Fig. 1

The lack of CD244 in monocytes inhibited melanoma tumorigenesis. (A, B, D) 1 × 10⁶ of B16F10 cells were subcutaneously inoculated into the right flank of mice. (A) CD244 expression in NK cells, DCs, monocytes and macrophages in the skin of WT naïve mice and within the B16F10 tumor mass of WT tumor-bearing mice, 14 days after tumor inoculation, was analyzed using flow cytometry. The skin samples were derived from mice that did not undergo tumor inoculation and obtained from the identical location as the tumor site in mice subjected to tumor inoculation. Representative histograms (left) display surface CD244 expression on NK cells, DCs, monocytes and macrophages from the skin (top) and the tumor (bottom). The percentages of CD244-expressing cells in NK cells, DCs, monocytes and macrophages from both skin and tumor are presented as a bar graph (right). (B) Tumor growth in WT and CD244^−/− mice is depicted (n = 4 in each group). (C) The process for generating littermate CD244^fl/fl and CD244^fl/flLysM^cre mice is illustrated. (D) B16F10 tumor growth in littermate CD244^fl/fl and CD244^fl/flLysM^cre mice is shown (n = 4 in each group) (left). The relative tumor volume on 14 days after tumor inoculation (n (number of samples) = 35 of CD244^fl/fl and 36 of CD244^fl/flLysM^cre mice) (right). Significance was indicated as ****P < 0.0001, and the statistical analysis was performed using two-way ANOVA (B, D (left)) or unpaired Student’s t-test (A, D (right)). Data are representative of two (A), three (B) or nine (D (left)) or compiled from nine (D (right)) independent experiments