Molecular basis of deficient IL-2 production in T cells from patients with systemic lupus erythematosus

EE Solomou, YT Juang, MF Gourley… - The Journal of …, 2001 - journals.aai.org
EE Solomou, YT Juang, MF Gourley, GM Kammer, GC Tsokos
The Journal of Immunology, 2001journals.aai.org
Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease characterized
by diverse cellular and biochemical aberrations, including decreased production of IL-2.
Here we show that nuclear extracts from unstimulated SLE T cells, unlike extracts from
normal T cells, express increased amounts of phosphorylated cAMP-responsive element
modulator (p-CREM) that binds the− 180 site of the IL-2 promoter. Nuclear extracts from
stimulated normal T cells display increased binding of phosphorylated cAMP-responsive …
Abstract
Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease characterized by diverse cellular and biochemical aberrations, including decreased production of IL-2. Here we show that nuclear extracts from unstimulated SLE T cells, unlike extracts from normal T cells, express increased amounts of phosphorylated cAMP-responsive element modulator (p-CREM) that binds the− 180 site of the IL-2 promoter. Nuclear extracts from stimulated normal T cells display increased binding of phosphorylated cAMP-responsive element binding protein (p-CREB) to the− 180 site of the IL-2 promoter, whereas nuclear extracts from stimulated SLE T cells display primarily p-CREM and decreased p-CREB binding. In SLE T cells, p-CREM bound to the transcriptional coactivators, CREB binding protein and p300. Increased expression of p-CREM correlated with decreased production of IL-2. The transcription of a reporter gene driven by the− 180 site was enhanced in normal T cells, but was suppressed in SLE T cells. These experiments demonstrate that transcriptional repression is responsible for the decreased production of IL-2 by SLE T cells.
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