A migrating DPEGFPxOT-I effector CTL initiating firm contact with a tissue macrophage. As described in Fig. 8, T cells (green, track) engaging in interactions with macrophages (cyan) were captured with two-photon microscopy. The macrophage is identified by the presence of autofluorescent particles within its cytoplasm. The time is indicated on the top margin (min:sec).
