Fig 1: Differences in LN stromal structural patterns based on gene reporters. (A) Whole views of inguinal LNs isolated from various reporter mice. Vertical sections of LNs were stained with antibodies against fluorescent protein (FP) and desmin or VCAM-1. White arrows in the panel of Ccl21a-tdTomato indicate HEVs. (B) Average fluorescent intensity profiles of the rectangular boxed region along with the cortex-medulla axis in (A). The image of the region of interest (ROI) is replicated in the upper part and the boundary between subcompartments is indicated by dotted lines. Note the absence of or low FP expression in the follicular area (asterisks), the sharp peak in FP in the outer margin of the follicle (arrowhead in Pdgfrb-EYFP), and the higher signal around the boundary of the T cell area and medulla (open arrows). F, follicle; T, T cell area (paracortex); and M, medulla. (C) Flow cytometric analysis of FSCs. CD45− LN cells (left) were further fractionated by CD31 and PDPN expression (right), and the CD31− non-endothelial fraction was defined as FSCs including PDPN+ conventional fibroblastic reticular cells (FRCs) and PDPN− cells (gated, respectively). (D) FP expression in PDPN+ and PDPN− cells. Open histograms show the corresponding cell fraction of wild type mice.