BCR inhibitors completely abrogate TLR9 responses in ZAP-70–positive CLL. (A) IgM secretion by Zap-70–positive CLL cells stimulated with DSP30 for 48 hours in the presence of increasing doses P505-15 or ibrutinib, respectively. Curves represent the mean ± SEM of n = 3 patient samples relative to IgM levels in the absence of inhibitors. (B) sIgM production of Zap-70–positive CLL cells stimulated with DSP30 for 48 hours with or without cotreatment of 30 nM P505-15 or ibrutinib, respectively. Data are presented as the mean ± SEM of n = 10 patient samples in a bar diagram. Asterisks indicate P values: **P < .01. (C) Viability of Zap-70–positive CLL cells stimulated with DSP30 for 48 hours in the presence of increasing doses P505-15 or ibrutinib, respectively. Curves represent the mean ± SEM from n = 3 (DSP30 stimulated) patient samples relative to cells cultured without inhibitor. The dotted line indicates the dose of inhibitor required to reach viability of unstimulated cells. (D) Viability of Zap-70–positive CLL cells stimulated with DSP30 for 48 hours in the absence or presence of 30 nM P505-15 or ibrutinib, respectively. Data are presented as the mean ± SEM of n = 10 patient samples in a bar diagram. P values are indicated by asterisks: **P < .01; ***P < .001. (E) Viability of DSP30-stimulated CLL cells cultured with or without 30 nM P505-15 in ZAP-70 subgroups. Data are presented in a bar diagram as the mean ± SEM of n = 24 patient samples. P values are indicated by asterisks: ****P < .0001; ***P < .001; **P < .01; *P < .05. (F) Expression profile of BH3 proteins in CLL cells stimulated with DSP30 for 48 hours in the presence or absence of 30 nM P505-15. Data show western blot analyses of 2 representative patient samples out of n = 5 tested.