Figure 4. ⁸⁹Zr-oxine microPET/CT imaging demonstrates CXCR4 dependent BM homing of transferred BM cells.

Groups of mice received ⁸⁹Zr-oxine-labeled BM cells (2×10⁷ cells at 16.6 kBq/10⁶ cells)); A. Control mice (n=4), B. mice receiving plerixafor (5 mg/kg) i.v. 15 min before the BM cell transfer, and C. mice receiving plerixafor (5 mg/kg) and G-CSF (2.5ug) i.v. 15 min before the BM transfer. All recipient mice received a lethal whole-body irradiation at 9.5 Gy 24h prior to cell transfer. PET images indicates that in comparison to the control, plerixafor alone or plerixafor/G-CSF inhibited the initial donor cell migration to the BM. Addition of G-CSF to plerixafor sustained the suppression of BM homing (%ID/mL: percent of injected dose per mL of tissue, Representative images of 4 experiments). D. Quantification of spinal ⁸⁹Zr activity demonstrated inhibition of BM homing with plerixafor at the 0–2 h time points and prolonged inhibition with plerixafor/G-CSF. An example of regions of interest set on the images are shown at the right. Asterisks indicate statistical significance within each time point. *:P < 0.05, **:P < 0.01, ***:P < 0.001, ****:P< 0.0001. White bar: control, patterned bar: plerixafor, and black bar: plerixafor/G-CSF.