Fig. 3.
Alterations in immune cell localization and activation with or without DEX treatment can be detected by [18F]FHBG and [18F]FDG PET imaging. (A) Schematic diagram of imaging schedule and DEX treatment. Mice were injected i.v with [18F]FHBG and imaged on day 8, 10, and 14 (B) and i.p with [18F]FDG and imaged on day 9, 13, and 15 (F). The coronal section displayed is centered at the tumor (TUM) and DLNs (1.6-mm thickness). (B and F) Shown are untreated mice (No DEX) (Left) and DEX-treated mice (DEX) (Right). Representative of a total of 10 animals performed in three separate experiments. ROIs were drawn to quantify [18F]FHBG (C) and [18F]FDG (G) uptake in the TUM and DLN on different days post tumor challenge. The quantification of [18F]FHBG and [18F]FDG signals was calculated as a ratio of %ID/g at region of interest to the %ID/g at a background region. Immediately after whole-body imaging, each organ was isolated day 14 post challenge to assess organ size to the [18F]FHBG (D) and [18F]FDG (H) signal. (H) Naive unchallenged C57BL/6 mouse lymph nodes were used as a control. Representative of three animals from each group. CON MUS, contralateral muscle; CON LNs, contralateral LNs. (E) Picture of the DLNs and CON LNs from untreated (No DEX) and DEX-treated (DEX) mice.