FIGURE 6.

CC-220 reduces B cell Aiolos and Ikaros expression in HC and SLE patients independent of IL-21 STAT3 signaling. (A) Chemical structure of CC-220. (B) B cells from HC were stimulated with CD40L and anti-IgM for 24 h. Cells were then treated with DMSO or CC-220 (10 nM) for 1 h at 37°C, then exposed to IL-21 for 15 min and p-STAT3 levels determined in CD19⁺CD27^lo naive B cells (left) or CD19⁺CD27^hi memory B cells (right) by flow cytometry. (C) B cells from HCs were treated with the indicated amounts of CC-220 for 0.25, 2, 6, and 24 h at 37°C, and expression of Aiolos and Ikaros were measured by Western blot. (D) Inhibition of Aiolos (top) and Ikaros (bottom) expression by CC-220 in indicated populations are shown as mean percent ± SEM relative to untreated HC Aiolos or Ikaros expression (n = 10). Statistical comparisons are by one-way ANOVA and Dunnett’s multiple-comparison test compared with HC vehicle control: *p < 0.05, **p < 0.005, ***p < 0.001, ****p < 0.0001.