The −180 Site of the IL-2 Promoter Is the Target of CREB/CREM Binding in T Cell Anergy
| Autor: | Jonathan D. Powell, Cara G. Lerner, Gerald R. Ewoldt, Ronald H. Schwartz |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 163:6631-6639 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Anergic T cells display a marked decrease in their ability to produce IL-2 even in the presence of optimal TCR and costimulatory signals. Using IL-2 enhancer/promoter-driven reporter constructs, we have previously identified a region that appears to be a target for cis transcriptional repression in anergy. This region of the promoter, which shares partial homology with a consensus AP-1-binding sequence, is located about −180 bp from the transcriptional start site. In the present study, we demonstrate that cAMP response element-binding protein/cAMP response element modulator (CREB/CREM), activating transcription factor-2/c-Jun, and Jun-Jun/Oct complexes bind to this site. However, the induction of anergy by prolonged stimulation through the TCR led to an increase in binding of only the CREB/CREM complex. Furthermore, the level of binding of this complex appeared to be up-regulated in both resting and restimulated anergic T cells. Finally, an IL-2 promoter-driven reporter construct that contained a mutation that specifically reduced the binding of the CREB/CREM complex displayed a decreased ability to be affected by anergy, while a construct that contained a mutation that decreased the binding of the Jun-Jun/Oct complex was still susceptible to anergy. These findings suggest that the −180 region of the IL-2 promoter is the target of a CREB/CREM transcriptional inhibitor that contributes to the repression of IL-2 production in T cell anergy. |
| Databáze: | OpenAIRE |
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