Recombinant CXCL14 inhibits CML CD34⁺CD38^– LSC growth and promotes their response to TKI treatment in vitro. (A) Experimental design for assessing the effect of CXCL14 on CML CD34⁺CD38^– LSCs by LTC-IC and CAFC assays using primary BM MSCs. FACS-sorted BM MSCs from healthy donors (NBM) or patients with CML were expanded and plated 1 day before seeding CML CD34⁺CD38⁻ BM cells into the culture in presence of CXCL14 (10 ng/mL). Imatinib (IM, 0.5 μM) was added at 2 days after coculture initiation, and the cultures were maintained for 6 weeks. For CAFC assay, the colonies were counted and transferred to methylcellulose for CFU-C assay. (B) LTC-ICs derived from CML CD34⁺CD38^– LSCs cocultured with NBM or CML MSCs. Horizontal bars represent median values, and each dot represents the mean of triplicate or duplicate measurements from an individual BM sample. The data were from 7 patients with CML. The differences were determined by paired t test and one-way analysis of variance Friedman test. Green and red dots indicate data from the same patient but from different culture experiments with different donor MSCs. (C) CAFCs derived from CML CD34⁺CD38^– LSCs cocultured with CML MSCs. Horizontal bars represent mean values, and each dot represents triplicate measurements on an individual patient. Shown are normalized CAFCs based on that in the nontreated groups. The data were from 6 patients with CML. The statistical differences were determined by paired t test and 1-way analysis of variance Friedman test. (D) Lineage distribution within the CAFC-derived CFU-Cs after treatment in the cocultures of CML CD34⁺CD38^– LSCs with CML MSCs. Data shown are from 1 representative patient included in the assay in panel C. See also supplemental Figure 6.