CD4 or CD8 T-cell depletion led to increased ALL relapse with dasatinib treatment. (A) Schematic plot shows the timeline of leukemia inoculation and treatment with dasatinib and anti-CD4 or anti-CD8 antibodies. (B) Flow cytometric analysis of CD4 or CD8 T-cell depletion after 3 days of antibody injection. We also confirmed CD4 and CD8 T-cell depletion once every week by flow cytometry (data not shown). (C) Leukemia burden was measured immediately before CD4 or CD8 antibody injection (ie, day 13 from leukemia inoculation). There was no significant difference in leukemia progression across 3 groups up to this time point. (D-F) Leukemia burden is plotted as a function of time for B6 mice treated with dasatinib, after CD4 T-cell (D) or CD8 T-cell (E) depletion, or without T-cell depletion (isotype antibody control) (F). Shaded areas indicate the duration of chemotherapy. (G) Kaplan-Meier survival curves of B6 mice treated with dasatinib or vehicle after CD4 or CD8 T-cell depletion. The differences in survival were detected by log-rank (Mantel-Cox) test. bid, twice per day; ns, not significant.