A single cell suspension from thymi and spleens of 4–6 week-old mice was obtained using a Dounce homogenizer. Cells were first preincubated for 10 min on ice with Fc receptor-blocking anti-CD16/32 (clone 93) antibody in PBS-1% biotin-free BSA solution and then stained for 20 min with specific primary antibodies. Biotinylated primary antibodies were revealed with streptavidin conjugated fluorescent dyes (SAv-PE/Cy7, SAv-APC, SAv-APC/Cy7). Labeled cells were analyzed on BD FACSCantoII (BD Biosciences) or CytoFLEX (Beckman Coulter) flow cytometers and data analysis was performed using FlowJo software (FlowJo, LLC). Clones of monoclonal antibodies were: anti-CCR6 (29–2L17), anti-CD3ε (145–2C11), anti-CD4 (GK1.5), anti-CD5 (53–7.3), anti-CD8 (53–6.7), anti-CD11c (N418), CD24 (M1/69), anti-CD25 (PC61), anti-CD27 (LG.3A10), anti-CD28 (E18), anti-CD44 (IM7), anti-CD45.1 (A20), anti-CD45.2 (104), anti-CD71 (RI7217), anti-CD73 (TY/11.8), anti-CD117 (c-Kit, 2B8) anti-B220 (RA3–6B2), anti-CD11b (Mac1, M1/70), anti-γδT-cell (GL3), hamster IgG-PE/Cy7 (HTK888), anti-Ly6G/Ly6C (GR1, RB6–8C5), anti-Nk1.1 (PK136), anti-Tcrβ (H57–597), anti-Tcrβ(Vα2) (B20.1), Ter-119 (all from Biolegend). Splenocytes were analyzed as previously described (18 (link)).