The IFN-α-C/EBPβ axis induces exhaustion of LSCs in vivo. (A) Schematic illustration of experimental procedures for serial BM transplantation. Primary recipient mice were intraperitoneally injected with vehicle or poly I:C at day 9 after BM transplantation. BM cells were harvested from the primary recipient mice at day 17, and then subjected to flow cytometric analysis or serial transplantation into secondary recipient mice. (B-C) Representative flow cytometric data of BM cells obtained from primary recipient mice at day 17; (right) frequencies of GFP⁺ leukemic cells in lin⁻ c-kit⁺ and CD150⁺ immature populations. Data are means ± SD of 7 or 8 recipients from 2 independent experiments. *P < .05; **P < .01. (D) Survival curve of secondary recipient mice. Representative data from 3 independent experiments are shown.