SLE sera stimulate the expression of CREM and its binding to the –180 element of IL-2 promoter. (A) SLE sera induce CREM mRNA. Normal T cells were stimulated with normal, RA, or SLE sera for 2 hours before RNA was analyzed for the expression level of CREM and actin. (B) Cumulative analysis of the effect of SLE sera on the expression of CREM mRNA. The y axis represents the ratio between the mRNA expression levels of CREM and those of actin in normal T cells treated with SLE, RA, or normal serum. (C) SLE sera induce the expression of CREM in the nucleus. Normal T cells were cultured for 2 hours in RPMI containing 1% serum from normal, RA, or SLE patients. Nuclear proteins were harvested and assayed using Western blotting with the indicated antibodies. Shown are 2 representative Western blots, each containing simultaneously purified nuclear proteins from normal T cells treated with normal, RA, or SLE serum. (D) Cumulative effect of SLE sera on the expression of nuclear CREM protein in normal T cells. The y axis represents the ratio of the expression levels of CREM to those of CREB protein in normal T cells treated with normal, RA, or SLE sera. (E) Increased formation of –180 complex in normal T cells treated with SLE sera. Nuclear proteins from normal T cells treated with sera from normal, RA, or SLE patients were analyzed by EMSA to measure their binding activity to oligonucleotides encoding the –180 element. (F) The y axis represents the –180/protein complex intensity in the T cells treated with SLE, RA, or normal serum. *P < 0.05.