Fig. 3
Inhibition of DC generation by the CM of RIG-I-dificient tumorspheres and its restoration by anti-TGF-β1. a − c CD14+ monocytes were cultured for 14 days in a medium containing 40 ng/ml of GM-CSF and 40 ng/ml of IL-4 in the presence and absence of 1 μg/ml of TGF-β1 neutralizing antibody. Half of the medium was replaced every day with the CM of RIG-I KD or reference SMMC-7721 tumorspheres or a fresh medium, to each of which 40 ng/ml of GM-CSF, 40 ng/ml of IL-4 and 1 μg/ml of TGF-β1 were added if necessary, starting 1 day after seeding. HLA-DR and CD86 expression on generated DCs was assessed by flow cytometry after gating on a CD11c+ population. DCs with fluorescence intensity higher than the level of the dotted line in (a) are regarded as positive populations. d Mitomycin C-treated DCs were co-cultured with allogeneic CD3+ T cells for 72 h, and the proliferation of T cells was then determined by measuring [3H] thymidine uptake during the next 16 h of culture. The values are presented as means ± SD (n = 3). *P < 0.05, **P < 0.01 and ***P < 0.001