TRANSPLANTATION In vivo imaging of graft-versus-host-disease in mice

We have developed a mouse system by which to track the migration and homing of cells in a setting of bone marrow trans-plantation (BMT)–induced graft-versus-host disease (GVHD) after systemic infu-sion using enhanced green fluorescence protein (eGFP) transgenic (Tg) cells and a simple application of a fluorescence ste-reomicroscope outfitted with a color charge-coupled device (CCD) camera. Whole body images of anesthetized mice taken at various time points after cell infusion revealed the early migration of allogeneic cells to peripheral lymphoid organs, with later infiltration of GVHD target organs. Localization of eGFP Tg cells could be seen through the skin of shaved mice, and internal organs were easily discernible. After allogeneic or syn-geneic eGFP Tg cell infusion, representa-tive mice were dissected to better visual-ize deeper internal organs and tissues. Infusion of different cell populations re-vealed distinct homing patterns, and this method also provided a simple way to iden-tify the critical time points for expansion of the transplanted cells in various organs. This simple application of the fluorescence stereomicroscope will be valuable for GVHD and graft-versus-tumor studies in which vi-sualization of cellular migration, expansion, and cell-cell interactions will be more infor-mative when analyzed by such an intravital method. (Blood. 2004;103:3590-3598) © 2004 by The American Society of Hematolog