Figure 5.

IL-6-ERK signaling is involved in promoting M2-skewed phenotype of IFN-stimulated transitional monocytes, and potentially in contributing to pro-tumoral polarization of TAMs under poly(I:C) treatment. (a) BM mononuclear cells were treated with M-SCF (20 ng/ml) ± IFN (100 U/ml) for 24 h, in the presence or absence of IL-6 neutralizing antibody (5 μg/ml). The cells were harvested and subjected to WB analyses. (b,c) BM mononuclear cells were treated with M-SCF (20 ng/ml) ± IFN (100 U/ml) for 48 h, in the presence or absence of U0126 (2.5 μM). The cells were harvested and subjected to WB analyses (b) or qPCR (n = 3, ± SEM) (c). (d–f) The mice were injected with 1 × 10⁶ LLC cells in the flanks. Tumor-bearing mice were treated ± poly(I:C) ± U0126 (20 μmol/kg) (i.p.) every 2 days. Tumors were harvested after 4 treatments. In (d), the time-dependent changes in tumor sizes are presented (± SEM, n = 4). Multiple unpaired t tests (using Holm–Šídák method) were performed to compare measurements from different groups. The adjusted P values for the end-point data were shown on the graph. At the end of the animal experiment, the tumors were harvested. Results from WB (e) or qPCR analyses [n = 4, ± SEM] (f) are presented. Unpaired t tests were performed for individual markers. Asterisks in this figure correspond to P values (***P < 0.001; **P < 0.01; *P < 0.05; ns not significant).