Synergistic action of protein kinase C θ and calcineurin is sufficient for Fas ligand expression and induction of a crmA-sensitive apoptosis pathway in Jurkat T cells

Villunger, Andreas; Ghaffari-Tabrizi, Nassim; Tinhofer, Ingeborg; Krumböck, Nina; Bauer, Birgit; Schneider, Thomas J.; Kasibhatla, Shailaja; Greil, Richard; Baier‐Bitterlich, Gabriele; Überall, Florian; Green, Douglas R.; Baier, Gottfried

doi:10.1002/(sici)1521-4141(199911)29:11<3549::aid-immu3549>3.0.co;2-q

Cited by 48 publications

(42 citation statements)

References 38 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PKC has been previously implicated in activation-induced FasL transcription. 22,23 In addition, PKC has been involved in activation-induced degranulation of cytolytic granules. 24 Surprisingly, bisindolylmaleimide I (Bim I, Gö 6850), which inhibits various PKC isoforms, 25 failed to block PMA-induced degranulation of preformed FasL (Figure 5b), whereas it efficiently blocked PMA/ionomycininduced NFAT reporter activation (data not shown).…”

Section: Resultsmentioning

confidence: 99%

“…20 As PKC not only has an important function in FasL transcription 22,23 but was also reported to localize to the immunological synapse in cytotoxic T lymphocytes after contact with the target cell, 34 we analyzed a possible role of PKC in activation-induced FasL degranulation. Interestingly, TCR-stimulated lytic granule exocytosis was shown to be PKC-dependent.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

et al. 2008

View full text Add to dashboard Cite

Fas (CD95/Apo-1) ligand is a potent inducer of apoptosis and one of the major killing effector mechanisms of cytotoxic T cells. Thus, Fas ligand activity has to be tightly regulated, involving various transcriptional and post-transcriptional processes. For example, preformed Fas ligand is stored in secretory lysosomes of activated T cells, and rapidly released by degranulation upon reactivation. In this study, we analyzed the minimal requirements for activation-induced degranulation of Fas ligand. T cell receptor activation can be mimicked by calcium ionophore and phorbol ester. Unexpectedly, we found that stimulation with phorbol ester alone is sufficient to trigger Fas ligand release, whereas calcium ionophore is neither sufficient nor necessary. The relevance of this process was confirmed in primary CD4 þ and CD8 þ T cells and NK cells. Although the activation of protein kinase(s) was absolutely required for Fas ligand degranulation, protein kinase C or A were not involved. Previous reports have shown that preformed Fas ligand co-localizes with other markers of cytolytic granules. We found, however, that the activationinduced degranulation of Fas ligand has distinct requirements and involves different mechanisms than those of the granule markers CD63 and CD107a/Lamp-1. We conclude that activation-induced degranulation of Fas ligand in cytotoxic lymphocytes is differently regulated than other classical cytotoxic granule proteins.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Consistently, NF-AT mutants of the PKA phosphorylation sites lost 14-3-3 binding, translocated to the nucleus, and became transcriptionally active. 37 In contrast, upon TCR stimulation, NF-AT is dephosphorylated by calcineurin, which is established to functionally cooperate with PKC 38,39 in this pathway. This Ca 2ϩ /calcinerurin/PKC pathway leads to activation and nuclear entry of NF-AT and subsequent IL-2 production of the activated T cells.…”

Section: Discussionmentioning

confidence: 99%

PKCθ and PKA are antagonistic partners in the NF-AT transactivation pathway of primary mouse CD3+ T lymphocytes

