Figure 4
In vivo Bioluminescent Signal Within Different Lymphoid Tissues. To determine the correlation between T-lux T cell numbers and bioluminescent signal in vivo, we adoptively transferred T-lux CD3+ cells (3.5 × 106) into CD45.1-positive, congenic B6 recipients. Three days post-transfer, light emission was determined for whole body, as well as defined anatomical regions (Regions of Interest, or ROI), including cervical, peripheral, and mesenteric lymph nodes and spleen, and compared to actual T cell numbers recovered from these tissues. FACS analysis was performed on cells obtained from recipient mice and representative plots are shown (left panel). Tissue source is indicated for each FACS plot. Cells were first gated on live CD3-positive lymphocytes. Recipient CD45.1 allotype is shown on the y-axis and donor CD45.2 on x-axis. Numbers indicate the percentages of donor (T-lux) T cells of the total live CD3+ T cells in each tissue. The composite of bioluminescence images (right panel; left image) shows a non-normalized pseudocolor image, with the analyzed ROIs indicated by arrows; the same pseudocolor image is overlayed on a photographic image of the mouse (right panel; right image).