scholarly journals Distinct Requirements for C-C Chemokine and IL-2 Production by Naive, Previously Activated, and Anergic T Cells

2000 ◽  
Vol 164 (8) ◽  
pp. 3996-4002 ◽  
Author(s):  
Cara G. Lerner ◽  
Maureen R. Horton ◽  
Ronald H. Schwartz ◽  
Jonathan D. Powell
Keyword(s):  
T Cells ◽  
Anergic T Cells

scholarly journals Silencing of the Il2 gene transcription is regulated by epigenetic changes in anergic T cells

2012 ◽  
Vol 42 (9) ◽  
pp. 2471-2483 ◽  
Author(s):  
Sanmay Bandyopadhyay ◽  
Cristina Montagna ◽  
Fernando Macian
Keyword(s):  
T Cells ◽  
Gene Transcription ◽  
Epigenetic Changes ◽  
Anergic T Cells

scholarly journals Interleukin-10 induces a long-term antigen-specific anergic state in human CD4+ T cells.

1996 ◽  
Vol 184 (1) ◽  
pp. 19-29 ◽  
Author(s):  
H Groux ◽  
M Bigler ◽  
J E de Vries ◽  
M G Roncarolo
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Interleukin 10 ◽  
Necrosis Factor Alpha ◽  
T Cell Anergy ◽  
Factor Alpha ◽  
Cell Anergy ◽  
Anergic T Cells ◽  
Macrophage Colony

Human CD4+ T cells, activated by allogeneic monocytes in a primary mixed lymphocyte reaction in the presence of exogenous interleukin (IL) 10, specifically failed to proliferate after restimulation with the same alloantigens. A comparable state of T cell unresponsiveness could be induced by activation of CD4+ T cells by cross-linked anti-CD3 monoclonal antibodies (mAbs) in the presence of exogenous IL-10. The anergic T cells failed to produce IL-2, IL-5, IL-10, interferon gamma, tumor necrosis factor alpha, and granulocyte/macrophage colony-stimulating factor. The IL-10-induced anergic state was long-lasting. T cell anergy could not be reversed after restimulation of the cells with anti-CD3 and anti-CD28 mAbs, although CD3 and CD28 expression was normal. In addition, restimulation of anergized T cells with anti-CD3 mAbs induced normal Ca2+ fluxes and resulted in increased CD3, CD28, and class II major histocompatibility complex expression, indicating that calcineurin-mediated signaling occurs in these anergic cells. However, the expression of the IL-2 receptor alpha chain was not upregulated, which may account for the failure of exogenous IL-2 to reverse the anergic state. Interestingly, anergic T cells and their nonanergic counterparts showed comparable levels of proliferation and cytokine production after activation with phorbol myristate acetate and Ca2+ ionophore, indicating that a direct activation of a protein kinase C-dependent pathway can overcome the tolerizing effect of IL-10. Taken together, these data demonstrate that IL-10 induces T cell anergy and therefore may play an important role in the induction and maintenance of antigen-specific T cell tolerance.

scholarly journals Negative transcriptional regulation in anergic T cells.

1995 ◽  
Vol 92 (6) ◽  
pp. 2375-2378 ◽  
Author(s):  
J. C. Becker ◽  
T. Brabletz ◽  
T. Kirchner ◽  
C. T. Conrad ◽  
E. B. Brocker ◽  
...  
Keyword(s):  
T Cells ◽  
Transcriptional Regulation ◽  
Anergic T Cells

scholarly journals Both Maturation and Survival of Human Dendritic Cells are Impaired in the Presence of Anergic/Suppressor T Cells

2003 ◽  
Vol 10 (1) ◽  
pp. 61-65 ◽  
Author(s):  
L. Frasca ◽  
C. Scottà ◽  
G. Lombardi ◽  
E. Piccolella
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Costimulatory Molecule ◽  
T Cell Suppression ◽  
Cell Suppression ◽  
Anergic T Cells ◽  
Human Dendritic Cells

T cell suppression is a well established phenomenon, but the mechanisms involved are still a matter of debate. Mouse anergic T cells were shown to suppress responder T cell activation by inhibiting the antigen presenting function of DC. In the present work we studied the effects of co-culturing human anergic CD4+T cells with autologous dendritic cells (DC) at different stages of maturation. Either DC maturation or survival, depending on whether immature or mature DC where used as APC, was impaired in the presence of anergic cells. Indeed, MHC and costimulatory molecule up-regulation was inhibited in immature DC, whereas apoptotic phenomena were favored in mature DC and consequently in responder T cells. Defective ligation of CD40 by CD40L (CD154) was responsible for CD95-mediated and spontaneous apoptosis of DC as well as for a failure of their maturation process. These findings indicate that lack of activation of CD40 on DC by CD40L-defective anergic cells might be the primary event involved in T cell suppression and support the role of CD40 signaling in regulating both activation and survival of DC.