Hermann-Kleiter

Thuille

Pfeifhofer

et al. 2006

Blood

Self Cite

View full text Add to dashboard Cite

We here investigate the crosstalk of PKC and PKA signaling during primary CD3 ؉ T-lymphocyte activation using pharmacologic inhibitors and activators in combination with our established panel of PKC isotype-deficient mouse T cells in vitro. PKC and PKA inversely affect the CD3/ CD28-induced IL-2 expression, whereas other PKC isotypes are dispensable in this signaling pathway. Gene ablation of PKC selectively results in a profound reduction of IL-2 production; however, complete abrogation of IL-2 production in these PKC ؊/؊ T cells was achieved only by simultaneous coactivation of the cAMP/PKA pathway in CD3 ؉ T cells. Conversely, the reduced IL-2 production in PKC inhibitor-treated T cells can be rescued by inhibition of the cAMP/PKA pathway in wild-type but not in PKC ؊ IntroductionFollowing T-cell receptor (TCR) stimulation, lymphocyte activation threshold is coordinated by a complex interplay of distinct signal transduction pathways. The "fine-tuning" of signaling cascades is considered as a crucial step during T-cell activation in order to result in adequate amplitude of an immune response. The molecular processes that regulate the precise level of the immune activation and their complex interpathway integration are, however, still poorly understood. Among several signaling pathways, protein kinase C (PKC) plays an important role in the cellular activation pathway downstream of the antigen receptor. PKC, in particular, is known to translocate to the immunologic synapse. 1 Once activated, PKC plays a critical role in TCR signaling. 2 This is confirmed by analysis of CD3 ϩ T cells of mice lacking PKC. Ex vivo, PKC-deficient T cells are mostly TCR unresponsive and deficient in the production of interleukin 2 (IL-2) due to an impaired transactivation of NF-B, AP-1, and NF-AT. [3][4][5] In strict contrast, the cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) pathway represents a negative regulatory mechanism that controls IL-2 expression in T cells. cAMP itself has been demonstrated to activate directly a class of cyclic nucleotide ion channels 6,7 as well as the Rap1 guanine exchange factors Epac1 and Epac2. 8 The principle cAMP receptor in lymphoid cells, however, is PKA. 9 cAMP is produced after TCR stimulation in T lymphocytes, suggesting the cAMP-mediated repression of T-cell activation may represent a physiologic negative feedback control mechanism. 10 Suppression of cAMP signaling is thus required for T-cell activation. 11 Among other mechanisms, cAMP inhibition is mediated by de novo transcriptional induction of phosphodiesterases (PDEs) upon T-cell activation. In T cells, PDE4 seems to play a particularly important role. 12,13 Increased PDE4 expression in T cells is associated with increased IL-2 production via its hydrolysis of cAMP. 12 Inversely, PDE4 blockade is shown to augment cAMP levels and thus known to abrogate cytokine secretion and proliferation in T cells through inhibition of NF-B and NF-AT and activation of CREB. 13 Several direct targets of cAMP/PKA signaling have be...

show abstract

“…Experiments were performed by cotransfecting a NF-kB-reporter plasmid (0.5-mg) (pNF-kB-luc, Clontech) in the presence or absence of the expression vector CMV-Notch3IC (1.5-mg) (Bellavia et al, 2000) and/or of DN-PKCy (1.5-mg), kindly provided by Dr Baier (Villunger et al, 1999). Renilla luciferase reporter vector pTK-Renilla-Luc (0.5 ng) was also incorporated into each transfection (Promega, Madison, WI, USA).…”

Section: Plasmids Cell Transfection and Luciferase Assaymentioning

confidence: 99%

PKCθ mediates pre-TCR signaling and contributes to Notch3-induced T-cell leukemia

et al. 2004

View full text Add to dashboard Cite

Synergistic action of protein kinase C θ and calcineurin is sufficient for Fas ligand expression and induction of a crmA-sensitive apoptosis pathway in Jurkat T cells

Cited by 48 publications

References 38 publications

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

PKCθ and PKA are antagonistic partners in the NF-AT transactivation pathway of primary mouse CD3+ T lymphocytes

PKCθ mediates pre-TCR signaling and contributes to Notch3-induced T-cell leukemia

Contact Info

Product

Resources

About