Figure 5.

hetIL-15 treatment results in recruitment of XCR1⁺CD103⁺IRF8⁺ cDC1 into tumors. (A) Gating strategy for the characterization of cDC1. (B) The frequency of tumor-infiltrating CD103⁺XCR1⁺IRF8⁺ cDC1 was determined in MC38 (left panel) and TC-1 tumors (right panel) recovered from hetIL-15 or PBS-treated control mice. The number of CD103⁺XCR1⁺IRF8⁺ cDC1 cells in each tumor was normalized per million of cells present in the tumor suspension. The values from individual animals and mean±SEM are shown. (C) Heatmap representing the immune cell composition of tumors on hetIL-15 treatment. Cell scores were calculated for different immune cell subsets as described in material and methods. (D–E) RNA cell score for cytotoxic cells (D) and dendritic cells (E) was calculated for tumors recovered from control (gray, n=5) and hetIL-15 (blue, n=6) treated mice using Nanostring measurements as described in material and methods. Individuals animals and mean±SEM are shown. P values are from Mann-Whitney U test. cDC1, conventional type 1 dendritic cells; hetIL-15, heterodimeric interleukin-15; SEM, Standard error of the mean.