Figure 1.

Tracking of transferred cells using ⁸⁹Zr-oxine PET in murine models. A) Activated OT-1 CD8 T cells distribute to antigen-expressing B16-OVA tumor (white dashed circle), while naïve OT-1 CD8 T cells do not. Naïve OT-1 CD8 T cells (left) and activated OT-1 CD8 T cells (right, adapted from ⁴⁰) were labeled with ⁸⁹Zr-oxine (222 kBq/8 x 10⁶ cells and 248.5 kBq/7.7 x 10⁶ cells, respectively) and intravenously transferred to tumor-bearing recipient mice. PET/CT images acquired on 2nd day after transfer are shown. Also note the different distribution between naïve and activated OT-1 CD8 T cells outside the tumor. B) Activated OT-1 CD8 T cells distribute to antigen-expressing B16-OVA tumor (cyan circle) but not to antigen-negative B16 tumor (white dashed circle). Activated OT-1 CD8 T cells labeled with ⁸⁹Zr-oxine (185 kBq/8 x 10⁶ cells) were intravenously transferred to the recipient. MicroPET/CT images acquired on 4th day after transfer are shown. Left: maximum intensity projection MIP PET/CT, right: transverse plane. C) Distribution of transferred bone marrow cells. Donor bone marrow cells were labeled with ⁸⁹Zr-oxine (16.6 kBq/2.0 x 10⁷ cells) and intravenously transferred to the recipient. PET/CT imaging was performed at indicated time points after transfer, with multiple intramuscular injections of deferoxamine to prevent accumulation of free ⁸⁹Zr within bone. Transferred bone marrow cells initially distribute to the lungs, followed by distribution within 4 hours to the bone marrow, liver, and spleen. Adapted from ⁵⁵.