Distinct dsRNA moieties induce differential responses in both murine and human B-ALL cells and LICs in vitro. (A) B-ALL cells from Eμ-Ret mice were stimulated with the indicated ligands or left unstimulated and viable cells number measured after 48 hours. Results are pooled from at least 5 individual experiments. (B) Cultures of leukemia cells isolated from Eμ-Ret mice were assessed for live (annexin-negative and 7AAD-negative), dead (annexin-positive and 7AAD-positive), apoptotic (annexin-positive and 7AAD-negative), and proliferating (BrdU⁺) cell characteristics after 48 hours in the presence or absence of Poly(A:U). Results are pooled from 3 individual experiments. (C) E2A-PBX1, (D) patient-derived B-ALL leukemic blasts, and (E) purified LICs from the spleen and BM of 2- to 8-week-old Eμ-Ret mice were exposed to Poly(A:U), Poly(I:C), or 5′ppp-dsRNA for 48 hours, and the number of viable cells was measured. Results are pooled from at least 5 individual experiments. Individual patient samples are color-coded in panel D. In all experiments, cell counts were quantified using CountBright beads. Dunnett multiple comparison test; bars represent mean ± standard deviation (SD); ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001; ns, not significant.