Figure 4

CFSE-labeled T-cells homed specifically to the paracortex of lymph nodes. Brightfield images show that mesenteric lymph node consists of cortex (C) and paracortex (P) substructures (a–c). In fluorescent images, homing sites in the paracortex regions are visible as green clusters (d, e). We hypothesize that both types of exogenous T-cells came to the lymph nodes (d, e) but only the alloreactive T-cells were primed and proliferated (e). Color-coded volume rendering of CFSE intensity in lymph node also shows that the allogeneic T-cells significantly lost CFSE intensity as compared to syngeneic T-cells which indicates rapid proliferation (g, h). Autofluorescence of lymph nodes of the control group was negligibly low (f).