Figure 2. Role of TNFα in the anthracycline-mediated recruitment, functional activation and maturation of antigen-presenting cells. (A–D) BALB/c mice harboring MyrPalm-mEGFP-expressing CT26 colon carcinomas (tumor surface 25–45 mm²) were treated with doxorubicin (DX) or an equivalent volume of PBS, as a single intratumoral injection (day 0). On the same day, a fraction of mice was initiated on a course of intraperitoneal etanercept (ETA). On day 3, tumors were harvested, dissociated into single-cell suspensions and stained with either a CD45-specific (A) or with CD11b-, CD11c-, Ly6C- and Ly6G-targeting antibodies, alone (B) or combined with antibodies specific for MHC Class II molecules (C and D). (A) reports representative dot plots and quantitative data on the percentage of CD45⁺ tumor-infiltrating leukocytes (TILs) emitting a GFP-associated fluorescence (indicative of the uptake of tumor-associated antigens). In (B), representative dot plots and quantitative data on the anthracycline-elicited recruitment of CD11b⁺Ly6G⁻Ly6C^hi, CD11b⁺Ly6G⁻Ly6C^low and CD11b⁺Ly6G⁺ cells into the tumor bed are illustrated. In (A) and (B), numbers indicate the percentage of cells found in the corresponding gate. (C) and (D) depict representative expression profiles of MHC Class II molecules among CD11c⁺ and CD11b⁺Ly6G^-Ly6C^hi cells, respectively, and the corresponding quantitative data (means ± SEM, n = 3). ns, non-significant; *p < 0.05, (unpaired, two-tailed Student’s t-test), as compared with the same cell population isolated from tumors treated with PBS or DX only (in the absence of ETA).