Visualizing endogenous NK cells and DCs using Ncr1^GFP/+ × CD11c-YFP mice. Ncr1^GFP/+ × CD11c-YFP mice were adoptively transferred with SNARF-labeled CD8 T cells. A day later, popliteal LNs were harvested, and frozen sections were stained with an anti-B220 Ab and imaged by confocal microscopy. Images were then subjected to spectral unmixing. (A) Individual pseudocolored images showing DCs (YFP-positive cells, pseudocolored in green), NK cells (GFP positive, pseudocolored in red), adoptively transferred T cells (blue), and B cells (B220⁺ cells, white). (B) Representative confocal image showing that LN NK cells (red) are enriched at the T cell–B cell zone interface. (C) The density of NK cells was compared in the most peripheral layer of the T-cell zone (≤ 100 μm below B cell follicles) or in the rest of the T-cell area (mean ± SEM). Scale bar, 100 μm.