Expression of Ets-1 and FOXP3 mRNA in CD4+CD25+ T regulatory cells from patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with complex genetic predisposing factors involved. Ets-1 transcription factor plays an important role in the suppressive activity of CD4(+)CD25(+) Treg cells and stable expression of FOXP3. To find its potential role in the pathogenesis of SLE, we investigate the mRNA expression of Ets-1 and FOXP3 mRNA in CD4(+)CD25(+) Treg cells from patients with SLE. Real-time transcription-polymerase chain reaction analysis was used to determine the expression of Ets-1 and FOXP3 mRNA in CD4(+)CD25(+) Treg cells from 36 patients with SLE and 18 sex-and-age-matched healthy controls. The Ets-1 mRNA expression level was decreased in patients with SLE [0.225 (0.135, 0.337)] than healthy controls [0.528 (0.303, 0.681)] (P<0.001). The expression levels of FOXP3 mRNA were lower in SLE patients [0.608 (0.272, 1.164)] than healthy controls [0.919 (0.690, 1.223)], but the difference was not significant (P = 0.106). Significant reduction in Ets-1 and FOXP3 expression was also found in new-onset SLE subgroup when compared with healthy controls (P<0.001). The level of Ets-1 and FOXP3 mRNA was not significantly different in hyperactive and lower active SLE group when compared with inactive SLE group, respectively (P>0.05). There were no significant differences between SLE with lupus nephritis (LN) and SLE without LN either (P>0.05). Associations of Ets-1 and FOXP3 mRNA expression levels with major clinical and laboratory parameters of SLE patients were also analyzed. However, no significant association was found. Significant positive correlation was found between Ets-1 and FOXP3 mRNA expression in CD4(+)CD25(+) Treg cells from SLE patients (r = 0.698, P<0.001). Our results found that the expression levels of Ets-1 mRNA were decreased in SLE patients and Ets-1 expression was positively correlated with the expression of FOXP3. It indicated that Ets-1 may play an important role in the stable expression of FOXP3 in CD4(+)CD25(+) Treg cells.