory infiltrates of T cells, macrophages and B cells in the central nervous system (CNS) contribute to the pathogenesis of multiple sclerosis (MS). The passage of T cells through the blood-brain barrier can be suppressed with antibodies directed against alpha-4 integrins (VLA-4) that mediate T-cell adherence. This treatment, in phase III of clinical trial evaluation, reduces lesion development in MS patients. In the ongoing inflammatory disease process the consequences of T-cell inhibitory anti-VLA-4 antibodies on inflammatory compounds are still poorly investigated. We show that anti-VLA-4 antibody treatment during the late preclinical phase of the acute experimental autoimmune encephalomyelitis (EAE) MS rat model interrupts T-cell egress out of the vascular compartment and suppresses clinical disease and histological alterations but macrophage recruitment in the CNS is not fully compromised. Among the treated EAE animals not developing disease, none presented foci of T-cell infiltration in CNS. However, in 75% of the treated EAE rats monocyte ingress in CNS was observedin vivo by magnetic resonance imaging with the ultrasmall superparamagnetic iron oxide contrast agent. Our data shed new light on the role of remaining macrophage brain infiltration in an induced but interrupted T-cell-mediated EAE disease process.

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