Fig. 3. CD40 stimulation induces Bcl-XL expression via canonical as well as non-canonical NF-κB signaling.

A HEK293T cells were transfected with luciferase reporter gene constructs carrying Bcl-XL promoter truncations. NF-κB binding sites were predicted using JASPAR database⁵¹. Promoter activity was measured 24 h post-transfection. Bars represent the mean ± SEM of the luciferase activation normalized to the empty pGL3-basic vector (n = 3). B HEK293T cells were transfected with luciferase reporter gene constructs carrying p100 promoter truncations, or a p100 promoter, where the first NF-κB1 binding site was scrambled (depicted by an arrow). NF-κB binding sites were predicted using JASPAR database⁵¹. Promoter activity was measured 24 h post-transfection. Bars represent the ± SEM of the luciferase activation normalized to the empty pGL3-basic vector (n = 7). C Bcl-XL, p100, and Mcl-1 mRNA expression by CLL cells over time after stimulation with CD40L measured by real-time PCR (n = 6). Results are shown as the mean ± SEM. D CLL cells were cultured on 3T3 or 3T40L for 6, 16, or 24 h. Protein lysates were probed for p100, p-p65, p52, Bcl-XL, and actin as loading control.