The 32Dp210 murine leukemia model recapitulates features of clinical AML progression. (A) Progression of 32Dp210 leukemia. Upper panel: serial in vivo bioluminescence images of C3H mice on days 7, 14, 21, and 28 after IV inoculation of 1 × 10⁴ 32Dp210 murine leukemia cells on day 0. Lower panels: Left panel: level of PD-1 expression on T cells in naïve vs tumor-bearing mice detected by antibody staining and flow cytometric analysis (red bar, naïve non-leukemia-bearing mice; blue bar, leukemia-bearing mice). Middle panel: level of PD-1 expression on CD3⁺CD8⁺T cells in naïve vs leukemia-bearing mice (red bar, naïve mice; blue bar, tumor-bearing mice). Right panel: level of PD-L1 expression on 32Dp210-GFP⁺ cells in culture and after transplantation in vivo (red bar, 32Dp210 cells in ex vivo culture; blue bar, 32Dp210 cells harvested from leukemic mice after IV inoculation). Error bars are SEM. (B) 32Dp210-GFP⁺ leukemia cells selectively home to bone marrow compartment early after IV inoculation. The percentage of 32Dp210-GFP⁺ cells detected in peripheral blood, spleen, and bone marrow (depicted as bar graphs sequentially from left to right) was detected by antibody staining and flow cytometric analyses on days 1, 2, 3, 4, and 7 after IV injection of 1 × 10⁴ 32Dp210-GFP⁺ cells in C3H mice. The mean percentage of GFP⁺ cells in each tissue is indicated on the y-axis. Error bars are SEM.