Ccl3 secreted by NK cells crosstalked mainly with NK cells in vivo. (A) Scheme of the experiment. Mixed BM chimeras (panel 1) were infected with mCMV and analyzed ex vivo 16 h after infection. BM chimeras reconstituted solely with non-reporter cells (panel 2) and equally infected with mCMV were used as autofluorescence control for the Venus and tdTomato channels. (B) Representative one-photon intravital microscopy of liver from infected CCL3-EASER mice (see Videos 1 and 2). Red arrowheads indicate tdTomato⁺ cells, green arrowheads Venus⁺ cells, yellow arrowheads tdTomato⁺ Venus⁺ cells. Scale bar 50 µm. (C) Representative dot plots of Venus single positive (non-reporter) cell populations in liver, spleen, and blood analyzed by flow cytometry ex vivo. Green boxes indicate Venus single positive cells. Data are representative of two independent experiments (n = 5–6 mice per group).