Sequential transmigration (TM) of polymorphonuclear neutrophils (PMNs) and monocytes through human choroid plexus papilloma cells (HIBCPP). Shown is a sequential TM experiment comparing the TM of monocytes alone through HIBCPP with a co-culture of PMNs with monocytes. PMNs were added to the basolateral cell side 24 h after bacterial infection, followed by the application of 2’,7’-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetomethyl ester (BCECF-AM)-labeled monocytes 2 h later. Monocyte TM alone was analyzed in parallel without PMNs for 2 h (n = 3 in triplicate). **
P <0.01 compared to stimulated monocyte TM without PMN.