Impaired CD28-mediated co-stimulation in anergic T cells

1995 ◽  
Vol 7 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Gen Suzuki ◽  
Masayuki Nomura ◽  
Akiko Uzawa ◽  
Makoto Akashi ◽  
Yukiko Nakata
Keyword(s):  
T Cells ◽  
Anergic T Cells

scholarly journals PAG-Associated FynT Regulates Calcium Signaling and Promotes Anergy in T Lymphocytes

2007 ◽  
Vol 27 (5) ◽  
pp. 1960-1973 ◽  
Author(s):  
Dominique Davidson ◽  
Burkhart Schraven ◽  
André Veillette
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Phosphorylation ◽  
T Cell Activation ◽  
Protein Tyrosine Kinase ◽  
Cell Activation ◽  
T Cell Anergy ◽  
Cell Anergy ◽  
Anergic T Cells ◽  
Selective Enhancement

ABSTRACT Phosphoprotein associated with glycolipid-enriched membranes (PAG), also named Csk-binding protein (Cbp), is a transmembrane adaptor associated with lipid rafts. It is phosphorylated on multiple tyrosines located in the cytoplasmic domain. One tyrosine, tyrosine 314 (Y314) in the mouse, interacts with Csk, a protein tyrosine kinase that negatively regulates Src kinases. This interaction enables PAG to inhibit T-cell antigen receptor (TCR)-mediated T-cell activation. PAG also associates with the Src-related kinase FynT. Genetic studies indicated that FynT was required for PAG tyrosine phosphorylation and binding of PAG to Csk in T cells. Herein, we investigated the function and regulation of PAG-associated FynT. Our data showed that PAG was constitutively associated with FynT in unstimulated T cells and that this association was rapidly lost in response to TCR stimulation. Dissociation of the PAG-FynT complex preceded PAG dephosphorylation and PAG-Csk dissociation after TCR engagement. Interestingly, in anergic T cells, the association of PAG with FynT, but not Csk, was increased. Analyses of PAG mutants provided evidence that PAG interacted with FynT by way of tyrosines other than Y314. Enforced expression of a PAG variant interacting with FynT, but not Csk, caused a selective enhancement of TCR-triggered calcium fluxes in normal T cells. Furthermore, it promoted T-cell anergy. Both effects were absent in mice lacking FynT, implying that the effects were mediated by PAG-associated FynT. Hence, besides enabling PAG tyrosine phosphorylation and the PAG-Csk interaction, PAG-associated FynT can stimulate calcium signals and favor T-cell anergy. These data improve our comprehension of the function of PAG in T cells. They also further implicate FynT in T-cell anergy.

scholarly journals Conversion of Anergic T Cells Into Foxp3- IL-10+ Regulatory T Cells by a Second Antigen Stimulus In Vivo

2021 ◽  
Vol 12 ◽  
Author(s):  
Anna Sophie Thomann ◽  
Theresa Schneider ◽  
Laura Cyran ◽  
Ina Nathalie Eckert ◽  
Andreas Kerstan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Time Window ◽  
Common Mechanism ◽  
Short Term ◽  
Subsequent Conversion ◽  
Time Periods ◽  
Anergic T Cells ◽  
Tr1 Cells

T cell anergy is a common mechanism of T cell tolerance. However, although anergic T cells are retained for longer time periods in their hosts, they remain functionally passive. Here, we describe the induction of anergic CD4+ T cells in vivo by intravenous application of high doses of antigen and their subsequent conversion into suppressive Foxp3- IL-10+ Tr1 cells but not Foxp3+ Tregs. We describe the kinetics of up-regulation of several memory-, anergy- and suppression-related markers such as CD44, CD73, FR4, CD25, CD28, PD-1, Egr-2, Foxp3 and CTLA-4 in this process. The conversion into suppressive Tr1 cells correlates with the transient intracellular CTLA-4 expression and required the restimulation of anergic cells in a short-term time window. Restimulation after longer time periods, when CTLA-4 is down-regulated again retains the anergic state but does not lead to the induction of suppressor function. Our data require further functional investigations but at this stage may suggest a role for anergic T cells as a circulating pool of passive cells that may be re-activated into Tr1 cells upon short-term restimulation with high and systemic doses of antigen. It is tentative to speculate that such a scenario may represent cases of allergen responses in non-allergic individuals.

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