HEVs create lymphocyte pockets. (A-B) Confocal images of a LN section from a RAG-2°^/°ubiquitin-GFP chimera (green) stained for PNAd (red), sytox 63/nuclei (blue; A), or CD3 (blue) and B220 (red; B) expression, showing the individual HEV ECs and their “pockets” (arrowheads) containing lymphocytes. (*) = Perivascular channel. (C) Representative SEM and TEM pictures of HEV ECs obtained from WT LN sections. Images were pseudocolored to help delineate lymphocytes (L) and endothelial cells (E.C). Data are representative of 3 different experiments (2 mice per experiment, ∼ 20 analyzed HEVs per experiment).