Fluorescent-labeled neutrophils accumulate in the ipsilateral ADLNs and reach the paracortical region. (A) Bone marrow neutrophils were labeled with CFSE (green) or PKH26 (red) and injected inside the left or right ear dorsum concomitantly with 10⁶ CFUs of wild-type BCG (i-ii). Four hours later, green neutrophils were detected only in the left ADLNs and red neutrophils in the right ADLNs (iii-iv). In 3 independent experiments analyzed, no mixed green and red neutrophils were ever observed. Control mock-injection induced only moderate infiltration of fluorescent neutrophils in the regional ADLNs (i-ii). (B) At 12 hours after injection, Ly-6G⁺ neutrophils (green) were detected inside the T-cell (CD4⁺ and CD8⁺ in red) area of the ADLNs (i). CD11c⁺(red) DCs were also detected in the same zone and contacts between neutrophils and DCs could be observed (ii, arrows). Images were acquired as in Figure 3B.