(a–c) 1 × 106 non-T cells were stimulated with 100 μg/ml poly(I:C) in the presence or absence of 1 × 106 pan-T (a), CD4+ T cells or CD8+ T cells (b), or OT-II transgenic CD4+ T cells or OT-I transgenic CD8+ T cells (c). (d) To prevent close contacts between non-T cells and T cells, non-T cells were cultured in the lower chamber of a Transwell system containing T cells in the upper chamber. (e,f) CD4+CD25+ (Treg) or CD4+CD25− (non-Treg) T cells from wild-type mouse with a ratio of non-T cell to T cell of 1:0.5 (e), or GFP− T cell (non-Treg) or GFP+ T cells (Treg) from FoxP3 knock-in mouse (f), were added to non-T cells. The ratio of non-T cells to GFP+ or GFP− T cell was 1:0.5. *P < 0.05, **P < 0.01, by t-test. The results are representative of at least two independent experiments for each panel (n = 6 per group).