Ro 31-9790 does not affect lymphocyte migration from the blood into lymphoid organs but inhibits shedding of L-selectin during migration into LNs.
(A) Mice were pretreated with 100 mg/kg Ro 31-9790 (▪) or vehicle alone (■) and 40 × 106 CFSE-labeled lymphocytes injected. The number of CFSE-labeled cells in LNs, spleen, and blood was measured 30 minutes and 60 minutes after injection. Bars are mean percent CFSE-labeled cells ± SEM and the number of mice analyzed is given below each bar. (B) CFSE-labeled lymphocytes harvested from LNs, spleen, and blood were analyzed for L-selectin expression. The total number of L-selectin–positive lymphocytes in each tissue was not affected by Ro 31-9790. However, the level of L-selectin was higher on lymphocytes harvested from LNs, but not the spleen or blood, of mice treated with Ro 31-9790. Bars are mean fluorescence intensities of L-selectin–positive lymphocytes (± SEM, n = 3) in mice treated with Ro 31-9790 (▪) and vehicle (■) with percent positive lymphocytes given below each bar. *P < .005. (C) Representative 2-color FACS profiles showing CFSE-labeled cells in lymphoid organs 60 minutes after injection (left side) and L-selectin expression on CFSE-labeled migrants (right side). Note lack of crossover of CFSE label from FL1 into FL2, which was used to measure L-selectin.
