CpG-ODN–mediated induction of PRDM1 is variable and correlates with IL-21 responsiveness in individual CLL cases. (A) Western blot showing levels of PRDM1 protein in representative responsive and nonresponsive CLL clones after being left untreated or following treatment with either IL-21 (21; 50 ng/mL) or CpG-ODN (CpG; 0.5 µg/mL) for 16 hours (n = 38). (B) PRDM1 induction in representative responsive and nonresponsive samples after 2 days in culture with indicated concentrations of CpG-ODN (CpG) (n = 38). (C) PRDM1 induction following 16 hours exposure to CpG-ODN correlates with: (i) PRDM1-induction after 16 hours IL-21 treatment, and (ii) iCa2+ responsiveness following anti-IgM stimulation. Induced PRDM1α was calculated by subtracting untreated from treated measurements by western blot densitometry. Fold PRDM1 induction was calculated as in Figure 1C. The results of statistical evaluation are shown, (i) Spearman’s coefficient, and (ii) Pearson’s coefficient.
