We prepared single-cell suspensions of spleen, lymph node or tumor tissues by mechanic dispersion followed by collagenase D/DNase I treatment as described before 10 . For extracellular staining of immune markers 1 × 10 6 of freshly prepared cells suspended in PBS/2% FCS/0.1% w/v sodium azide was preincubated with FcγIII/IIR-specific antibody to block non-specific binding and stained with different combinations of fluorochrome-coupled antibodies to CD11c, I-A b (MHCII), CD40, CD80, B220, CD11b, Gr1, CD3, CD8 or CD4 (BD Biosciences). Prior to intracellular staining with antibodies to TLR9 (eBioscience), Dicer (Santa Cruz) or FoxP3 (eBioscience), various immune cell subsets were fixed in paraformaldehyde and permeated in methanol. Fluorescence data were collected on FACScalibur (Beckton Dickinson) and analyzed using FlowJo software (Tree Star).