Gene expression analysis of newborn LN stromal cells. (A) FACS analysis of P2 iLN CD45⁻ cells stained for VCAM-1 and ICAM-1. Each cell population was isolated to prepare cDNA and assessed for the expression of several genes by semiquantitative PCR. According to their gene expression patterns, the cells were classified in putative mesenchymal precursor cells (V⁻/I⁻), stromal organizer cells (V⁺/I⁺), and lymphatic/vascular endothelium (V⁻/I⁺). (B) Semiquantitative PCR analysis of the Ltbr and Nfkb genes involved in this pathway (Nfkb2, Relb), hyaluronan receptor (Lyve-1 and Prox-1), and chemokines (Cxcl13, Ccl21) in the 3 stromal cell populations present in P2 iLNs. Ratio of gene of interest (GOI) to β-actin is shown. Results shown correspond to 3 to 4 independent cell sorting and PCR experiments (Experiment 1, ♦; Experiment 2, ■; Experiment 3, ▴; and Experiment 4, ×). Statistical analysis was performed using the 2-tail t test. Statistically significant differences, as calculated by the P value, in the expression of specific genes in the 3 cell populations are shown in bold.