Murine 4T1 tumors are infiltrated with CD11c+CD86+MHC-II+ dendritic cells. (a) Frozen 4T1 tumor sections were stained with anti-CD11c antibodies and analyzed by inverted fluorescent microscopy. Tumor-infiltrating CD11c+ DC are shown in red (4T1 left panel and LLC right panel). (b) CD11c+ cells isolated by magnetic cell sorting were further analyzed by cytometry for the expression of CD11b, MHC-II, CD86, Gr-1, and PDCA-1. (c, d) The expression of CD80 and CD86 by spDC or TIDC isolated from 4T1 tumor was evaluated immediately after isolation (D0) and after an overnight culture (D1). Dot plots quadrants were defined using isotype controls and the values are the percent of live cells in each quadrant. Results are representative of four independent experiments.