Fig. 1

Expression level of BCL-6 in CD4⁺ T cells from systemic lupus erythematosus (SLE) patients and healthy controls. a Relative BCL-6 mRNA levels in CD4⁺ T cells isolated from healthy controls or SLE patients (n = 30 for each group) were assessed by real-time PCR and normalized to those of GAPDH. b BCL-6 protein expression in CD4⁺ T cells isolated from healthy controls or SLE patients (n = 30 for each group) was analyzed by western blot analysis. One representative blot is shown (upper panel). The intensities of the bands were semiquantitated and normalized to that of the band for GAPDH (lower panel). c The correlation between BCL-6 protein level and anti-dsDNA titer (n = 30). d The correlation between BCL-6 protein level and SLE Disease Activity Index (SLEDAI) score (n = 30). e Representative western blot showing BCL-6 expression levels in normal CD4⁺ T cells after activation of the TCR (left panel). The intensities of the bands were semiquantitated and normalized to that of the band for GAPDH (right panel). Data represent the mean of three independent experiments. f Histograms showing CD4⁺ T cells expressing CD25 and CD69 as determined by flow cytometry (**P < 0.01)