Overexpression of CD123 prevents FL engraftment. (A) Experimental design of engraftment studies: 3 × 106 CD45.1 e14.5 murine FL cells transduced to express either low CD123 (EV) or overexpress CD123 (CD123-high-WT) were transplanted into lethally irradiated recipient mice. (B) Survival of mice engrafted with CD123-low cells (n = 8) or CD123-high-WT cells (n = 8). Mean survival of CD123-high-WT was 10.75 ± 1.16 days; CD123-low mice were humanely euthanized at 6 weeks after engraftment. Solid lines/bars, CD123-low (EV); hashed lines/bars, CD123-high-WT. (C) Flow cytometric analysis for GFP and CD123 expression on input cells injected into mice for engraftment studies (i) CD123-low (EV) and (ii) CD123-high-WT. (D) Viability of murine FL cells transduced to express CD123-low (EV) or CD123-high-WT assessed using Fixable Viability Stain 780 (FVS 780). Red bars, total cell population; blue bars, GFP +ve (transduced) cells only. The average of 3 experiments with the standard error is indicated. (E) Survival of mice engrafted with EV (purple hashed line; n = 6), HoxA9-transduced cells alone (dotted and dashed red line; n = 5), HoxA9 + high CD123 (solid light green line; n = 3), or HoxA9 + IL-3 (solid blue line; n = 6). White blood cell count (F) and spleen weight (G) for mice engrafted with EV, HoxA9-transduced cells alone, HoxA9 + high CD123, or HoxA9 + IL-3 at time of analysis as in panel E.
