Number of dendritic cells and presentation of tumor antigens by macrophages are normal in MR^−/− mice. (A) Langerin-positive cells were counted in the ears and lymph nodes in non–tumor-bearing and tumor-bearing MR^−/− and WT mice (n = 4 in all groups). In tumor-bearing mice, the Langerin-positive cells were counted in non–tumor-containing area. The values are means (± SEM) per mm of epithelial surface of the ears. (B) Langerin-positive cells in lymph nodes (LNs) of non–tumor-bearing mice and in lymph node metastases of mice with tumors. The values are means (± SEM) per mm² for the lymph nodes/metastases. (C) The ability of macrophages (MOs) to present tumor antigen was measured using proliferation assays. Different combinations of macrophages and T cells from MR^−/− and WT mice were used as indicated in the figure. The results are expressed as means (± SEM).